225 powered by 2 x Class 91s

[370001]

Apologies if this has been covered elsewhere.

I was wondering whether an IC225 set has ever been push-pulled by 2 Class 91s (in the same configuration as an IC125) and if so, what was the acceleration like? Could 225s be extended to 11 coaches using 2 91s? I realise this would create a surplus of Mk4s however. Just interested in operability.

I am aware that shortly after the introduction of the 225s, Class 43s (the ones fitted with buffers) were used as a powered DVT for the sets. Also aware of OHLE wave caused by front panto and potential for rear panto not contacting the OHLE.

Looking forward to my second trip of the year on a 225 this afternoon from KGX-DON.

 

[jopsuk]

I think there's been some test runs in recent years using two 91s, as part of the research for the IEP.

As for 11 carriages? I've seen claims that's how long BR proposed making them. Kings Cross would have easily coped, I'd guess some stations might have problems. I'd have thought a longer formation might foul the crossovers at Edinburgh Waverly?

 

[TrainBoy98]

Not really related, but couldn't a 225 with 91 at the front have a 43 (with buffers) permanently attached as part of a set? Surely this would make the train bi-mode saving having them with IEP?

 

[HSTEd]

Not really related, but couldn't a 225 with 91 at the front have a 43 (with buffers) permanently attached as part of a set? Surely this would make the train bi-mode saving having them with IEP?

This happened with Mark 3 rakes prior to the Mark 4s arriving.

Unfortunately I have doubts about the performance of a single HST power car hauling an entire Mark 4+91 set.

And having to fit some sort of static converter rig in the HST's luggage compartment to support the loco style ETS.

 

[Monty]

Not really related, but couldn't a 225 with 91 at the front have a 43 (with buffers) permanently attached as part of a set? Surely this would make the train bi-mode saving having them with IEP?

You could in theory I guess but I see two problems with that. A single class 43 may struggle to pull a 9-Car 225 set with a dead 91 in tow. Secondly where do you find spare Class 43 power cars from? Unless you build new stock (like the IEP) there will be no spare power cars to use in such a venture.

 

[ryan125hst]

Apologies if this has been covered elsewhere.

I was wondering whether an IC225 set has ever been push-pulled by 2 Class 91s (in the same configuration as an IC125) and if so, what was the acceleration like? Could 225s be extended to 11 coaches using 2 91s? I realise this would create a surplus of Mk4s however. Just interested in operability.

I am aware that shortly after the introduction of the 225s, Class 43s (the ones fitted with buffers) were used as a powered DVT for the sets. Also aware of OHLE wave caused by front panto and potential for rear panto not contacting the OHLE.

Looking forward to my second trip of the year on a 225 this afternoon from KGX-DON.

Presumably though, the second Class 91 would replace the DVT? If this was the case, you would need to add a luggage van and guards compartment to one of the Mark 4 passenger coaches, maybe in a way similar to the TGS in a HST.

As for 11 coaches, you would end up with less sets as there are only enough coaches for 30 sets at 9 coaches per set (and I think there are one or two spares), so they would end up with around 24 sets. East Coast currently use 27 per day, so they would need more stock from somewhere.

Out of interest, what formation would you like to see if they were made into 11 coaches?

 

[370001]

Presumably though, the second Class 91 would replace the DVT? If this was the case, you would need to add a luggage van and guards compartment to one of the Mark 4 passenger coaches, maybe in a way similar to the TGS in a HST.

As for 11 coaches, you would end up with less sets as there are only enough coaches for 30 sets at 9 coaches per set (and I think there are one or two spares), so they would end up with around 24 sets. East Coast currently use 27 per day, so they would need more stock from somewhere.

Out of interest, what formation would you like to see if they were made into 11 coaches?

To be honest I was interested more in operability rather than proposing a standard running configuration. I know the sums don't add up and there are physical constraints at some stations. I was simply curious if a set had ever been push-pulled by 2 91s and what the performance was like.

 

[D365]

Weren't the 91s (+225+DVT) designed to be operated in formations of up to 11 cars? If a return was made to the 91 + Mk3/4 + 43 formation, the latter loco wouldn't be able to pull the set on its own - after all, 1+7-9 HST sets aren't possible. Although I would like to own a rake myself

 

[TrainBoy98]

Ah, ok, just a thought

 

[sprinterguy]

Weren't the 91s (+225+DVT) designed to be operated in formations of up to 11 cars?

One of the later (1981) proposals for a production fleet of APTs envisaged a steamlined power car at either end sandwiching eleven passenger carriages, which would have been very similar to an 11-car IC225 with a 91 at each end. During the development of the IC225 project, it was initially (1986) stated that the IC225s would be formed of a class 91 loco, eleven passenger carriages and a DVT, although the length of the formation was cut back by the time that the trains were ordered due to lower passenger forecasts. Eleven carriages was decreed to be the maximum length of train that was possible with a single locomotive due to the propulsive forces that would be enacted on the carriage adjacent to the locomotive when in propelling mode.

If a return was made to the 91 + Mk3/4 + 43 formation, the latter loco wouldn't be able to pull the set on its own - after all, 1+7-9 HST sets aren't possible. Although I would like to own a rake myself

1+7 and 1+8 HST formations can and have operated in extreme circumstances, however their rate of acceleration is obviously markedly slower than a "healthy" HST set and they have difficulty reaching and maintaining 125mph. This might be less of an issue on the sections of route where an HST power car would be expected to haul an IC225 set, as East Coast's off wires sections of route are generally slower than 125mph and no more than 100mph. Also, although admittedly it would probably be unfeasible to implement so late on in the HST power cars' lives, even at the time that the production HSTs were built a 3,000hp power unit was available that would fit into the HST power car bodyshell, although this would increase the axle weight.
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As for 11 coaches, you would end up with less sets as there are only enough coaches for 30 sets at 9 coaches per set (and I think there are one or two spares), so they would end up with around 24 sets. East Coast currently use 27 per day, so they would need more stock from somewhere.

GNER had a proposal to lengthen the 225 sets to ten carriages by adding an additional mark 4 carriage into 27 rakes, split from three existing sets. Three modified mark 3 sets would have been formed up to replace the disbanded mark 4 rakes.

 

[Bridge189]

I'm sure its been mentioned that MK4s are nearly double the weight of MK3s so any proposal that an HST power car could push/pull a dead 91+ 9 MK4s up un wired sections is laughable. They can hardly manage push/pulling a one engine out EC HST with 9 coaches.

 

[HSTEd]

I'm sure its been mentioned that MK4s are nearly double the weight of MK3s so any proposal that an HST power car could push/pull a dead 91+ 9 MK4s up un wired sections is laughable. They can hardly manage push/pulling a one engine out EC HST with 9 coaches.

What?
Mark 3s come in at 35-40t each and Mark 4s come in at 40-45t... hardly double.

 

[asylumxl]

I'm sure its been mentioned that MK4s are nearly double the weight of MK3s so any proposal that an HST power car could push/pull a dead 91+ 9 MK4s up un wired sections is laughable. They can hardly manage push/pulling a one engine out EC HST with 9 coaches.

The weight is not much different. The track access charges on the other hand are almost double for a MK4.

 

[Bridge189]

The weight is not much different. The track access charges on the other hand are almost double for a MK4.

I knew something was almost double!

Even the 10t weight difference and a dead 91 will still cause a single HST power car to struggle push/pulling them along. It's a total non starter idea, NR would have a fit.

 

[sprinterguy]

Even the 10t weight difference and a dead 91 will still cause a single HST power car to struggle push/pulling them along. It's a total non starter idea, NR would have a fit.

Absolutely, I never suggested that a single HST power car in it's present form would be capable of hauling an entire IC225 formation over, say, the formidable gradients of the Highland Main line. You are undoubtedly correct that the idea is a non-starter.

 

[Bevan Price]

Would the "overhead" be capable of providing enough current for two 91's, especially if more than one train was in the area ?

 

[DaveNewcastle]

Absolutely, I never suggested that a single HST power car in it's present form would be capable of hauling an entire IC225 formation over, say, the formidable gradients of the Highland Main line. You are undoubtedly correct that the idea is a non-starter.

I travelled on the southbound Chieftan with a failing power car. It started cutting out early on the journey on the climb up to Slochd. I seem to recall arriving into Edinburgh a few minutes late, but most of that delay was accounted for by a delay at Carrbridge.

I'm sure its been mentioned that MK4s are nearly double the weight of MK3s so any proposal that an HST power car could push/pull a dead 91+ 9 MK4s up un wired sections is laughable. They can hardly manage push/pulling a one engine out EC HST with 9 coaches.

See my remark above. I've travelled on other HST sets in service between Kings Cross and the North East with just one power car, and the loss of timetabled arrivals was more a consequence of failure to achieve 125mph than the more modest, though noticeable lower acceleration. Disregarding the error in asserting 'nearly double the weight', I've seen a northbound 225 set, in service, hauled by a 91 with another 91 DIT coupled immediately behind it - I cannot comment on its timetabling.

 

[O L Leigh]

There is no need to add another Cl91 to the IC225 formation. The single loco is man enough to handle the weight of the set and the timetable of the ECML. They are configured to work in a certain way and adding the additional power would not add anything.

O L Leigh

 

[ffm]

Erm, what about the loss of trains this would cause? There are only 31 91s and always a couple in maintenance. So only 14 trains, or so. Whether it could be done, or not, is therefore completely immaterial.

 

[D365]

2x 91 haulage is not needed. They were designed to haul up to 11 Mk4s, and more? There was a proposal by GNER a while back to split up a few rakes, give the stricken 91s and DVTs some Mk3s and lengthen the rest of the IC225s to 10 or 11 cars. Would put a lot more work on the locos though; perhaps 11 car IEP would be better if longer trains are an aspiration.

 

[matchmaker]

Absolutely, I never suggested that a single HST power car in it's present form would be capable of hauling an entire IC225 formation over, say, the formidable gradients of the Highland Main line. You are undoubtedly correct that the idea is a non-starter.

An HST with a failed power car is not allowed north of Blair Atholl without assistance.

 

[ryan125hst]

An HST with a failed power car is not allowed north of Blair Atholl without assistance.

What are the reasons for this? Is it because of steep gradients, so by having assistance prevents damage to the track or delays to other services?

 

[sprinterguy]

What are the reasons for this? Is it because of steep gradients, so by having assistance prevents damage to the track or delays to other services?

As far as I know it is due to the gradients; I thought that I could recall such a ruling, but wasn't entirely sure, so thanks to matchmaker for confirming it. I think that I remember reading that a class 37 has been turned out on at least one occasion to provide the necessary assistance, which in terms of power output seems to rather defy the point (Assuming that the entire HST formation would be being hauled "dead" as would be usual when an HST is being hauled).

 

[GNER 91128]

I could imagine there being greater acceleration and breaking from having two 91s working together. Wouldn't the 225 be classed as an EMU if there were two 91s opperating together?

 

[ryan125hst]

I could imagine there being greater acceleration and breaking from having two 91s working together. Wouldn't the 225 be classed as an EMU if there were two 91s opperating together?

I doubt it. It is still two locomotives pulling/pushing a rake of passenger coaches. If Chiltern removed the DVT and added a second Class 67, could that be considered a multiple unit?

I think I understand why you think that though. Eurostars are EMU's, but are almost two locomotives hauling articulated coaches (although the coaches next to the locomotive do have motors, but at the end nearest to the power car only).

 

[Yew]

I doubt it. It is still two locomotives pulling/pushing a rake of passenger coaches. If Chiltern removed the DVT and added a second Class 67, could that be considered a multiple unit?

I think I understand why you think that though. Eurostars are EMU's, but are almost two locomotives hauling articulated coaches (although the coaches next to the locomotive do have motors, but at the end nearest to the power car only).

HST's where originally classed as DMU's

 

[D365]

It's somewhat of a difficult matter to judge? I imagine the situation with a 91+Mk4+91 formation would be quite similar to that with HSTs when they were introduced.

 

[ryan125hst]

HST's where originally classed as DMU's

That's true. Wasn't it the fact that the locomotives, and possibly even the coaches, were often moved between sets, so the set numbers on the front were wrong, that caused them to be classed as locomotives and coaches?

With that, you do wonder where the line between loco + coaches and EMU or DMU lies. A multiple unit normally has traction equipment or engines, air compressors, motor alternators ect, distributed throughout the train. A HST has none of that, as the engine, motors, air compressor ect are all in the Class 43.

 

[jopsuk]

I could imagine there being greater acceleration and breaking from having two 91s working together. Wouldn't the 225 be classed as an EMU if there were two 91s opperating together?

I'll go with "no"- the Edinburgh - Glasgow shuttle, before the 47/7s and DBSOs, was operated by top-and-tail, working in multiple, class 27s. This was not counted as an MU formation.

 

[GNER 91128]

I'll go with "no"- the Edinburgh - Glasgow shuttle, before the 47/7s and DBSOs, was operated by top-and-tail, working in multiple, class 27s. This was not counted as an MU formation.

Ah right okies.