Douglas Generator

[Neil Ashley]

I picked up an example of this type of generator at the weekend which in its original form produced 130 volts at 2.75 kVA. Post war it was converted to 230 volts for the civilian market.

The owner throught it was for Bofors Guns but the only examples with power mounts are presumably the SP versions which have there own pto driven generators.
Assuming it is WW2 as it is painted in war-time brown can anyone comment on its use?

If post -war the Bristol Bofors presumably needed a generator.

Pictures to follow as I am having problems posting.

[Neil Ashley]

Pictures now attached.

The photograph is of one recently offered on E-Bay

[Godwin Hampton]

The early Bofors guns in British servce could be hand or motor driven. The layers would dismount, leaving only the loader. The gun would then be aimed using the predictor, which would automatically apply aim-off to point the barrel at the future position of the target.

Of course the target data would have to be fed into the predictor, which then made the necessary computations electro-mechanically.

The predictor would control motors on the mounting which traversed and elevated the gun, and the loader would load and fire it using his foot pedal.

Electricity was needed for the motors and the predictor, and was supplied by a 2.25 kW generator powered by Coventry Climax, Enfield, Scott & Jowett and J.A.P & Kelvinator. Doulas is not mentioned in the 1942 Drill Book that lists the others.

With the introduction of the Stiffkey sight, with an extra crew member on the mounting applying corrections directly to the sight, the predictor and motors became superfluous and were discontinued in production.

The self-propelled Bofors on Morris chassis had a Stiffkey sight, so would not need electric power.

The Bristol Bofors relied on battery power, with a small single-cylinder J.A.P engine driving a recharging dynamo fitted at the back of the loading platform.

I have a Coventry-Climax generator, and its' handbook. Since the generator is probably the same, let me know if you need any information about the electrical side. Outside my set is very similar to yours. Obviosly the trailer is a later addition, and the set was manhandled using 4 porter bars fitting in sockets at the upper ends.

[Neil Ashley]

Godwin

Thank you for the information. Having never seen a powered ground mount in preservation I forgot they existed.

Presumably if the radar controled mount was any good they must have been surperior to the Stiffkey sight. The cost of the mounts and the availabilty of suitable Radar Sets was probably the greatest limiting factor in their use.

There is a picture in Terry Ganders book showing the post war use of an american SCR 584 radar set. He notes that they were used very effectively against V1 Flying Bombs in 1944.

I will send you an e-mail about your manuals.