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Seeking info on early "ABC Motors" APU/GPU

Guest mark_pilkington

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Guest mark_pilkington

Our museum has acquired a very old ABC two cylinder engine set up with a cooling fan and base frame for either aircraft Auxillary Power Unit (APU) or Ground Power Unit (GPU) use.

ABC was the All British Engine Company Pty Ltd established in 1912 and later became ABC Motors Ltd.


The company owner was Ronald Charteris and the chief engineer was Granville Bradshaw. They built a variety of A.B.C. engine types until the end of WWI, including the unsuccessful Dragonfly radial (BGE; S). During WWI, the firm began development of horizontally-opposed auxiliary power units (APU) for aircraft and ground power units (GPU). A 5hp A.B.C. flat twin provided onboard electrical power for a nose-mounted searchlight on the Supermarine Night Hawk and was a pioneering APU application (JMB). A.B.C. did little with aeroengines from 1919-1923 and concentrated on motorcycles. Their initial HOAE were motorcycle engines converted into low-power aircraft engines. They then built some widely-used low-power HOAE until they left the business at the end of 1926. However, they did build the A.B.C. Robin light aircraft in 1929 with an A.B.C. Scorpion II. Subsequently, the firm concentrated on GPU and APU production through and after WWII.

Can anyone identify the ABC engine in the attached photos and confirm its vintage and application?

The 5hp ABC flat twin to provide onboard electrical power on the Supermarine Night Hawk seems a similar possibility as our engine is of a similar small size and has a based plate for something to be "driven" by the ABC motor, such as an electric generator, or perhaps bilge pump?

I doubt a relic of a rare Supermarine Night Hawk may have arrived in Australia, however the RAAF had both Supermarine Southhamptons and seagull III aircraft, perhaps they carried similar ABC APU's based on the HOAE engines built by ABC until 1926 - as mentioned above?

I am aware the Sunderland also carried an ABC APU however I suspect it was much larger and more modern than our example?

The engine bears resemblance to the ABC unit construction engine in the ABC/Sopwith 1920 motor bike

I found a close up of a 1921 Sopwith aircraft Company built ABC motorcycle on the web and there are many similarities with our engine.

I also found a 1914 ABC motorbike example, the high back casting holding the magneto, the general cylinder/fin design, and the valve at the top dead centre position and rocker arm attachment, as well as the square shape of the crankcase




Flat-twin engine of a 1921 ABC motorcycleThis was the real ABC motorcycle, built by Sopwith Aviation Company at Kingston-on Thames, a company which built aircraft during the Great War and afterwards took over Bradshaw’s newest creation. This was a transverse-mounted 398cc flat twin with overhead valves, 4 speed gearbox, chain drive, spring frame and fork with automatic lubrication. Often regarded as the predecessor of the first BMW motorcycle, the Sopwith-ABC was an advanced be under developed design when Sopwith put it on the market. The valve gear was unreliable, the lubrication poor and although they could sell more than they made the ABC failed and by 1921 ABC Sopwith were in liquidation, mainly because the cutting edge design led to many guarantee claims.

I have posted photos on this aviation website http://forum.keypublishing.co.uk/showthread.php?t=74994

I have "reversed" my engine image to have it orientated the same as the engine in the bike to emphasise the comparisons.

there are differences in the inlet manifold location on the cylinder head but a lot of similarities much the same?

Anyone recognise it? or have a source of further information? including the use of such engines as Auxillary Power Units and Ground Power Units during WW1?


Mark Pilkington


The Australian National Aviation Museum


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  • 4 months later...
Guest BrianDevey

From what I know about the ABC flat wtin motor cyles the engine shown is diffferent because it has 'inlet over exhaust' configuration whereas the later ABC/Sopwith motors are of overhead valve configuration. I guess that someone out there, more knowledgable than myself, might be able to say whethere this motor is similar to the earlier fore and aft models .

Hope this helps

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Only two Supermarine PB31 E Nighthawks were ordered. Only one flew and it is possible that the 2nd was never even built. The ABC 5 hp engine was used to drive both the generator for a searchlight and to blow hot air back to the enclosed cabin. Given that there was only one aircraft it would be quite remarkable if its ABC ended up in Australia and yet stranger things have happened. I believe Pemberton Billing the founder of Supermarine was a keen Imperialist and had interests in Australia. That engine in the photo does appear to drive a fan. I can think of no other British WW1 aircraft that had an ABC installed in this manner (and indeed it is remarked upon as a feature of the Nighthawk (an unofficial title as was the alternative Shitehawk)

I cannot see why the Southampton would carry a similar installation and can find no mention of such. There was no searchlight to power and the crew positions mitigated against this type of heating system. The Seagull AKA Walrus did not have this installation.

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  • 6 years later...
  • 2 years later...
Guest PaulStandeven

The man you need to talk to is Kim Siddorn.  He acquired a collection of ABC auxiliary power units, and wrote a book on such engines, Rather inconveniently , he died in December last year.  The family will have lots of information, and probably still has his collection of engines.  You can probably contact them indirectly via membership@regia.org or publicity@regia.org


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