Warbirds Online has recently visited the restoration site of several Bristol Hercules engines which will eventually power the Australian Beaufighter project under long term rebuild to airworthy condition at the Historic Aircraft Restoration Society (HARS) facility at Albion Park NSW.
The rebuilding of a Beaufighter is a very complex task and although the project based at the HARS facility has been under restoration for many years, it has not been until now that the time and resources have been available to accelerate progress on the project. There is only one other airworthy rebuild of a Beaufighter being undertaken anywhere else in the world, that being done at the Fighter Collection at Duxford in the UK.
One critical aspect of any Beaufighter restoration is the matter of locating of suitable engines and propellers. Postwar, the Beaufighter was removed from service in a fairly rapid manner along with most other aircraft which utilized the earlier series of Bristol Hercules power plants. This rapid scrapping of aircraft and engines has created a shortage of these engines, and more importantly the almost total absence of suitable propellers and propeller hubs. New technology has now allowed propellers and hubs to be manufactured from new and it is proposed to go down this path rather than continue to source original components.
The engines are being restored by Peter Brooke at Historical Aircraft Engines in Brisbane Queensland. There were 5 of these fantastic sleeve valve radials in evidence in the workshop on the day of my visit. Most of the engines are of the earlier wartime type of Hercules power plants. Post war the engine was built in upgraded versions which are not suitable for fitting to a Beaufighter but thankfully there are enough of the earlier engines on hand to construct suitable units for the Beaufighter project. At the time of my visit one engine had already been stripped and the complexity of the sleeve valve arrangement was plain to see – more like a complex clock movement than an internal combustion engine.
Of particular note was the unique nature of the all-important sleeve valves which are impossible to source and very difficult to replicate. Again, hopefully there are sufficient items in stock to allow the completion of the project.
The plan is to strip down the other engines and assess each one to determine its serviceability. From there the rebuilds will follow the usual practice of cleaning, machining, refurbishment of serviceable components and replacement or manufacture missing parts. Once the engines are rebuilt they will undergo a full testing program prior to being installed in the Beaufighter.
Sleeve valve engines have a poor reputation for reliability and durability. However this is largely not justified and as Peter Brooke said on the day “they are like any engine, if well designed and built they are as reliable as any”. The sleeve valve design was also derided as a result of the Napier Sabre inline engine which was certainly not a highly regarded engine. Throughout World War II the Bristol Hercules engine provided excellent service in a large variety of aircraft.
Peter and Historical Aircraft Engines have a long term enviable reputation for the excellent work they do on the refurbishment of radial engines. Although the work on the Hercules is complex Peter is confident that within a couple of years the refurbishment of the engines will be completed successfully and that they will prove to be reliable and long term performers.
Warbirds Online will be following this fantastic project and at regular intervals will report on the progress of the restoration.
We wish to thank Peter Brooke and Historical Aircraft Engines for their help in allowing us to report on this fantastic project. There can’t be a single Warbird enthusiast who can’t wait to see a Beaufighter fly again in Australia.
© John Parker 2014