Bristol Centaurus contraprops

[Schneiderman]

A few projects from around 1943 featured Centaurus power and contra-rotating propellers, for example fighters such as the Folland Fo117 and the Boulton Paul P.103B. Does anyone know whether such an engine was ever built and flight tested?

 

[Deltafan]

As I read the Wikipédia page on the Bristol Centaurus engine, and my own list of contra-rotating planes (on another website), till 1957 :

https://en.wikipedia.org/wiki/Bristol_Centaurus
https://forum.aviationsmilitaires.net/viewtopic.php?f=45&t=941

-We can say the Brabazon. But it was contra-rotating for two coupled engines (not only one engine).

-Fairey Battle (Fairey Monarch), Folland Fo.108 (Napier Sabre E.118), Hawker Tornado (RR Vulture II) and Fury (RR Griffon 85) had contra-rotating propellers, but not with Centaurus.

But Wikipédia can made mistakes, and my list is maybe not finished...

 

[Hood]

I think your right, I can't find any record of a contra-rotating propeller Centaurus actually flying. It seems all the Centaurus equipped aircraft and testbeds had normal propellers.
I presume fitting five-blade propellers removed the need to consider contra-props.

 

[Schneiderman]

Thanks Hood, I could find no reference to bench of flight tests either. Chris Gibson says in Nimrod's Geneisis(page 55) that Centaurus and Hercules could not be fitted with a contraprop which had me wondering whether it had been tried and found problematic.

 

[Arjen]

From 'JANE's Fighting Aircraft of World War II', Bracken Books 1989 (reformatted reprint of JAWA 1945-46):

The latest model in the Centaurus Series of which details were available at the time of writing was the CE.22 SM. This engine is a forward development of the Centaurus XVIII and 57 Series and is the prototype of the Centaurus 130 which will power the Airspeed Ambassador and other British civil transport aircraft.
[...]
The Centaurus 130 will normally have a single-stage supercharger but the two-speed version will be available, and the engine is designed to facilitate the application of other developments in supercharging and fuel systems. The airscrew reduction gear will be suitable for reversing airscrews and an alternative reduction gear can be provided for counter-rotating airscrews if required.

According to 'Airspeed Aircraft since 1931' by H.A. Taylor, Putnam 1970, the Ambassador's powerplant was Airspeed's own development of the Centaurus 661.

 

[kitnut617]

Interesting topic, I had wondered too. Because the Vickers 'C' Type bomber was supposed to have contra-rotating Centaurus' too.

 

[CJGibson]

I'll check my notes when I get home, but somebody told the Air Ministry it couldn't be done. I wonder if it was the same bloke who said the Victor couldn't carry Skybolts.

Contra-props would have made sense for a flying boat. The Nomad-powered boats had contraprops, but as Hood says, the five-bladed props may have been simpler and just as efficient. Fit a gull wing.

Chris

 

[Schneiderman]

Thanks Chris.
Looking at the list of contraprop aircraft on Deltafans site it does not look as if there were many aircraft sporting a radial and contraprop. Mainly there's a bunch of shortlived 'oddball' engines plus the well-known UK ones.

 

[Hood]

Yeah I can't think of many radials with contra-props.
To add to Arjen's earlier post, I flick through Alex Lumsden's British Piston Engines doesn't indicate any provision for contra-propellers for any of the Centaurus series.

 

[kitnut617]

The PW XR-4360-10 comes to mind but not much else.

 

[Piper106]

There were one off experimental variants of the Republic P-47 Thunderbolt and the Voight F4U Corsair tested with counterprops. Both cases it was a experimental version of the P&W R-2800 engine.

 

[GeorgeA]

And of course the never-flown Lycoming XR-7755.

 

[Kevin Renner]

And of course the never-flown Lycoming XR-7755.

Which of course never flew ue to the inability of designers to fit both an oil well and the required refinery into an airframe

 

[riggerrob]

Installing more propeller blades (e.g. 5 on production Centarus in Sea Fury) absorbs more power within a fixed prop diameter, by increasing disc density.

But, it does not solve problems with asymmetric thrust. For example, later model Spitfires (with RR Griffin engines and 6-bladed, contra-props) were much easier to fly than early Spitfires (RR Merlin engine and 2, 3, 4 or 5 blade propeller.

 

[kitnut617]

If anything test flew a contra-prop Centaurus it would have been the Folland Fo.108. Phil Buttler told me he'd seen photos of it fitted with a Sabre VIII (contra-prop Sabre VII).
But what about the Curtiss XP-60C ?

 

[Justo Miranda]

Curtiss XP-60C (Model 95C) technical data

Power plant: one 2,100 hp Pratt & Whitney R-2800-53, 18 cylinder,air-cooled radial engine, with General Electric turbo-supercharger, driving a six-bladed contra-rotating propeller with 12.1 ft of diameter, wingspan: 41.4 ft (12.62 m), length: 34 ft (10.38 m), height: 12.3 ft (3.75 m), wing area: 284 sq.ft (25.54 sq.m), maximum speed: 414 mph (666 kph), maximum weight: 11,835 lbs (5,368 kg), climb rate: 3,890 ft/min (1,186 m/min), service ceiling: 37,900 ft (11,552 m), armament: four 0.50 cal M2 wing mounted machine guns.

 

[Schneiderman]

If anything test flew a contra-prop Centaurus it would have been the Folland Fo.108. Phil Buttler told me he'd seen photos of it fitted with a Sabre VIII (contra-prop Sabre VII).

Interesting. This must be a relatively recent find as it is not mentioned in his Air Britain article in 2006.

 

[kitnut617]

Yes, later than 2006 but not just a year or so ago. I was trying to find out what the Centaurus engines were on the Vickers Type C bomber and I had posed the question to him. Probably around 2010 or later though.