The Battle of Britain 75 th Anniversary. The Battle of Britain February, 2014 Barry Latter Early Design and Development of the Hurricane and Spitfire

The Battle of BritainThe Battle of Britain

The Battle of Britain75th Anniversary


February, 2014

Barry Latter

Early Design and Development of the

Hurricane and Spitfire


Thomas Sopwith(1888 – 1989)

WW1 airplane pilot, instructor and designer

Liquidated his own company in 1919

Led the Hawker Company from 1922 until 1974


Harry Hawker(1889 – 1921)

Demonstration and test pilot for Sopwith

Formed Hawker Engineering Company

in 1919

Died in crash following hemorrhage in flight


Sydney Camm(1893 – 1966)

Hired by Sopwith in 1923

Chief Designer 1925

British Air Ministry issued spec for “Light Day Bomber” in

1926

Camm designed Hawker Hart in 1928


Hawker Hart - first flight June 1928




Prototype Hurricane K5083


Flight LieutenantP.W.S. “George” Bulman

Chief Test PilotHawker Aircraft

Known for precise and well timed air show

appearances


Hurricane basic fuselage structure

The Battle of BritainThe Battle of BritainThe Dumb-bell Spar

Camm’s rolled steel main spar – the “Dumb bell spar”

The Battle of BritainThe Battle of BritainHurricane fuselage

structural joints

Bolted for ease of maintenance

Wooden formers are then bolted to resulting

structure

Wooden stringers then attached to formers top

hold fabric skin







One of the first Hurricanes delivered to the RAF 1938

Note the Watts two-blade fixed-pitch wooden propeller

The Battle of BritainThe Battle of Britain Hurricane deliveries

First production deliveries to 111 Sqn at Northolt began in December 1937 with delivery of first 600 batch complete by October 1939

Subsequent mod program for fitting Merlin III engines, Rotol or DH variable pitch props and armor.

Hurricane 1 built by Hawker and Gloster (part of Hawker-Siddeley Group)


PZ865 – “The Last of the Many”Cranfield College of Aeronautics 1961

Flown by Hugh Mereweather


PZ865 Hurricane IICBattle of Britain Memorial Flight


PZ865 2014 – colors of 34 Sqn. SEACRAF Coningsby


Supermarine Spitfire


Reginald “R.J.” Mitchell1895 – 1937

Chief DesignerSupermarine Aviation Works (Vickers) Ltd

“Mitchell wedded good engineering to

aerodynamic grace and made science his guide”

(Colston Shepherd – 1949)


The Battle of BritainThe Battle of BritainEarnest Hives(1886 – 1965)

Chief test driver 1908

Head of the Experimental Department 1916

Head of development RR “R” engine

General works manager 1936

Elected to the board 1937


Rolls-Royce “R” engine

Rated at 2350 hp powered

S-6BBecame the Griffon

PV-12 initially at 1100 hp

Developed into Merlin rated ultimately at 2600 hp


Supermarine S-5 1927

Supermarine S-6 1929 Supermarine S-6B 1931

The Battle of BritainThe Battle of BritainAir Ministry Specification F.7/30

“A fighter capable of at least 250 mph and armed with four machine guns”

Supermarine Type 224

The winning “Gloster Gladiator”


“ ….. The (Vickers-Supermarine) design team would do better by devoting their time not to the official experimental fighter (i.e.F.7/30) but to a real killer fighter……my opposite number in Rolls-Royce…A.F Sidgreaves and I decided that our two companies should … finance … such an aircraft ……

…. that in no circumstances would any technical member of the Air Ministry be consulted or allowed to interfere with the designer”Sir Robert McLean – Chairman Vickers Aviation Ltd.


F7/30 refined – Supermarine Drawing 30000 sheet 11Dated September 1934

The Battle of BritainThe Battle of BritainBeverley Shenstone

Canadian aerodynamicist

Joined Vickers-Supermarine in 1932

Used Ludwig Prandtl’s theories of elliptic wing planforms in the

Spitfire design

Spitfire wings (NACA 2200 series) were VERY thin by comparison with others - 13% root T/C tapering to 6% T/C at tip




Joseph (Joe) Smith(1897 – 1956)

Chief Draughtsman under Mitchell

Succeeded Mitchell in 1937 as manager

of Design Department and

then Chief designer


Joseph Smith’s Spitfire main spar

construction






L-R “Mutt” Summers, “Agony” Payn, RJM, S. Scott-hall, Jeffrey Quill


The Battle of BritainThe Battle of Britain Spitfire deliveries

First production Mk.I deliveries were to 19 Sqn at Duxford between August and December of 1938

Subsequent mod program for fitting Merlin III engines, Rotol or DH variable pitch props, armor and conversion to metal covered wings

Mk.II deliveries began in June 1940 but Mk.Is bore the brunt of the Battle


Airplane

Max. speed

@

Altitude

FT height

SL 5,000 ft

15,000 ft

20,000 ft

25,000 ft

Mk.1Spitfire

355 18,500965 bhp

282 302 342 351 340

Mk.1Hurricane

311 17,500965 bhp

246 264 303 305 290

Maximum speed in mph at:

Ref. “Birth of a Legend” by Jeffrey Quill


Airplane Weightempty

Max. Weight

Span Length Engine Service Ceiling

(100 fpm)

Mk.1Spitfire

4810 lb. 5785 lb. 36’ 10” 29’ 11” RRMerlin III

37,400 ft.

Mk.1Hurricane

4982 lb. 6532 lb. 40’ 0” 31’ 4” RR Merlin III

35,000 ft.



Airplane

Operational ceiling

(500 fpm)

Time to Operational

ceiling

ROC @ 25,000 ft

Time to 25,000 ft

Mk.1Spitfire

34,000 ft 21 min 33 sec 1660 fpm 11 min 33 sec

Mk.1Hurricane

31,400 ft 21 min 15 sec 1260 fpm 13 min 12 sec



At the start of the Battle,

32 squadrons of Hurricanes were operational

19 squadrons of Spitfires were operational

By August 1940

10 Group had 3 sqns of Hurricanes, 3 sqns Spitfires11 Group had 13 sqns Hurricanes, 6 sqns Spitfires12 Group had 5 sqns Hurricanes, 6 sqns Spitfires13 group had 8 Sqns Hurricanes, 3 sqns Spitfires



Charles Kettering(1876-1958)

General Motors Corporation's research chief

Initiated investigation into

causes of “Knocking” (aka “pinking”)


Tom Midgley(1889 – 1944)

Lead mechanical Engineer & Chemist

GM

Developed “Ethyl” (Tetra Ethyl Lead)

Suffered ill effects of lead poisoning


Sir Harry Ricardo(1885 – 1974)

Engine researcher and inventor

Developed variable compression engine to test “Octane Rating” of

gasoline fuels


Questions?



Back up slides


Supermarine S-4 1925

Napier Lion engine

Curtiss C.R.3 1923

D-12 engine

Supermarine S-51927

Napier Lion engine




Hawker Fury


Rolls-Royce Kestrel

Hawker Hart In-service 1930





The Battle of BritainThe Battle of BritainNo. 65 (East

India) Squadron RAF Hornchurch

June 1940

W/Cdr. Robert Stanford Tuck DSO, DFC & two bars, AFC

(27 victories when shot down in February

1942)



Curtiss D-12 engine

Fairey Fox light bomberIn-service 1926,

initially powered by a Curtiss D-12 … then RR

Kestrel



Henri Biard – 1922 Schneider Trophy winner


The Battle of BritainThe Battle of BritainVickers-Supermarine – the war years

Mk.1 Spitfire

Mk. V Spitfire

Mk. IX Spitfire

The Battle of BritainThe Battle of BritainHawker - Siddeley

In 1933, H.G. Hawker Engineering was renamed Hawker Aviation

In 1935, Tommy Sopwith acquired………..Gloster Aircraft

Armstrong-Whitworth Aircraft

Armstrong Siddeley Motors

A.V. Roe

….. and created Hawker – Siddeley

The Battle of BritainThe Battle of BritainSupermarine Spitfire Production(includes derivative models up to Spiteful)

Mk.1 – 1550 – Merlin III rated at 1030 HPMk.II – 921 - Merlin III rated at 1030 HP

Mk.V – 6476 – Merlin 45 rated at 1470 HP

Mk. IX – 5653 – Merlin 66 rated at 1575 HP

Mk. XIV/Mk. XVI – 2010 – Griffon 65 rated at 2050 HP

A total of 20, 351 Spitfires were manufactured by the end of production in 1948

The Battle of BritainThe Battle of BritainWhat made the Spitfire design so good?

• Basic semi-elliptic wing planform• Low wing loading - 21-25 lb/sq. in.• Knife edge elliptic wing tips• Wing twist +2 deg to – 0.5 deg • Thin wing• Gentle pressure gradients – more stable boundary layer• Wing/body fairing• Small tail unit• “Meredith” effect on lower wing surface components• Minimal frontal area cowling• Ultra slim fuselage


Dennis Crowley-Milling


The Battle of BritainThe Battle of BritainJoe Smith

The Battle of BritainThe Battle of BritainJ9052, the prototype Hart, first flew in June 1928, being delivered to the Aeroplane and Armament Experimental

Establishment at RAF Martlesham Heath on 8 September.

It demonstrated good performance and handling, reaching 176 mph (283 km/h) in level flight and 282 miles per hour (454 km/h) in a vertical dive. The competition culminated in the choice of the Hawker Hart in April 1929.

General characteristicsCrew: 2Length: 29 ft 4 in (8.94 m)Wingspan: 37 ft 3 in (11.36 m)Height: 10 ft 5 in (3.18 m)Wing area: 349.5 ft² (32.5 m²)Airfoil: RAF 28[10]Empty weight: 2,530 lb (1,150 kg)Max. takeoff weight: 4,596 lb (2,089 kg)Powerplant: 1 × Rolls-Royce Kestrel IB water-cooled V12 engine, 510 hp (380 kW)

The Battle of BritainThe Battle of BritainPerformance

Maximum speed: 161 kn (185 mph, 298 km/h) at 13,000 ftStall speed: 39 kn (45 mph, 72 km/h) [41]Range: 374 nmi (430 mi, 692 km)Service ceiling: 22,800 ft (6,950 m)Wing loading: 13.2 lb/ft² (64.3 kg/m²)Power/mass: 0.11 hp/lb (0.182 kW/kg)Climb to 10,000 ft 8 minutes, 30 seconds

Armament

Guns: 1 × synchronized forward firing .303 in (7.7 mm) Vickers machine gun, 1 × .303 in (7.7 mm) Lewis Gun on Scarff ring in rear cockpit.Bombs: Up to 500 lb (227 kg) bombs under wings.

The Battle of BritainThe Battle of Britain Hurricane 1 details

Merlin II engine – 1030 hp/3000 rpm/16250/6.25 psid boostWatts two bladed fixed pitch Type Z28 prop/ 11’3” dia 73 lb.

(Later) Merlin III – 1029 hp/3000 rpm/16250/6.75 psid boostRotol three bladed constant speed right hand Type RMS7 prop/ 35 degree pitch range/ 10’3” dia. Also fitted with DH two position prop.

40’0” span/ 31’4” long/ height 13’2” with Watts prop vertical/ 12’11 ½ “ Rotol prop (one blade vertical).

258 Sq. In gross wing area. 77 Imp. gals. fuel

Inward retracting MLG/ 7’7” track/800 X 10” wheels on Vickers Pneumatic oleo/ Dunlop pneumatic brakes

6447lb (Merlin III with Rotol prop) normal loaded weight/18galls coolant/8 Brownings 212lb plus 2660 rounds (202 lb)

The Battle of BritainThe Battle of BritainSydney Camm

Joined Hawkers as a 29 year old draughtsman in 1923.

“…A hard swearing, hook nosed, tall 30-year old” – Harald Penrose

“…The finest designer of aircraft that there has ever been” – Tommy Sopwith

“…He was a genius, but often quite impossible” – Tommy Sopwith

Camm became Chief Designer in 1925

The Battle of BritainThe Battle of BritainHawker Audax – Army cooperation

(1930)

Hawker Osprey – Navy (1932)

Hawker Fury – single seat RAF fighter (1931)




Schneider Trophy


Documents

The Battle of Britain 75 th Anniversary. The Battle of Britain February, 2014 Barry Latter Early Design and Development of the Hurricane and Spitfire