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Rolls-Royce RB Designations


Jul 25, 2007
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Rolls-Royce Limited/Rolls-Royce (1971) Limited/Rolls-Royce plc 'RB' Designations

(Moderator: I have placed this listing here because its emphasis is on the designation system rather than details of the engines themselves. If this is positioning is deemed inappropriate, please move or delete this entry.)

I am not aware of any complete listing of Rolls-Royce's 'RB' engine designations. I have begun a listing of RB designations from online sources but large gaps remain. A particularly frustrating example is the AJ.25/AP.25 Tweed - there are plenty of references to these turbojet/turboprop engines but never with an 'RB' designation attached!

Other examples are the designations of the proposed aft-fan versions of Avon and Medway. Can any forum members fill some of these 'RB' designation gaps?

A note on style. The designation style was originally RB followed by a period followed by a model number. I have used that form although both Rolls-Royce and outside sources often dropped the period, substituted a dash, or closed the gap. I have used the latter form for the revived 'RB' designations applied by Rolls-Royce plc (since that now seems to be standard).

Rolls-Royce plc designations - RB282, RB285, RB2011, RB3011 - are listed separately at the bottom. Other designations systems relating to Rolls-Royce turbine engines are described below (but are not listed).


RB Designations - 'R' for Rolls, 'B' for Barnoldswick

As is fairly well-known, the 'RB' designations applied to Rolls-Royce engines date from the take-over of the Rover works at Barnoldswick in Lancashire. Rolls-Royce chose to retain Rover's original model numbers. Thus the W.2B/B.23 (or B/23) and W.2B-500/B.26 (or B/26) became the RB.23 Welland and RB.26 Derwent respectively.

So, the 'B' stood for Barnoldswick but, when the design office was moved to Derby in mid-1948, 'RB' became the general Rolls-Royce prefix for aircraft turbine engines.

Earlier Rolls-Royce Jet Engine Designations

Rolls-Royce work on turbojet engines dated back to at least September 1940 with the CR.1. An axial flow CR.4 engine ran in 1942 - the 'CR' standing for Contra Rotating. an engine of exceptional technical interest, was on the drawing board in September 1940, and an experimental prototype ran on the test bed in 1942.

Lionel Haworth's first jet design was the 1941 WR.1. Also run in 1942, this engine was based on Frank Whittle's Power Jets W.1 with a Rolls-Royce compressor. Presumably, the designation stood for 'Whittle/Rolls-Royce No.1' or something similar.

Then there was the RCA.1, RCA.2 and RCA.3. The latter was a 3-shaft compound axial-flow turbojet design by Lionel Haworth ... but I have no clue what their acronym stood for :(

Other Rolls-Royce Engine Designation Forms

Besides the 'RB' system, there were a number of designation systems applied to Rolls-Royce turbine engines. These include:

Rolls-Royce Descriptive Designations

AJ. = Axial Jet: eg AJ.25 Tweed turbojet variant; AJ.65 (leading to Avon). [2]
The designation numeral refers to 1/10th of thrust in pounds.

AP. = Axial Propeller: eg AP.25 Tweed turboprop/turboshaft variant

BJ. = Bypass Jet: eg. BJ.45/BJ.80 Conway

[2] In Enzyklopädische Abhandlung über ausgeführte Strahltriebwerke (Karl Leist, Verlag für Sozialwissenschaften, 1963, pg 202), there is mention of AJ.50 and AJ.60 without details ... but I've seen no other references to these designations.

Most commonly applied - by both Rolls-Royce and the press - were the Ministry of Supply designations for individual R-R engine types. MS designations included RA. for Avon, RCo. for Conway, RDa. for Dart, RSp. for Spey, RSr. for Soar, RTy. for Tyne, etc.

Other Rolls-Royce engine designations were the 'RZ' series for rocket engines and, more recently a new 'RR' series. These include Rolls-Royce Small Engine products - such as the RR300, RR500, etc. - and RR1004 (for the Gem 2). There have also been a series of acronyms for joint ventures with other firms.

Joint Venture Aero-Engine Designations

BR = BMW Rolls-Royce AeroEngines GmbH; as in BR700 series
- NB: BR became wholly-owned Rolls-Royce Germany in 2000

MTR - MTU Turbomeca Rolls-Royce GmbH; as in MTR390 (Eurocopter Tiger)

RJ = Rolls-Royce/JAEC, as in RJ500 (CFM56 rival)
- Japanese Aero Engine Corp = IHI, Kawasaki, and Mitsubishi

RT = Rolls-Royce/Turbomeca; as in RT.172 for RB.172 Adour

RTM = Rolls-Royce/Turbomeca/MTU; as in RTM322

An exception seems to have been with joint products with SNECMA. The latter retained its own 'M' series of designations with Rolls-Royce applying its own 'RB' designations to the same engine projects.

Note that Rolls-Royce Bristol Engine Division (BED) retained 'BS' designations although later developments sometimes received 'RB' designations. Rolls-Royce Small Engine Division (SED) sometimes received 'H' designations - such as Gnome H1200 and Gnome H1800 - for SED's Leavesden, Hertfordshire location.

A numerical listing of known (to me) RB. designations follows:


Jul 25, 2007
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Rolls-Royce RB (R-R Barnoldswick) Engine Designations

RB.23 - Welland military turbojet, from 1942 Whittle W.2
- RB.23 desig. based on Rover model number B/23 or W.2B/23

RB.26 - Orig. desig. for Derwent ('straight-through' Welland)
- RB.26 desig. based on Rover model number B/26 or W.2B/26

RB.37 - 1943 Derwent military turbojet, improved Welland
- RB.37 desig. based on Rover model number B/37 or W.2B/37

RB.39 - 1945 Clyde axial turbojet AJ.25 or turboprop AP.25
-- 4,030 eshp AP.25 intended for Wyvern TF Mk.2, cancelled

RB.40 - Derwent Mk.8 turbojet,* centrifugal compressor
- RB.40: 3,600 lbf, Avro 707, Fairey Delta 1, Fokker S.14
-- * RB.40 was a 2.6 scale-up of the RB.37 Derwent

RB.41 - 1944 Nene turbojet, centrifugal compressor
- RB.41: ~5,000 lbf, military & civilian use
-- Pratt & Whitney J42: Licensed US RB.41 Nene
-- Klimov VK-1: Unlicensed Soviet RB.41 Nene copy
-- Wopen WP-5 : Licenced vers. of unlicensed VK-1

RB.44 - 1948 Tay turbojet, centrifugal compressor
- RB.44: Enlarged Nene, 6,000-7,000 lbf, Tay Viscount
-- Hispano-Suiza Tay : Fr. licensed, Mystere II/III/IV
-- Hispano-Suiza Verdon: French devel. for Mystere IVA
-- Pratt & Whitney J48: Licensed US RB.44 Tay

RB.50 - 1944 Trent, turboprop development of RB.23 Welland
- RB.50: Flown 1945, Gloster Meteor F.1, 5-blade Rotol props
-- RB.50 Meteor installation produced 750 shp + 1,000 lbf

RB.52 - [Project] 1945 Clyde II turboprop, centrifugal compressor
-- http://www.secretprojects.co.uk/forum/index.php/topic,1016.msg151888.html#msg151888

RB.53 - 1946 Dart turboprop, centrifugal compressor
- RB.53: Devel. begun for RAF single turboprop trainer
-- Ministry of Supply designation in RDa. series

RB.55 - Derwent V/Derwent 5 (?? typo ??)
-- https://zh.scribd.com/doc/128144658/Military-Turbojet-Turbofan-Specifications
- RB.55: (??) Poss. Derwent V desig., June 1945 0.855 scale Nene
-- Derwent 5: FMA I.Ae. 27, Gloster Meteor F.4, Nord 1601
-- Klimov RD-500: Unlicensed Soviet Derwent V copy
-- Derwent 5/17: 3,600 lbf, Avro Canada C.102 (x 4)

RB.60 - [Project] 1946-47 small gas turbine,* ~500 bhp
- RB.60: Based on Merlin 46 2-stage blower components
-- * Automotive or aviation (turboprop or turbojet)
-- http://www.secretprojects.co.uk/forum/index.php/topic,1016.msg152237.html#msg152237

RB.71 - No details

RB.78 - No details

RB.80 - Conway, built Jan 1950 as single RCo.2 turbofan*
- RB.80 orig. designed to use Avon and Tweed components
-- * Orig. designated BJ.45, then BJ.80 for 'Bypass Jet'
-- Ministry of Supply designation in RCo. series

RB.82 - 1951 expendable turbojet for cruise missiles
- RB.82: Design dropped in favour of RB.93 Soar

RB.84 - No details

RB.90 - Avon 200 augmented military turbojet, aka Volvo RM5
-- Ministry of Supply designation RA.
-- https://www.flightglobal.com/pdfarchive/view/1968/1968%20-%200026.html

RB.93 - 1953 Soar, improved RB.82, 1,750 lbf, canc. March 1965
- RB.93 licenced by Westinghouse as J-81 for US missiles
-- Ministry of Supply designation in RSr. series

RB.102 - [Project] Bristol Olympus with large front fan
-- http://www.secretprojects.co.uk/forum/index.php/topic,1682.msg110948.html#msg110948

RB.103 - 2,200 lbf turbojet lift-jet, Dassault Balzac V-001
-- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%201541.html

RB.106 - [Project] turbojet 15,000 lbf dry, 20,750 lbf reheat
- RB.106: Intended as Avon replacement, project cancelled in March 1957
-- https://www.flightglobal.com/pdfarchive/view/1956/1956%20-%201246.html
-- Poss. named 'Thames', for SR.177, EE P.6D

RB.107 - [??] Mentioned with Meteor refurbishment
-- https://www.flightglobal.com/pdfarchive/view/1979/1979%20-%202068.html

RB.108 - 1955 2,210 lb-2,340 lb single-shaft turbojet lift-jet
- RB.108: Short SC.1, Dassault Balzac, var. hover rigs, P.1126
-- https://www.flightglobal.com/pdfarchive/view/1956/1956%20-%201246.html

RB.109 - 1955 Tyne twin-shaft turboprop engines
-- Ministry of Supply designation in RTy. series
-- https://www.flightglobal.com/pdfarchive/view/1956/1956%20-%201246.html

RB.115 - [Project] Small turbojet (21-inch diameter?)
- RB.115 intended for Bristol Type 188, Hawker P.1107/P.1108
-- http://www.secretprojects.co.uk/forum/index.php/topic,22731.msg230300.html#msg230300

RB.121 - [Project] supersonic turbojet for GOR.339 bombers
- RB.121: Opt'l engine for HP 100, Vickers SP-4 (Small Swallow)
-- TSR 2: Britain's Lost Bomber, Damien Burke

RB.122 - [Project] Scaled-up RB.106 for O.R. F.155, cancelled
- RB.122: Enlarged RB.106 intended for Fairey Delta III fighter

RB.123 - [Project] 10,250 lbf for EE P.10.M3 recce aircraft
-- http://www.secretprojects.co.uk/forum/index.php/topic,12700.msg125275.html#msg125275

RB.124 - (??) NB: appears as What-If ('RB.124 Skylon II')

RB.126 - [Project] 13,400 lbf (dry) for English Electric P.8 (F.155T)

RB.127 - [Project] 1955, for R-156T Mach 3 recce requirement

RB.128 - [Project] Supersonic turbojet related to RB.106/RB.122
- RB.128 - More powerful development of RB.122

RB.133 - [Project] More powerful Avon RA.24 turbojet
- RB.133: 2 x 13,880 lbf for Developed Sea Vixen
-- 2 x RB.133 for Canberra PR.9 and Hawker P.1128
- RB.133: Optional engine for EE/Short P.17 to GOR.339
-- TSR.2: Britain's Lost Bomber, Damien Burke

RB.138 - (??) NB: Typo for RB.318 turboprop/turboshaft concept
-- https://www.flightglobal.com/pdfarchive/view/1979/1979%20-%200085.html

RB.140 - Medway, 1957/58 development engine, 8,000 lbf
- RB.140: Aimed at 4-jet aircraft to BEA requirement
-- https://www.flightglobal.com/FlightPDFArchive/1959/1959%20-%201813.PDF

RB.141 - Medway, 1959 low-bypass turbofan, for Airco DH.121
- RB.141: Aimed at 3-jet aircraft to BEA requirement
-- 13,790 lbf RB.141-3 considered for Caravelle 7 project
-- https://www.flightglobal.com/pdfarchive/view/1959/1959%20-%202806.html

RB.142 - Medway military variant (conventional + vectored thrust)
- Conventional reheated RB.142R consid. for GOR.339 candidates*
-- * Avro 739, EE/Short P.17, Hawker P.1129, Vickers 571, etc.
- RB.142: Rear vectored-thrust engine for AW.681 and HS.681

RB.144 - [Project] 1957 lift-fan for civilian VTOL airliners
- RB.144: Boulton Paul P.143 VTOL airliner (x 10), P.144 (x 2)

RB.145 - 1961 RB.108 deriv., extra compressor stage, with MAN Turbo
- RB.145 : RB.108 with extra compressor stage and higher thrust
-- Light, non-expendable lift/cruise turbojet - 2,750 lbf dry
- RB.145R: Deflecting/tilting lift/thrust vers., 3,650 lbf reheat
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201019.html

RB.146 - 12,690 lbf Avon 300/301/302/302C with improved compressor
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201018.html
-- https://www.flightglobal.com/pdfarchive/view/1965/1965%20-%200042.html

RB.151 - [Project] 1958 30,000 lbf turbojet, SST powerplant

RB.153 - Designation is used twice for turbojet than turbofan
- RB.153 [1] : Turbojet devel. based on R-R/MAN Turbo RB.145
-- RB.153/17: 1959-60 3,934 lbf dry, 5,463 lbf reheat, VJ 101
-- http://www.secretprojects.co.uk/forum/index.php/topic,2069.msg137053.html#msg137053
- RB.153 [2] : 1963 'scaled-down Spey', R-R/MAN joint project
- RB.153 : Twin rear thrust deflectors + reheat for P.1157
-- https://www.flightglobal.com/pdfarchive/view/1966/1966%20-%201395.html
- RB.153 : Considered for upgraded variant of HAL Marut fighter
-- http://www.secretprojects.co.uk/forum/index.php/topic,14359.msg144876.html#msg144876

RB.154 - [Project] Civilian turbojet
- RB.154: Boulton Paul P.145 twin-boomed VTOL transport (x 4)

RB.155 - [Project] lift-jet turbojet
- RB.155: Boulton Paul VTOL P.144A (x 1), P.196 (x 8 in four pods)

RB.156 - Poss. not used to avoid confusion with AM Spec (Avro 730)

RB.157 - (?? liftjet ??)

RB.158 - [Project] 1959 34,000 lbf turbojet, Mach 2.0 SST

RB.159 - [Project] 1959 16,000 lbf turbojet based on Avon RA29-5

RB.160 - [Project] 1959 34,000 lbf turbojet, SST powerplant

RB.161 - [Project] Turbofan/lift-jet development of RB.153 turbojet
- RB.161: For unbuilt unbuilt Avro 778, VFW-Fokker VAK 191B (RB.161-31)

RB.162 - 1962 single-shaft turbojet lift-jet (RB.162-30, -81) or booster
- eg: 5,2501b RB.162-86 booster engine on Hawker Siddeley Trident 3B
- Lift-jet for P.1144, P.1149, P.1155, P.1159, Fiat G.222

RB.163 - Spey civil variant, orig. for BEA's Airco DH.121 airliner
- eg: 16,900 lb Spey RB.163-6 in BAC One-Eleven 700
-- Ministry of Supply designation in RSp. series
-- AR 963: Proposed licensed produced vers. by Allison

RB.165 - (??) Vectoring-thrust engine for VTOL aircraft
- RB.165: 1959-60, 9,000 lbf for MD 620 Cavalier, + 4 RB.153
- RB.165: (x 2) for MD 630 Cavalier, + 2 x RB.162 lift jets

RB.166 - 'RB.166-62' typo for RB.168-62

RB.167 - [Project] Jan 1960 20,000 lbf turbojet, Mach 2.2 SST
-- RB.169.7 and RB.169.8 listed in French Gov't Concorde files
- ??: [Project] March 1960 2-shaft 20,000 lbf engine for SST

RB.168 - Spey turbofan, military variants
- RB.168-1A Mk 101: Blackburn Buccaneer S.2,11,100 lbf
- RB.168-62: Uprated Spey for Saab 37 XE-1 (RAF Viggen)
- RB.168-25R Mk 201: McDonnell Douglas F-4K/F-4M Phantoms
- RB.168-89R: [Project] Spey devel., 12,210 lbf dry/ 20,430 lbf reheat
-- Associated with AST.403 (Harrier/Jaguar repl.) studies
-- Ministry of Supply designation in RSp. series
-- AR 168R: Joint R-R/Allison vers. for TFX competition
-- TF41: Allison Model 912 (RB.168-62) for LTV A-7D Corsair

RB.169 - [Project] 1962? ~25,000 lbf turbojet, Mach 2.2 SST
-- Poss. Olympus desig. for early Sud-Dassault/BAC Concorde design
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201020.html

RB.170 - [Project] Mar 1960 24,000 lbf bypass turbojet, Mach 2.7 SST

RB.171 - [Project] Mar 1960 20,000 lbf bypass turbojet, Mach 2.2 SST

RB.172 - R-R/Turbomeca T260 Adour, military & short-haul transport
- RB.172-T260: Adour military turbofan, aka RT.172
- RB.172-45: (x 2) for Breguet Br.121 (led to Jaguar)
- RB.172: For DH.126/HS.131/HS.136 studies, Dassault Mystere 30
-- https://www.flightglobal.com/pdfarchive/view/1965/1965%20-%200043.html

RB.173 - [Project] Smaller, 7,500 lbf derivative of Spey
- RB.173: Aimed at Viscount jet devel. (or replacement?)

RB.174 - 1961 Medway advanced civil development, ~15,000 lbf
- RB.174 "a modernized RB. 141" for Sud 10A Nouvelle Caravelle
-- https://www.flightglobal.com/FlightPDFArchive/1961/1961%20-%201650.PDF

RB.175 - [Project] Turbofan lift jet deriv. of RB.162, not built
- RB.175: RB.162 gas generator to drive fully-ducted front fan
-- The 8,000 lbf RB.175 specified for NATO BMR-4 transport
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201895.html
-- https://www.flightglobal.com/pdfarchive/view/1965/1965%20-%200043.html

RB.176 - [Project] RB.162 deriv., turbine compressor/'air producer'
- RB.176: Proposed for Fairy Rotodyne & 'blown' SC.5/21 Belfast
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201895.html

RB.177 - [Project] Medway deriv. military turbofan
-- 4 x RB.177-22-23,000 lbf for BAC VC10 MRA variant to OR.357
-- 1 x RB.177 proposed for Saab 37 Viggen, ~15,000 lbf (dry)
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201015.html

RB.178 - [Project] 1961 'Super Conway', high-bypass Medway devel.
- RB.178: Led to development of third generation RB.203 Trent
-- Orig. intended as SST engine, B747 1st subsonic application
-- HBN 100 'Airbus' (x 2), B747* and SC.5/41 Jet Belfast (x 4)
-- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%202365.html
- RB.178-16: July 1966 2-shaft trials engine
- RB-178-51: First 3-spool version, 44,000 lbf,* abandoned
-- * Gunston has proposed rating as 45,000 lbf (reply #2)
- RB-178-61: 2-spool test engine, 27,500 lbf (likely a typo for RB.18-176)
-- https://www.flightglobal.com/FlightPDFArchive/1967/1967%20-%200028.PDF
- RB.178 demonstrator program terminated in 1966
-- * Proposed RB.178 joint production with General Electric
-- http://www.secretprojects.co.uk/forum/index.php?topic=12702.0

RB.179 - [Project] May 1961 6,000lbf turbofan for Fokker project

RB.180 - [Project] Turbofan 'reduced-scale Spey', 6,800 lbf*
- RB.180" Planned for Fokker F.28, Avro 778F 'Jet Andover'
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201020.html
-- * Some sources list 6,250 lbf as output for RB.180 turbofan

RB.181 - [Project] single-shaft turbojet VTOL lift-jet
- RB.181: Reduced-scale RB.162 for Lockheed-Short CL-704
-- https://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201895.html

RB.182 - (??) 1964, revealed but no details
-- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%200649.html

RB.183 - Spey Junior/Tay, simplified/reduced-scale RB.163
- RB.183-1 orig. for Fokker-VFW F.28, HP.127 Jet Herald
- RB.183-2 Mk.555-15 Spey Junior; Mk.555-15, -15H, -15P
- RB.183-3 Mk.611 Tay, on Fokker F100.70, Gulfstream V
- RB.183-3 Mk.611-8 Tay, Gulfstream IV/G300/G400/C-20G/H
- RB.183-3 Mk.620-15 Tay, used on Fokker F70
- RB.183-3 Mk.650 Tay, F100, GIV, BAC 111
- RB.183-3 Mk.651 Tay, F100, Boeing 727 (re-engining)
- RB.183-3 Mk.670 Tay, B727, DC-9, B737, MD-96 (proposed)
- RB.183-55515P Tay, used on Fokker F28 Mk4000

RB.185 - (??) 1964, revealed but no details
-- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%200649.html

RB.189 - 1969 3rd generation lift jet, Mirage IIIV, etc.
- RB.189: Joint project with Allison, for HS.1019E6
-- RB.189 led to 9,000 lbf RR-Allison XV99-RA-1 project

RB.190 - No details

RB.191 - 'RB.191-12', typo for RB.193-12 engine in VAK 191B
-- Interavia, vol 26, Sept 1971, pp 1037-1039
-- http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720009345.pdf

RB.192 - (??) Common typo for both RB 162 and RB.193
-- Poss. not used to avoided confusion with AM Spec RB.192D ??

RB.193 - 1964 3-shaft military turbofan, related to Bristol BS.53
- RR/MAN RB.193 4-poster vectored lift/propulsion, VFW/Fokker 191B
- eg: 2 x afterburning RB.193s for Saab Viggen project 37 XE-3
-- https://www.flightglobal.com/pdfarchive/view/1966/1966%20-%201395.html
-- Offered as 'New Pegasus' 11-61 (Harrier II) & 11-21 (AV-88)

RB.198 - (??) Mentioned as a lift jet engine by Walter J. Boyne
-- Air Warfare: An International Encyclopedia, Volume 1, pg 204
- RB.198: Typo for RB.178, The Airbus A380, Graham Simons, pg 38

RB.199 - Turbo-Union (R-R, MTU, FiatAvio) turbofan for Tornado
-- https://www.flightglobal.com/FlightPDFArchive/1981/1981%20-%202736.PDF
- RB.199-34R: [Project] ~1973 V/STOL, 8,530 lbf dry/ 15,300 lbf reheat
- RB.199-42R: [Project] ~1973 V/STOL, 9,700 lbf dry/ 17,000 lbf reheat
- RB.199-52R: [Project] 9,220 lbf dry/ 14,810 lbf reheat
-- Associated with AST.403 (Harrier/Jaguar repl.) studies

RB.200 - (??) Wikipedia listing, poss. confusion with EJ 200

RB.202 - Late '60s high bypass turbofan lift jet
- RB.202-25: HS.141 V/STOL airliner (16 x 10,300 lbf)
- RB.202-25 (x 12) for Dornier Do 231C/M project

RB.203 - Trent, 1967 3-spool Advanced Technology Engine turbofan
- RB.203: High bypass, RB.172 core, planned RB.163 Spey replacement
-- Intended for HS.136 (underwing) and HS.144 (rear-mounted) studies

RB.204 - [Project] 3-spool high-bypass civil turbofan, ~10,000 lbf
- RB.204: Related to more developed RB.207 project
-- https://www.flightglobal.com/FlightPDFArchive/1967/1967%20-%200028.PDF

RB.205 - [Project] 3-spool high-bypass civil turbofan, ~20,000 lbf
- RB.205: Related to RB.207, proposed for W.German 4-jet airliner
-- https://www.flightglobal.com/FlightPDFArchive/1967/1967%20-%200029.PDF

RB.207 - [Project] 1965 large 3-spool high-bypass turbofan
- RB.207: eg 47,500 lb RB.207-01 intended for Airbus A300
-- RB.207 was Rolls-Royce/SNECMA/MAN-Turbo joint project
-- RB.207 also considered for BAC Three-Eleven (x 2)
-- Based on RB.178 work, effectively, a scaled-up RB.211

RB.208 - [Project] Large high bypass turbofan for Airbus
- RB.208: Listed in French Gov't Airbus files for 1966
-- Ricardo Miguel Vidal lists as 1950s lift-jet, pg 2914

RB.209 - Marine Tyne (Tyne RM1A, RM1C, and RM3C naval turbines)

RB.211 - Large 3-spool high-bypass turbofan engine series
- RB.211: Orig. devel. for Lockheed L-1011, RB.206 devel.

RB.213 - [Project] 3-shaft civil turbofan, owing to RB.193/RB.203
- RB.213: Developed primarily for the BAC One-Eleven 500
-- https://www.flightglobal.com/FlightPDFArchive/1968/1968%20-%200024.pdf

RB.220 - 1970s high bypass ratio (6.5) turbofan, scaled-down RB.211
- RB.220: 2 x 27,000 lbf underwing for HS.141 V/STOL airliner
- RB.220: 2 x ~23,870 lbf underwing for Dornier Do 231C/M*
-- * RB.220 power for Do 231C/M listed as 10,886 kg of thrust

RB.221 - (??) Common typo for RB.211 in non-aviation press

RB.223 - [Project] Marine turbine, project def. study 1976
-- Rolls-Royce Industrial & Marine Division Project study
-- Poss. project desig. for WR-21 maritime gas turbine ??

RB.225 - [Project] Higher-bypass turbofan deriv. of Spey
- RB.225: Project may have led to the R-R Tay

RB.226 - [Project] STOL transport Spey turbofan deriv.
- RB.226: 1973 turbofan, 17,640-19,840 lbf range
-- https://www.flightglobal.com/FlightPDFArchive/1973/1973%20-%200032.PDF

RB.227 - [Project] Lift-jet (?? related to RB.228 ??)
- RB.227-01: [Project] Lift engine, 9,850-10,780 lbf

RB.228: [Project] Lift-jet (?? related to RB.227 ??)
- RB.228-02: [Project] Lift engine, 15,500 lbf

RB.228 - [Project] Powerplant for BAC P.71 bomber for Royal Navy

RB.230 - (??) Typo for RB.220 vectored turbofan for Do 231
-- http://www.airvectors.net/avdevtol.html

RB.231 - [Project] 10,900 lbf dry/ 15,600 lbf reheat turbofan
- RB.231-02: Small turbofan for HS.1203 'Super Gnat'

RB.235 - [Project] 3-shaft turbofan, reduced-scale RB.211 deriv.
- RB.235: CFM56 rival, RB.235 abandoned to join P&W in JT10D
- RB.235: 'Cropped fan', 25-30,000 lbf, Turbo-Union devel.
-- https://www.flightglobal.com/pdfarchive/view/1975/1975%20-%200048.html

RB.236 - [Project] Small turbofan for Hawker-Siddeley HS.1215

RB.238 - [Project] c.1975 air superiority fighter turbofan
- RB.238: For Hawker-Siddeley HS.1200 series fighter studies

RB.246: [Project] New engine type (no details)
- RB.246-06: Associated with AST.403 studies

RB.250: [Project] ~2000 supersonic turbofan for Sukhoi SSBJ
- RB.250: Poss. typo for RB.260, possibly related to RB.577

RB.260: [Project] ~2000 supersonic turbofan for Sukhoi SSBJ
- RB.260: Poss. typo for RB.250, possibly related to RB.577

RB.277 - [Project] Small turbofan for Hawker-Siddeley HS.1192
- RB.277: Unsure if HS.1192* lift or diverted propulsion jets
-- * HS.1192 was a Jaguar-ish STOL strike a/c to AST 396
-- http://www.harrier.org.uk/history/images/p1192.jpg

RB.282 - See RB282 turbofan below

RB.283 - See RB282 turbofan below

RB.285 - See RB285 turbofan below

RB.318 - Alfa Romeo/R-R/MTU joint study for small turboprop
- RB.318: Became the 580 shp Alfa Romeo AR.318 turboprop
-- https://www.flightglobal.com/pdfarchive/view/1983/1983%20-%200898.html

RB.340 - [Project] c.1975 small military turbofan
- RB.340: Hs.1200 series air superiority fighter projects

RB.346 - [Project] c.1975 small military turbofan
- RB.346: Poss. intended for HS.1200 air superiority fighter

RB.400 - 'RB.400-50', typo for RB.409-50R (qv)

RB.401 - 1973-74 high bypass civil/military turbofan
- RB.401: 2-spool, 5,100-5,540 lbf, Viper replacement
- RB.401-06: Demonstrator engine run 1975
- RB.401-20: [Project] Propfan/open rotor derivative
-- http://www.flightglobal.com/pdfarchive/view/1976/1976%20-%200482.html
-- RB.406 Variable Cycle Engine (VCE) for HS.1198 fighter
-- Further RB.406 development eclipsed by RB.432 (??)

RB.403 - 'RB.403-10R', a typo for RB.431-10R project (qv)

RB.406 - [Project] Vectored-thrust Variable Cycle Engine (VCE)
- RB.406-04: For 1975 HS.1198 single-engined v/STOL fighter

RB.407 - R-R/Snecma M45M 2-stafe low bypass turbofan
- RB.407: Aimed at bizjets and military trainers*
-- * With concentric bypass flow routed to afterburner

RB.409 - [Project] 1975 small military turbofan, ~9,700 lbf
- RB.409: For Kingston's HS.1204 air superiority fighter
- RB.409-07R: [Project] Cropped fan RB.199 development
-- Consid. for BAC P.97.5,965 lbf dry/ 10,150 lbf reheat
-- Associated with AST.403 (Harrier/Jaguar repl.) studies
- RB.409-50R: [Project] RB.199 devel. 8,770 lbf dry/ 15,475 lbf reheat
-- Consid. for modified Tornado for AST.403 (Harrier/Jaguar repl.)
- RB.409-70R: [Project] RB.199 development project
-- Associated with AST.403 (Harrier/Jaguar repl.) studies

RB.410 - R-R/Snecma M45S,* variable-pitch geared turbofan
- RB.410: c.1975 (??), 10-18,5000 lbf M45H-01 (RB.411) deriv.
-- * NB: M45SD was desig. on non-flying demonstrator engine
-- eg: RB.410D-2 (M4SSD-02) rated at 10,072 lbf (take-off)
-- https://www.flightglobal.com/pdfarchive/view/1972/1972%20-%202730.html

RB.411 - R-R/Snecma M57HA, 8,750 shp turboshaft deriv. of M45H
- RB.411: Intended for heavy-lift helicopters, cropped M45H fan
-- RB.411 x 2 to power tilt-wing Westland WG22 V/STOL airliner

RB.415 - R-R/Snecma M45SF fixed-pitch geared low bypass turbofan
- RB.415: 11,700 lbf, intended for HS.146/BAe.146 airliner

RB.419 - [Project] 1983 3-stage geared-fan turbofan for STOL transports
- RB.419 : Derived from RB.168 core with adapted TF41 low-press. compressor
-- Dowty Rotol variable-pitch fan (based on M45SD demonstrator fan)
- RB.419-03: Funded by Cdn gov't for Advanced Stol Transport (AST)*
-- https://www.flightglobal.com/pdfarchive/view/1983/1983%20-%201856.html
-- * DHC Augmentor-Wing project 'Powered Lift STOVL Support Aircraft'
-- Diagram: http://www.dtic.mil/dtic/tr/fulltext/u2/p004060.pdf (10-6)

RB.420 - [Project] 1970 26,000 lb non-vectoring Pegasus offered to NASA
- RB.420 running on liquid hydrogen for Space Shuttle powered return
-- aka Pegasus 420-01

RB.422 - [Project] Pegasus devel. series, 31,400-44,600 lbf
- RB.422-04: PCB, 25,580-26,860 lbf dry/38,100-40,000 lbf reheat
- RB.422-06: 4-nozzle non-PCB vers. from 1972, for HS.1184-7
- RB.422-21: 4-nozzle subsonic derivative of RB.422-48 (below)
- RB.422-43: 4-nozzle supersonic vers., Plenum Chamber Burning
- RB.422-48: 3-poster Plenum Chamber Burning (PCB) turbofan
-- Alt to Pegasus PCB for P.1212/P.1216 ASTOVL fighter concepts
-- https://www.flightglobal.com/pdfarchive/view/1981/1981%20-%202426.html
- RB.422-49: PCB vers. with afterburning on single rear nozzle
- RB.422-56: 2-nozzle, mixed-flow vers. for transonic applications
- RB.422-60: Orig. RB.422-X, BAe P.1216 ASTOVL, P.1219, P.1220 V/STOL
- RB.422-??: P.1214 ASTOVL, P.1230 V/STOL

RB.423 - R-R/Snecma M45R ultra-low bypass gas-generator
- RB.423: Intended for helicopter tip-jet propulsion

RB.424 - R-R/Snecma M45T variable-pitch geared turbofan
- RB.424: 6,300-12,000 lbf, for augmentor-wing STOLs

RB.427 - R-R/Snecma M45SE, proposed M45H (RB.411) derivative
- RB.427: (?? turbofan or turboshaft ??)

RB.428 - [Project] 3-poster turbofan with PCB, for HS.1185-26
-- http://www.harrier.org.uk/history/pegasus.htm

RB.431 - [Project] ~1975 turbofan, non-vectored Pegasus deriv.
- RB.431: 'Straight-through' Pegasus variant for HS.1202
- RB.431-10R: [Project] 'Straight-through' Pegasus turbofan
-- RB.431-10R project: 15,850 lbf dry/ 28,030 lbf reheat
-- Associated with AST.403 (Harrier/Jaguar repl.) studies

RB.432 - [Project] 16,000-19,000 lbf turbofan study project
- RB.432: Contributed to joint projects, eg: RJ500 & V2500

RB.433 - [Project] 1977 16,000 lbf VP-fan turbofan study
- RB.433: Based on M45 core, geared fan based on M45SD-02
-- For USN multi-mission V/STOL A, then AEW, ASW, & COD a/c
-- https://www.flightglobal.com/FlightPDFArchive/1977/1977%20-%203260.PDF
-- RB.433 project repl. planned 16,000 lbf refanned Spey 67
-- https://www.flightglobal.com/FlightPDFArchive/1978/1978%20-%200050.PDF

RB.506 - [Project] 1981 turboprop based on RTM322 turboshaft
- RB.506: Dart replacement to rival CT7 and PW117/PW120
-- https://www.flightglobal.com/FlightPDFArchive/1981/1981%20-%200928.PDF

RB.508 - Renumbered Pegasus 18-06 , 26,000 lbf
-- http://www.harrier.org.uk/history/pegasus.htm

RB.509 - [Project] 'Contra Fan' propfan, ~13,000 shp
- RB.509: Geared propfan (pusher), fan diameter 3.90 m
- RB.509: Related to RB.529, development begun 1986
-- RB509-05-FPTCR for Future Large Aircraft (FLA)
-- RB509-11 pusher for civil applications (??)
-- https://www.flightglobal.com/FlightPDFArchive/1986/1986%20-%202295.PDF
-- http://www.secretprojects.co.uk/forum/index.php/topic,603.msg4503.html#msg4503

RB.529 - [Project] Ducted counter-rotating propfan
- RB.529: 'Contra Fan' propfan, related to RB.509 (above)

RB.532 - [Project] Vectored thrust turbofan for P.1216
- RB.532: P.1216-41 (alt. to RB.422-60 or Pegasus 11 PCB)
-- XG.30 (never run) was to be demo engine for the RB.532

RB.533 - [Project] Vectored thrust, non-PCB turbofan
- RB.533: Intended for BAe P.1229 project and others

RB.535 - [Project] Turboprop, RTM322 core + reduction gear*
-- * RM Vidal says Dart reduction gear to be used
-- NB: 'RB 535 E4' common misuse of RB211-535E4

RB.543 - [Project] Adour upgrade/replacement turbofan
- RB.543: Adour 871E fan upgrade, ~7,500 lbf (dry)
- RB.543-02R: Reheat, ~12,000 lbf, for Embraer project

RB.545 - [Project] Swallow air-breathing rocket, for BAe HOTOL
- RB.545: Hydrogen fuel w/ air at low alt., LOX at higher alt.

RB.546 - (typo for RB.545 Swallow)

RB.549 - (??) Poss. 'Contra Fan' development (??)
-- Los Motores Aeroespaciales A-Z, pg 3022
-- http://www.aeroteca.com/motoraz/motor%20a-z%202012v8.11.pdf

RB.550 - [Project] 3,200-5,000 shp turboprop engine
- RB.550: R-R Dart replacement based on RTM322 core
-- RM.550 aimed at ATP, ATR72, Fokker 50, and others
-- https://www.flightglobal.com/FlightPDFArchive/1986/1986%20-%201762.PDF
-- https://www.flightglobal.com/FlightPDFArchive/1986/1986%20-%202295.PDF

RB.571 - [Project] Hybrid turbofan for ASTOVL applications
- RB.571: Lift nozzle + vectored thrust + conv. afterburner
-- Intended for naval variant of Eurofighter EFA/EF 2000
-- https://www.flightglobal.com/FlightPDFArchive/1989/1989%20-%202869.PDF

RB577: [Project] ~2000 supersonic medium-BPR turbofan
-- Likely Trent core with lower (2.5:1) bypass ratio
- RB.577-T800-Su1: Soyuz VK21 repl. for Sukhoi SSBJ*
-- * 2 x 62,000 lbf (versus 3 x Soyuz VK21 turbofans)
- RB577-260-LM2: NASA QSV IIPS Study*
-- * June 2003 tests, Nozzle Acoustic Test Rig
-- "Based on earlier design for SSBJ"
-- http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080047730.pdf

RB.578 - [Project] Pegasus 11-61 devel., 25,300 lbf dry
- RB.578: Stowable lift nozzles and rear afterburner
-- 27,000 lbf in lift mode, 41,300 lbf in reheat

RB.580 - [Project] Turbofan, AE 1107/T406 deriv. core
- RB.580: 7,100 lbf, for small regional and bizjets
-- Eclipsed RTM322 turbofan deriv. (related to RB.506?)
-- https://www.flightglobal.com/FlightPDFArchive/1989/1989%20-%202327.PDF


Revived RB Designations - Rolls-Royce plc

RB282 - ~10-20,000 lbf small twin-spool, 2-shaft turbofan for bizjets
- RB282: Dassault Falcon 5X (2009 lost out to Snecma Silvercrest)
- RB282: Offered for Airbus A320 re-engining

RB283 - (?? typo ??)

RB285 - ~20-30,000 lbf small twin-spool, 3-shaft turbofan
- RB285: Offered for Airbus A320 re-engining
- RB285: Short-listeded for Irkut MC-21 (PD-14M/PW1428)

RB2011 - [Project] Contra-rotating propfan, becomes RB3011

RB3011 - [Project] Contra-rotating propfan, tractor/pusher
- RB3011: Intended for 180-300 pax airliners
-- Certification planned for 2017-2018


Hope that was helpful/useful. Any additions and/or corrections gratefully received :D


Senior Member
Sep 6, 2006
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This is the most comprehensive RB list I've ever seen.

A couple of additions from Bill Gunston's 'The Development of Jet and Turbine Aero Engines', 4th Ed.

A full scale two-shaft engine for trials, run July 1966

Gunston has the proposed rating as 45,000lbf.

Certificated Feb 1972

Development in 50,000lbf class, developed to 60,600lbf ultimately.

With 73.2in fan and additional seventh IP compressor stage, rated 37,400lbf. Entered service 1983.

Modified -535 series with 74.5in fan, 43,100lbf.

Developed from 1988, scaled up 535E with new fan, 8-stage IP spool and improved 6-stage HP spool. Became Trent in 1989. Led to Trent 700 and Trent 800.

Some additional RB. numbers for projects for V/STOL fighters circa 1973 from official files I've seen:

Project, 8,530lbf dry/ 15,300lbf reheat

Project, 9,700lb dry/ 17,000lbf

Lift engine project, 9,850-10,780lbf

Lift engine project, 15,500lbf

Project, 10,900lbf dry/ 15,600lbf reheat

Project, 25,580-26,860lbf dry/ 38,100-40,000lbf reheat (PCB)


CLEARANCE: Above Top Secret
May 26, 2006
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Amazing work my dear Apophenia.


Senior Member
Sep 6, 2006
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A few more RB. designations for project engines associated with AST.403 studies.

Spey development project, 12,210lbf dry/ 20,430lbf reheat.

Development project, 9220lbf dry/ 14,810lbf reheat.

A new engine project.

A cropped fan RB.199 development project. Considered for BAC P.97.5965lbf dry/ 10,150lbf reheat.

RB.199 development project. Considered for modified Tornado to meet AST.403, 8,770lbf dry/ 15,475lbf reheat.

RB.199 development project.

Straight-through Pegasus turbofan project, 15,850lbf dry/ 28,030lbf reheat.


Jul 25, 2007
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Excellent stuff ... many thanks Hood!


Jul 25, 2007
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A few links and two geared turbofan projects have been added - the RB.419 geared turbofan for STOVL transports, and the RB.433 aimed at the USN's V/STOL A program.

Does anyone know of a RB.403 Pegasus derivative? Aviones de Caza para Europa (pg.27, C. Gilson, et al, De la Revista Internacional de Defensa, Ñ 3/1978) has this:

Este “RB.403—1OR Pegasus” desprovisto de toberas orientables, es un modelo bastante interesante para un avión de caza. Se trata de un reactor de doble flujo, de elevado coeficiente de derivación, cuyo modo de funcionamiento no corresponde exactamente a todas las misiones: previstas del AST403; obligaría también a llevar mayor cantidad de combustible, pero este inconveniente sería compensado, al menos en parte, por una buena relación empuje-peso.

So, is this "RB.403-10R Pegasus" another nozzle-less Pegasus? Or is this simply a typo for the RB.431-10R project?


CLEARANCE: Confidential
Feb 19, 2010
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What a superbly thorough list. Great stuff.

I'm very curious to know more about this one. The Flight article doesn't provide much to go on:

RB.205: Related to RB.207, proposed for W.German 4-jet airliner.


CLEARANCE: Above Top Secret
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Senior Member
Apr 2, 2006
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RB.577-T800-Su1 proposed for Sukhoi SSBJ in early 00s



Jul 25, 2007
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Thanks flateric! The RB577 has been added to the list.

Slightly OT: In your Nov 2013 Take-off magazine article on the Sukhoi SSBJ, you said this:

The Rolls-Royce RR260 and RR557 turbofans, which are still on the drawing board, and variants of Russian engines have been mulled over as the powerplant for the bizjet.

First off, what is/was the RR260? And, noting the 'RR557'/RB557 discrepancy, is it possible that this RR260 could/should be 'RB260'?


CLEARANCE: Above Top Secret
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Apr 2, 2006
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obviously that was a typo
regarding RB.260 (or 250?) see attachment



Jul 25, 2007
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Excellent, thanks flateric! So, now we can add the RB.260 (with a note on the RB.250 possibility) to the list. Cheers!


Senior Member
Sep 6, 2006
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Re: the RB.403-10R Pegasus development.
I haven't come across anything yet but I'm still going through some files. Most of the Pegasus developments mentioned don't seem to have RB numbers (except for the straight-through RB.431). I suspect it might be a typo but I won't commit to confirming that just yet.


Jul 25, 2007
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Thanks for checking Hood. I suspect a typo but it'd be nice to know for sure.


Senior Member
Sep 6, 2006
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I'm now sure that RB.403-10R is a typo.

I've found another typo error in the official files too, in one document the HS.1207-2 is described as having two RB.400-50 but I'm sure this is a typo for RB.409-50R.


Jul 25, 2007
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Cheers Hood! Notes on those typos have now been added.


Senior Member
May 9, 2008
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RB.178 - [Project] 1961 'Super Conway', high-bypass Medway devel.
- RB.178: Led to development of third generation RB.203 Trent
-- Orig. intended as SST engine, B747 1st subsonic application
-- HBN 100 'Airbus' (x 2), B747* and SC.5/41 Jet Belfast (x 4)
-- https://www.flightglobal.com/pdfarchive/view/1964/1964%20-%202365.html
- RB.178-16: July 1966 2-shaft trials engine
- RB-178-51: First 3-spool version, 44,000 lbf,* abandoned
-- * Gunston has proposed rating as 45,000 lbf (reply #2)
- RB-178-61: 2-spool test engine, 27,500 lbf
-- https://www.flightglobal.com/FlightPDFArchive/1967/1967%20-%200028.PDF
- RB.178 demonstrator program terminated in 1966
-- * Proposed RB.178 joint production with General Electric
-- http://www.secretprojects.co.uk/forum/index.php?topic=12702.0

I think RB.178-61 is a typo, the trials engine was the -16

Engine dimensions:
Demo engine RB.178-61, Two-spool version, bypass 2.75:1, diameter 62.5" = 1.58 m (from Flight 1967 - 0028), 27.5 klbf

From Aviation Magazine International - Numéro 448 - 1-8-1966:
- demo engine 11566 kgf = 113.4 kN = 25.4 klbf
- Two-spool version with bypass ratio 4:1: length 3.35 m diameter 2.5 m, thrust 11500-13500 kgf = 112.7-132.4 kN = 25.3-29.7 klbf
- Three-spool version (as proposed for Boeing 747) diameter 3.35 m, thrust 20000-23000 kgf = 196-225 kN = 44-50.7 klbf

From 'Transatlantic Betrayal, the RB.211 and demise of Rolls Royce ltd', page 92:
- RB.178-14 was a two-spool demonstrator, 27 klb, bypass ratio 2.3:1, 25% lower specific fuel consumption than predecessors.
- RB.178-16 intended for VC-10 DB.265 Superb
after cancellation of Superb in 1966, RR's Lombard ordered the RB.178 to be scaled up to get it accepted as a Boeing 747 engine

1966-1399 Flight: RB.178-51 at 44klb designed for Boeing 747 and unidentified Airbus. Bypass ratio 6:1, dry weight 7724 lb.

so plenty of disagreement between sources. I asked RR Heritage Trust for information on RB.178, but didn't get an answer. I've built 2 models (Jet Belfast and VC-10 Superb) with RB.178 using the 1.58 m diameter figure...


Jul 25, 2007
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'RB.178-61' being a typo does make sense Hobbes. That would explain why a lower-power twin-spool engine 'follows' the higher-powered triple-spool RB.178-51!