Future of Class 91s after introduction of SETs?

[ainsworth74]

Why is this - last one built?

Yup last built though no longer the last in the TOPS numbers for the class as there is a 91132 which was originally 91023 but gained a different number (rather than just having 100 added as the rest) after refurbishment due to it being involved in both Great Heck and Hatfield accidents.

On the compatibility:
Mark 4s have been run with Class 89 and 90. Presumably they could also therefore work with 86 and 87?

As far as I'm aware Mark 4s could be hauled by any locomotive on the network (electric or diesel) as long as there is a TSOE vehicle (that's the vehicle that is next to the 91 in a IC225 formation) or a DVT (with pointy end facing outwards) in the formation. Of course only locomotives equipped with TDM could talk to the DVT for use in push/pull operations (or AAR locomotives if you converted the Mark 4s).

 

[Top Shed]

I don't know about acceleration combined with an HST power car they set off like a porsche! Possibility for an electric diesel hybrid set yet again to the right destinations?

No matter how many miles and how obsolete some of the electronics have become I am sure they will find further use.

Indeed I once thought I was funny at Doncaster when a member of GNER staff was removing a dead bird or something from a 91 pantograph (lowered) with a pole when I said "It wouldn't have happened to a deltic"! When he retorted "No you are right there we would be taking it off and it would be going over there to have a main generator or engine rebuilt because it would be unable to carry on". With that I shut the f@£$ up when he lifted the rear pantograph and off it went to the smoke without further delay!
And yes I got my coat after being "Old Man ed" yet again.

 

[Philip Phlopp]

I don't know about acceleration combined with an HST power car they set off like a porsche! Possibility for an electric diesel hybrid set yet again to the right destinations?

No matter how many miles and how obsolete some of the electronics have become I am sure they will find further use.

Indeed I once thought I was funny at Doncaster when a member of GNER staff was removing a dead bird or something from a 91 pantograph (lowered) with a pole when I said "It wouldn't have happened to a deltic"! When he retorted "No you are right there we would be taking it off and it would be going over there to have a main generator or engine rebuilt because it would be unable to carry on". With that I shut the f@£$ up when he lifted the rear pantograph and off it went to the smoke without further delay!
And yes I got my coat after being "Old Man ed" yet again.

The enthusiast stuff doing the rounds at the moment is a Class 68 at one end, 9 Mark 4 coaches in the middle and a Class 88 or Class 91 at the other end to make some sort of hybrid set, with the little diesel in the Class 68 providing a little extra push when away from electrified routes.

The problem with all that is speed, acceleration and pathing. Nobody is going to run a diesel and an electric at the same time under the wires, defeats the whole purpose of electrification, and away from the wires, acceleration will be slow compared with most DMU types, causing pathing issues.

 

[Top Shed]

Reduce the mk4s to seven And I would imagine the combo of 91 and 68 would be a useful one out on the network somewhere. Indeed that would give more capacity at rush hour between Newcastle and Liverpool stopping at major stations only.

Obviously there is more to it than that with pathing etc.
The 89 with eight mk3s and a HST power car was acceleration I have never witnessed before or since.

 

[E&W Lucas]

Why is this - last one built?

Out of curiosity, can a 91 pull coaching stock without anything on the rear end?

Yes. However, if you want speeds above 110, the rearmost vehicle also has to be fitted with an operating brake control unit.
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The enthusiast stuff doing the rounds at the moment is a Class 68 at one end, 9 Mark 4 coaches in the middle and a Class 88 or Class 91 at the other end to make some sort of hybrid set, with the little diesel in the Class 68 providing a little extra push when away from electrified routes.

There's about as much chance of that happening, as a Mk IV set running about with Locomotion on one end, and The Rocket at the other.

 

[IanXC]

Reduce the mk4s to seven And I would imagine the combo of 91 and 68 would be a useful one out on the network somewhere.

Erm...

The enthusiast stuff doing the rounds at the moment is a Class 68 at one end, 9 Mark 4 coaches in the middle and a Class 88 or Class 91 at the other end to make some sort of hybrid set, with the little diesel in the Class 68 providing a little extra push when away from electrified routes.

The problem with all that is speed, acceleration and pathing. Nobody is going to run a diesel and an electric at the same time under the wires, defeats the whole purpose of electrification, and away from the wires, acceleration will be slow compared with most DMU types, causing pathing issues.

Surely if such a service were found, and you wanted a bimode locohauled Mark 4 solution the answer is clearly to use class 88s?

 

[61653 HTAFC]

Erm...



Surely if such a service were found, and you wanted a bimode locohauled Mark 4 solution the answer is clearly to use class 88s?

The diesel engine in 88s is small, not very powerful, and won't have much of a fuel tank. They're not really a bi-mode solution in the way that the SETs are. They'd be capable of limping into Kings Cross in the event of a power outage at Finsbury Park but not of getting the Chieftain to Inverness.

 

[Philip Phlopp]

Yes. However, if you want speeds above 110, the rearmost vehicle also has to be fitted with an operating brake control unit.
--- old post above --- --- new post below ---


There's about as much chance of that happening, as a Mk IV set running about with Locomotion on one end, and The Rocket at the other.

The running costs and track access charges for such a combination would be astronomical and when taking leasing charges into account, it's almost certainly going to be cheaper to buy a new unit with low track access charges, that doesn't have to carry around two bloody heavy locomotives.

The IEP bi-mode units are incredibly light for all that they can do.

 

[IanXC]

The diesel engine in 88s is small, not very powerful, and won't have much of a fuel tank. They're not really a bi-mode solution in the way that the SETs are. They'd be capable of limping into Kings Cross in the event of a power outage at Finsbury Park but not of getting the Chieftain to Inverness.

:$ feeling a bit out of date! The Vosshoh Euro Dual specification gives a diesel output the same as a 68, however seems to be rather lower in UK spec.

 

[Philip Phlopp]

:$ feeling a bit out of date! The Vosshoh Euro Dual specification gives a diesel output the same as a 68, however seems to be rather lower in UK spec.

CAT C27 @ 710kW/900hp. It's much the same output as the single MTU emergency engine which will feature on the electric IEP sets, good for a little shunting type work, low speed movements up a freight only branch, movements around docks, that sort of thing.

The engine's 2.3 tonnes, plus alternator, cooler group, fuel, lube and coolant, it'll come in around 4 tonnes. The locomotive would probably need ballasted out in any case, so doing it with a small engine is an intelligent way of doing it.

 

[SpacePhoenix]

It must have been a site seeing two fully functioning class 91s on a 225 set! Shame there doesn't appear to be any videos of it Only video I found when googling with 2 class 91s on a train was either 2 on a light engine move or where one is being towed dead

 

[ainsworth74]

I believe the testing was overnight unfortunately so it's unlikely that there are any videos in existence.

 

[D365]

I believe the testing was overnight unfortunately so it's unlikely that there are any videos in existence.

The same words were spoken of the fabled '378 to Moorgate' test run

 

[sprinterguy]

The same words were spoken of the fabled '378 to Moorgate' test run

Although there were at least actual paths posted for the class 91 trials:
http://www.railforums.co.uk/showthread.php?t=54940

 

[ainsworth74]

Although there were at least actual paths posted for the class 91 trials:
http://www.railforums.co.uk/showthread.php?t=54940

Crickey was it as long ago as 2011?! I wasn't even a moderator back then and some of the members in that thread I haven't seen a very long time...

 

[sprinterguy]

Crickey was it as long ago as 2011?! I wasn't even a moderator back then and some of the members in that thread I haven't seen a very long time...

I know; that surprised me, too. hock:

 

[Philip Phlopp]

Crickey was it as long ago as 2011?! I wasn't even a moderator back then and some of the members in that thread I haven't seen a very long time...

It was for the development work leading to the UK Series 1 OLE, to understand very approximately what sort of requirements 2 x 5 car IEP units would place on overhead lines at 125mph.