[Alex Blair (RIP)]

Terrapin MK I (1942 1944)

It was a design by Thornycroft.
500 were build after June 1943 by Morris Commercial.

It has two 95 hp (64 Kw) Ford V-8 petrol engines.
Both engines have a 3 speed gearbox that drives a single speed transfer box and finally to a worm drive. Each engine is driving (only the centre two wheels on each side) OR (all four wheels on each side) This is not clear to me.
Each engine drives one propeller.

Steering the Terrapin works with two handles that operate a break on each side, a bit like steering a BobCat.
But this will give BIG problems if one engine fails. :-)
The two front wheels are placed much higher, the two rear wheels are placed a little higher, this will allow normal road travel with the skit steering. With 4 or 3 wheels on the ground there will be much wind-up in the transmission. The driver and the two engines are placed in the middle of the vehicle, In the front and in the rear there is a (to small) cargo space.

Engines: 2 x Ford V-8 petrol 95 hp
Speed land: 25 water: 8 km/h
Range: 240 km
Length: 7000 width: 2670 height: 2920
Weight: 7000 kg load 4000 kg
Tyre size: 13.00x24

They were used later in the Normandy landing??, in Holland and in the Rhine basis. Fully loaded there was little free-board to be used in other than very calm waters.

Photo's taken at Zeeland Netherlands.
Bottom photo, taken in Domburg, Netherlands.

A surviving Terrapin was used by the Scotland Electricity board as a ferry around Edinburgh until 1970.
The hulk of another Terrapin (scrap) is rusting in Sussex.
One Terrapin is in Melbourne, Australia.



OR.....

Terrapin USA (1961)

It was build by Wilson Nuttall Raimond Engineers of Chestertown Maryland.

Steering accomplished by a special hydraulic system
Two hydraulic cylinders for changing the horizontal position of the sections
One hydraulic cylinder for changing the vertical position of the sections

Each caterpillar track had four independently spring-loaded road wheels with pneumatic tyres,
a drive sprocket and a tension wheel. Road wheels were installed on a balancing arm with
air/hydraulic suspension with 250 mm travel. The tracks are made from 2 rubber bands connected by cleats with a step of 164 mm, made from the aluminium heat-treated alloy.

Engine: International V-eight carburettor liquid-cooled 210 hp at 4000 r/min
Gearbox: 5 speed Spicer
Torque divider and Rockwell axles with a locking differential
Speed land: 50 km/h water: 5 km/h
All four tracks where driven by the engine.
Crew 2
passengers 6
Size front: Length 5700 mm Width: 2400mm Height: 3450 mm.
Weight (front part) 5870 kg load: 450 kg

Size rear Length: 6000 mm Width: 2400 mm
Weight: (rear part) 5440 kg load: 2720 kg

Fuel consumption 250 litre/100 km
Range on land 160 km

Passenger compartment is warmed by the cooling system of engine.
From this vehicle the Polecat II was developed.