RB.106, RB.122 and RB.128 and Zeus turbojets

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We rather need a decent definition of what the RB.106 was, we have a few bits of information and even a rumoured name as the "Thames", which I find a little suspect for a fighter engine, but it does fit RR's naming conventions.

Supposedly a 'drop in' replacement for the Avon. RR seems to see it as a powerplant for single engined fighters, and one thats superior in the supersonic regime. Seems also to put out more power at low speeds compared to the Avon, but its efficiency falls back to similar levels in the transonic regime, perhaps a feature of diameter?

Reheat seems rather closer to the later reheated Spey, does this reflect their development of the reheat unit?

RR also seems to have toyed with the idea of a scaled down variant for twin engined fighters, we know of at least two aircraft designs that incorporated this.

A scaled up version is aimed at the F155T fighters, by increasing diameter.
 
The 'normal' figure I have from BSP.1 is 15,000lb and the reheated figure seems a little more fluid though over 21,000lb.

Scaled up version must be able to match the Gyron at least (RB.122), the scaled down version has two figures (unknown RB No.), possibly reflecting either the understanding of what they could get out of it or different sizes (diameters) of engine. Those being 7,000lb (for the Bristol design) and 10,000lb (for the EE design) both the mach2 soaking effort (I forget the ER number). The latter is said to have a reheated thrust of 12,100lb, possibly so low because of a small chamber diameter or due to the efficiency of the turobjet in burning up the oxigen and leaving so little left for reheating.

But does this relate to nearby RR numbers? Such as the very small RB.123?

We do know it superseeds the scaled up Avon.
We also know its a two spool engine, and it uses a lot of titanium.
Rumour has it the Orenda Iriquois had a lot of its influence on it.
 
The scaled up RB.106 for the F.155T was RB.122 and there is an RB.128 designation floating around as well. Apparently there is a sketch of the RB.128 somewhere in the national archives.

R.B. 106. No official mention has yet been made of any engine with this designation, but references to such a unit have appeared several times in various publications. All such reports referred to it as a high-thrust turbojet and it is described as having a two-spool layout. An American report states that westinghouse are anxious to manufacture it under licence.
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From: http://www.flightglobal.com/pdfarchive/view/1956/1956 - 1246.html?search=RB.106

CF-105 and RB.106

http://www.flightglobal.com/pdfarchive/view/1956/1956 - 1246.html?search=RB.106

Derbyshire record office: D5290/2/5 1960s

Contents:
Miscellaneous file containing drawings of RZ.2, RZ.3, RZ.12 and RZ.14 rocket engines, plus drawings of RB.128 jet engine and other aeronautical projects, 1960s

Also, Professor G L Wilde worked on the RB.128 supersonic engine: http://archive.pepublishing.com/content/0k715gp17xm85717/

Flight Global estimated that expenditure on the RB.106 totaled £100,000- a paltry sum given that £4.75 million had been spent on the Orion turboprop at cancellation.

Source: http://www.flightglobal.com/pdfarchive/view/1967/1967 - 1672.html
 
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National Archives

AVIA 65/12 Sponsorship of RB 106: financial policy 1953
AVIA 53/457 Westinghouse Corporation/Rolls Royce Ltd agreement for technical collaboration in axial engine field 1953-1958
AVIA 54/1333 Rolls Royce turbine engines: general data 1949-1955
AVIA 65/592 Rolls Royce Avon engines: development policy 1955-1961
 
Rolls Royce designed a successor to the Avon turbojet, the RB106. It was intended to be approximately the same size but have a higher thrust. The only thrust I've found mentioned for it was 21,750 lbs. Was this wet or dry?

Bristol designed an engined named the "Zeus" which was intended to be a competitor to the RB106 but I have been unable to find any specifications for it. Does anybody know what it's size/performance was intended to be? Did it ever make it off the drawing board (or even that far)?
 
Bristol Zeus Reported
THE following is a rough translation, from the Italian, of a recent paragraph in Alata:

"People in industrial circles are speaking of a new Bristol turbojet with the name Zeus. This engine is to have an expected rating of 9,000kg(19,200lb) thrust."
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BE.30Bristol Siddeley Zeus two-spool turbojet.Intended for Avro 726 interceptorRated at 8000 / 10000lb (35.6 / 44.5KN).
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[http://www.skomer.u-net.com/projects/turbines.htm]
 
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Hot Breath said:
Rolls Royce designed a successor to the Avon turbojet, the RB106. It was intended to be approximately the same size but have a higher thrust. The only thrust I've found mentioned for it was 21,750 lbs. Was this wet or dry?

Bristol designed an engined named the "Zeus" which was intended to be a competitor to the RB106 but I have been unable to find any specifications for it. Does anybody know what it's size/performance was intended to be? Did it ever make it off the drawing board (or even that far)?
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RB.106 thrust level was 15,000lb dry and with afterburner, 20,750lb
 

Pencil technical drawing of the RB.128 jet engine | The National Archives

The official archive of the UK government. Our vision is to lead and transform information management, guarantee the survival of today's information for tomorrow and bring history to life for everyone.
discovery.nationalarchives.gov.uk discovery.nationalarchives.gov.uk

Pencil technical drawing of the RB.128 jet engine

Derbyshire Record Office
New Street
Matlock
England
DE4 3FE
 
Bristol BE.30 was proposed in late 1953 and utilised contra-rotting spools, proposed for a developed version of the AW.169. Bristol competitor to the RB.106?

I have to say, with Bristol, Rolls Royce, Armstrong Siddeley and DeHavilland all working on supersonic jet engines in this period (and at least three of them getting government funding, DeHavilland, RR and ASM) the sense of waste through duplication is remarkable.
 
Or the incentive of competition driving them on? Rationalisation seemed to slow things down. Aubrey Jones was against the over concentration of the industry and state direction/control. Odd how right wing Sandys and Amery pursued it.
 

Aubrey Jones

www.telegraph.co.uk www.telegraph.co.uk

Jones supported a different form of rationalisation, with firms having a more diverse base as with Hawker Siddeley taking over Brush. He recognised it was not competetive against the US. Fewer projects were needed but still from private firms who competed.

Sandys and Amery still believed the UK could take on the US, with European collaboration if needed. Concorde, VC10, Trident resulted.

Jones' section outlining his views is the most modern sounding part of the Plowden report.
 
There seems to be several common threads in the decline of the British aircraft industry

1. Too many players competing for a limited market. This goes back to the pre-war period. One of the things that always mystified me was how Napier was able to continue in the aero engine business through the 1930s - the Dagger had to be more trouble than it was worth. I would agree that there were too many projects for supersonic engines and that it would have been better to put more attention on engines that could be used for commercial aviation.

2. Hide bound business management . Outstanding people such as Roy Fedden, Frank Whittle and Stewqrt Tresilian were hamstrung by inept business leaders (who often owed their positions to family connections) and ended up being pushed out.

3. Faulty planning. Surely someone in a position of authority must have realized that the big flying boats had limited prospects in the post-war environment.

I would note that these sorts of things were not unique to the UK, but the UK was not in a position to afford them.
 
rinkol said:
One of the things that always mystified me was how Napier was able to continue in the aero engine business through the 1930s - the Dagger had to be more trouble than it was worth.
I would note that these sorts of things were not unique to the UK, but the UK was not in a position to afford them.
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It caught up with them during the war with the Sabre resulting in English Electric buying them out.
 
This was cut from my P.1121 book.

Rolls-Royce RB.106

RB.106 was an advanced twin-spool jet engine design apparently intended to be dimensionally interchangeable with the Avon. Initially aimed at 10,000lb thrust, by November 1954 this design was clearly too small for the OR.329 fighter and a scaled-up RB.106 (37in diameter increasing to 41in) was being prepared (this becoming the RB.122). Development of the smaller design continued with design and materials improvements, eventually being expected to have a design thrust of about 15,000lbf, 20,750lbf in reheat. The RB.106 project was cancelled in March 1957, at a reported total cost to the taxpayer of about £100,000.

Rolls-Royce RB.122

This engine was essentially a scaled-up RB.106 for OR.329 fighters. It used eleven compressor stages across two spools, possibly a four-stage LP compressor and seven-stage HP compressor though this could not be verified. The first stage was transonic and two stage turbines were used on each spool, with design turbine inlet temperature being 1,275ºK. Dry thrust was 19,500lbf, and 27,800lbf with reheat. Compressor diameter was 40in, maximum diameter 41.3in, and reheat pipe diameter 45.25 in. Weight was expected to be 4,642lb compared to 4,200lb for PS.26 Gyron, due to the greater compression ratio requiring more stages, while design air mass flow rate was almost identical to Gyron. It promised similar thrust to the Gyron at a slight weight penalty but with lower fuel consumption, and hence was listed as the first choice engine by several F.155T submissions. Relatively little work was done on it, but as a scaled-up version of RB.106 (which had resulted in some hardware) Rolls-Royce were confident in their ability to deliver. However, Rolls-Royce would not commit company resources to make prototype engines without a sizable and firm order, which ruled it out of consideration the P.1121.

Rolls-Royce RB.128

A further development of RB.122, which was even larger with increased mass-flow and pushed thrust to 23,000lbf dry and 31,600lbf with reheat. Weight was 250lb higher than RB.122, SFC 7% higher in dry thrust but 6% lower with reheat. The second issue of Fairey's F.155T brochure proposed a revised design with RB.128 engines and rocket engines deleted. Like the RB.122, lack of orders meant it did not proceed.
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Interesting and impressive. Thank you for sharing that.

Any and all of these developments, would have quite some potential had they been turned into hardware.

Did you come across anything on the scaled down version during your research?
 
Was the fuel efficiency of the RB.106 'Thames' ever mentioned does anyone know? One would hope that with it being a later design increased efficiency would mean twice the thrust but not twice the thirst, but thought I'd ask if specific fuel consumption estimates had been made anywhere. Thanks.
 
I would suspect at best 0.7, but 0.8 wouldn't be bad.
 
J75 made 0.74
While Iriquois made 0.85
AL21 made 0.76 at idle and 0.86 at full military power.
J93 made 0.7

So it depends but if it was expected to be more efficient than Avon...then it has to be better than 0.932.

The two that are closest to RB.106 would be Iriquois and J93.
 
Not terribly informative, the P.1097 internal view gives some idea of the RB.106 external shape.
hawker-p1097-png.713235
 
Anyone have any ideas on the piping down the side which then goes in rings around the jet pipe at a few points? I'd think it's compressor bleed for jet pipe cooling, but the pipes seem to pass through the keel underneath the engine which is odd - i.e. Is it an airframe component or engine component? It's quite an unusual feature
 
I believe you are correct that it is compressor air bleed for nacelle cooling around the turbine and AB duct. In turbojet engines, the skin of these components can get red hot, with heat shields and/or cooling airflow needed to protect the airframe.

One of the big advantages of mixed flow turbofan engines is that they are “self cooling” with the fan bypass air shielding the hot bits from the airframe. Even very low bypass turbofans that are essentially running a turbojet cycle (I.e. “leaky turbojet”) benefit from this self cooling capability.
 
I've a long held suspicion that RR's afterburner design for the Spey is rooted in the earlier RB.106.
Certainly they are similar diameters.

But I've not got good enough diagrams of either to really confirm or deny.
It's equally possible RR had to start again and they bear only a superficial relationship.
 
Cheers. I suppose I'm just used to looking at turbofans so the ducting is really noticeable. I'm still surprised that the ducting appears to go through the central keel rather than be integral with the engine. I wonder how the engine was planned to be removed?
 
zen said:
The 'normal' figure I have from BSP.1 is 15,000lb and the reheated figure seems a little more fluid though over 21,000lb.

Scaled up version must be able to match the Gyron at least (RB.122), the scaled down version has two figures (unknown RB No.), possibly reflecting either the understanding of what they could get out of it or different sizes (diameters) of engine. Those being 7,000lb (for the Bristol design) and 10,000lb (for the EE design) both the mach2 soaking effort (I forget the ER number). The latter is said to have a reheated thrust of 12,100lb, possibly so low because of a small chamber diameter or due to the efficiency of the turobjet in burning up the oxigen and leaving so little left for reheating.
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Turbojets (and turbofan cores) only burn about 1/4 of the air they take in, the rest is used for cooling and is unburned. A 21% thrust increase isn't bad for a 1950s afterburner.



JFC Fuller said:
Bristol BE.30 was proposed in late 1953 and utilised contra-rotting spools, proposed for a developed version of the AW.169. Bristol competitor to the RB.106?

I have to say, with Bristol, Rolls Royce, Armstrong Siddeley and DeHavilland all working on supersonic jet engines in this period (and at least three of them getting government funding, DeHavilland, RR and ASM) the sense of waste through duplication is remarkable.
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4 competitors is a healthy engineering competition. Even the Soviets kept multiple different design bureaus around for competition.
 

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