ED 92

[Richard Scott]

Rather wacky idea came into my head that there are a few stored 92s out there with minimal chance of running again. There's also a lot of diesel hauled freight running under wires for many miles. I know this is expensive and would be a small fleet so probably not worth investment but how about adding a diesel engine (MTU or CAT of about 3000hp) to make a versatile loco? They are already a Co-Co design so weight less of an issue. Know there would be cooler groups etc to add and maybe there would be a reduction in electric power but not sure that would be a problem? They also have advantage of 3 phase drives so likely to be better than a 66 on diesel power?
Unlikely to ever happen due to costs, lack of appetite/foresight for much electric hauled freight?

 

[pdeaves]

My immediate thought is, where would you put the diesel engine? There is no space inside a 92 for anything new. To add one would mean removing something else, which would mean a complete rebuild of the guts. Obviously not impossible, but not simple.

 

[gazthomas]

They're temperamental enough as electrics let alone Ed's!

 

[popeter45]

not a installation of a engine inside a 92 but maybe install some hand of High power connection so they could be powered by a generator van over electrified lines? (a bit like RENFE class 730's)

 

[MarkyT]

They are peculiar locos specially built for Chunnel services, with two sets of independent traction equipment inside. That was to comply with special regulations for the tunnel with the theory that a train could successfully make its way safely out of the tunnel even with half the loco completely shut down. The trouble is it means the loco is absolutely jam-packed with heavy equipment that is far bulkier than similarly specced state of the art kit available today. There's definitely no room to accommodate even a moderately sized 'last mile' diesel and its ancillaries without a complete rebuild, which would likely have to be so comprehensive it would be more expensive than a new build.

 

[SeanG]

Would it be possible to remove one of the sets of traction equipment then, assuming that everything is duplicated? The small diesel engine could then be put in that space?

In reality though, would it be easier, cheaper and more practical in the long run to buy new?

 

[ABB125]

Would it be possible to remove one of the sets of traction equipment then, assuming that everything is duplicated? The small diesel engine could then be put in that space?

In reality though, would it be easier, cheaper and more practical in the long run to buy new?

That sounds possible to my non-traction-engineer mind. But like you say, is it worth it?
How about class 90s - do they have space for an engine?

 

[Bald Rick]

Happy to be corrected here, but there’s no space in any electric loco for a Diesel engine. Why would you build any loco with a load of spare space in it?

What would be possible is to get an old Diesel engine, re-engine it (because modern engines are much smaller for a given power output then even 30 years ago), and then put a transformer / modern electronics in to turn it into an ED. However, I suspect it would be much cheaper to just buy some 88s.

 

[hwl]

Happy to be corrected here, but there’s no space in any electric loco for a Diesel engine. Why would you build any loco with a ,pad of spare space in it?

What would be possible is to get an old Diesel engine, re-engine it (because modern engines are much smaller for a given power output then even 30 years ago), and then put a transformer / modern electronics in to turn it into an ED. However, I suspect it would be much cheaper to just buy some 88s.

Agreed
The 92s have the least spare space of any UK electric loco. It might be possible to rip out the original GTO 3phase drivers an replace with IGBT a generate a bit of space but then would still have EMC re-certification issues.

 

[hwl]

Would it be possible to remove one of the sets of traction equipment then, assuming that everything is duplicated? The small diesel engine could then be put in that space?

The duplication isn't all like that though. As I understand you could only remove one set of HV gear saving less than a cab worth of space. The rest causes confusion as it has individual axle control with 6 sets of traction electrics (split co-located 3 and 3 for each bogie) which is now the norm but was novel then.
Greater traction efficiency means more space taken up by control electronics.
For example the newer US diesel locos are bulkier because they have to find space for lots more 3phase driver electronics.

 

[MarkyT]

...there’s no space in any electric loco for a Diesel engine. What would be possible is to get an old Diesel engine, re-engine it (because modern engines are much smaller for a given power output then even 30 years ago), and then put a transformer / modern electronics in to turn it into an ED. However, I suspect it would be much cheaper to just buy some 88s.

Most modern general-purpose electric locos in mainland Europe carry a significant ballast weight on board to get their driving axle load, and thus adhesion, up to a useful value, because regardless of size, the kit required for electric-only operation is simply not heavy enough on its own. This is part of the argument for at least a 'last mile' diesel generator on board to act as that ballast, and these are becoming increasingly common on the latest designs.

The 92s have the least spare space of any UK electric loco. It might be possible to rip out the original GTO 3phase drivers an replace with IGBT a generate a bit of space but then would still have EMC re-certification issues.

Loading gauge is a major issue in UK, as always. Vossloh/Stadler had great difficulty adapting their Eurodual design for the UK profile which is why the 88 can only accommodate a small last-mile diesel instead of the full-size line haul unit used elsewhere. Space for exhaust treatment at the roof level in particular is a big constraint in UK and the bigger the engine, the larger the exhaust stages.

 

[Bald Rick]

Most modern general-purpose electric locos in mainland Europe carry a significant ballast weight on board to get their driving axle load, and thus adhesion, up to a useful value, because regardless of size, the kit required for electric-only operation is simply not heavy enough on its own. This is part of the argument for at least a 'last mile' diesel generator on board to act as that ballast, and these are becoming increasingly common on the latest designs.

Loading gauge is a major issue in UK, as always. Vossloh/Stadler had great difficulty adapting their Eurodual design for the UK profile which is why the 88 can only accommodate a small last-mile diesel instead of the full-size line haul unit used elsewhere. Space for exhaust treatment at the roof level in particular is a big constraint in UK and the bigger the engine, the larger the exhaust stages.

There’s a great article about the 88s by Walmsley in this month’s Modern Railways.

Whilst it is a small engine, it still has (almost) the power of a Class 20.

 

[JohnMcL7]

There’s a great article about the 88s by Walmsley in this month’s Modern Railways.

Whilst it is a small engine, it still has (almost) the power of a Class 20.

Arguably a class 20 doesn't have much power given they often ran in pairs, is the 1000bhp useful? I never see much about 88's here although it is a very small fleet.

 

[MarkyT]

There’s a great article about the 88s by Walmsley in this month’s Modern Railways.

Whilst it is a small engine, it still has (almost) the power of a Class 20.

Agreed it's a very useful size engine and with the axle load and modern traction control, no doubt very capable for what it's built for at moderate speed. Used to be part owner of a couple of class 20s in preservation - nice piece of kit! I think I'm going to have to sign up for MR online to avoid having to go out and find it physically and risking a fine!

 

[MarkyT]

Arguably a class 20 doesn't have much power given they often ran in pairs, is the 1000bhp useful? I never see much about 88's here although it is a very small fleet.

It's tractive effort that's important for starting and keeping very heavy things moving. On reasonably graded track, 1000hp is plenty if it's not speed you're after as it's adhesion that limits what you can put down into the rails. Look what an 08 can move at walking pace. There were a number of reason 20s went around in pairs. The earliest batch were really built for singular use on short pick up and transfer type goods services which quickly went out of fashion, but by coupling a pair nose to nose, operators found they had a decent moderately powered heavy haul combo, with eight driven axles that could start pretty much anything on rough colliery track, and overcame staff concerns about visibility when driving them nose first, which, along with their underlying reliability, is why they survived and were joined by a second late 60s order after many of the other similarly sized designs were abandoned and scrapped. Some of the later batch came new fitted with a slow speed control for 'merry go round' loading and unloading operations, and I think some of but not all the earlier locos were also retrofitted with this. The two I was involved with had no slow speed control, but I remember seeing the equipment on other scrap examples we crawled over for spares in Glasgow.

 

[JohnMcL7]

I was meaning specifically is the 1000bhp on the 88 useful compared to pure electric locomotives?

 

[MarkyT]

I was meaning specifically is the 1000bhp on the 88 useful compared to pure electric locomotives?

Pretty good for the last mile work on freight-only branches, where not interworking with a high-density passenger service, or starting from an unelectrified siding to pick up the wires at the junction etc. Not that much cop for long-distance heavy haulage once on the busy mainline, but that's when the pan should be going up.