Class 90 top speed

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HSTEd

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A class 90 is ordinarily rated for 110mph, but since now have access to far superior speedometers and the like for measuring train speed, would it be possible to make use of some of the overspeed factor that is required for all trains in testing to improve the speed of the train operationally?

Although I would ideally like a 125mph Class 90, I imagine that even uprating to just 115mph or 120mph would be extremely useful, especially with the number lying around available, and the number in freight service that can be displaced by available Class 92s.
 
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sprinterguy

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I can't think of anywhere where more than 110mph would be useful for a class 90 unless East Coast could source a handful of mark 3 rakes and DVTs to replace their HSTs on those diagrams that are completely under the wires, but that idea was already dropped about four years ago by NXEC.
 

HSTEd

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I can't think of anywhere where more than 110mph would be useful for a class 90 unless East Coast could source a handful of mark 3 rakes and DVTs to replace their HSTs on those diagrams that are completely under the wires, but that idea was already dropped about four years ago by NXEC.
Bargain Basement Midland Main Line electric rolling stock, since they are committing to be mostly 125mph by the time it is done right?

The rolling stock would be ex-HST Mark 3 trailers.
 

sprinterguy

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Bargain Basement Midland Main Line electric rolling stock, since they are committing to be mostly 125mph by the time it is done right?

The rolling stock would be ex-HST Mark 3 trailers.
So you would support a hugely expensive complete strip-out and rewire of rolling stock that would only have ten years of life left in it at a stretch? Not to mention the expensive internal and external refurbishment requirement to make the carriages DDA compliant; fitting power doors, altering the vestibules, accomodating DDA compliant toilets and also treating corrosion as it appears. And this on top of regearing the 90s for a higher speed? A number of class 90s have also been out of service for a considerable amount of time, so no doubt an extensive overhaul would be required, and similar can be expected of the DVTs that have been out of use and in store at Long Marston for a considerable period of time.

I thought that something like this would go completely against the grain of your stringent policy of "extending the life of mark 3s and Sprinters past 2020 for a few more years of life is not worth it"?
 

HSTEd

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So you would support a hugely expensive complete strip-out and rewire of rolling stock that would only have ten years of life left in it at a stretch? Not to mention the expensive internal and external refurbishment requirement to make the carriages DDA compliant; fitting power doors, altering the vestibules, accomodating DDA compliant toilets and also treating corrosion as it appears. And this on top of regearing the 90s for a higher speed? A number of class 90s have also been out of service for a considerable amount of time, so no doubt an extensive overhaul would be required, and similar can be expected of the DVTs that have been out of use and in store at Long Marston for a considerable period of time.

I thought that something like this would go completely against the grain of your stringent policy of "extending the life of mark 3s and Sprinters past 2020 for a few more years of life is not worth it"?
I sort of forgot that it wont be done for another decade. :|
 

sprinterguy

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I sort of forgot that it wont be done for another decade. :|
Alas that it takes so long to get things done in the world of railways! It's sometimes difficult to envisage the sorts of timescales involved. But at least the Midland Mainline is expected to be electrified before the end of the decade. It is amazing what can be done if the Government puts it's mind to the task.
 

Yew

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I suppose if It was decided to Keep the HST coaching rakes, It could be possible That 90's. XCould the 91/HST combos from the ECML be tried on the MML with 90's if the Electric trains arent ready, but the wires are?
 

sprinterguy

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I suppose if It was decided to Keep the HST coaching rakes, It could be possible That 90's. XCould the 91/HST combos from the ECML be tried on the MML with 90's if the Electric trains arent ready, but the wires are?
What 91/HST combos?

If you are referring to the short term class 91 + Mark 3 formations that operated briefly in the late eighties, these were only possible because the buffer fitted HST power cars converted for use as surrogate DVTs were fitted with TDM to allow them to work in multiple with the class 91s, which AFAIK has since been removed from the small number of power cars that ever had it.

Plus, that would largely demolish the benefits of electrification in terms of emissions, as the HST power cars would have to be kept running to provide train supply power, and keeping them running on idle while being hauled/propelled risked damage to the traction motors so they also provided traction power for the most part of this short period of operation.
 

Manchester77

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Could I just ask a quick question.
Why, in the late 80s, did they use surrogate HSTs as stand in DVTs. How come they didn't use the mark 3 DVTs?
Thanks:)
 

Bald Rick

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The 91 / HST combos were originally intended to have the HST running purely for hotel power for the MkIIIs. However it proved too difficult to have the HST cab control systems NOT control the Valenta in the HST, so the T&RS engineers simply connected up the two control systems and volia - 8,000hp+
 

Bald Rick

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Could I just ask a quick question.
Why, in the late 80s, did they use surrogate HSTs as stand in DVTs. How come they didn't use the mark 3 DVTs?
Thanks:)
MkIII DVTs weren't available in any quantity, and worked with different TDM control system. And the HSTs weren't surrogate. If anything the Cl91 was a surrogate powercar.
 

HSTEd

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Could I just ask a quick question.
Why, in the late 80s, did they use surrogate HSTs as stand in DVTs. How come they didn't use the mark 3 DVTs?
Thanks:)
There were no Mark 3 DVTs spare and even if there had been, they would have been unable to operate on the 125mph timetable.

And there were no Mark 4s at the time, so they were using HST trailer Mark 3s with no motor-alternator sets fitted.
 

John55

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The 91 / HST combos were originally intended to have the HST running purely for hotel power for the MkIIIs. However it proved too difficult to have the HST cab control systems NOT control the Valenta in the HST, so the T&RS engineers simply connected up the two control systems and volia - 8,000hp+
My memory was that leaving the diesel idling to produce ETH only lead to exhaust fires in the HST power cars so the easiest solution was to let the engines run normally and blow out the excess fuel causing the fires.
 

Peter Mugridge

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There were no Mark 3 DVTs spare and even if there had been, they would have been unable to operate on the 125mph timetable.
They could have done had they been available - the data panels on all the West Coast Mk 3 stock read "125 mph" even though they were only use up to 110mph; I asked VT about this a few years ago and the answer was that they were indeed maintained to the 125mph standard in order to give a smoother ride and greater reliability.
 

David

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The 91 / HST combos were originally intended to have the HST running purely for hotel power for the MkIIIs. However it proved too difficult to have the HST cab control systems NOT control the Valenta in the HST, so the T&RS engineers simply connected up the two control systems and volia - 8,000hp+
Best thing about those formations was that they went like the proverbial of a shovel! :shock: :lol:
 

Royston Vasey

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They could have done had they been available - the data panels on all the West Coast Mk 3 stock read "125 mph" even though they were only use up to 110mph; I asked VT about this a few years ago and the answer was that they were indeed maintained to the 125mph standard in order to give a smoother ride and greater reliability.
Indeed. They are fitted with T4 high speed bogies which were tested up to 145 mph and were considered for the Mk 4s.
 

colchesterken

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Someone from GA was interviewed on local tellie last night, nothing in the new plan for GEML this bloke said the ultimate aim would be for 110 running on Norwich run

we have 125 coaches and 110 locos which could be pushed to 115

If the problem is signal spacing how about a quick rewire to show 2 greens which would show a clear run for max speed
 

TGV

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The 91 / HST combos were originally intended to have the HST running purely for hotel power for the MkIIIs. However it proved too difficult to have the HST cab control systems NOT control the Valenta in the HST, so the T&RS engineers simply connected up the two control systems and volia - 8,000hp+
All that and still less than half the power of a 373/2 that GNER would get to use about a decade later.
 

The Informer

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If I remember rightly the class 90's were more than capable of 125mph running but it was the unsprung weight on the bogies which would have caused considerable track damage at that speed. I'm sure someone could verify that. It was a long long time ago when I heard it!
 

Bald Rick

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Someone from GA was interviewed on local tellie last night, nothing in the new plan for GEML this bloke said the ultimate aim would be for 110 running on Norwich run

we have 125 coaches and 110 locos which could be pushed to 115

If the problem is signal spacing how about a quick rewire to show 2 greens which would show a clear run for max speed
The problem is the level crossings. And the overhead line. And the power supply. And the track quality. And the formation. Other than that everything is fine ;)
 

Peter Mugridge

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If I remember rightly the class 90's were more than capable of 125mph running but it was the unsprung weight on the bogies which would have caused considerable track damage at that speed. I'm sure someone could verify that. It was a long long time ago when I heard it!
They were originally publicised as 125mph locos when the order to build them was placed; I presume it was this issue which resulted in them becoming 110mph locos when they were actually built?
 

Cherry_Picker

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If the problem is signal spacing how about a quick rewire to show 2 greens which would show a clear run for max speed
They tried that on the East Coast for 140mph running with flashing greens and it didnt last. Unfortunately on the railway (and in life in general) "solving" one problem tends to create five more.
 
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