question: Speed of Swordfish?

[delcyros]

Gentlemen, this is a more special question.

The Swordfish torpedobomber, credited with the sinking of italian BB´s at Taranto and beeing famous for the hit on Bismarck´s steering gear (which turned out to be fatal for her) has several different speeds posted for torpedo attacks.

I got confused about that, so maybe one out of You can help me out? I am searching for

A) the max. speed lightly loaden
B) the max. sustainable speed in low altitude with and without torpedoe
C) the servicable speed of ´41 timeframe

posted figures range from 95 mp/h to 134 mp/h.


Thanks in advance,

[trackend]

This is the most comprehensive specs I have for the StringBag Del and is taken from the SwordFish Story by Ray Sturtivant although it does'nt give unladen performance.

Power Plant
Bristol Pegasus Mk IIIM3 (or MK 30) Nine Cylinder Radial air cooled supercharged engine rated at 775hp at 2300RPM at sea level and 690hp at 2300rpm at 3500ft (five minute combat rating 750hp at 2525rpm at 4750ft when fitted with Fairey Reed three bladed fixed pitch metal propeller)

Fuel Capacity
155 Imperial gallons in main fuselage tank and a further 12.5 Imperial gallons in gravity tank. Provision for 60 Imperial gallon auxiliary tank slung from torpedo crutches beneath centre fuselage.

Dimensions
Span (upper mainplane) 45ft 6in. (lower mainplane) 43ft 9in.
Width with mainplanes folded 17ft 3in.
Length (tail down) 36ft 1in, (flying attitude) 36ft 4in.
Height (tail down) 12ft 10.5in, (flying attitude) 13ft 5.75in.
Gross wing area 607 sq ft.

Weights (MK1 late production)
Empty 4,700lbs
Empty equpped 5,200lbs
Loaded 8,100lbs
Maximum loaded 8,700lbs
Maximum overload 9,250lbs

Armament
One fixed forward firing Vickers .303 machine gun x 600 rounds
One Lewis .303 machine gun x 6 magazines mounted on Fairey high speed.
fleximount
Loads included Optional, one 1,610 lb torpedo. one 1,500lb sea mine or 1,500lb of bombs (which could comprise of 2 500lb bombs beneath fuselage and 2 250lb bombs beneath lower main plane or one 500lb bomb beneath lower each lower main plane.
The MkII could instead carry four 60lb rockets underneath each lower mainplane.

Performance (MkI late production at 8,700lbs loaded weight)
Maximum speed 132mph at sea level, 139mph at 4,750ft.
Maximum cruising speed 128mph at 5,000ft with maximum weak mixture power.
Economical cruising speed 104mph at 5,000ft.
Range with 1,500lb bomb load at economical cruising speed & no external stores 546 miles. With 60 Imperial gallon external tank 1,030 miles.
Initial climb rate 1,200ft/min.
Time to 5,000ft at 8,700lbs weight 10 minutes.
Service ceiling (9,250lbs weight) 10,700ft, (8,700lbs weight) 12,400ft.
Maxmium unloaded ceiling 19,250ft.
Take off distance (to clear 50ft max load) 725yds.
Deck run into 20 kt wind 180yds, 30kt wind 115yds, 40kt wind 62yds.
Landing run (over 50ft at 8,700lbs) 550yds.

I have some other figures from issued middle east documents for the Swordfish in seaplane configuration but the ones above are about (as far as I can find out) the most accurate.
As for kills the Fleet Air Arm museum in Yoevilton seems to settle around 300,000 tonnes + of merchantile shipping excluding mine layed kills and 20 submarines through direct involvement as for naval vessels this list includes obviously several capital and numorous smaller vessels ranging from cruisers too gun boats, as for anti tank and air to air action I have not been very successfull in this but there are quite a few accounts in various articals of kills in this area.

[FLYBOYJ]

Track, I knew you would come through on this!!!

[delcyros]

Thank You very much, Track!

Any idea what the typical approach speeds with torpedoes were? I have heard rumors that approach was quite fast (around 120 mp/h) and only lowered for dropping the torpedoes. Could be interesting.

[trackend]

You know me too well FB

As for torpedo runs Del It seems to have varied, The accounts I have on the Bismark attack although not totally unchallegable seem to have been very slow given that the gunnery control for anti aircraft weapons on board had problems calculating the closing speed as it was below the normal settings available
so it appears to be around 90 kts.

Charles Lamb (in War in a Stringbag) gives several accounts of torpedo attacks and describes the use of the very crude but highly effective sight which consisted of a bar mounted across the center wing support this had a row of lights on, each representing (I believe as Im at work) 5 knts by estimating ship speed all that was required was to count off the required lamps and launch your fish (at the right distance of course) when the ships bow was in alignment with the correct light.
When I get a chance over the weekend I'll have a butches in my books and get an average launch speed for you.

[Bernhart]

was at an airshow about ten years ago, there was a swordfish there, and an older gentleman was standing there. Starting talking to him and he talked about flying swordfishes. Said he remebers flying off the cliffs of dover and because stalling speed was so slow he said you could fly into a good headwind and hover