nfield
Posts: 38
Joined: Fri Dec 13, 2002 9:09 pm

Engine Name Designations

Mon Oct 13, 2003 6:38 pm

Anyone know why RR jet engines are named after UK rivers (Avon, Spey, Trent...and so on), except the RB211? Also, how do manufaturers arrive at the final number designation eg: RB211-535?
 
BR715-A1-30
Posts: 6525
Joined: Thu May 30, 2002 9:30 am

RE: Engine Name Designations

Tue Oct 14, 2003 12:10 am

The Final Numbers are like Subdesignators. BR715 has 3 different thrust ratings A1 being the 18,500, B1 being the 20,000 and C1 being the 21,000 pound thrust. -535, -524 G/H, and T are just subdesignators indicating the same engine, but different thrust ratings. Such as GE90-90B or GE90-94 or GE90-115B. PW4000 as in PW4094 ETC... Usually, the final numbers indicate the thrust rating, or the specific model engine.
Puhdiddle
 
Air1727
Posts: 318
Joined: Mon Aug 25, 2003 10:57 am

RE: Engine Name Designations

Tue Oct 14, 2003 7:40 am

Believe it or not, the 211 means nothing. RB means Rolls-Barnoldswick, named after the birthplace of the powerplant. The sub-desigs are simply thrust classes.
In the Alaska bush I'd rather have a two hour bladder and three hours of gas than vice versa.
 
nfield
Posts: 38
Joined: Fri Dec 13, 2002 9:09 pm

RE: Engine Name Designations

Wed Oct 15, 2003 1:34 am

Thanks for the informative responses
Nick
 
backfire
Posts: 3467
Joined: Fri Oct 06, 2006 8:01 am

RE: Engine Name Designations

Tue Oct 21, 2003 5:10 pm

Believe it or not, the 211 means nothing.


Perhaps. But remember that at the earliest stages of Airbus' life, there was a British project to create a new passenger aircraft to address the needs of airlines at the time.

Since BAC had already developed the "One Eleven", the new project was dubbed the "Two Eleven". I can't be certain, but I believe that it was intended that Rolls-Royce develop an engine for this aircraft. While the BAC Two-Eleven never went beyond the planning stage, Rolls-Royce nevertheless developed the engine - the RB211.
 
Panman
Posts: 603
Joined: Mon Aug 09, 1999 8:25 pm

RE: Engine Name Designations

Tue Oct 21, 2003 10:55 pm

As far as I remember it hte sub designations do not simply refer to thrust designations. Everytime that a modification is made to the original design the manufacturer changes the sub designation. So if for example the material used in the The NGVs is changed for a slightly more heat resistant material, the sub designation is going to change. Change the internal cooling air paths slightly - sub designation change. Move part of the accessories to a different location in the gear train - sub designation change.

pAnMaN
 
Duncan
Posts: 134
Joined: Mon Apr 08, 2002 1:14 am

RE: Engine Name Designations

Wed Oct 22, 2003 10:06 am

The 535 and 524 are completely different engines, yes, their thrust rating is different, but also their fan diameter, nacelle, engine mounts, everything really, there are no (or maybe 1 or 2 ) common parts between the 2 engines. Just like the GE90 series, where the dash number is an indication of the fan diameter (in inches) the GE90-115 has a 115 in. fan diameter (flipping big is you ask me).

Thrust bumping is common, for example the V2500-A1 and -A5 are basically the same engine with a thrust bump for the A5. The RB211-535E4 has an E4-B and E4-C variant, each is a thrust bump from it's previous version. The 524 is a completely different design (have I already said that??) it is not a thrust bump of the 535 just as the PW4198 is not a thrust bump of the 4094 or the GE90-115B is not a thrust bump to the GE90-90. The CFM56-7 is not a thrust bump to the CFM56-5 which is not a thrust bump to the CFM56-3, they are all different designs, different engines each deisgned for a specific airframe. Minor changes do not necessitate a engine designation change, if there is a change which affects the type certificate or operation of the engine, then I think there would need to be a designation change, otherwise minor changes should be just identified on the date plate or in the records of the engine.

Also, even the Trent Engines are officially called RB211-Trents.

Duncan

 
gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

RE: Engine Name Designations

Thu Oct 23, 2003 2:36 am

Just like the GE90 series, where the dash number is an indication of the fan diameter (in inches) the GE90-115 has a 115 in. fan diameter (flipping big is you ask me).

This is not accurate. The dash number in the PW4000 indicates fan size, and is almost never used since people know the fan diameter pretty much by the manufacturer and thrust codes.

The fan in the GE90-115B is 128 in vs 123 for the GE90-94B.

There is no PW4198, its the PW4098, and it is just a thrust bump of the PW4094. If there were a PW4198, it would be a different engine than the PW4098. The GE90-115B is not a completely different engine to the GE90-90B, it does however incorporate different components.

The G, H, and G/H-T in the RB211s designates added technologies, not just thrust. The -T is the Trent HPC system, and I don't know what the others are.
 
ConcordeBoy
Posts: 16852
Joined: Thu Feb 01, 2001 8:04 am

RE: Engine Name Designations

Thu Oct 23, 2003 4:00 am

The fan in the GE90-115B is 128 in vs 123 for the GE90-94B.

Incorrect, they're considerably larger than that and there's only an inch between them.

GE90-115B fan diameter = 135in
GE90-94B fan diameter = 134in

Source: GE's GE90 webpage
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