idea for a class 94 articulated locomotive

[popeter45]

so seeing the thread about adapting class 92's into bi-mode and the issues with that i had this idea instead for a new locomotive that is a high power Bi-Mode locomotive

a Bo-Bo-Bo articulated configuration with 2 halfs:
a 6500 hp electric car with a drive cab at one end that like the class 92 can pick up from either 750V DC or 25Kv AC, maybe even support other voltages for possible cross-Europe use
a 4000 hp Diesel car with a drive cab at the other end, designed for future retrofitting with other systems instead like hydrogen and/or battery depending on what becomes the norm once diesel is phased out

both cars out feed the same electrical system to drive the same motors in the bogies

design could be made for a high top speed so could also be used for passenger use similar to the class 68

 

[MarkyT]

so seeing the thread about adapting class 92's into bi-mode and the issues with that i had this idea instead for a new locomotive that is a high power Bi-Mode locomotive

a Bo-Bo-Bo articulated configuration with 2 halfs:
a 6500 hp electric car with a drive cab at one end that like the class 92 can pick up from either 750V DC or 25Kv AC, maybe even support other voltages for possible cross-Europe use
a 4000 hp Diesel car with a drive cab at the other end, designed for future retrofitting with other systems instead like hydrogen and/or battery depending on what becomes the norm once diesel is phased out

both cars out feed the same electrical system to drive the same motors in the bogies

design could be made for a high top speed so could also be used for passenger use similar to the class 68

I like the idea in principle but for freight I'd go for a permanently coupled pair of short single cab Bo-Bos instead for even more powered axles and (thus) tractive effort. I'd also incorporate a reasonably sized battery from the start to allow as much urban mileage as possible to be local emissions-free, regardless of electrification status (while wiring and its enabling works catches up). Any semblance to a coupled pair of class 20s is purely coincidental! Here's my favourite double electric loco, the Swiss BLS Ae 8/8: https://www.bls.ch/en/unternehmen/ueber-uns/flotte/flotte-ae485-ae88-lokomotive

 

[apk55]

I would have thought the problem with a Bo-Bo-Bo design would be weight distribution. With a locomotive you want the weight on all axles to be the same. In order to do this on a Bo-Bo-Bo design you would need all the heavy items such as the diesel engine and transformer near the outer ends to avoid putting too much weight on the center bogie. However as the cabs are located there there is a problem.
Therefore I agree with the suggestion of a Bo-Bo+Bo-Bo design. Thoughts would be one half having a transformer and the other half having a large diesel engine, effectively a modified class 68 permanently coupled to a modified class 88- the center cabs and drawgear removed.

 

[gazthomas]

Why bother. Back in the day freight used to happily switch between diesel and electric

 

[MarkyT]

I would have thought the problem with a Bo-Bo-Bo design would be weight distribution. With a locomotive you want the weight on all axles to be the same. In order to do this on a Bo-Bo-Bo design you would need all the heavy items such as the diesel engine and transformer near the outer ends to avoid putting too much weight on the center bogie. However as the cabs are located there there is a problem.
Therefore I agree with the suggestion of a Bo-Bo+Bo-Bo design. Thoughts would be one half having a transformer and the other half having a large diesel engine, effectively a modified class 68 permanently coupled to a modified class 88- the center cabs and drawgear removed.

My thoughts exactly. I think 68 and 88 can multiple already, but I don't believe there's any way for them to share power, although that in itself could be a useful modification to allow a conventional double cab 68 in a combo to shut down its engine and power its traction motors from the coupled 88s pantograph.

 

[MarkyT]

Why bother. Back in the day freight used to happily switch between diesel and electric

These various freight bi-mode/hybrid ideas would allow the same to happen without extra stops being introduced for a traction change.

 

[43096]

These various freight bi-mode/hybrid ideas would allow the same to happen without extra stops being introduced for a traction change.

But involves carting around an unused loco on each part of the journey, which requires extra fuel (cost) and extra locos (cost).

 

[apk55]

My suggestion of a bi mode Bo-Bo+Bo-Bo locomotive would have all axles powered all of the time with a power link between the electric and diesel sides. Therefore the starting tractive effort in all modes would be over 600Kn, enough to shift either a massive load or start and accelerate a lighter load quickly from stationary. The latter could be important if paths are required through congested areas

 

[MarkyT]

My suggestion of a bi mode Bo-Bo+Bo-Bo locomotive would have all axles powered all of the time with a power link between the electric and diesel sides. Therefore the starting tractive effort in all modes would be over 600Kn, enough to shift either a massive load or start and accelerate a lighter load quickly from stationary. The latter could be important if paths are required through congested areas

Exactly, and without inner cabs the whole unit could be a bit shorter than two conventional double cab locos coupled.

 

[Dr Hoo]

Why bother. Back in the day freight used to happily switch between diesel and electric

Yeah. The Woodhead scheme was such a massive success, wasn't it?

 

[MarkyT]

Yeah. The Woodhead scheme was such a massive success, wasn't it?

That was really a 'steam age' scheme when there were loads of depots, yards and staff all over the network to allow such traction changes. Rundown of its predominant remaining traffic killed it in the end though.

 

[gazthomas]

Yeah. The Woodhead scheme was such a massive success, wasn't it?

That was more the sign of the times along with absolute technology. Sorry!

I'd give this idea up as a bad job. Our efforts should really be focussed on more electrification rather than unique schemes like this or using Hydrogen

 

[AndrewE]

Yeah. The Woodhead scheme was such a massive success, wasn't it?

Yes it was. Regenerative braking, worked reliably, unfortunately rendered unnecessary by the loss of its bread-and-better traffic.

 

[43096]

I'd give this idea up as a bad job. Our efforts should really be focussed on more electrification rather than unique schemes like this or using Hydrogen

Which is the right answer.

 

[GRALISTAIR]

Our efforts should really be focussed on more electrification rather than unique schemes like this or using Hydrogen

Which is the right answer.

Bionic duckweed anyone?

 

[gazthomas]

Bionic duckweed anyone?

Still a bit low density, but if we can convert into flying pellets that might help

 

[GRALISTAIR]

In all seriousness, if the diesel engine in this suggested Class 94 design could run on biodiesel, that would surely help the overall Carbon targets too?

 

[AndrewE]

In all seriousness, if the diesel engine in this suggested Class 94 design could run on biodiesel, that would surely help the overall Carbon targets too?

Not if it is wasting diesel fuel (of any kind) dragging a dead electric loco round, and the electricity supplied through the wires is being wasted dragging a dead diesel. All to save paying a shunter (and just maybe a second driver for a short overlap period) because of our obsession with de-manning.

 

[popeter45]

Not if it is wasting diesel fuel (of any kind) dragging a dead electric loco round, and the electricity supplied through the wires is being wasted dragging a dead diesel. All to save paying a shunter (and just maybe a second driver for a short overlap period) because of our obsession with de-manning.

this idea isnt dragging a dead loco around, sharing power makes it just a large Bi-Mode loco that can change power source at any point so can make far better use of partial electrification along a route

 

[GRALISTAIR]

Not if it is wasting diesel fuel (of any kind) dragging a dead electric loco round, and the electricity supplied through the wires is being wasted dragging a dead diesel. All to save paying a shunter (and just maybe a second driver for a short overlap period) because of our obsession with de-manning.

look I totally get where you are coming from. I am a total electrification enthusiast. I vividly remember in the 70s and 80s an electric loco would be detached at Preston from a Euston to Blackpool and then a 47 attached. Similar arrangements for freight though I can’t offhand think of an example.

However, whether we like it or not TOCs and FOCs and the DfT decide and we just have to go with what is palatable to them. If and it is a big if in my opinion, we are serious about reducing carbon, every approach needs at least considering.

 

[AndrewE]

look I totally get where you are coming from. I am a total electrification enthusiast. I vividly remember in the 70s and 80s an electric loco would be detached at Preston from a Euston to Blackpool and then a 47 attached. Similar arrangements for freight though I can’t offhand think of an example.
However, whether we like it or not TOCs and FOCs and the DfT decide and we just have to go with what is palatable to them. If and it is a big if in my opinion, we are serious about reducing carbon, every approach needs at least considering.

...so let's do what we did in the 70s and 80s: ban diesel under the wires. In fairness, it was taken a bit too far then: I remember programming (diagramming again now) diesel locos and men on trains that got a new electric loco at New St and had it taken off again at Wolverhampton!
Why should we allow the TOCs' and FOCs' commercial interests to over-ride the national imperative to cut the use of fossil fuels? Energy efficiency means not wasting it. The only "cost" is the extra person-hours needed when changing locos / traction. Quite often that coincides with a change of crew and direction anyway, so it's not much of an additional cost.

 

[Furrball]

Have something like a 68 and 88 able to share power like a slug locomotive in the states?

https://en.m.wikipedia.org/wiki/Slug_(railroad)

 

[GRALISTAIR]

...so let's do what we did in the 70s and 80s: ban diesel under the wires. In fairness, it was taken a bit too far then: I remember programming (diagramming again now) diesel locos and men on trains that got a new electric loco at New St and had it taken off again at Wolverhampton!
Why should we allow the TOCs' and FOCs' commercial interests to over-ride the national imperative to cut the use of fossil fuels? Energy efficiency means not wasting it. The only "cost" is the extra person-hours needed when changing locos / traction. Quite often that coincides with a change of crew and direction anyway, so it's not much of an additional cost.

Not sure how it would work but I personally would NOT BAN diesel under the wires. But there would be a bloody huge tax or incentive not to - something on those lines. I would allow say 10% max diesel under wires. So if my memory serves Euston - Preston is 209 and Preston -Blackpool is 17 - so 226 total 7.5% - Ok I know that is now all electrified but that would not work so perhaps the cutoff should be 5%.

No/very little diesel under the wires would be a quick win IMHO.

 

[AndrewE]

Not sure how it would work but I personally would NOT BAN diesel under the wires. But there would be a bloody huge tax or incentive not to - something on those lines. I would allow say 10% max diesel under wires. So if my memory serves Euston - Preston is 209 and Preston -Blackpool is 17 - so 226 total 7.5% - Ok I know that is now all electrified but that would not work so perhaps the cutoff should be 5%.
No/very little diesel under the wires would be a quick win IMHO.

I agree - I did say I thought it probably went too far in the initial enthusiasm to use the shiny new electrics. Also we still have lines where bimodes of some sort are needed but not yet available. Please get them de-bugged!

 

[GRALISTAIR]

I agree - I did say I thought it probably went too far in the initial enthusiasm to use the shiny new electrics. Also we still have lines where bimodes of some sort are needed but not yet available. Please get them de-bugged!

Agreed. MML is classic. Yes introduce the bimodes and progressively electrify to Sheffield and then the connectors. Doncaster 1st obviously then Leeds then York. When all electrics (EMUs I assume) are ordered AND DELIVERED and drivers trained, then cascade the bimodes elsewhere and then rinse and repeat. But if no EMU but loco and hauled stock then the proposed Class 94 by the OP.

 

[MarkyT]

Agreed. MML is classic. Yes introduce the bimodes and progressively electrify to Sheffield and then the connectors. Doncaster 1st obviously then Leeds then York. When all electrics (EMUs I assume) are ordered AND DELIVERED and drivers trained, then cascade the bimodes elsewhere and then rinse and repeat. But if no EMU but locoa and hauled stock then the proposed Class 94 by the OP.

Or convert the bi-modes to electric-only, ideally with some traction battery storage incorporated in the compartments formerly occupied by the diesels and fuel tanks. This would give the capability to make it to the next station in the event of power outages, whether planned or not, and allow some limited very difficult or expensive areas to remain unwired where that is expedient. With a widespread programme of mainline wiring, it could prove difficult to find suitable alternative route networks to redeploy significant intercity bi-mode fleets on, and the UK Hitachi products are specifically designed with modular diesel generator rafts that can be swapped for maintenance easily. Therefore the diesels and tanks could be removed permanently as well, say at a mid-life major overhaul.

 

[GRALISTAIR]

Or convert the bi-modes to electric-only, ideally with some traction battery storage incorporated in the compartments formerly occupied by the diesels and fuel tanks.

This sounds like a lower cost option and hence one the DafT would go for.

 

[43096]

...so let's do what we did in the 70s and 80s: ban diesel under the wires. In fairness, it was taken a bit too far then: I remember programming (diagramming again now) diesel locos and men on trains that got a new electric loco at New St and had it taken off again at Wolverhampton!
Why should we allow the TOCs' and FOCs' commercial interests to over-ride the national imperative to cut the use of fossil fuels? Energy efficiency means not wasting it. The only "cost" is the extra person-hours needed when changing locos / traction. Quite often that coincides with a change of crew and direction anyway, so it's not much of an additional cost.

It might be a better idea to start with de-carbonising road transport than worrying about diesels under the wires on the railway - the contribution of rail freight to the problem is negligible. To do otherwise smacks of “fiddling while Rome burns”.

 

[Domh245]

Or convert the bi-modes to electric-only, ideally with some traction battery storage incorporated in the compartments formerly occupied by the diesels and fuel tanks. This would give the capability to make it to the next station in the event of power outages, whether planned or not, and allow some limited very difficult or expensive areas to remain unwired where that is expedient. With a widespread programme of mainline wiring, it could prove difficult to find suitable alternative route networks to redeploy significant intercity bi-mode fleets on, and the UK Hitachi products are specifically designed with modular diesel generator rafts that can be swapped for maintenance easily. Therefore the diesels and tanks could be removed permanently as well, say at a mid-life major overhaul.

Agree with this - all of the bi-modal units in service (80x and 755s) have been designed so that they can easily have the diesel packs removed. This is especially relevant with MML where the units are particularly bespoke to fit around the needs of the line, no point forcing the (relatively) small fleet of irregular units onto another operator just because they will be delivered with diesel engines underneath them.

 

[popeter45]

so thinking about it with feedback from this thread refined the idea quite a bit
2 classes of short single cab / full-cab with a blunt cab locomotives with a shared design of body shell and sub-systems than can be coupled together to share power

class 94: 25Kv AC OHLE that can supply 6500hp each to the shared drive-train - basicly akin to the class 91
class 75: 5000hp 750v DC Third rail / 4000hp Electro-diesel - basicly a beefed up class 73

could each be used on there own to replace like for like other locomotives but as a singled shared fleet to reduce maintenance costs
could be used in same class pairs for high power jobs or mixed pairs for Bi mode operations