Snorkel in the US Navy - 1945 Onwards

8/16/2019 Snorkel in the US Navy - 1945 Onwards

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Snorkel in the US Navy - 1945 onwards

by Peter D Hulme

This article makes no claim to any direct knowledge of the systems of the US Navy,

the author having served in the Submarine Branch of the Royal Navy in the early days

of snorting. What follows is brief descrition of the US Navy snorkel conversion

garnered from the documents listed below and is intended to be comlementary to the

article Snorting in the Royal Navy ! "#$% &nward and as an ad'unct to the article US

Navy (uy Submarine )onversions "#$*!"#%$

The rimary sources are a detailed descrition of the +ngine nduction and +-haust

system of the leet Submarine rior to the /tting of snorkel system in )hater *,

0entilation System, 1T2+ 3++T T45+ SUB67RN+1 8une "#$9 Nav5ers "9"9:, and 1T2+

SUB67RN+1, art "%, The Snorkel System, revised "#%%, Nav5ers "9"9:!71. Both

being training manuals of the US Navy. The coy of the latter document was kindly

rovided by ;eith 7llen of the US7.

7ttached as aendices is a comlete descrition of the US Navy leet Submarine

snorkel system and oeration made available by Bob +mery of the Submariners

7ssociation of )anada West. The Royal )anadian Navy had at one time oerated two

former US Navy leet Submarines.

n this article have focused on snorting the US Navy, however there is a

comlimentary article Snorting in the Royal Navy ! "#$% &nward

USS Irex (SS 482). First US Navy snorkel as !er"e#te$ in t%is US submarine in &'4.

Not a u!!y. In later years s%e a!!eare$ in a more streamline$ "orm it% *uns et#

remove$ an$ a !lasti# sail (+SS 482)

Historical Outline

The /rst US Navy submarine laced in oerational service with snorkel was the USS

re- <SS =>?@ in "#$*, a leet Submarine of the Tench class originally comleted in

"#$%.

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See 7endi- 7 for details of the history of US Navy snorkel develoment leading u

to the conversion of the USS re-.

This successful conversion design was alied to the arallel (uy conversion

rogram, the /rst conversion comleted in "#$*.

3ater when the (uy conversions roved too e-ensive, a rogram was initiated to

add snorkel to "? leet Submarines of the similar Balao and Tench classes. n general

aart from snorkel, they remained as /rst built but to accommodate the snorkel masts,

the older style conning towers were converted to a steed /n as seen in the early

(uy conversions. This class of "? submarines were known as leet Snorkels. The

/tting of snorkel usually took lace as art of regular shiyard overhauls.

t should be noted that aart from the more formal rogram of "? submarines, others

were also /tted with snorkel throughout the US Navy Submarine leet.

7ll leet Submarines conversions of any tye were rogressively hased out as the USNavy Submarine Service moved to become entirely nuclear roelled. 7 signi/cant

number were handed over for service with foreign navies.

This information was taken from T2+ 3++T SUB67RN+ N T2+ U.S. N704 by

)ommander 8ohn A 7lden. US Navy <ret@.

+-tract from 7dmiral (alantin1s SUB67RN+ 7A6R73 5age "=9

USS Pi#kerel (SS ,24) as one o" t%e u!!y II. Un$er %er innovative- $arin* ski!!er-

omman$er Paul / S#%rat0- s%e $emonstrate$ t%e ultimate !er"orman#e o" t%e

snorkel. S%e as t%e 1rst u!!y to be $e!loye$ to t%e Far ast- an$ in returnin* toPearl Harbour "rom Hon* 3on* s%e snorkelle$ all t%e ay- ,&'4 miles in ,, %ours. It

re5uire$ #are"ul !lannin*- su!erb en*ine o!eration an$ maintenan#e- an$ *reat

!%ysi#al stamina an$ $etermination. Her tenty6one $ays #ontinuously submer*e$ in

&', remaine$ a re#or$ until &',8- %en nu#lear !oere$ Seaol" ma$e %er sixty

$ay test.

Note. 5resumably the 7dmiral means a record for the US Navy as 26S 7lliance was

submerged for =: days continuously during her snort cruise in "#$*. 2owever she only

covered ="#= miles. The 5ickerel aarently achieving the remarkable average

submerged snorkel seed of ":.>? knots er day.

While the detail in 7endi- tem " aears to reeat much of what has been stated

in 7endi- B, 7endi- ), 7endi- A and 7endi- about the leet Submarine

conversions, it should be areciated the US Navy submarine veteran who contributed

this anecdote is describing the snorkel system on the new diesel submarine Blueback,

one of three Barbel class constructed for US Navy after the war, with snorkel

integrated into the design.

The Barbel class were the only US Navy diesel submarines with the revolutionary hull

shaed develoed in the trial submarine USS 7lbacore <7(SS %9#@, launched in "#%>.

ncidentally this shae became the basis of the hulls of US Navy SSN submarines

starting with the Ski'ack class of "#%?. The USS Barbel <USS %?:@ was commission in

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"#%#, more than a decade after the /rst snorkel submarine, USS re- <USS $?>@, "#$*,

yet in rincile little had changed.

t is of interest that he con/rms other sources that suggest that the Barbel class had a

similar snorkel system to that of the much earlier ost war Tang class.

The lead submarine, USS Tang <SS %9=@ was launched in "#%", and from these dates

we can seculate that the both the snorkel systems for the conversions and the new

submarines were being develoed at the same time. The only signi/cant dierence

aears to have been the use of a dry induction mast in the new submarines that also

only had one engine room. There the US Navy diesel snorkel story stos.

Documents

7 full descrition of develoment and alication will be found in these attached

documents.

• 7endi- 7 Submarine Snorkel System Aeveloment in the US Navy.

• 7endi- B 7ir nduction C Snorkel nduction Systems.

• 7endi- ) Snorkel +-haust System.

• 7endi- A Snorkel +lectrical C +ngine Safety )ircuit Systems.

• 7endi- + leet Submarine Snorkel &erating 5rocedure.

• 7endi- 7necdotes.

• 7endi- ( U!Boat 2istory, Aeveloment C +Duiment, "#"$ to "#$% by Aavid

6iller.

A SUA!" O# $H% &ON'%!S(ON

Before roceeding it should made clear that all the main iing is outside the ressure

hull under the outer shell. n the simle diagrams mentioned below, eDuiment within

the ressure hull is so indicated.

Basically the systems used in the US Navy leet Submarines were similar to those

described in the comanion article Snorting in the Royal Navy ! "#$% &nward . That is

a single air induction mast and a single e-haust mast, but all rather more comlicated

in alication.

There were two engine rooms each with two diesel!generators. These big submarines

were not direct drive, with at all times the screws being driven by electric motors

sulied from the batteries alone when submerged and the diesel!generators when

surfaced. The four diesel!generators could be arranged for 1all roulsion1 for

ma-imum surface seed <"# knots@ or both roulsion and charging the batteries.

0arious sources suggest that this roulsion arrangement was more suitable or

snorkelling than direct drive, in that no forward way was lost when snorkelling wasshut down due to a temorary loss of trim, the battery continuing to suly the motors

without any break in suly.





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This roulsion arrangement also brought about a rather dierent crew organisation

for snorkelling than the early Royal Navy direct drive, where the engines were directly

roelling the submarine, see 7endi- +. n the ost war scene, the Royal Navy

adoted this method of 1all!electric1 roulsion in the converted T )lass and the

5arthian )lass C &beron )lass. The later Royal Navy Uholder )lass, like all modern

multi!engine single screw submarines, had the single screw driven e-clusively by onelarge electric motor.

There has been a suggestion that the four stroke Royal Navy engines were more

tolerant of being occasionally Eooded through the oen e-haust than the US Navy two

stroke. 7endi- 7necdote $ gives a clue about this asect of snorkelling. t is known

the US Navy engine iston heads were modi/ed for snorkel.

)re-Snorkel (nduction

&n the surface the main engine air inlet was through a =9 inch ventilation stack and

valve <also described as the main induction valve@ in a comartment in the lower afterart of the bridge, oen to the sea when dived.

The stack was mounted on the outside of the ressure hull, raised by mounting legs.

The stack distributed air to the two engine rooms and shis ventilation through >> inch

ies installed on the outside of the ressure hull.

The outut air of the iing was admitted through the ressure hull into each engine

room by a manually oerated induction hull valve. 7 detailed drawing of this hull valve

is shown in 7endi- B.

7lso connected to the =9 inch ventilation stack was an additional outlet ie feeding

the aft air inlet for the ventilation system with a similar but smaller hull valve.

To reca, on the surface air was taken in through the bridge structure and fed into

each to the two engine room comartments, with additional air fed into the vessel for

ventilation. +ach oint of entry into the ressure hull could be sealed for diving by an

ad'acent hand oerated valve. 7 simle line diagram has been rovided to assist the

reader of this section of the summary,

Fig 1. Snort Induction Line Diagram

7%is is a mu#% sim!li1e$ $ia*ram o" t%e snorkel #onversion o" a US Navy eetsubmarine. It is in#lu$e$ to *ive t%e rea$er some i$ea o" t%e 9!lumbin*9 $es#ribe$ in

$etail in t%e a!!en$i#es. 7%e bla#k is !re #onversion. 7%e blue an$ re$ s%o t%e

a$$itions.


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Inset on t%e 1*ure are t%umbnail si0e !%oto*ra!%s o" t%e :; in#% ventilation sta#k an$

an in$u#tion %ull valve.

)re Snorkel %*haust

+ach engine had inboard and outboard e-haust valves, in much the same

arrangement as the Royal Navy. 2owever the individual outboard valves to each of the

four surface muFers were hydraulically oerated.

t is interesting to note that the inboard valve aears to be a sluice tye as /tted in

"#9? to Royal )anadian Navy 1&1 class.

Both inboard and outboard e-haust valves were water cooled, the inboard by water

from the engine fresh water system, the outboard by water from the engine salt water

system.

So to reca, the original engine e-haust set!u was Duite straightforward with each of

the four engines having searate valves and muFers.

Snorkel (nduction &onversion

The conversion to snorkel involved the relacement of the former conning tower

structure with a modern style steed 1Sail1 suorting the eriscoes and the various



masts including the telescoic snorkel induction mast and the single telescoic snorkel

e-haust mast.

The induction air from the snorkel mast was taken through a large water searator and

a hydraulically oerated shut o induction valve to a new inlet in the structure of the

=9 inch ventilation stack still in its former osition but now enclosed by the after artof the sail as shown inset in ig ".

The distribution of air from the =9 inch ventilation stack remained as before aart from

a change in the shi1s ventilation system that aears to have been simli/ed.

5reviously there had been a artial bye!ass from >> inch ie feeding the main

induction to the aft engine room. This bye!ass sulied air to the single ventilation

hull valve aft in the manoeuvring room, while the "9 inch ie from the =9 inch

ventilation stack fed a ventilation hull valve in the forward engine room. 2ence there

were two smaller tye ventilation hull valves.

n the snort conversion the hull valve in the forward engine room and the artial bye!

ass were aarently removed. The shi1s "9 inch ventilation ie then simly ran

from the =9 inch ventilation stack to the e-isting ventilation hull valve aft. No te-t

e-lanation of this asect of the conversion is available but this is the arrangement

shown in all the drawings associated with this article and aendices. 7lso there is

nothing in the te-t to indicate ma'or changes in the battery ventilation as was the case

with the (uy conversions.

Snorkel %*haust &onversion

Turning to the engine e-haust, obviously the reviously four Duite searate enginee-haust systems had to be 'oined together to form a single ie to the snorkel e-haust

mast.

t was also considered desirable to isolate the iing etc, of the unused engines from

that of the snorkelling engines. The result was a relatively comlicated set of valves

and iing. 7 comlete descrition is rovided in 7endi- ), but a simle line

diagram has been rovided to assist the reader.

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Fig 2. Fleet Submarine Snorkel Exhaust System

t should be noted most of the e-haust iing is ressure tight and not Eooded at any

time. )heck drains were /tted.

(nduction ast Head 'alve

The induction mast had a head valve that closed to revent the ingress of sea water if

the submarine lost trim and went below snorkel deth. Unlike the British who

develoed their own version of the widely used U!Boat Eoat oerated valve, the US

Navy adoted a design where the head valve was oened and closed by high ressure

air, controlled by electrically oerated valves.



7endi- 7 suggests this alternative to the U!Boat Eoat valve, was another (erman

develoment and this is con/rmed by 7endi- (. Though this reference also states

the develoment was not comleted before WW ended.

t is Duite clear from a hotograh of the snorkel head valve from U!=%:=, that Eoat

valves were being used on at least one of the latest (erman tye GG submarines ofWW. The scuttled U!=%:= was raised by the Swedish Navy and dismantled. 6ore

hotograhs can be seen here

t is reasonable to assume that the Tye GG U!Boats ut into trials service by the US

Navy had similar Eoat valves, but that the US Navy chose to roceed and comlete the

develoment of the (erman electro!neumatic snorkel head valve and this became

standard in the US Navy.

The celandic owned website UBoat.net that e-tensively records the history of the

(erman U!boat Service, shows a ost WW drawing of three dierent U!Boat snorkel

head valves with little background te-t. ncluded are the Eoat and the electro!neumatic versions. No original (erman source is given for these drawings.

Regardless of the origin of the design, the US Navy e-clusively used an electro!

neumatic electrical head valve control system automatically oerated by salt water

sensitive electrodes mounted on the snort head.

Thus if the electrodes were Eooded, the head valve was closed. The closing of the

head valve was assisted by srings and should the air ressure fail the srings would

close the head valve. When the electrodes were clear of sea water, the head valve

would again be oened by 25 air.

%*haust ast

Unlike Royal Navy conversions with a simle oen outlet to the sea , the US Navy

snorkel e-haust mast had a fairly comle- diuser head that added a venturi!like

action to aid in the e-haust rocess. t was of course still oen to mast Eooding if the

engine back ressure droed too much.

The e-haust mast raising mechanism was driven by the same hydraulic motor that

raised the induction mast, but the gearing was such that the reDuired relative

dierence in heights when raised was achieved by using a dierent gear ratio for each

mast, hence the induction mast and e-haust masts were raised as one unit, described

in 7endi- ). and the relative heights can be seen in the hotograhs below. This

arrangement has similarities to the (erman Tye GG U!Boat in that both masts were

raised by the same mechanism, but in the GG the two tubes were 'oined at the to

with the inlets and outlets Duite close together however further discussion of the Tye

GG is beyond the scoe of this article.

The main Snorkel +-haust 0alve <7ble@ was Duite sohisticated in its oeration. When

the hydraulic ressure was alied to oen the valve, it would not oen until assisted

by the increasing engine back ressure. The valve was designed to shut hydraulically

against the engine e-haust ressure should the mast Eood.

Automation



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t should be noted that unlike Royal Navy submarines, there were automatic engine

shut down facilities triggered by low vacuum, low engine back ressure and low

engine rm. 7endi- 7necdote No. ", gives detail of the later Barbel class system

that was basically similar to the original leet Boat conversion

Note+ t is understood from various US Navy Sub0et sources that only one engineroom <two AH(@ was used for snorkelling, usually the two forward AH(. 2owever in the

(uy (7 conversions, one diesel!generator was removed to make eDuiment sace,

detail of the lay!out and oeration is not known.

ast )hoto,rahs

Provi$e$ by <ob mery o" Submariner9s +sso#iation o" ana$a =est.

USS Dio$on SS:4' (+ II u!!y) =est!a# &';. SN>/3? INDU7I>N @ AH+US7

B+S7S /+ISD

7%is !%oto*ra!%- t%ou*%t to be USS %o!!er SS:42 (a &+ u!!y #onversion ) isin#lu$e$ be#ause o" its novelty an$ t%at it *ives anot%er vie an*le. 7%e to men are







sat on t%e ex%aust %ea$- t%e in$u#tion mast is imme$iately "orar$ o" t%em. 7%ey

a!!ear to be takin* !%oto*ra!%s.

A$$A&. SU/A!(N%

The "#%% US Navy training document includes a reference to the ost!war submarines

with snorkel /tted as art of the overall design, as 7TT7); SUB67RN+S. They were in

fact the twin screw Tang class, the last numerically signi/cant diesel class in the US

Navy built in ost WW. The 5arthian )lass C &beron )lass of the Royal Navy

submarines may reasonably said to be comarable. Both classes being the roduct of

the early ost!war thinking of both navies. There is some discussion in the (uy

conversions article.

&ne of the key changes was that unlike the US Navy conversions and British ractice,

the snorkel induction mast remained dry, that is not Eooded when not in use. The

induction mast head valve was aarently caable of keeing the mast watertight at

any oerating deth.

&ne drawing shows the induction being formed by two smaller ies rather that one

single but larger tube.

t is assumed the main reason for this dry mast was that it avoided dealing with ?:::

lbs of sea water that in the conversions had to be either Eooded into the induction

mast when not in use or drained into the submarine when rearing snorkel. 7ll these

actions eect the management of the trim of the boat. 5resumably the lesser amount

of water in the e-haust mast of about =::: lbs, was tolerable. &ne can seculate that

this dry snort mast allowed a faster transit from snorkelling to a safe deth if in danger

of attack.

7nother signi/cant change was the use of the snorkel induction mast head valve as

the engine induction when running on the surface. This induction method seems to

have been the attern for most new ost war submarines.

f the snorkel induction mast was still e-tended at "?% feet, it was automatically

ressed down to the lowered osition.

6uch the same systems aear to have been used in the advanced class of three

submarines, the Barbel class of "#%#. 7s reviously mentioned, there is Duite a lot of

detail in 7endi- 7necdote No. "













Aendi* A

Su0marine Snorkel System Develoment in the US Navy



USS /6; snorkel mast. Bast is !ermanently 1xe$ to t%e Starboar$ si$e o" t%e

teles#o!in* ra$io mast. 7%e stran*e C%ookC is t%e en*ine ex%aust. 7%e /6; as t%e

test !lat"orm "or !er"e#tin* t%e US version o" t%e Dut#% invention o" t%e snorkel. =%en

t%e ermans inva$e$ Hollan$ t%ey took t%e te#%nolo*y an$ in#or!orate$ it in to t%e U6

<oat. P%oto taken +u*ust &'4, in Ft. ?au$er$ale- Flori$a Durin* snorkel testin*

o!erations.

P%oto !rovi$e$ by /ay ar*an %ose "at%er serve$ on t%e /;.

Several snorkel systems or snorkel!like systems were installed on board US

submarines. Simon 3ake used an engine e-haust system that utiliIed a ie e-tending

above the main deck aft. The 7lligator <"?9>@ had an 1air tube1 to allow air to be drawn

into the boat while it was submerged at a shallow deth. The )SS 2unley had a similar

air tube system. 8ohn 2olland1s 5lunger <"?#?@ was to have a coiled hose system which

had a Eoat to ermit air to be drawn in from a deeer deth than either the 7lligator or

2unley.

The snorkel system design and testing rogram for what can be called the 1standard

submarine snorkel1 is summarised belowJ



5ortsmouth Naval Shiyard <;ittery, 6+@ erformed the design work on a snorkel

system as an indeendent design using catured bluerints and a snorkel mast

system catured in Toulon, rance. )N& directed, on >: 8anuary "#$%, that an

accelerated design and build rogram be instituted and an R!)lass submarine be

selected for e-erimentation <this is eDuivalent to the +ngineering Aeveloment 6odel

in today1s language@. K)N& letter of >9 8anuary "#$%L.

The R9 was selected and the snorkel was /tted in 5ortsmouth during the eriod ":

7ril to >: 6ay "#$%. The system was tested and rovided information on the eects

of the snorkel on ersonnel and eDuiment. 5iing was installed on the main deck for

simlicity and the snorkel mast was /-ed in an uright osition. R9 took the system to

lorida in 7ugust "#$% for testing in an 7SW setting. The boat oerated for three days

in southern waters <out of t. 3auderdale@ during the eriod = to >% 7ugust "#$% and

three ma'or engine casualties were reorted. 2owever it is unknown whether these

were due to the snorkel or were due to other factors such as age and maintenance.

The system1s comonents were removed rior to the decommissioning of the boat inSetember "#$%.

USS /62 SS' Provi$e$ by /i#k ?arsen BBB (SSS) (ret)

The ne-t testing hase was held aboard the USS Sirago <SS!$?%@ KNoteJ this is not the&da- <SS!$?$@L immediately after her commissioning <)ommissioning was on ":

Setember "#$%@. 5reliminary tests took lace at 5ortsmouth during the eriod "" to

"= Setember "#$%. The tests were to determine if the design was adeDuate and the

eect of snorkelling on diesel engines and ersonnel.

MSirago had four airbanks 6orse ": cylinder A=? ?!"H? engines numbered ?$?%?*

through ?$?%#:. &nly one engine was /tted with the e-haust ducting for testing,

number ?$?%??. The tests on "" Setember tested the machinery, calibration of the

measurement eDuiment and ersonnel orientation. +ngine standardiIation runs were

carried out on the ">th. These included runs at snorkel deth <alongside@ to determine

the eect of the varying back ressure on engine seed and loading. &n the "=th runswere made which simulated wave action on the <Eoat tye@ head valve cycling. The

system was dismantled starting on "* Setember.

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+lectric Boat )omany had been designing their own snorkel system. They asked the

Navy to rovide the data that had been comiled during the testing of R9 and Sirago.

The comany roosed on "> 8une "#$% that a system be ut aboard either

)lamagore <SS!=$=@ or )obbler <SS!=$$@. The Navy nsector of Shibuilding selected

)lamagore. 2owever, in +lectric Boat1s oinion the )lamagore was too close to

comletion and ushed for the )obbler in a test lan dated "# 8une "#$%. BuShisaroved the lan on $ 8uly "#$%. The test was not a full snorkel system but a

ressure variation test using 'ust the ower oerated head valve. The head valve was

to be fastened to a late which was then mounted on the after engine room hatch.

2owever, in the builder1s underway trials <rior to the head valve testing@ the lube oil

systems of the four main engines had roblems and the testing was delayed. +lectric

Boat withdrew from further snorkel design for Eeet submarines.

The re- <SS!$?>@ received the /rst 1full u1 snorkel system in 5ortsmouth Naval

Shiyard starting in Aecember "#$9. The system was evaluated in e-tensive testing

during the eriod 8uly "#$* to ebruary "#$?. She was then the /rst US submarine tobecome oerational with a snorkel.

+-tracted from Warshi nternational 0olume $" Numbers " and $. ONow 2ear ThisO

column by 6r. ). Wright. 5rimary research done by 6r. 6ark ) 8ones and 6r ) Wright.

+dited for content by 6r 8im )hristley

5rimary source material can be found in BuShis (eneral )orresondence iles )!

SSHS$"!%, )!SSHS9?, )SS?= and SS?= in the National 7rchives.

Aendi* /

Air (nduction 2 Snorkel (nduction Systems

Ba$e available by <ob mery o" t%e Submariners +sso#iation o" ana$a =est

A(N (NDU&$(ON





While on the surface air is introduced into the submarine through the main induction

valve, the largest valve on the submarine. The main induction is =9 inches in diameter

and is located in the after art of the sail aro-. >? feet above the keel. t is of the

oet mushroom tye with an umbrella tye hood. 7ir entering through the valve

must /rst ass under this hood, which hels reduce water or sray during heavier

seas. The main induction valve oerating mechanism is located in the forward end ofthe after battery comartment and is normally oerated hydraulically from the

hydraulic manifold in the control room.

(NDU&$(ON HU33 'A3'%S

)onnected to the main induction are three air induction lines, along with a line to the

snorkel induction system. The shi1s ventilation line is "9 inches in diameter and runs

aft to a oint above the forward end of the forward engine room. 2ere it accesses the

ressure hull via the shi1s ventilation hull valve and into the ventilation suly

system. Two larger induction lines, >> inches in diameter, also run aft from the main

induction. The ort line accesses the ressure hull via the forward engine room

induction hull valve and sulies the forward engines. The starboard line accesses the

ressure hull via the after engine room induction hull valve and sulies the after

engines. 7n inboard hood surrounds the engine induction hull oenings, with a sheet

metal iing leading to the lower Eats to revent water carry!overs to machinery and

crew. 7ll outboard induction lines, valves and /ttings are designed for ma-imum

submergence ressure. There are drain lines installed to indicate Eooded iing and

the induction iing will hold aro-. "? tons of seawater if Eooded during a casualty.

The three induction hull valves are of the Eaer tye and their oerating gear

consists of a lever with a Duick release mechanism. They are manually oerated by a

hand lever with a cam locking device held oen by a Duick release locking device.

When the Duick release gri is deressed, the locking device is withdrawn and the

valves seat with their own weight. 7 gagging screw is rovided so the valves can be

gagged shut internally for ressure tests or other damage control uroses.



INDU7I>N HU?? E+?E

SNO!.%3 (NDU&$(ON AS$

The snorkel induction mast is made u of a vertical, /-ed base ie and a telescoingsection. The telescoing section may be comletely retracted into the base ie or

ositioned above it at various redetermined oerating ositions. The telescoing

section is raised and lowered by hydraulically driven gears and shafting. The e-haust

mast and induction mast are geared together and are raised and lowered

simultaneously. The /-ed base ie forms a watertight tube for an air intake between

its uermost e-tremity and the iing leading to the branch lines of the main

induction valve.

When the telescoing section is in one of its oerating ositions, the watertight tube is

e-tended to the height of the head valve. n the housed osition, or any osition other

than an oerating osition, the mast will Eood at the 'uncture of the two iing

sections. Watertight seals are formed between the two sections of iing when the

mast is in the oerating ositions. The seals consist of built u circular steel bands

around the lower outer surface of the telescoing section and circular neorene

<rubber@ insert gaskets that are imbedded in the inner surface of the /-ed base ie.

The neorene gaskets are installed at seci/ed ntervals in the ie to rovide for

multi height snorkel oeration.

When the snorkel induction mast is Eooded, it contains aro-imately ?,::: ounds of

seawater. 5rior to snorkelling, the water must be removed from the snorkel induction

mast. The water is drained or blown to negative tank.



7s noted above, the snorkel induction mast is constructed to ermit snorkelling at

various deths. t can be oerated in con'unction with radar antennas and eriscoes

in such a way that all are e-osed to the roer amount for ma-imum ePciency and

minimum e-osure.

Snorkelling can be conducted at either the No. " eriscoe deth or the search radardeth, with the actual snorkelling deth being usually controlled by the sea state.

When there is an increased risk of Eooding through the main induction when surfaced

during articularly heavy weather, the main induction valve can be shut and the

snorkel induction mast utiliIed to introduce oerating air into the submarine.

SNO!.%3 H%AD 'A3'%

The snorkel head valve, together with its housing, is a unit caing the snorkel

induction mast. The snorkel head valve is a >"O oet tye, Duick shutting valve

designed to minimiIe the amount of water taken into the induction system duringsnorkel oerations. When snorkelling, the head valve housing is normally the only art

of the submarine e-osed above the water1s surface, with the e-cetion of antennas

and masts which may be in use.

The head valve is automatically oerated by an electro neumatic control system,

which is installed as a art of the head valve safety circuit. When the head valve

electrodes, which are e-ternally mounted on the head valve housing below the level of

the valve seat, are above the water1s surface, service air is admitted by the head

valve control valve to hold the head valve oen against sring ressure. f the

electrodes are immersed, the head valve control valve vents o. the oening air and

sulies service air to the other side of the ower cylinder, causing the head valve to

shut by air ressure, sring ressure, and the weight of the valve. Thus the head valve

is oened by air ressure alone and shut by sring ressure, air ressure, and the

weight of the valve.

The head valve control system is designed to 1fail safe1. The head valve will shut if air

ressure andHor electric ower fail.

7n electro neumatic control valve located in the control room controls the snorkel

head valve. The control valve is normally oerated automatically by a solenoid

installed as a art of the head valve safety circuit. nstalled on the control valve is ahand oerated latch, which is used to hold the head valve oen <if desired@ while

oerating under normal surface conditions. The head valve may be held oen during

submerged oerations if desired. 7n emergency shut control valve is also rovided in

the air suly system.

A$%! S%)A!A$O!

7 water searator is installed in the snorkel induction iing between the snorkel

induction mast and the snorkel induction valve. The water searator is cylindrical in

shae. This water searator works on the rincile that the inertia force of a column of

air can be utiliIed to direct the air in a swirling motion inside the circular chamber.



When snorkelling, the engine scavenging air blower creates a vacuum in the shi,

resulting in a constant intake of air through the snorkel induction mast and attached

iing. The incoming air is assed through the water searator in a swirling motion.

This action carries the heavier dros of water to the outer edge of the revolving air

column where they are collected on a saw tooth edge baFe late and allowed to run

down the baFe late into the drain rovided in the base of the water searator.

Water collected there is drained to negative tank or to the um room bilges <the

water is usually drained to negative tank@.

SNO!.%3 (NDU&$(ON 'A3'%

The air asses from the water searator through induction iing to the main

induction stack. The snorkel induction valve is located in this line between the water

searator and the trunk of the main induction valve.

The snorkel induction valve is aro-imately "% inches in diameter, is of the Eaertye and seats with air ressure. t is hydraulically oerated from the snorkel control

manifold located in the control room and may be manually oerated from the crew1s

galley if hydraulic ower is lost.

Aendi* &

Snorkel %*haust System




The snorkel e-haust mast is a vertical telescoing mast housed in the conning tower

sail and mounted abaft the snorkel induction mast.

7 central snorkel e-haust line e-tends from the base of the snorkel e-haust mast

within the suerstructure to the vicinity of the forward engine room. 7t this oint the

line divides into two branch lines, one line going toward the forward main engines " C

>, and the other line going toward the after main engines = C $. +ach branch line

further divides into two more lines with each division going to an engine e-haust

system. These lines connect to the engine e-haust lines between the inboard and

outboard e-haust valves. The connection is made in the forward, vertical face of the

outboard e-haust valve housing.

3ocated in the horiIontal iing near the base of the e-haust mast is the main snorkel

e-haust valve <7ble 0alve@ which serves as the sea valve in the Snorkel +-haust

System.

)aing the e-haust mast is an e-haust gas diuser late that aids in reducing a

telltale lume of water while snorkelling.

The Snorkel +-haust System consists of the following ieces of eDuimentJ

". the snorkel e-haust mast.



>. the snorkel e-haust diuser late.

=. the main snorkel e-haust valve <7ble 0alve@.

$. the forward engine room snorkel e-haust valve <Baker 0alve@.

%. the after engine room snorkel e-haust valve <)harlie 0alve@.

9. the e-haust iing.

%HAUS$ AS$

The snorkel e-haust mast is made u of a /-ed base ie structure designed to

receive a second telescoing section of ie. This mast is designed for snorkel

oerations at induction mast oerating deth. The lower li of the fully e-tended

telescoing section of the e-haust mast forms a metal to metal bevel seat with a built

u li surrounding the to of the /-ed base ie. 7t the lower osition a close /t

between the base ie and the telescoing section e-ists. No seal is formed, but thero-imity of the two ies recludes raid Eooding. The water that does enter the

mast is raidly vaoriIed and blown out by the engine e-haust gases.

The snorkel e-haust mast is geared to the induction mast and raises and lowers with

it.

The e-haust mast does not raise as high as the induction mast, thereby ermitting the

e-haust to be e'ected below the surface of the sea. Such an arrangement reduces the

amount of snorkel engine e-haust and sray that may be visible to a searching shi or

aircraft.

7t the start of snorkelling all the water in the snorkel e-haust mast <aro-. =::: lbs@

is blown to sea by engine e-haust ressure.

%HAUS$ D(##US%! )3A$%

The diuser is designed to break u the e-haust gas stream and radially e'ect the

gases into the surrounding water. t consists of a cylindrical framework with vertical

vanes mounted around the erihery of this framework. The forward side of the

framework is shielded by a circular iece of sheet metal. This shield revents dynamic

water ressure, due to own shis1 motion, from imeding e-haust in'ection. 7 large

deEector late is mounted on to of the diuser, and e-haust gasses e'ected from the

snorkel e-haust mast are radially discharged through the vanes and forced to bubble

to the surface around the erihery of the deEector late.

A(N SNO!.%3 %HAUS$ 'A3'% 6A/3% 'A3'%7

The main snorkel e-haust valve is located in the snorkel e-haust iing near the base

of the snorkel e-haust mast.

This valve seals the after Snorkel +-haust Systems from the free Eooding e-haust

mast, acting as the snorkel eDuivalent of an engine outboard e-haust valve.

This valve is a "% inch hinged Eaer tye unit housed in a cylindrical metal structure.



The main snorkel e-haust valve is designed for hydraulic or manual oerations, the

oerating gear being located in the overhead of the shi1s galley.

The main snorkel e-haust valve is also known as 7ble 0alve and is designed so that a

combination of hydraulic ressure and engine back!ressure is reDuired to oen it.

t is oened hydraulically by concurrence of all of the following conditionsJ

". 7ble 0alve in the 15ower 5osition1 and hydraulic ower available.

>. control room lever in 1)ontrol in +ngine Room1 osition.

=. engine safety circuit energiIed.

$. e-haust back ressure "* si or above.

%. 7ble 0alve control lever in engine room is oened.

7ble 0alve may also be oerated by hand from the after battery comartment.

#O!A!D %N8(N% !OO SNO!.%3 %HAUS$ 'A3'% 6/A.%! 'A3'%7

The forward engine room snorkel e-haust valve is located in the snorkel e-haust

iing above the forward engine room. t can be oerated hydraulically from the

snorkel hydraulic manifold located in the forward engine room, or manually at the

valve oerating gear in the forward engine room. This valve receives the e-haust

gases from " C > main engines. The forward engine room snorkel e-haust valve is shut

when surface cruising. f the valve was oened, or was not installed, engine noises

would be magni/ed by the resonance of the e-haust iing and carried as far as themain snorkel e-haust valve. Saces such as the bridge area and the radio room would

be diPcult to work in under these circumstances. The valve also serves as an

additional safety factor in the Snorkel +-haust System. The forward engine room

snorkel e-haust valve is also known as Baker 0alve.

A#$%! %N8(N% !OO SNO!.%3 %HAUS$ 'A3'% 6&HA!3(% 'A3'%7

The after engine room snorkel e-haust valve is located in the snorkel e-haust iing

above the after engine room. t is designed for hydraulic or manual oeration, the

oerating gear being located in the after engine room. This valve receives the e-haust

gases from = C $ main engines. t serves the same urose as the forward engineroom snorkel e-haust valve and it is shut when not snorkelling. The after engine room

snorkel e-haust valve is also known as )harlie 0alve.

SNO!.%3 AS$ HO(S$(N8 %&HAN(S

The snorkel hoist mechanism is designed to raise the snorkel induction and e-haust

masts simultaneously. When the masts are in either of the two oerating ositions, the

e-haust mast is at a reset distance below the snorkel head valve. This laces the

snorkel head valve above water and the to of the snorkel e-haust mast beneath the

surface of the water.



2oisting ower is sulied by main hydraulic ressure, driving a modi/ed % 7 +nd

hydraulic motor, which in turn drives gears meshing with rack gearing on the induction

and e-haust masts.

By using a dierent gear ratio, the induction mast travels a greater distance than the

e-haust mast for the same number of turns of the hydraulic motor. This ermits thetwo masts to be in the roer relative height ositions although starting from the

same initial level.

SNO!.%3 %HAUS$ )()(N8

The snorkel e-haust iing, valves and /ttings between the main snorkel e-haust

valve <7ble 0alve@ and the four main engine outboard e-haust valves are designed for

ma-imum submergence ressure, with drain lines installed to indicate Eooded iing.

Aendi* D

Snorkel %lectrical 2 %n,ine Saety &ircuit Systems


SNO!.%3 %3%&$!(&A3 S"S$%

The snorkel electrical system rovides the electrical controls which oerate the snorkel

system1s hydraulic and neumatic control devices, indicating lights and horns. 5ower

for this system is normally sulied from the ">: volt, 9: cycle single hase, a c bus

on the ) switchboard.

The snorkel system is so designed that the loss of all a!c ower or ower to the diesel

engine safety circuit will cause a shutdown of snorkelling.

AS$ 3%'%3 (ND(&A$(N8 &(!&U($

This circuit indicates the osition of the snorkel mast in any of three ositionsJ 67ST

U5, 67ST N 3&W+R &5+R7TN( 5&ST&N, and 67ST A&WN. Three lights on the

control room snorkel anel indicate the aroriate osition.

H%AD 'A3'% (ND(&A$(N8 &(!&U($

This circuit rovides indication of the osition of the head valve, either &5+N or S2UT.

H%AD 'A3'% O)%!A$(N8 &(!&U($

This circuit controls the oeration of the head valve so that water will not be taken in

through the induction mast while snorkelling. Three electrodes located in the head

valve housing normally control the head valve. The head valve may also be oened or

shut manually by the head valve control switch located in the control room. The three

electrodes are mounted at ">: degree intervals around the erihery of the head

valve housing, slightly below the valve seat. The electrodes are designated 5&RT,

ST7RB&7RA and 7T. The electrodes are connected into the control circuit by switches

located on the control room snorkel anel. The switches are designatedJ 7T, 5&RT,

and ST7RB&7RA.



When the head valve oerating circuit is energiIed, a wave washing over one of the

electrodes will cause it to be shorted out. This action will de energiIe the head valve

control solenoid and the head valve will be forced shut by shis service air ressure

and sring ressure. 7s soon as the electrode short is removed, the head valve control

solenoid is energiIed and shis service air forces the head valve oen.

3ocated on the control room snorkel anel is a test switch to simulate shorting out an

electrode. 7lso located in the control room is a diving oPcerQs switch with which the

diving oPcer can cause the head valve to oen or shut at any time.

(NDU&$(ON AS$ #3OOD%D (ND(&A$(N8 &(!&U($

To rovide indication of a Eooded snorkel induction mast, there is an electrode located

in the snorkel air induction ie between the water searator and the snorkel

nduction valve. f water collects in this section of the induction iing, the electrode is

shorted and a Easher unit warns ersonnel in the control room. There is a test switch

that is used to test the circuit by hand for roer oeration. The switch is sringloaded so it is normally in the oen osition.

SNO!.%3 O!D%! &(!&U($

The snorkel order circuit rovides a means of transmitting signals from the control

room to the engine rooms and the manoeuvring room. The snorkel order switch is

located on the snorkel control anel in the control room. 5ositions on the switch are

labelled SN&R;+3, S+)UR+ SN&R;+3 and &.

When the order switch is turned to SN&R;+3, green indicating lights are lighted on all

four control anels <control room, forward engine room, after engine room, andmanoeuvring room@.

When the order switch is turned to S+)UR+ SN&R;+3, red indicating lights are lighted

on all four control anels and horns sound in the engine rooms and the manoeuvring

room.

When the switch is turned to &., the system is comletely de energised and no

indication shows on any of the anels.

A(N SNO!.%3 %HAUS$ 'A3'% H"D!AU3(& &ON$!O3 'A3'%S

The main snorkel e-haust valve, referred to as 7ble 0alve, can be shut, but N&T

oened from the control room at any time. The control valve is of the sool tye, four

way and manually oerated. The two oerating ositions areJ )&NTR&3 N +N(N+

R&&6 and +6+R(+N)4 S2UT.

or normal snorkel oerations, the control room 7ble 0alve control valve is laced in

the )&NTR&3 N +N(N+ R&&6 osition.

The 7ble 0alve remote control valve is located in an engine room and is solenoid

oerated during normal oerations, but there is a rovision for manually overriding the

solenoid.



When the control room control valve is laced in the +6+R(+N)4 S2UT osition, the

hydraulic lines from the 7ble 0alve remote control valve are locked and the control

room control valve sends shutting oil to the 7ble 0alve ower iston.

The 7ble 0alve remote control valve has three ositionsJ &5+N, N+UTR73, and S2UT.

The remote control valve is ket in the N+UTR73 osition rior to snorkelling by aremovable in. When the in is removed, 7ble 0alve remote control valve solenoid

when energised can move the control valve to the &5+N osition against sring

ressure. With the in out and the solenoid de energiIed, the control <sool@ valve will

be moved to the S2UT osition by sring ressure.

7t the commencement of a snorkel start, the snorkel engine discharges e-haust gas

into the snorkel e-haust line. 7ble 0alve is shut, therefore, e-haust back ressure will

build u in the e-haust line. 7 bellows oerated back ressure switch, located in the

snorkel e-haust ie above the crew1s mess, e-ands as e-haust ressure builds u.

When the back ressure reaches "* si, the back ressure switch shuts and energiIes

7ble 0alve remote control valve solenoid. The energiIed solenoid moves 7ble 0alve

control valve to the &5+N osition. This seDuence of events allows ressure from the

hydraulic system to oen 7ble 0alve.

7s the e-haust mast blows dry and back ressure dros to about =!9 si, the back!

ressure byass switch is shut. The back ressure by ass switch kees 7ble 0alve

remote control valve and the engine shutdown solenoids energiIed when the back

ressure switch oens.

f at any time the circuit is interruted by either 2(2 B7); 5R+SSUR+, 3&W R56,

2(2 07)UU6, or 3&SS & 7) 5&W+R, 7ble 0alve remote control valve is de!energiIedand sring ressure forces the remote control valve sool valve to the S2UT osition,

thus sending shutting oil to 7ble 0alve.

A(N %N8(N% SHU$DON SO3%NO(D

3ocated in the manoeuvring room this solenoid holds the main engine shutdown valve

in the shut osition when energiIed. When de!energiIed, sring ressure will oen the

main engine shutdown valve allowing shis service air to shut down all running

engines. This solenoid has three lams in arallel with it to indicate to both engine

rooms and the manoeuvring room when this solenoid is energiIed.

D(%S%3 %N8(N% SA#%$" &(!&U($

The safety cut!out circuit oerates automatically to shut down the engine1s air

ressure under certain conditions. The safety devices are installed in the circuit in

such a manner that the oeration of any of the devices will cause the engines to shut

down and the main snorkel e-haust valve <7ble 0alve@ to shut.

The safety devices areJ 07)UU6 36T )UT!&UT, 2(2 B7); 5R+SSUR+ )UT!&UT, and

3&W R56 )UT!&UT.

". 07)UU6 36T )UT!&UTJ There are two vacuum limit cut!outs, one located in

each engine room. They are normally shut, bellows!oerated switches, designedto function when the vacuum in either engine room increases to si- inches. This

vacuum will result when the head valve or the induction hull valve is shut for



any length of time while an engine is running. +ither of the two cut!outs may

function to sto the engines.

>. 2(2 B7); 5R+SSUR+ )UT!&UTJ There are two high back!ressure cut!out

switches. &ne located in the snorkel e-haust line of each engine room. The high

back!ressure cut!out switches are installed to revent damage to an engineresulting from e-cessive e-haust back ressure. The switches are normally shut,

bellows oerated tye, designed to oen at "% si. When the back ressure on

any switch e-ceeds "% si the switch oens and the engines are shut down. This

switch is byassed when blowing the e-haust mast and is laced in the circuit

after the engine is running.

=. 3&W R56 )UT!&UTJ There are four low rm cut!outs, one located on each

engine. +ach cut!out controls only the engine to which it is connected and is

oerated by engine fresh water ressure. The low rm cut!out functions to shut

down the engine when the engine seed dros below $:: rm. f more than one

engine is on the line and only one dros below $:: rm the remainder

continues to oerate and the main snorkel e-haust valve remains oen. The

main snorkel e-haust valve will remain oen until all low rm cut!outs have

functioned.

The snorkel safety circuit, when oened by any of the above causes, actuates the

engine air shut down tri and also shuts 7ble 0alve.

n addition to the safety features described, the oerating limit circuit is eDuied with

a SN&R;+3 S2UT!A&WN SWT)2 in each engine room. Aeressing a ushbutton on

this circuit will cause the main engines to shut down.

Byass switches are rovided to allow the engines to be started regardless of the

osition of the back!ressure or low rm cutout switches. This feature is necessary in

order to byass those safety devices when the engines are started at the

commencement of snorkelling.

%N8(N% A(! $%)%!A$U!% A3A! &(!&U($

This circuit is installed to revent e-cessive blower temeratures while snorkelling and

rovides indication of dierence in temerature of the air intake and outlet of each

main engine scavenging air blower. When the temerature dierential reaches "9:degrees, a warning light and warning bell are energiIed. The warning light remains

lighted as long as the temerature dierential is "9: degrees, however, a contact

maker in the engine throttle may secure ower to the warning bell when the throttle is

in the sto osition. 7 switch located on each of the warning anels may also secure

the warning bell. This alarm merely warns the engine room watch, it does not shut

down the engine. This circuit is installed on each main engine blower and failure to

shut down the engine may result in a wied blower caused by metal to metal contact

as the blower arts e-and with heat.

Aendi* %



#leet Su0marine Snorkel Oeratin, )rocedure


F?7 SU<B+/IN SN>/3? PIPIN

SN>/3? INDU7I>N (<?U) SN>/3? AH+US7 (/D)

The order for secure snorkelling given by either the )ommanding &Pcer or )onning

&Pcer, deending uon the circumstances. The submarine1s transition from a normal

submerged routine to that of snorkelling was accomlished by the regular watch

section. Snorkelling could be conducted with a ma-imum of two engines and, to

reserve watertight integrity, normally carried out in one engine room.

%'O3U$(ON ON )!%)A!(N8 $O SNO!.%3

The order was relayed on the "6) by the helmsman. i.e. 15reare to Snorkel, Two 6ain

+ngines 5roulsion )harge.1

ANO%U'!(N8 !OO

7cknowledged on the *6). 15reare to Snorkel, Two 6ain +ngines 5roulsion )harge,

6anoeuvring 7ye.1

Signalled the +ngine 5riority to the Snorkelling +ngine Room by either the engine roomwith the lowest hours or, if there were rior snorkels during the dived time, by utilising

the coldest engines.

&ON$!O3 !OO

Raised the Snorkel nduction C +-haust 6asts.

+nergiIed the Snorkel )ontrol )ircuits.

Arained the Snorkel nduction 6ast to Negative Tank.

5laced control of the 6ain Snorkel +-haust 0alve <7ble 0alve@ to the Snorkelling +ngineRoom.



A#$%! /A$$%!" &O)A!$%N$

5laced the Snorkel nduction 0alve &erating (ear into 5ower.

5laced the 6ain Snorkel +-haust 0alve &erating (ear into 5ower.

SNO!.%33(N8 %N8(N% !OO

3ined u the engine room C engines for snorkel oeration.

5laced the +ngine Room Snorkel +-haust 0alve <Baker or )harlie@ oerating gear in

5ower.

%'O3U$(ON ON &O%N&(N8 $O SNO!.%3

7t the order 1)ommence Snorkelling1 on the "6) the Snorkel nduction 0alve was

oened from the Snorkel 2ydraulic 6anifold in the control room on orders from the

Aiving &Pcer.

Uon the Snorkel nduction 0alve being oened the Snorkelling +ngine Room watch

keeers oened their +ngine 7ir nduction 2ull 0alve. The Snorkelling +ngine Room

Throttleman then commenced rolling one engine with starting air whilst the &iler

oened the aro-. == "H= turns hand cranked nboard +-haust 0alve.

7t engine start the Throttleman oened his +ngine Room Snorkel +-haust 0alve <Baker

or )harlie@, shut his engine e-haust dum <e-haust dumed into the engine room bilge

during engine roll and initial start@ and, uon the engine building suPcient e-haust

back ressure to blow the Snorkel +-haust 6ast dry, oened the 6ain Snorkel +-haust

0alve <7ble 0alve@.

When rigging for snorkelling, the nduction 6ast was drained to negative tank to

maintain the submarine1s trim, amounting to aro-imately ?,::: ounds. n addition,

when the +-haust 6ast was blown dry, the Aiving &Pcer Eooded =,::: ounds of

water from sea to negative tank to comensate for the water blown from the e-haust

mast, for a total of aro-imately "",::: ounds.

S%&U!% SNO!.%33(N8

When the order 1Secure Snorkelling1 was assed on the "6), or terminated by any of

the Snorkel +lectrical or +ngine Safety )ircuits, immediately C simultaneously theengines were stoed, all +-haust 0alves and Snorkel nduction 0alves were shut, and

the Snorkel 6asts lowered and housed. When the masts were lowered they Eooded

from sea, thus making the submarine heavier by aro-imately "",::: ounds. This

e-tra weight is immediately comensated for by the raid blowing of "",::: ounds of

sea water from negative tank thus maintaining the trim of the submarine.

Aendi* #

US Navy Su0vets Anecdotes

Anecdote No 1



:ames ;)at; )atterson< US Navy Su0 'et< Docent< USS /lue0ack e*hi0it at the

Ore,on useum o Science and (ndustry Deceased =>>?

&ver Duite a long eriod 5at graciously rovided detailed notes about snorkelling

aboard the USS Blueback <SS%?"@, a Otear droO Barbel class submarine,

commissioned "#%# and was in service for =" years. These were the last diesel!electricsubmarines in the US Navy, but the design was taken over by the Autch and

develoed into the modern submarines of today. t is believed the ost war 8aanese

designs were also develoed from the Barbel class.

Before rearing, at my reDuest, a full descrition of the snorkelling aboard Blueback,

5at had already answered my various messages with seci/c Duestions about Oshut

downO if the snorkel head submerged and the boat could not recover before

unaccetable conditions arose in the boat. have included his several atient answers

as a comilation, but the date order is not always clear as the original +!mails were

lost in a comuter crash. ortunately the main content had been saved in a te-t /le to

disc and here it is. trust readers will /nd much of interest.

SNO!.%3 )!O&%DU!%S A/OA!D $H% USS /3U%/A&.

When the word is assed to reare to snorkel the submarine will come to eriscoe

deth. n each comartment watch standers will rig the comartments. This for most

art means the right line u of ventilation and to line u the engines to run and if a

battery charge is to be done the boat will rigged for that also.

n manoeuvring room the engine consul oerator will ut the snorkel safety switch in

the byass osition and the 'unior controller will ut the snorkelHsurface switch in the

snorkel osition, this switch has four ositions, snorkel, surface, and two tri ositions.

&nce the boat is rigged for snorkel the &&A <&Pcer of the deck@ will order the snorkel

mast raised by the )&W <)hief of the watch@. 7fter the mast is raised the &&A will

have the )&W test the head valve while he checks the mechanical indicator thru the

eriscoe. 7fter the head valve is tested the word is assed to commence snorkelling.

The )&W will then oen the main induction valve. This valve is located at the bottom

of the snorkel mast. The valve allows air to ass from the mast to the main induction

ie to the engine room. 7fter the main induction valve is oened the engine oerator

will oen the hull induction valve. This allows air into the engine room from the maininduction ie. The engine oerator then starts the engine and oens the engine hull

e-haust and the snorkel e-haust valves.

7t "*si of back ressure the main snorkel e-haust valve will oen automatically. The

high back ressure will blow the water from the free Eooding snorkel e-haust mast.

When they have all the engines started the engine oerator will ut the snorkel safety

switch in the on osition.

&nce the boat is snorkelling and the order to secure snorkelling is given the 'unior

controller will ut the surfaceHsnorkel switch to the tried osition. This will kick out

the fuel racks it also kicks o all generators and it shuts the main snorkel e-haustvalve.



The engine oerator shuts the engine hull e-haust and the snorkel e-haust valves and

the hull induction valve. The )&W shuts the main induction and the head valve and

lowers the snorkel mast. This has been a normal light o and secure snorkel.

f there is over a ">si back ressure or 9 inches of vacuum or the rm of the fastest

running engine goes below $:: rm the snorkel safety circuit will shut the mainsnorkel e-haust valve and kick out the fuel racks and tri o the generators.

SNO!.%3 SHU$ DON DU% $O UN(N$%N$(ONA3 SU/%!8%N&% O# $H%

SNO!.%3 H%AD - USS /lue0ack .

The snorkel head valve would shut when too much salt water would short out some

electrodes and that would cause "::si air to oerate a valve we called the 1Duick as a

wink1 valve. That valve would send >>%si air to the shut side of the head valve iston,

this was all done automatically and was really Duick as a wink. When the water

washed o the head valve the Duick as a wink valve would then aly the >>%si air to

the oen side of the head valve. Then the head valve would oen automatically.

We could run all three engines while we were snorkelling. f the dive lost the bubble

and the head valve shut the engines would suck the air out of the boat until we

reached a 9 inch vacuum and then the main snorkel e-haust valve would shut

automatically. 7t ">si of engine back ressure the engines would shut down

automatically.

With three engines running it only takes about one minute to get to si- inches of

vacuum. With only one engine running it takes about si- or seven minutes. f you are

on one engine and the dive lost the bubble and went to dee the engine back ressure

would build u and the engine would shut down at ">si.

7lso if the rm of the fastest engine droed below $:: rm, the engines

automatically shut down. They /gured that an engine running only at $:: rm would

not have enough back ressure to kee water out of the engine.

7ll the engines were automatically shut down on high back ressure because the /rst

thing to haen would be the main snorkel e-haust valve would automatically shut

and this would always kee water out of the engines.

The main snorkel e-haust valve was always shut automatically by the snorkel safety

circuits. The engine inboard and engine snorkel valves were shut by the crew. When

say the crew that means they Eied a switch. 7ll the sea valves were electro!

hydraulic.

QUESI!" Does t%e 7an* #lass %ave t%e same snorkel set6u! as t%e <arbel #lass

Ges it $oes. 7%e 7an* #lass as t%e 1rst #lass to %ave only %ave t%e sin*le in$u#tion

!i!e. 7%e u!!y subs %a$ t%e same sa"ety #ir#uits- ; in#%es va#uum lo r!m an$

ba#k !ressure #ut out. 7%ey %a$ a main in$u#tion valve "or t%e en*ines. It as in t%e

sail ust above t%e main $e#k. 7%e snorkel air oul$ #ome into t%e snorkel %ea$ valve

an$ t%en $on t%e mast to t%e snorkel in$u#tion valve.

+"ter !assin* t%ru t%e valve air oul$ $um! into t%e main in$u#tion !i!e.



7%ere as a #%an*e valve in t%e #ontrol room t%at t%e >= oul$ *ive #ontrol o" t%e

main snorkel ex%aust valve (also #alle$ +<? valve) to t%e en*ine room- %e #oul$ not

o!en t%e valve but %e #oul$ take #ontrol o" t%e valve an$ t%en s%ut it.

=%en t%ey starte$ to snorkel t%e !riority en*ine room oul$ take #ontrol o" able

valve. 7%ey oul$ o!en it %en t%e en*ine starte$ to run an$ t%ey %a$ enou*% ba#k !ressure to blo t%e mast.

>n#e t%e en*ine as runnin* ok t%ey oul$ !ut able valve on t%e lat#%. 7%is as a

relay t%at oul$ %ol$ able valve o!en until t%e sa"ety #ir#uit as tri!!e$ an$ t%en t%e

relay oul$ s%ut t%e valve an$ t%e en*ines ere also s%ut $on.

I %o!e t%is %el!s you.

Pat

2i 5eter

I also as on a u!!y sub. It as t%e USS Sea ?eo!ar$ SS 48: in &';'6&'2.

>n t%e u!!y boats you #an snorkel it% all en*ines. I t%ank t%e 4 en*ine as

remove$ on some u!!y boats.. 7%at as t%e ay it as on t%e to u!!y boats t%at

I as on.

2i 5eter < re"errin* to <arbel #lass@

7%e snorkel in$u#tion mast is a $ry mast. Hoever t%e I man o" at#% oul$ o!en a

$rain to ne*ative tank in t%e #ontrol room. 7%ere is a si*%t *lass so %e #oul$ #%e#k

an$ make sure t%e mast %a$ not oo$e$. 7%e $rain oul$ $um! into ne*ative tank

an$ i" you ere snorkellin* in ba$ eat%er a lot o" ater oul$ as% $on t%e mast

an$ t%en into ne*ative tank. ver so o"ten t%e >= oul$ %ave to !um! t%e tank

ba#k to t%e snorkel mark. He oul$ !um! t%e tank to sea.

Still lookin* "or t%e $rain*s- I kno I still %ave t%em.

I like t%e 5uestions be#ause it kee!s me s%ar! an$ makes me t%ink

Pat

2i 5eter

7%e Sea ?eo!ar$ an$ t%e <lueba#k %a$ a Prairie Basker an$ t%ey orke$ *oo$. >ne o"

t%e !roblems o" usin* a Prairie Basker %en snorkellin* t%e boat oul$ a#t very li*%t

a"t an$ you %a$ to oo$ in a lot o" ei*%t- I t%ink e oul$ %ave to oo$ in about &,k

a"t an$ in t%e #enter to snorkel more t%an about ' knots.

Pat

2i 5eter



It as aroun$ t%e %ole a"t !art o" t%e boat an$ on t%e s#res. No t%at I t%ink ba#k it

may %ave been 2 en*ine t%at as remove$. >l$ a*e is sittin* in. Never %ear$ about

any valve !roblems but t%at $oesn9t mean t%ere asn9t any ( re"errin* to en*ine

valves) I $o kno t%ey %a$ to s%ut $on t%e #om!ressor be#ause o" %i*% tem! a lot o"

tines- but t%e system oul$ %i$e t%e noise "rom t%e en*ines very *oo$.

=e snorkelle$ about & yar$s "rom a tin #an an$ t%ey sai$ t%e boat soun$e$ like

rain ater. =e %a$ all t%ree en*ines on line. 7%e system orke$ but as %ar$ to kee!

on line.

Pat

Authors Note+

understand one engine was removed from some of the ( (uy conversions to

allow the 5rairie 6asker comressor to be installed. This was Duite some time after the

original (uy conversion.

5rairie 6asker was a system where the hull was covered in a skin of bubbles and

bubbles were used to reduce screw cavitation noise ! the web has several useful

references. The British e-erimental version was known as N(2TS2RT and as far as

is known only the only British submarine so /tted was the trials submarine Scotsman.

Several destroyers had trial sets.

7nswer to +!mail re erformance legend late.

7%e term 8J' means 8K en*ine out!ut an$ 'K *en out!ut. 7%e max r!m o" t%e

en*ines on snorkel as 2,- t%is as set be#ause t%ey #oul$ not *et enou*% air $ont%e snorkel mast it% t%e ba#k !ressure t%e en*ines run it% on snorkel. 7%is #lass o"

boat as to %ave $iLerent ty!e o" en*ines %oever t%ey ere "oun$ to be unsuite$ "or

sub servi#e. 7%e "Jm en*ines ere installe$ an$ it as "oun$ t%at t%e in$u#tion !i!e

as to small a"ter losin* some bloers.

think 5at is referring to the comact vertical 1ancake1 engines that were /tted in the

Tang class but were so troublesome they had to be removed and the hull lengthened

to allow the /tting of conventional engines. This situation may well have imacted on

the design of the Barbel class.

Anecdote No =

rom Rik Nilsson US Navy Sub 0et in answer to +!mail Duestion. < His eb site is %ere@

very time I reminis#e snorkellin*- I #an remember t%e rat% o" t%e en*inemen

a*ainst us !lanesmen %o alloe$ t%e boat to $ri"t $on #ausin* t%e en*ine #ylin$er

relie" valves to !o! an$ 1ll t%e #om!artment it% noxious "umes. I #an almost smell

t%em to t%is $ay.

In seas o" lon*- %eavy sells- it as sometimes %ar$ seaty ork #rankin* t%e !lanes

%eels (even in !oer mo$eM)- kee!in* $e!t% so t%e intake valve as as lo as

!ossible in t%e aves- yet not #y#lin* #lose$ "re5uently


http://rnsubs.co.uk/dits-bits/articles/development/scotsman-trials.html

http://saragossa.net/cubby/cubby.php


http://rnsubs.co.uk/dits-bits/articles/development/scotsman-trials.html

http://saragossa.net/cubby/cubby.php



Unlike t%e ori*inal Dut#% an$ erman im!lementations- %i#% I believe ere sin*6u!

!i!es it% a oat valve %ea$- t%e 1nal US Navy version #onsiste$ o" %y$rauli#ally

o!erate$ tan$em verti#al teles#o!in* masts installe$ in t%e a"t o" t%e sail. 7%e "orar$

!i!e as t%e intake an$ exten$e$ sli*%tly more t%an ,; "eet above t%e keel. 7%e %ea$

valve as ele#tro6%y$rauli#- #losin* automati#ally %en $ouse$ it% seaater. 7%e

ex%aust sto!!e$ ust s%ort o" t%e sur"a#e at snorkellin* $e!t% (,2 to ,4 "eet keel$e!t%)- an$ en$e$ in a !er"orate$ %ea$ un$er a !late to $is!erse t%e *ases as a #lou$

o" bubbles. 7%is %el!e$ %i$e t%e $iesel smoke- an$ re$u#e$ t%e noise si*nature.

7%e loer en$ o" t%e intake mast #onne#te$ to t%e existin* main in$u#tion trunk

t%rou*% a ater se!aratin* #%amber. 7%e en*ine intakes alays $re t%eir air $ire#tly

"rom t%e interior o" t%e boat- %i#% as "e$ "rom t%e main in$u#tion in t%e "orar$

en*ine room. For t%is reason- an$ $ue to t%e #on$ition o" #om!artment $oors bein*

#lose$ %ile submer*e$- only t%e "orar$ en*ines- en*ines one an$ to- ere use$

"or snorkellin*.

a#% en*ine ex%aust #onne#te$ to a snorkel ex%aust %ea$er outsi$e t%e %ull t%rou*%

a sin* #%e#k valve outboar$ o" t%e en*ine ex%aust #oolin* system. 7%e ex%aust mast

as not test6$e!t% rate$- an$ "ree6oo$e$ %en $ivin*. +ny ater in t%e intake mast

as $raine$ into one o" t%e inboar$ tanks (!ossibly t%e ne*ative tank)- %ile t%e

ex%aust as !ur*e$ u!ar$s by t%e en*ine ex%aust !ressure. Snorkel start6u!

#onsiste$ o" "ully raisin* t%e masts- an$ %en t%e %ea$ valve o!ene$- t%e intake as

$raine$ to ne*ative tank. 7%e ne*ative tank inboar$ vent as s%ut an$ t%e tank as

!um!e$ to sea. 7%e inboar$ en*ine ex%aust valves ere release$- $rainin* any ater

to t%e bil*e- an$ an attem!t as ma$e to start an en*ine to #lear t%e snorkel ex%aust.

=%en ex%aust !ressure rose above sea !ressure- about to atmos!%eres at snorkel

$e!t%- t%e snorkel #%e#k valve o!ene$ to !ur*e t%e mast. n*ine #ylin$er %ea$s %a$

ba#k6!ressure release valves to !revent en*ine $ama*e i" t%e $e!t% as too *reat- or

ater as in*este$.

7%e rus% o" "res% air a"ter a lon* submer*en#e as *reatly a!!re#iate$- even t%ou*%

e kne e ere less Cstealt%yC %ile snorkellin*. 7%e $onsi$e as t%at %en e

sto!!e$ snorkellin*- our !ur*e$ ol"a#tory senses %a$ to rea$ust to t%e normal stinky

submarine atmos!%ere a*ain. +lso- most o"ten in t%e +tlanti#- t%e air at ni*%t is #%illy.

I" you orke$ or sle!t next to an air #on$itionin* vent- you mi*%t %ave to !ut on a

a#ket.

7%e o#eans- even on C#almC $ays- are not !er"e#tly still. ?on*6!erio$ sells as ell as

sea #%o! "rom in$ #an make snorkellin* an un!leasant ex!erien#e. =%en t%e

automati# snorkel %ea$ valve #loses- it9s like someone a!!lie$ a va#uum atta#%ment

to your "a#e. Gour ears !o!- your tear $u#ts an$ sinuses $rain- et#. It #an be messy i"

you9re aslee!.

In me$ium to rou*% seas- t%e !lanesmen %a$ to ork %ar$ to kee! t%e %ea$ valve

"rom #losin* too lon*. 7%ere as a va#uum sa"ety sensor in t%e system t%at #ut oL

"uel %en t%e !ressure in t%e boat $ro!!e$ somet%in* like J&t% o" an in#% o"

mer#ury ($oes t%at soun$ reasonable). I seem to re#all t%at i" it staye$ #lose$ more

t%an &, or 2 se#on$s- t%e en*ines oul$ s%ut $on- bot% "rom la#k o" air an$ ex#essex%aust !ressure. I9ve been in t%e en*ine rooms %en t%is %a!!ens an$ remember



t%e #ylin$er relie"9s 1llin* t%e #om!artment it% $ark- #%okin*- eye6burnin* "umes in a

matter o" se#on$s.

I" t%e boat as steamin* $onin$ at less t%an sur"a#e in$ s!ee$- it oul$ be 5uite

!ossible to su#k en*ine ex%aust into t%e snorkel intake. I #an9t remember t%at bein*

an o"ten o##urren#e- but t%en- I as only aboar$ ubera "or to years. It #oul$ be t%at e alays #%an*e$ #ourses %en !ossible un$er t%e #ir#umstan#es- so as to stay

%ea$in* into t%e in$ %ile #%ar*in* batteries submer*e$.

I $o re#all t%at in t%e loer +tlanti# latitu$es- e %a$ ater va!our CmistC "orm in t%e

boat at times- $ue to arm in$u#te$ air #on$ensin* in our ot%erise #ool submer*e$

atmos!%ere at t%e onset o" snorkellin*. Baybe t%at9s %at t%e Darter !%oto*ra!%er

#au*%t on 1lm ( No.: belo). 7%e %ea$y- oxy*enate$ "res% air oul$ tem!orarily

!ur*e our nostrils an$ make us more #ons#ious o" t%e ever6!ervasive $iesel (an$ ot%er

smells) in t%e boat.

Anecdote No @

This icture came from the web. The comment recorded with the ictures wasJ I %a$

t%e lu#k to !ull USS Darter "rom early &'84 to early &'8,. Darter as one o" "our

$iesel boats at t%e time. 7%ey %ave all *one no. Gou #an see %o t%i#k t%e $iesel

smoke *ot %en you 9snorkel it% a tailin$.

The Aarter was a class of one submarine, a derivative of the Tang class.

&bviously e-haust gases in the atmoshere of a snorkelling submarines can only be

seen as an undesirable health haIard and worthy of some comment, so Rik Nilsson

being a US Navy Sub0et was asked about this hotograh, see his comments above in

his anecdote No.>

There have been unsubstantiated web reorts of Soviet submarine crews suering

serious illness due to snorkelling.

The author with service on Royal Navy 7 )lass and T )lass submarines has no

recollections of e-haust gases being drawn from the surface into the submarine, down

the induction mast along with air and so checked with members of the BarrowSubmariners orum. n their resonses most also wrote that they also had no

http://rnsubs.co.uk/boats/subs/a-class.html


http://rnsubs.co.uk/boats/subs/a-class.html




recollection of e-haust gas in the submarine due to snorting. There were a number of

comments on SSN similar that included in the anecdote reroduced below.

#rom a ormer !oyal Navy watch keein, su0marine ocer on SS. and SSN

in the late si*tiesBseventies (t is in act a comosite o a num0er o orum

ostin,s 0y the same erson and 0rou,ht to,ether with the ermission

ertainly I remember it- you nee$e$ 5uite s!e#i1# #on$itions- snortin* $on in$ at

t%e ri*%t s!ee$ so t%at your ex%aust as *ently blon "orar$ to t%e in$u#tion mast.

It as not a !leasant ex!erien#e anyay- so most likely avoi$e$ %enever !ossible-

%en#e t%e limite$ ex!erien#e by ot%er members o" t%e Forum o" *ettin* 9one9s on9

ba#k.

7%e reality is t%at any boat is at risk o" 9*ettin* it9s on ex%aust "umes ba#k9 i" t%e

#on$itions are ri*%t- an$ t%at is t%e boat *oin* exa#tly $on in$- at a s!ee$ sli*%tly

less t%an t%e in$ s!ee$- t%en t%e ex%aust %i#% is $is#%ar*e$ but a "e "eet aay

"rom t%e in$u#tion mast must *et su#ke$ ba#k. <oats it% en*ines t%at %ave a %i*%erba#k !ressure #a!ability an$ t%us maintain a ell submer*e$ snort ex%aust may $o

better as t%e ex%aust is some%at #leane$ an$ $iLuse$ by bubblin* t%rou*% sea

ater. 7%ose it% !oor ba#k !ressure !er"orman#e %i#% %a$ non or sli*%tly

submer*e$ ex%austs (most soviet boats "or exam!le) oul$ ten$ to suLer more.

It as also a !roblem on t%e sur"a#e even it% t%e sur"a#e muers %en *oin* $on

in$ at about in$ s!ee$ %ere t%e ex%aust oul$ sirl aroun$ t%e 1n. /emember

t%e se#on$ary !ur!ose o" snortin* a"ter #%ar*in* t%e batteries as to re!lenis% t%e

oxy*en in t%e boat. I am sure t%e ventilation system also $re "rom t%e area o" t%e

in$u#tion system an$ ex%auste$ ba#k into t%e en*ine room.

It as orst runnin* on t%e sur"a#e on $iesels on an SSN in t%ose #on$itions be#ause

as t%ey %a$ no sur"a#e muer you use$ t%e snort ex%aust mast- an$ it nee$e$

#oolin* ater ine#te$ into t%e ex%aust- so *oin* $onin$ you %a$ a ni#e $ieselly

s!ray onto t%e bri$*e- $i$ a %ole at#% like t%at a"ter e %as a S/+B an$ sur"a#e

a"ter a main t%rottle steam leak- not ni#e.

By earlier #omments on t%e !oor ba#k !ressure !er"orman#e o" Soviet boats are a

$im re#olle#tion "rom my $ays in t%e Navy- an$ a!!lie$ to t%e =%iskyJ/omeo !erio$

boats- t%eir more mo$ern ones may %ave over#ome t%e !roblem. ertainly ba#k

!ressure as alays re!orte$ as t%e reason e #%ose me#%ani#al s#reamers(su!er#%ar*ers) on t%e P@> boats $es!ite t%eir noise. Bore re#ently I $o believe t%e

ermans %ave ma$e turbo #%ar*ers ork at %i*%er ba#k !ressures.

)OS$S&!()$

&n the 1getting your own back1 roblem, it has occurred to me that the ideal conditions

for ingesting ones own e-haust are a wind seed similar to the boats and that the sea

will be relatively calm so control roblems would be minor. n general though it is

highly unlikely any boat would ersist in a course that was likely to ashy-iate the

crew.

Anecdote No 4



7%is little ane#$ote ori*inally #ame "rom %ere

>n most <oats- t%e en*ine use$ to blo t%e sta#k- ere t%e one9s it% t%e most

runnin* %ours on t%em. /eason bein*- t%at i" somet%in* ent ron* an$ s%e oo$e$-

%at t%e %ell- e %ave to over%aul %er in 4 %ours anyay.

7s did this little ditty that follows. The e-letive substitutes can make reading a little

diPcult for eole not used to US swear words, but the substance of the te-t gives a

deal of technical and oerational information.

Thanks to 6yron 2oward +N"<SS@ USS Bream SS>$=

# ty$ical con%ersation &rom the 'honoured' Engine (oom )ent something

like this

hrottleman C+= OOOOO- not a*ain- >3- lets line it u!- li*%t er oL an$ !ray it $on9t

oo$C

!iler u%- u%- u%- u%- ( t%at9s t%e soun$ %e ma$e o!enin* t%e inboar$ ex%aust valve

9#ause t%e stem as all #arbone$ u!)- UH- UH- UH- UH- ( a total o" :: &J: turns later)

OOOOOOOO- t%ou*%t I9as never *onna *it t%e OOOOOOOO o!en)

hrottleman C%ol$ t%at OOOOOO by6!ass t%is time- till I kno#k your OOOOOOO %an$ oL o"

it- >/ G>U9?? < ?IEIN IN 7H OOOOOOOOO <I?SC.

n*ine rolls : or 8 times- ($e!en$in* on %o #ute t%e t%rottle as tryin* to be-

s%oin* oL to t%e ot%er n*ine /oom).

hrottleman C>3- t%ey 1nally *ave me t%e OOOOOOOO or$ to li*%t oL- *rab t%atOOOOOOOO by6!ass sit#%- an$ remember- $on9t let *o on your on.

n*ine starts rattlin* an$ rollin*- %a#ks- #ou*%s- bel#%es an$ starts 1rin*- 2 or :

#ylin$ers at a time. Finally- it roars into li"e- t%e t%rottleman yanks t%e snorkel ex%aust

valve o!en- t%e oiler- tryin* to be #ute yells C#an I le**o- #an I le**o- %u%C but

remembers t%e !revious t%reat an$ %ol$s a $eat% *ri! on it. +bout t%at time t%e

n*ine $ies an$ starts rollin* to a %alt. 7%e t%rottleman- in one smoot% #ontinuous

motion s%oves t%e snorkel ex%aust valve lever ba#k to t%e #lose !osition an$ kno#ks

t%e oilers %an$ oL ust in time to kee! it "rom oo$in*- but t%e airbox $oor s!rin*s are

all s%ot an$ eak so t%ey blo o!en an$ 1ll t%e en*ine room it% t%at $eli*%t"ul- lun*6searin*- eye6aterin* bla#k smoke e all love$ so $early.

hrottleman COOOOOOO t%at as "un %y in t%e OOOO $on9t t%ey let me blo t%e sta#k

it% t%at ot%er OOOOOO o" OOOOO. Seems like t%e &st in #%ar*e o" t%e en*ine room alays

mana*e$ to be on t%e 8 to &2- an$ e never- never ever snorkelle$ on %is at#%-

ex#e!t $urin* eet o!ts an$ t%en it asn9t every OOOOOOO ni*%t- no as it.

I %ear tell t%at t%e events "or snorkellin* on a FB (Fairbanks Borse) boat ere a ta$

$iLerent.

!iler C>% s%oot- %y #oul$n9t t%ey %ave aite$ until e 1nis%e$ our #ookies an$

milkC.

http://members.cox.net/rsamsonss328/Snorkel.html

http://members.cox.net/rsamsonss328/Snorkel.html



hrottleman C=ell ust %urry u!- %en e s%ut $on- you #an *o u! to t%e res

Dinette an$ *et us some i#e #ream it% %i!!e$ #ream an$ #%erries on to!- >3

!iler C>%- I *uess so. I ust is% t%ey oul$n9t $o t%is so o"ten. It %urts my ears %en

t%ose silly ol$ !lanesmen $i! t%e %ea$ valve.

hrottleman C =ell it %urts mine too but ya ust %ave to learn to *rit your teet% an$

!ut u! it% it. /emember- you #oul$ %ave been sent to one o" t%ose nasty < boats

it% t%eir $irty ol$ immy en*inesC.

!iler >%- I kno an$ I am so t%ank"ul t%at $i$n9t %a!!en.

Anecdote No 5

7dmiral (alantin <US Navy ret @ in his book SUB67RN+ 7A6R73, tells us more about

the snorkel voyage of the USS 5ickerel <SS %>$@ mentioned in the oening of the main

article.

In*enuity an$ %umour- to attributes o" su##ess"ul submariners- ere not la#kin* on

Pi#kerel. In %is re!ort- Paul S#%rat0 ( a!tain) sai$ C7%e most a##urate an$ reliable

in$i#ator va#uum in$i#ator aboar$ is almost too %omely "or mention in an oQ#ial

re!ort. 7o alert t%e manoeuvrin* room #ontrollerman to stan$ by to !ull #lear %en

t%e %ea$ valve is #y#le$- t%e ele#tri#ians !la#e$ a re$6!ainte$ #on$om over a mout%

o" a bottle. +s soon as t%e va#uum in#rease$- t%e #on$om stan$s u! ri*i$- !ointin* a

luri$ 1n*er o" #aution at t%e #ontrollerman.

Anecdote No C

Some years ago had an +!mail e-change with a retired US Navy submarine oPcer.

Unfortunately due to a comuter crash and my failure to back u +!mails, lost all the

messages, however one item stayed in my mind so here is the gist.

7%e !arti#ular u!!y submarine- relatively late in its servi#e li"e- %a$ a small $iesel6

*enerator 1tte$ $on t%e #entreline on soun$ re$u#in* mounts. +!!arently its

!ur!ose as to a !rovi$e a 5uieter means o" snorkellin* at slo s!ee$s %ile

su!!lyin* t%e s%i!9s ele#tri#al loa$. It as not a *reat su##ess as t%e oQ#er re!orte$ it

s!ent more time in bits bein* re!aire$ t%an in servi#e. Hoever it as an interestin*

i$ea t%at mi*%t %ave been !ursue$ i" t%e US Navy %a$ !ersiste$ it% $iesel

submarines.

Anecdote No ?

rom ! 3)AR ritI Steiner US Navy <ret.@

I serve$ in to snorkel boats- /a0orba#k (n*ineer >Q#er in &';&6;2). S%e as a

u!!y II+. <lue*ill as a "ormer SS3 it% a <R/64 !assive array sonar t%at ra!!e$

aroun$ t%e bo. It as an ama0in* !ie#e o" *ear. =e #oul$ $ete#t- #lassi"y an$ tra#k

s%i!s an$ ot%er submarines at astonis%in*ly *reat ran*es. <ot% ere :6en*ine boats.

=e #oul$ snorkel at 68 knots. +nyt%in* "aster t%an t%at an$ t%e masts an$ !eris#o!es

oul$ oul$9ve vibrate$ so ba$ly t%ey9$ !robably %ave broken in t%e Cu!C !osition

(not a $esirable event). =e #oul$ only snorkel on to en*ines any%o 6 t%ree oul$



%ave !ulle$ su#% a va#uum in t%e boat t%at e9$ %ave s%ut $on anytime t%e %ea$

valve s%ut. =e use$ stan$ar$ air#ra"t altimeters to kee! visual tra#k o" %at Caltitu$eC

e ere at. It9s been a lon* time sin#e I $i$ any snorkellin*- but as I remember it- on

to en*ines at 8J' e9$ CyC at &-8 "eet. =%en t%e %ea$ valve s%ut e9$ C#limbC

"aster t%an an F64. It as 5uite a si*%t at#%in* t%e altimeter %an$s *o aroun$. Not to

mention %avin* your ear$rums !o!!in* (i" you ere lu#ky) an$ your sinuses su#ke$$ry (very messy). +s best I #an re#all "rom nearly , years a*o- t%e en*ines oul$

s%ut $on automati#ally at ;-, "eet.

>ne o" t%e t%in*s t%at snorkellin* "or#e$ as an in#rease in t%e lobe6to6lobe #learan#e

in t%e en*ine s#aven*in* bloers to #om!ensate "or t%eir %avin* to run in a !artial

va#uum. =it%out t%e in#rease- t%ey9$ %ave %eate$ u! an$ i!e$ (t%ereby ruinin* your

%ole !atrol).

I #an9t t%ink o" a *oo$ reason "or %avin* to snorkel at %i*% s!ee$s anyay. Gou9re

noisy as %ell %en you snorkel 6 at any s!ee$. Gou essentially ren$er yoursel" $ea"-

!assive sonar6ise. In an environment %ere ot%er- un"rien$ly submarines mi*%t lurk-

t%at9s not a *oo$ ay to be.

7%e orst kin$ o" snorkellin* as in a #%o!!y sea an$ a %eavy seaay. =%en t%e sea

as%e$ over t%e %ea$ valve ele#tro$es- it oul$ s%ut. 7%e en*ines #ontinue$ to su#k

air out o" t%e boat- so e9$ C#limb.C It as a stran*e sensation as t%e air oul$

su$$enly #%ill in t%e boat. 7%en ust as "ast as it s%ut t%e sea oul$ !ass an$ %ea$

valve oul$ o!en. CDonC in 9altitu$eC e oul$ *o as t%e atmos!%eri# air rus%e$

ba#k in t%rou*% t%e snorkel in$u#tion. +n$ t%e #y#le oul$ re!eat itsel" over an$ over-

=e #alle$ it a C#%atterin* %ea$ valve.C

Pretty soon everybo$y oul$ be annoye$. Peo!le slee!in* oul$ be ake$ u! by t%eir

!o!!in* ears an$ $rainin* sinuses. Peo!le alrea$y aake- oul$ ust bit#% about it

an$ en$ure it. Usually- be#ause submariners ?>E to a*itate t%eir s%i!mates- several

o" t%em oul$ alk t%rou*% t%e ontrol /oom (one6at6a time) an$ ask t%e Divin*

>Q#er i" %e #oul$n9t #ontrol t%e $e!t% a little better.

I ma$e my very 1rst $ive as $ivin* oQ#er aboar$ Irex %ile an >Q#er Stu$ent in

Submarine S#%ool in &',8. 7%e year be"ore- s%e %a$ been 1tte$ it% t%e rein"or#e$

1bre*lass- so6#alle$ CNort% +tlanti#C sail.

I soun$e$ t%e $ivin* alarm an$ s%oute$ Clear t%e bri$*eMC 7%e lookouts vanis%e$. I"oun$ mysel" in a very lonely !osition %i*% ato! t%e sail o" a s%i! t%at as sinkin*

beneat% my "eet. 7%e C#lear t%e bri$*eC $rill involve$ turnin* a"t an$ *oin* $on a

la$$er to a !lat"orm $e#k %al"ay to t%e u!!er #onnin* toer %at#%. 7%en a"ter a '

$e*ree turn to t%e ri*%t you9$ *o $on anot%er la$$er- turn &8 an$ you9$ be at t%e

u!!er %at#%- %i#% be"ore #onversion oul$9ve been at your "eet.

7%e la$$ers %a$ stainless steel verti#al %an$ rails. =e %a$ been a$vise$ by s%i!9s

#om!any t%at t%e ay $on as s!ee$e$ u! by loosely *ri!!in* t%ese rails an$

$ro!!in* $on. Folloin* t%eir su**estion I $i$ t%at an$ $arne$ near oun$ u! a

#asualty at t%e !lat"orm $e#k. + 1lm o" ater unevenly $istribute$ on ea#% rail %a$

be#ome a lubri#ant beteen my %an$ an$ t%e rail- resultin* in t%at %an$9s sli!!in*

%ile t%e ot%er one %el$ "ast. I believe you #an ima*ine %o t%at tor5ue$ my bo$y. I



as lu#ky to lan$ on bot% "eet it%out breakin* an ankle or se!aratin* a s%oul$er. I

#oul$ easily %ave !ani#ke$- but I $i$n9t. I turne$ an$ !atiently $es#en$e$ t%e se#on$

la$$er ste!6by6ste!. I $ro!!e$ into t%e #onnin* toer an$ yanke$ t%e %at#% s%ut it%

!lenty o" time to s!are 7%e $ive ent ell a"ter t%at.

In &';& as /a0orba#k9s n*ineer >Q#er in t%e s%i!yar$ I oversa t%e installation o"%er Nort% +tlanti# sail- t%e 1rst in t%e Pa#i1# Fleet. <y t%en I9$ be#ome a mu#%

CsaltierC submariner an$ asn9t #on#erne$ about %urryin* $on t%e la$$ers. >n sea

trials t%e n*ineer >Q#er alays makes t%e 1rst $ive. <ase$ on my Irex ex!erien#e I

sim!ly took my time. +"ter all t%e boat $i$n9t submer*e any "aster t%an it $i$ be"ore.

=%ile I9m at it- it as ama0in* %at #oul$ be $one to #on1*ure t%e Snorkel x%aust

System in ays t%at t%e ori*inal $esi*ners never ima*ine$. +s a submariner I9m sure

you9re ell aare o" t%e in*enuity t%at #%ara#teri0es t%is uni5ue bree$.

CHmmm look at t%is. Su!!ose e #onne#te$ t%is to t%at an$ s%ut t%is valve. 7%en e

#oul$ $o t%is. ?et9s try it.C

For exam!le- %ile visitin* Hon* 3on*- <lue*ill as neste$ starboar$ si$e to a US

$estroyer t%at as moore$ to a buoy. 7%e DD as !re!arin* to $e!art H3 an$ %a$ all

%an$s at 5uarters in t%eir ni#e- #lean %ite uni"orms. +s soon as it as rea$y to *o- e

ere *oin* #ast oL an$ to move to our bert% at HBS 7amar.

=e %a$ statione$ t%e manoeuvrin* at#% but %a$n9t yet arme$ u! t%e en*ines. I

as stan$in* to!si$e a"t %en one o" my lea$in* en*inemen !o!!e$ %is %ea$ u! out

o" t%e a"ter en*ine room %at#%. =it% an evil *rin %e sai$- CBr. Steiner- let9s *et t%em

9skimmers9.C I aske$ %im %o. He sai$- C?et9s #ross #onne#t 4 to t%e outboar$

ex%austs "or & an$ 2 t%rou*% t%e Snorkel x%aust System an$ roll t%e en*ines to

make sure t%ere9s !lenty o" ra "uel in 9em. =%en e *et t%e si*nal "rom manoeuvrin*

e9ll start all t%ree to*et%er. =%en t%ey9re runnin* e9ll !o! o!en t%e outboar$

ex%austs "or & an$ 2 an$ let t%e 9skimmers9 %ave it.C I tol$ %im t%at as 1ne it% me.

7%e $estroyer as to leear$.

I staye$ to!si$e an$ at#%e$ it% $eli*%t as our en*ines blaste$ a broa$si$e o" $ense

bla#k smoke onto t%e DD. It as soon invisible. =%en t%e smoke 1nally #leare$ t%ere

asn9t a %ite6uni"orme$ CskimmerC any%ere to be "oun$ on t%e DD9s !ort si$e.

7%is as a #lassi# $is!lay o" t%e submariner9s9 in*enuity #ombine$ it% %is innate- !u#kis% instin#t to a*itate. 7%e CskimmersC no $oubt ere ma$ as %ell- but t%e $eli*%t

e took "rom t%is as t%at t%ey %a$ no i$ea e9$ $eliberately ruine$ t%eir $ay an$

t%ere as not%in* t%ey #oul$ $o about it.

Ho!e t%is %el!s

Frit0

5eter, here1s another ersonal anecdote you may /nd interestingJ

7%e year be"ore I be#ame n*ineer >Q#er in /a0orba#k %er %ie" n*ineman #ame u!

it% a brilliant i$ea.



+ll o" our snorkel6#a!able submarines %a$ retaine$ t%eir ori*inal #on1*uration it%

res!e#t to t%e muers t%at t%ey %a$ $urin* ==II. 7%ese ere a $rone$6ty!e it%

!ressuri0e$ sea ater !ourin* into t%em to $am!en t%e $iesels9 roar 6 it oul$9ve

been extremely ba$ "orm to be #au*%t on t%e sur"a#e- by bein* %ear$.

7%ese $evi#es ere ei*%teen "eet lon*- an*e6to6an*e. 7%ey ere #onne#te$ to t%ein$ivi$ual en*ines9 outboar$ ex%aust risers at one en$ an$ to t%e overboar$ ex%aust

!i!e on t%e ot%er. <e#ause o" t%e $oubly #orrosive eLe#t o" sea ater an$ $iesel

ex%aust *asses- t%ey %a$ to be re!la#e$ on avera*e every tenty6"our mont%s. +s

time !asse$ t%e su!!ly o" re!la#ement muers %a$ $in$le$. .

7%e %ie" %a$ a solution. He #orre#tly re#kone$ t%at %enever e ere $oin* CSneaky

PeteC o!erations- e snorkelle$ to #%ar*e t%e batteries- so t%e ori*inal !ur!ose "or t%e

muers as moot. He su**este$ re!la#in* t%e muers it% a strai*%t !i!e t%rou*%

%i#% t%e same C$ronin*C ater oul$ be "or#e$.

>BSU<P+ a!!rove$ t%e i$ea on a trial basis- an$ aut%ori0e$ t%e re!la#ement o"one o" /a0orba#k9s muer it% a strai*%t !i!e "or evaluation !ur!oses. 7%e boat as

in t%e San Fran#is#o Naval S%i!yar$ at Hunters Point. 7%e s%i!yar$ manu"a#ture$ an

ei*%teen "oot6lon*- #ir#ular strai*%t !i!e it% a!!ro!riate an*es "rom :J46in#% Cbla#k

ironC an$ installe$ it beteen t%e outboar$ ex%aust riser an$ tail!i!e "or t%e :

en*ine. It asn9t a!!re#iably lou$er t%an t%e muer. >BSU<P+ bou*%t it %olesale

an$ re#ommen$e$ to t%e %ie" o" <USHIPS t%at strai*%t !i!es be#ome a stan$ar$

SHIP+?7 to be a##om!lis%e$ Fleet i$e at ea#% submarine9s next overall. It as so

or$ere$ it% t%e !roviso t%at t%ey be ma$e o" :J46in#% #orrosion resistant steel- i.e.-

stainless steel t%at oul$ never %ave to be re!la#e$. 7%e era o" submarine muLers

as %istory.

Fast "orar$ to &';&. /a0orba#k as at Hunters !oint "or a mu#%6nee$e$ #om!lete

over%aul. =e ere to re#eive t%e rein"or#e$ 1bre*lass Nort% +tlanti# sail. =e also

ere to re!la#e all o" t%e su!erstru#ture aba"t t%e "orar$ en$ o" t%e sail it%

rein"or#e$ 1bre*lass C#lam s%ellC se#tions. Naturally- e ere also *oin* to *et t%ree

ne stainless steel strai*%t !i!es.

nter Frit0- t%e ever #urious- C=%y is it like t%atC n*ineer >Q#er. I aske$ t%e

s%i!yar$ man (one al =oolley) %o as res!onsible "or installin* t%e strai*%t !i!es

%y t%ey %a$ to be so lon*. =as t%ere some a#ousti# reason No- t%ere as no reason

"or it ot%er t%an to 1t beteen t%e an*es so t%e ex%aust #oul$ !ass t%rou*% t%e

tail!i!e %i#% itsel" !asse$ t%rou*% t%e %ole in t%e s%eet metal su!erstru#ture t%at

%a$ been t%ere sin#e #onversion. (7%is as a mani"estation o" t%e C=e9ve alays $one

it t%is ayC syn$rome.)

I sai$. Cal- e9re *ettin* an entire ne su!erstru#ture- so t%e yar$9s *oin* to %ave to

#ut %oles in it "or t%e ex%austs- ri*%tC

C/i*%t.C

C>kay- $esi*n a !i!e "or me t%at atta#%es to t%e outboar$ ex%aust an*e an$ t%en

sim!ly turns in t%e s%ortest !ossible ra$ius to !ass t%rou*% t%e %ole in t%esu!erstru#ture. I9ll take it to my > an$ i" %e a*rees e9ll mar#% it u! t%e %ill.C



He a*ree$. 7%e s%i!yar$ #oul$n9t %ave #are$ less. >BSU<P+ love$ it an$ tol$

<USHIPS %o also bou*%t it an$ issue$ a ne SHIP+?7 re!la#in* t%e !revious one.

/a0orba#k *ot t%e 1rst t%ree ne s%ort !i!es. very ot%er $iesel boat in t%e Fleet t%at

$i$n9t alrea$y %ave t%e lon* strai*%t !i!es by t%en *ot t%em- too.

7%e s%ort !i!es #onsiste$ o" a an*e el$e$ to a :J46in#% transition se#tion about a"oot lon* on its s%ortest $imension an$ about t%ree "eet on its lon*est #reatin* a "orty6

1ve $e*ree an*le. 7%is as el$e$ to anot%er se#tion %i#% turne$ t%e $ire#tion o"

o anot%er "orty61ve $e*rees. i.e. $ire#tly to starboar$ or !ort- %ere a 1nal strai*%t

se#tion a #ou!le o" "eet lon* ent t%rou*% t%e su!erstru#ture.

+ resi$ual bene1t "or /a0orba#k as t%at >BSU<P+ alloe$ us to kee! t%e

substantial savin*s "rom t%e "un$s t%at %a$ alrea$y been allo#ate$ "or a lon* !i!e

re!la#ement. =e a!!lie$ t%ese savin*s to lots o" $esirable !roe#ts t%at e ot%erise

oul$ %ave never a##om!lis%e$

<est-Frit0

#OO$NO$%

ritI, after reading the comleted article added to his already very informative

anecdote and made a review comment that is most welcome from an e-erienced US

Navy submarine oPcer.

It meets it% my a!!roval an$ +/NS BG !raise. =?? D>NM >ne minor item #au*%t

my attention

C Hoever in t%e u!!y II+ #onversions- one $iesel6*enerator as remove$ to make

e5ui!ment s!a#e- $etail o" t%e lay6out an$ o!eration is not knon.C

/a0orba#k (SS:'4) as a u!!y II+. /e*ar$in* t%e above un#ertainty- I believe t%at

t%is s%oul$ #lear t%in* u!. 7%e 2 n*ine (Port) as remove$ "rom t%e Forar$ n*ine

/oom. 7%e air #om!ressors- trim an$ $rain !um!s- va#uum !um!- IB> !um!- an$

Hy$rauli# +##umulator- air #on$itioners- /e"ri*eration unit- an$ IBs ere move$

"rom t%e Pum! /oom (un$er t%e ontrol /oom $e#k) into t%e s!a#e va#ate$ by t%e

en*ine- bot% above an$ belo t%e $e#k !lates. 7%e IBs ere relo#ate$ to t%e

Banoeuvrin* /oom. 7%e va#ate$ s!a#e in t%e "ormer Pum! /oom be#ame t%e Sonar

/oom.

+s %as been state$ else%ere in t%e arti#le- e #oul$ snorkel on to en*ines only. +

t%ir$ en*ine oul$ %ave #reate$ too *reat a va#uum in t%e boat- %i#% in turn-

oul$9ve le"t too little mar*in be"ore rea#%in* Cameout altitu$e.C No !re"eren#e as

*iven to runnin* only t%e +"ter n*ine /oom9s en*ines %ile snorkellin*. 3ee!in* t%e

en*ines9 a##umulate$ runnin* times more or less e5ual as more o" a $e#i$in* "a#tor

in $eterminin* %i#% to oul$ be run at any *iven time.

USS <lue*ill (SS6242) "ormerly (SS36242) as a +7> #lass #onversion t%at also

remove$ t%e 2 en*ine. S%e as one o" about a $o0en +7>9s t%at *ot #onverte$. I

as C>le <lue9sC n*ineer >Q#er "or &, mont%s- t%en be#ame %er >!erations >Q#er

an$ Navi*ator.

http://rnsubs.co.uk/dits-bits/articles/development/us-snorkel/USN_snort.php#Note

http://rnsubs.co.uk/dits-bits/articles/development/us-snorkel/USN_snort.php#Note



In &'; $urin* my Submarine >Q#er Ruali1#ation 1nal exam- I ent to sea in USS

+IB+N (SS6:2:)- S%e $emonstrate$ t%e *reat- albeit uninten$e$- versatility o" t%e

snorkel system by- are your rea$y "or t%is- $ivin* on t%e snorkel.

Durin* t%is evolution s%e submer*e$ in t%e usual "as%ion- s%uttin* t%e main in$u#tion

valve %ile raisin* t%e snorkel mast- s%uttin* t%e main en*ine overboar$ ex%austvalves- an$ o!enin* t%e snorkel ex%aust valves. <y t%e time t%e boat rea#%e$

!eris#o!e $e!t% t%e snorkel mast as "ully raise$- t%e %ea$ valve as o!en an$ air

in$u#tion as bein* taken t%rou*% it. 7%e en*ines never sto!!e$ runnin*. 7%e main

snorkel ex%aust o!ene$ easily sin#e t%e snorkel ex%aust mast as never #om!letely

oo$e$. +IB+N $i$ t%is routinely.

I as $a00le$- to say t%e least. 7%is !rove$ t%at it #oul$ be $one- but not t%at it s%oul$

be $one. >n#e as enou*% "or me.

<est re*ar$s-

Frit0

Aendi* 8

U-/oat History< Develoment 2 %uiment< 1914 to 1945

by Davi$ Biller

!%3%'AN$ %$!A&$S

7ll four Stroke, two stroke considered but not alied in WW

The diesels had to be modi/ed to run with the SchnorchelJ the 67N 6#0 in the G)!$:,

for e-amle was /tted with secial camshafts with a 1normal1 osition giving an

e-haust ressure of :." atmosheres and a Schnorchel osition ,with a ressure :.$!

:.$% atmosheres.

+arly e-eriments on two tye U!%*!U%? involved removing a eriscoe and relacing

it with the Schnorchel tubes. This was followed by modi/ed tubes in Tye 0 U!>=%!

U>=9 in Set "#$=.

(erman e-haust discharge techniDues were dierent to the simle underwater outletadoted by the Royal Navy. British 7SW e-erience had showed that the submarine

could be detected by observation of the e-haust gases, while the (ermans ersisted

in thinking this was not so.

The (ermans develoed two versions of the all imortant air induction tube head

valve, the /rst a simle ball Eoat and later a ring Eoat. Both these methods were

adoted by the Royal Navy, /rst the ball and later the ring Eoat. 6iller reorts that an

electro!neumatic head valve was roduced but then adds a footnote that this tye of

valve was still under develoment when the war ended.

7s in the Royal Navy, the induction Eoat valve fell oen when lowered allowing the

mast tube to Eood. 7arently the ring Eoat had a vent valve that oened at =: m

