7 ton 'Otter' Specification:

Engine
A Perkins P6, 83 b.h.p. at 2,400 r.p.m. Maximum torque 203 lb. ft. at 1,400 r.p.m. Maximum torque for tippers was 183 1b. ft. at 1,200 r.p.m. The chassis was also available with a Gardner 4LK, 57 b.h.p. at 2,100 r.p.m. Maximum torque 161 lb. ft. at 900/1,300 r.p.m.

Clutch
11 inch dry, single cushioned plate type, totally enclosed and required no lubrication.

Gearbox
Unit construction type, with five forward speeds. Constant mesh 3rd and 4th, direct drive top. Gear ratios: first gear 6.61 to 1, second gear 3.75 to 1, third gear 2.41 to 1, fourth gear 1.47 to 1, fifth gear 1 to 1, reverse gear 6.28 to 1.

Transmission
Double-shaft, with resilient self-aligning centre bearing on the long wheelbase models, single-shaft on the short wheelbase models, the assembly being statically and dynamically balanced.

Front axle 'I' section steel forging, robust construction at the ends to take the braking torque. Hubs are mounted on taper roller bearings, with case hardened king pins and steel backed bushes.

Rear axle
2-speed, fully floating with electric shift control. In high speed ratio, the axle functioned as a conventional single reduction unit, the ratio being obtained through a spiral bevel pinion and matched crown wheel. In low ratio, planetary gears came into operation to provide a secondary reduction.

Steering
High efficiency heavy duty cam and roller type. 21 inch diameter steering wheel. Self-adjusting eccentric track rod joints. Left-hand steering was available to special order.

Suspension
Semi-elliptic springs were fitted front and rear. Shock absorbers could be supplied at extra cost.

Frame
A rigid frame assembly built of 8 inches deep side members, braced with deep channel section cross members.

Brakes
Two Leading Shoe, hydraulic type with vacuum servo assistance, operating on all four wheels to give positive and progressive braking.

Wheels and Tyres
8.25 x 20, 12-ply single front and twin rear tyres, fitted on interchangeable wide-base wheels of the 3-piece, 8-stud type. Complete spare wheel and mounting provided.

Electrical
Compensated voltage control system, with 12 volt, 108 ampere hour batteries, and 12 volt electric starter.

Fuel tank
17½ gallons capacity, incorporating magnetic type fuel gauge.

8 to 10 ton tractor Unit. Specification as above, except for the following:

Engine
A Perkins P6, 83 b.h.p. at 2,400 r.p.m. Maximum torque 203 lb. ft. at 1,400 r.p.m.

Gearbox
Four forward speeds. Constant mesh 2nd, 3rd and 4th, with exceptionally short and rigid shafts on ball and needle roller bearings in a cast iron case. Gear ratios: first gear 6.5 to 1, second gear 3.15 to 1, third gear 1.7 to 1, fourth gear 1 to 1, fifth gear 1 to 1, reverse gear 9.2 to 1.

Transmission
Single propeller shaft with needle roller universal joints and a sliding joint at the gearbox end.

Rear axle
Special heavy duty 2-speed unit, with ratios of 6.5 and 9.02, fully floating with spiral bevel functioning as a normal single reduction unit, planetary gears coming into operation for low axle ratio and giving a secondary reduction.

Suspension
Semi-elliptic springs were fitted front and rear. The primary leaves were shot-peened on the tension side to prolong their working life. Both front and rear springs being over-slung, anchored at the front, and shackled at the rear.

Brakes
Tractor brakes: Two Leading Shoe, hydraulic type with vacuum servo assistance, operating on all four wheels to give positive and progressive braking.

Trailer brakes: Provision was made on the chassis for mounting Clayton control valve SA.0248/C/I0. Control valve and connecting pipe were supplied by the trailer manufacturer.

Wheels and Tyres
8.25 x 20, 12 ply (or 9.00 x 10 ply for the export market) single front and twin rear tyres, fitted on interchangeable wide-base wheels of the 8-stud type. Complete spare wheel and mounting provided.