EasyStern® CWS Propeller Shaft System

Stern tube

EasyStern® ClampSeal

Composite bearing

Standby Seal

EasyStern® CWS Propeller Shaft SystemsEasyStern® Closed Water Lubricated Propeller Shaft

Systems are custom designed and engineered as a

complete package. The systems are water lubricated

(fresh water / glycol based coolant). By using two

propeller shaft seals (inside- and outside the vessel)

the system is closed and the liquid circulates through

the entire system. Closed water lubricated propeller

shaft systems have less total system wear and the

shaft bearings have a longer life span compared

to ‘open’ water lubricated propeller shaft systems,

special in waters containing high levels of solids. The

system requires an on-board lubrication

tank and a circulation pump. Several

key components of the closed water

lubricated propeller shaft system have

been awarded a Design Award METS

(DAME).

Custom Designed PropellersOur high skew propellers are custom designed to ensure

optimal performance. The blade section and blade area

ratio are optimized to minimise noise and vibration levels.

Propeller blades are machined on CNC milling machines.

Standard finish is according to ‘ISO Class I’ standard.

Optionally we offer the most accurate possible finish

according to ‘ISO Class S’ standard.

Shaft brackets (optional)Shaft brackets (V, P or Y type) are custom designed to

meet the hull shape of the vessel involved. The brackets

can be supplied in steel, stainless steel, aluminium or

aluminium bronze. The section of the bracket profile is

custom designed to guarantee minimal drag.

Stern tubesEasyStern® stern tubes are special designed to reduce

noise and vibration levels on board and eliminates bearing

alignment issues caused by welding (stress). EasyStern®

ClampSeals are clamping and sealing the stern tube

inside the outer tube and guarantee quick and easy stern

tube installation. Closed water lubricated stern tubes are

available in steel, stainless steel or aluminium bronze.

Propeller shaftsPropeller shafts are designed and manufactured

according to the applicable classification society rules

and regulations. Both keyed and keyless versions can be

supplied. The most widely used stainless steel grade is

Duplex 1.4462 with a restricted chemical composition to

ensure both added strength and corrosion resistance.

Other stainless steel grades are available on request.

AxiSeal® shaft sealsThe AxiSeal® is a dripless mechanical propeller shaft seal

which uses ceramic (SiC) gliding rings for sealing. This

sealing principle results in exceptional long service life.

The AxiSeal® requires no regular maintenance. Optional

available is the Standby Seal which can be used in case

of emergencies and/or inspections.

Axiseal® shaft seal

EasyStern® ClampSeal

Standby Seal Axiseal® shaft seal

Aft. Seal HousingThe Aft. Seal is specially designed to fit the EasyStern®

stern tube system and uses a triple JW lip-seal

arrangement with integrated rope guard. The Aft. Seal is

mounted onto the EasyStern® stern tube using a screw

thread connection. Installation is quick and easy. In case

inspection/replacement of the JW lip-seals is required,

only dismounting the Aft. Seal cover will be sufficient.

The Aft. Seal housing is of aluminium bronze and has a

filling and draining connection. The Aft. seal comes with a

duplex stainless steel wear sleeve to prevent shaft wear.

Thrust bearings and Flexible couplingsPropeller thrust is absorbed by a heavy duty thrust

bearing. Combined with a homokinetic (CV) shaft

(Aquadrive) or high elastic flexible coupling and mounting

the engine on soft engine mounts, optimal isolation of

noise and vibration is achieved. A flexible coupling only

(without thrust bearing) is a possible solution as well.

Without a thrust bearing isolation of noise and vibration

is less. The final choice depends on the yacht-owner

requirements and available budget.

Calculations › Shaft-alignment, Gap and Sac calculation

› Lateral vibration analyses

› Axial vibration analyses

› Torsional vibration analyses

Advantages of EasyStern® closed water lubricated Propeller Shaft System

› Less total system wear

› Much longer bearing life span

› Low noise and vibration levels

› Fully custom engineered

› Complete design and suplly incl. lubrication tank and

circulation pump

› High performance

Blokland Non Ferro bvLelystraat 106, 3364 AJ SliedrechtThe Netherlands

+31 (0) 184 413 789info@bloklandnonferro.nl www.bloklandnonferro.nl

Verkoop / Sales+31 (0) 184 420 015sales@bloklandnonferro.nl

Blokland Non Ferro bvBlokland Non Ferro is a Dutch family business, founded

in 1962 and active on the global marine market. The

company specializes in designen, producing and

supplying complete propulsion- and rudder systems for

yachts and small commercial vessels as well as box

coolers and heat exchangers for inland- and commercial

vessels and industrial applications.

With extended possibilities for design and production

of our products we offer you an attractive combination

of superior know-how, experience and production

possibilities.

We offer two kind of propulsion systems: › Fixed pitch propeller system

› Retractable propeller system

With numerous national and international references

Blokland Non Ferro has built a reputation of a highly

dependable quality player. We provide shipyard and naval

architects around the world with our solutions. For (small)

yachts as well as megayachts (both motor- and sailing

yachts). Blokland Non Ferro also produces technical

propulsion components and holds a comprehensive

stock so that customers can be serviced promptly.

Blokland Non Ferro offers you the following services: › Standard and custom designed propulsion- and rudder

systems

› Design and supply of box coolers and heat exchangers

› Sales and distribution of technical marine equipment

Blokland Non Ferro is committed to offer quality solutions

and products only. Comfort and noise reduction are basic

elements in our process of engineering.

Blokland Non Ferro operates worldwide from its premises

in Sliedrecht, The Netherlands.