Did class 91s ever operate at 140mph in passenger service?

[43 302]

Mod Note: Posts #1 - #9 originally in this thread.

Did the 91s ever run at 140mph in passenger service? I was under the impression that they didn't, except on test runs, but I just watched this video on YouTube that shows that a section of (what I assume is) the ECML having a 140mph speed limit. Not to add that this was a Class 91 with Mk3s.

 

[Kurolus Rex]

Did the 91s ever run at 140mph in passenger service? I was under the impression that they didn't, except on test runs, but I just watched this video on YouTube that shows that a section of (what I assume is) the ECML having a 140mph speed limit. Not to add that this was a Class 91 with Mk3s.

There were 140mph signs installed at some locations on the ECML which remained for a number of years along with the flashing green aspect.

Drivers were instructed to treat the 140mph speed limits as 125mph and flashing green signals the same as solid greens.

The test trains of course could go up to 140mph but they've never ran at that in regular service due to a lack of in-cab signalling.

 

[trebor79]

There were 140mph signs installed at some locations on the ECML which remained for a number of years along with the flashing green aspect.

Drivers were instructed to treat the 140mph speed limits as 125mph and flashing green signals the same as solid greens.

The test trains of course could go up to 140mph but they've never ran at that in regular service due to a lack of in-cab signalling.

I think the flashing greens still flash, sure I've glimpsed them fairly recently.
AFAIK the killer for 140mph operation was that the flashing green was deemed to be possible as a wrong side failure or a solid green mistaken for flashing in certain circumstances (such as catenary on curves creating a strobe effect).
Mind you, I'm sure I've been on Mk4s (and Mk3's) in the 1990s that were running in excess of 125mph..

 

[59CosG95]

I think the flashing greens still flash, sure I've glimpsed them fairly recently.
AFAIK the killer for 140mph operation was that the flashing green was deemed to be possible as a wrong side failure or a solid green mistaken for flashing in certain circumstances (such as catenary on curves creating a strobe effect).
Mind you, I'm sure I've been on Mk4s (and Mk3's) in the 1990s that were running in excess of 125mph..

Not to mention increased wear & tear on rails, ballast, wheels, OLE & pantographs, and the associated cost hike...

 

[43 302]

I think the flashing greens still flash, sure I've glimpsed them fairly recently.
AFAIK the killer for 140mph operation was that the flashing green was deemed to be possible as a wrong side failure or a solid green mistaken for flashing in certain circumstances (such as catenary on curves creating a strobe effect).
Mind you, I'm sure I've been on Mk4s (and Mk3's) in the 1990s that were running in excess of 125mph..

That's interesting to know. The 800s never seem to go past 124 or 125 mph even for a little bit.

 

[gimmea50anyday]

124mph is 200kph but 125 is 201kph (approx). I suspect 800s are running at 124mph because they think they are running at 200kph....

That’s my theory anyway......

 

[superkev]

124mph is 200kph but 125 is 201kph (approx). I suspect 800s are running at 124mph because they think they are running at 200kph....

That’s my theory anyway......

Probably mentioned before but on the subject of speeds are 800s classed as multiple units permitted higher curving speeds than previous.
K

 

[Strat-tastic]

Did the 91s ever run at 140mph in passenger service? I was under the impression that they didn't, except on test runs, but I just watched this video on YouTube that shows that a section of (what I assume is) the ECML having a 140mph speed limit. Not to add that this was a Class 91 with Mk3s.

What does the speed controller do? Act as a limiter?

 

[DannyMich2018]

Not to mention increased wear & tear on rails, ballast, wheels, OLE & pantographs, and the associated cost hike...

Ideally in the long term the line speed needs to be improved where necessary and possible- as there's a lot of places where even 100mph is not possible, such as the Morpeth curve, through Berwick Upon Tweed. there is very little 100mph+ stretches north of Newcastle, 100 mph over the Newark crossover and max 115mph through Grantham and Peterborough. Certainly north of Peterborough there are very few stations which permit full 125mph passing speeds.

 

[Kurolus Rex]

What does the speed controller do? Act as a limiter?

My understanding is as thus:

-Driver twists a knob which increases or decreases the speed set in 5mph increments. In the 91, an arrow on the outer rim of the speedometer indicates what speed is selected. In the DVT, the speed set has it's own seperate dial and turning the knob changes the position of the needle. This is located to the left of the speedometer.

-For the speed set to function, the driver must apply power in order to feed the system.

-The speed set will then only use as much power as necessary that you have supplied to reach or maintain the set speed.

-The speed set can use the Traction Brake to maintain a speed on a falling gradient or to reduce speed if the train's speed is greater than what the speed set is set to. In practice however drivers use the normal brake when reducing speed as the speed set can only provide a limited amount of braking. Power must be applied for the Traction Brake to work.

-I've heard from other users on this forum that this is no longer used, however i cannot verify this.

Note that i don't work in the industry so take the above with a grain of salt.

If someone more qualified could verify this then that would be very helpful!

 

[Strat-tastic]

Thanks

 

[PudseyBearHST]

My understanding is as thus:

-Driver twists a knob which increases or decreases the speed set in 5mph increments. In the 91, an arrow on the outer rim of the speedometer indicates what speed is selected. In the DVT, the speed set has it's own seperate dial and turning the knob changes the position of the needle. This is located to the left of the speedometer.

-For the speed set to function, the driver must apply power in order to feed the system.

-The speed set will then only use as much power as necessary that you have supplied to reach or maintain the set speed.

-The speed set can use the Traction Brake to maintain a speed on a falling gradient or to reduce speed if the train's speed is greater than what the speed set is set to. In practice however drivers use the normal brake when reducing speed as the speed set can only provide a limited amount of braking. Power must be applied for the Traction Brake to work.

Explanation looks spot on to me. It’s called an Automatic Speed Limiter. It uses the rheostatic (dynamic) braking if necessary for braking.

I've heard from other users on this forum that this is no longer used, however i cannot verify this.

Where’d you get this from? Are you talking about the speed limiter device as a whole or the device used for braking?

 

[class26]

Ideally in the long term the line speed needs to be improved where necessary and possible- as there's a lot of places where even 100mph is not possible, such as the Morpeth curve, through Berwick Upon Tweed. there is very little 100mph+ stretches north of Newcastle, 100 mph over the Newark crossover and max 115mph through Grantham and Peterborough. Certainly north of Peterborough there are very few stations which permit full 125mph passing speeds.

It`s only 100 mph through Grantham

 

[Jamesrob637]

Ideally in the long term the line speed needs to be improved where necessary and possible- as there's a lot of places where even 100mph is not possible, such as the Morpeth curve, through Berwick Upon Tweed. there is very little 100mph+ stretches north of Newcastle, 100 mph over the Newark crossover and max 115mph through Grantham and Peterborough. Certainly north of Peterborough there are very few stations which permit full 125mph passing speeds.

Someone once said there's actually quite a lot of 125 between Berwick and Edinburgh but how much can actually be taken at 125 in a non-tilting train is probably another story.

 

[bengley]

Someone once said there's actually quite a lot of 125 between Berwick and Edinburgh but how much can actually be taken at 125 in a non-tilting train is probably another story.

There are no tilt speeds on the East Coast Main Line, so if the line speed is 125, non-tilting trains can do it.

 

[Kurolus Rex]

Explanation looks spot on to me. It’s called an Automatic Speed Limiter. It uses the rheostatic (dynamic) braking if necessary for braking.



Where’d you get this from? Are you talking about the speed limiter device as a whole or the device used for braking?

I was referring to the speed set. I can't remember exactly where i heard it honestly, on another thread here i believe. I'll link it if i find it.

 

[Kurolus Rex]

Explanation looks spot on to me. It’s called an Automatic Speed Limiter. It uses the rheostatic (dynamic) braking if necessary for braking.



Where’d you get this from? Are you talking about the speed limiter device as a whole or the device used for braking?

Here it is:

89, 90 and 91 all have notchless power controllers. The first detent is minimum TE and then you can put the controller wherever you want. It’s not power per se but tractive effort, fully open is maximum demand. The DVTs also have notchless controller with an initial minimum detent. That’s converted into an 8 bit equivalent and sent down the TDM. The exception is the Mk3 DVTs converted for use with 67 or 68 which do have notches, though when used via TDM the same applies as when notchless.

If you use speed set the. You set the dial at the desired speed and open the controller as desired, the loco’s micro will then use the controller position to dictate the maximum TE to be used in getting to the set speed. Or not if that setting is too low. Equally the micro can use the rheostatic brake on the loco to reduce speed. Though I believe this is no longer the preferred driving method.

I suspect the document reference is a cut and paste error from the equivalent HST document.

90s have ammeters, 91s don’t. Diving technique effectively the same.

The 87s shouldn’t overload when pushing, the demand is controlled based upon the actual current seen in the traction motors (using the highest of the four), more likely poorly setup overloads....which is a tricky job that takes time and patience.

After reading again more carefully however it looks like the OP was referring to using the speed set to reduce speed, rather than its usage in general.

 

[delorean1984]

In response to your question, I have found this website regarding C91 testing

The Mk4 coaches arrive

If you look near the bottom of this page, the author of this website states that there was 140mph running as demonstration run but doesn't say if it was in passenger service.

 

[hexagon789]

Here it is:



After reading again more carefully however it looks like the OP was referring to using the speed set to reduce speed, rather than its usage in general.

Definitely still used to maintain speed, but it has always been against good practice to use the ASL for anything more than the smallest decreases in speed. The drivers instructions for class 90s state that anymore than 20mph and at speeds greater than 100 mph the driver should use the train brake.

The ASL can only use the rheostatic brake to reduce/control speed which is one the reasons I would take it that its use for heavy reductions in speed is not recommended.

 

[hexagon789]

124mph is 200kph but 125 is 201kph (approx). I suspect 800s are running at 124mph because they think they are running at 200kph....

That’s my theory anyway......

Yes, the maximum the speed control on an 80x will do is 200km/h so just over 124mph.

 

[hexagon789]

There were 140mph signs installed at some locations on the ECML which remained for a number of years along with the flashing green aspect.

There was also a section at the emd of that equipped with flashing greens which was signed 135 for curvature, I think at the northern end

 

[Chris NS]

This is what Nick Kingsley thinks stands in the way of 140mph operation, even with in-cab signalling:

Tilting at windmills

Edinburgh can be reached from London in a fastest time of 4 h 22 min today; HS2 reduces this to 3 h 33 min despite the new-build infra...

njak100.blogspot.com

TL;DR:

- It's unlikely 140mph would be accepted with the current number of level crossings.
- Timetabling 140mph services would be difficult on tracks shared by substantially slower services.
- It was unproven (as of 2012) whether in-cab signalling actually delivers benefits on existing railways as opposed to new-build.

 

[hexagon789]

This is what Nick Kingsley thinks stands in the way of 140mph operation, even with in-cab signalling:

Tilting at windmills

Edinburgh can be reached from London in a fastest time of 4 h 22 min today; HS2 reduces this to 3 h 33 min despite the new-build infra...

njak100.blogspot.com

TL;DR:

- It's unlikely 140mph would be accepted with the current number of level crossings.
- Timetabling 140mph services would be difficult on tracks shared by substantially slower services.
- It was unproven (as of 2012) whether in-cab signalling actually delivers benefits on existing railways as opposed to new-build.

It can be done in 3 hours 59 mins without cab-signalling and with two stops

And LNER has aspirations for a 4h-4h05 timing in a few years

 

[delorean1984]

On that website I posted it mentions when they tested the 91/MK4 sets they were able to do KX to Edinburgh in 3.5hrs non stop when they were able to run them at 140mph

 

[LNW-GW Joint]

This is what Nick Kingsley thinks stands in the way of 140mph operation, even with in-cab signalling:

Tilting at windmills

Edinburgh can be reached from London in a fastest time of 4 h 22 min today; HS2 reduces this to 3 h 33 min despite the new-build infra...

njak100.blogspot.com

- It's unlikely 140mph would be accepted with the current number of level crossings.
- Timetabling 140mph services would be difficult on tracks shared by substantially slower services.
- It was unproven (as of 2012) whether in-cab signalling actually delivers benefits on existing railways as opposed to new-build.

All of which still applies today, plus the issue of inadequate OHLE design and (until the current upgrade is completed) power supplies.
The DfT's high-speed investment eggs are now firmly in the HS2 basket, which after Phase 2b will move Edinburgh services to the West Coast route.
NR is struggling with implementing ETCS (a necessary precursor to running faster than 125mph) on the southern ECML and has dropped plans for the GWML.

 

[HowardGWR]

All of which still applies today, plus the issue of inadequate OHLE design and (until the current upgrade is completed) power supplies.
The DfT's high-speed investment eggs are now firmly in the HS2 basket, which after Phase 2b will move Edinburgh services to the West Coast route.
NR is struggling with implementing ETCS (a necessary precursor to running faster than 125mph) on the southern ECML and has dropped plans for the GWML.

My emphasis. You mean of course London to Edinburgh only, unless Peterborough to Edinburgh pax (as an example) will be expected to change onto an HS2 train at York. Perhaps they will?

 

[D365]

My emphasis. You mean of course London to Edinburgh only, unless Peterborough to Edinburgh pax (as an example) will be expected to change onto an HS2 train at York. Perhaps they will?

There is always the possibility of East Coast Trains picking up paths for additional services. However, future service expectations and predictions are nowhere in the realm of the original discussion.

 

[zn1]

I was referring to the speed set. I can't remember exactly where i heard it honestly, on another thread here i believe. I'll link it if i find it.

I was referring to the speed set. I can't remember exactly where i heard it honestly, on another thread here i believe. I'll link it if i find it.

you mean the cruise control dial, ..as fitted to class 89,90,91,92 locomotives and most modern EMU/DMU/DEMUS so the loco or unit doesnt break the line speed limit as set by its driver ?

 

[zn1]

As i recall The WCML/ECML weekly operating notices all had warnings that 140mph testing was taking place...whether it did on the WCML when 89/91 was being type tested i have no idea, but all staff were told

 

[hexagon789]

On that website I posted it mentions when they tested the 91/MK4 sets they were able to do KX to Edinburgh in 3.5hrs non stop when they were able to run them at 140mph

That was a test with a 91+5 Mk4+DVT, it was authorised to run at 140 wherever normal linespeed was 125.

In normal 125mph service, both BR and GNER had services timed at 3h59 with two intermediate stops. Timekeeping was variable as there was no recovery time in one direction and only one minute in the other.