Could differential speed restrictions be adjusted to enable 185s to use Sprinter speeds?

[Greybeard33]

The Hope Valley itself generally has a pretty good speed profile, so not surprised there's not much to be had there.

Is there any possibility that the differential speed restrictions in the Hope Valley could be adjusted, such that 185s could use what are currently the Sprinter speeds? These are 20mph faster over much of the route, e.g 90 instead of 70.

 

[Killingworth]

Is there any possibility that the differential speed restrictions in the Hope Valley could be adjusted, such that 185s could use what are currently the Sprinter speeds? These are 20mph faster over much of the route, e.g 90 instead of 70.

TPE have been asking that question for years. It's due to their weight. I've yet to hear what exactly needs doing and where to resolve that.

 

[Ianno87]

I presume the actual effect of the lower speeds for 185s is counteracted by their acceleration performance to some extent?

 

[The Planner]

TPE have been asking that question for years. It's due to their weight. I've yet to hear what exactly needs doing and where to resolve that.

Consider that a 158 is RA2, a 185 is RA5. They need a diet.

 

[Greybeard33]

I presume the actual effect of the lower speeds for 185s is counteracted by their acceleration performance to some extent?

Yes in comparison with the EMR 158s, but there have been suggestions that 185s might take over the Nottingham service in future. If they could use the higher speeds in combination with the better acceleration, there would surely be a worthwhile reduction in journey time?

 

[NoMorePacers]

Although I doubt it'd be simple either way it sounds like it'd be easier to remove SP speeds from the routes 185s go over (Hope Valley, Micklefield - Hull and York - Scarborough I think, plus I believe the slow lines from Thirsk to Northallerton) rather than try and get 185s to comply with them.

 

[zwk500]

Given that 185s have been running on routes with SP differentials for a while, there's presumably a very good reason why they haven't been done, which makes it very unlikely anything is going to be done soon.
It's also my understanding that only 1 set of differential speeds are permitted over a line, so if you wanted to put some 185 specific speed improvements you'd need to be careful you don't penalise sprinters.

I think the easiest thing to do would be to change the differentials speeds to MU rather than SP, even if you lose a couple of mins from the SP speeds. However the possibility of TPE Class 68 services would make this option problematic for operational flexibility.

 

[Philip]

Taking the Hope Valley line as an example, would there be a danger of derailment if a 185 driver ignored the SP restriction and got the train up to 90mph? Or is the restriction there to reduce track wear from the heavier units?

 

[jonnyfan]

I think the easiest thing to do would be to change the differentials speeds to MU rather than SP, even if you lose a couple of mins from the SP speeds. However the possibility of TPE Class 68 services would make this option problematic for operational flexibility.

As part of the Hope Valley upgrade I understand the SP differentials are being changed to MU ones. However 185s are not permitted to use MU speed differentials either so it doesn't help them.

 

[Killingworth]

As part of the Hope Valley upgrade I understand the SP differentials are being changed to MU ones. However 185s are not permitted to use MU speed differentials either so it doesn't help them.

So back to #2, what needs doing and where to allow 185s to use MU speed limits on the Hope Valley line - and any others where it would apply?

The long, deep, wet, Victorian tunnels must be one problem

 

[zwk500]

As part of the Hope Valley upgrade I understand the SP differentials are being changed to MU ones. However 185s are not permitted to use MU speed differentials either so it doesn't help them.

Really? Are they too heavy even for MU speeds or is it something different about them?

 

[jonnyfan]

So back to #2, what needs doing and where to allow 185s to use MU speed limits on the Hope Valley line - and any others where it would apply?

The long, deep, wet, Victorian tunnels must be one problem

I will have to pass on that one. But I imagine it's very expensive work!

Really? Are they too heavy even for MU speeds or is it something different about them?

They are very heavy, so cannot use the SP, MU and HST speed differentials anywhere on the network.
Whereas newer, lighter units, such as 195s can use the SP and MU differentials - they are far more 'track friendly'.

 

[TheBigD]

Really? Are they too heavy even for MU speeds or is it something different about them?

For comparison a 158 vehicle weighs around 38 tons, a 170 vehicle around 45 tons, and a 185 vehicle around 55 tons.

 

[Killingworth]

I will have to pass on that one. But I imagine it's very expensive work!


They are very heavy, so cannot use the SP, MU and HST speed differentials anywhere on the network.
Whereas newer, lighter units, such as 195s can use the SP and MU differentials - they are far more 'track friendly'.

Which begs the question, "who specified and procured the 185s, bearing in mind they'd not be able to use their full capabilities on many sections of the routes to which they're allocated?"

Come to that, are there any miles of the South Pennine route where they can use their 100mph potential, or even 90mph?

No wonder the clatter they make coming across junctions is noticeably noisier than other units.

 

[Senex]

Which begs the question, "who specified and procured the 185s, bearing in mind they'd not be able to use their full capabilities on many sections of the routes to which they're allocated?"

That seems to be the really interesting question. Are the only routes they work on where they can exploit their full potential Liverpool-Manchester-Huddersfield-Leeds-York and the sections of the WCML and ECML they use (they can't use SP speeds out to Hull in addition to the limitation on the South Pennine route), and were they specified in fact with only the Trans-Pennine route proper (the northern TP line) in mind? Just out of curiosity, I wonder what speeds they would be allowed on the WCML, the ECML, and the MML south to London.

 

[Peter Mugridge]

Which begs the question, "who specified and procured the 185s, bearing in mind they'd not be able to use their full capabilities on many sections of the routes to which they're allocated?"

This has all the hallmarks of DfT interference...?

 

[Starmill]

Which begs the question, "who specified and procured the 185s, bearing in mind they'd not be able to use their full capabilities on many sections of the routes to which they're allocated?"

Come to that, are there any miles of the South Pennine route where they can use their 100mph potential, or even 90mph?

No wonder the clatter they make coming across junctions is noticeably noisier than other units.

Permissible speed does rise to 90 miles / hour for all trains in two stretches between Sheffield and Swinton (South Yorkshire). They're not very far but there they are.

There may be others.

 

[The Planner]

That seems to be the really interesting question. Are the only routes they work on where they can exploit their full potential Liverpool-Manchester-Huddersfield-Leeds-York and the sections of the WCML and ECML they use (they can't use SP speeds out to Hull in addition to the limitation on the South Pennine route), and were they specified in fact with only the Trans-Pennine route proper (the northern TP line) in mind? Just out of curiosity, I wonder what speeds they would be allowed on the WCML, the ECML, and the MML south to London.

Whatever the prevailing line speed is without differentials.

 

[HSTEd]

Ultimately the 185s are not particularly well specified units for the British rail system.

Sure they are reliable, but they are massively overweight.

 

[mike57]

There are also SP speed differentials between York and Scarborough over a lot of the route and 185s have been in use for some years, and in fact I think a 158 still holds the record for the fastest York Scarborough time. The power to weight differential is not as big as you would think, by my calcs 13.3hp/ton for 185 v 10.3hp/ton for 158. The 'better accelaration' card has been played before but on long sections between stops (York Malton Seamer) I dont see it helping much. I suspect they are just too heavy.

 

[Kieran1990]

The 185s are so heavy due to the engines they have fitted which were chosen specifically for the North TP route between Manchester-Leeds-York.
They have same engines as the Class 180’s I believe

 

[61653 HTAFC]

Basically rather than changing anything on the units, you'd need to massively rebuild the infrastructure to cope with the stresses of the heavy units running at higher speeds.

 

[westcoaster]

Given that 185s have been running on routes with SP differentials for a while, there's presumably a very good reason why they haven't been done, which makes it very unlikely anything is going to be done soon.
It's also my understanding that only 1 set of differential speeds are permitted over a line, so if you wanted to put some 185 specific speed improvements you'd need to be careful you don't penalise sprinters.

I think the easiest thing to do would be to change the differentials speeds to MU rather than SP, even if you lose a couple of mins from the SP speeds. However the possibility of TPE Class 68 services would make this option problematic for operational flexibility.

Not sure that is the case,

We now have a tri speed differential
HST 125
110
EMU 100

in a few places.

 

[Killingworth]

Basically rather than changing anything on the units, you'd need to massively rebuild the infrastructure to cope with the stresses of the heavy units running at higher speeds.

Lots of heavier grade new rail to run a few heavier trains to save a few minutes on routes that are relatively lightly used but are used by other trains that don't need such track. So the 185s full performance will go largely unused for the rest of their lives.

 

[61653 HTAFC]

Lots of heavier grade new rail to run a few heavier trains to save a few minutes on routes that are relatively lightly used but are used by other trains that don't need such track. So the 185s full performance will go largely unused for the rest of their lives.

Indeed- the point I was making being that such drastic expenditure would be difficult to justify.

185s are a bit like Deltics in a sense- built for a specific job and not really the best fit for other use cases.

 

[Philip]

185s could have an engine (or possibly even two) removed from each unit to reduce their weight a lot and possibly enable them to not be as restricted in speed. The engines are powerful enough that even running on two engines permanently should still be enough to retain their good acceleration and 100mph top speed.

 

[edwin_m]

185s could have an engine (or possibly even two) removed from each unit to reduce their weight a lot and possibly enable them to not be as restricted in speed. The engines are powerful enough that even running on two engines permanently should still be enough to retain their good acceleration and 100mph top speed.

Maybe so, but it almost certainly wouldn't help with differential speeds. The critical parameter is likely to be the heaviest load on any axle, not the total weight of the train.

 

[CW2]

185s could have an engine (or possibly even two) removed from each unit to reduce their weight a lot and possibly enable them to not be as restricted in speed. The engines are powerful enough that even running on two engines permanently should still be enough to retain their good acceleration and 100mph top speed.

Hmm - doubtful.
They have one engine per vehicle, so removing one engine still leaves two heavy axle-load vehicles.
[Edit - edwin_m beat me to it!].

 

[notadriver]

185s could have an engine (or possibly even two) removed from each unit to reduce their weight a lot and possibly enable them to not be as restricted in speed. The engines are powerful enough that even running on two engines permanently should still be enough to retain their good acceleration and 100mph top speed.

The best way to reduce weight might be to install lightweight bogies - like the ones fitted to Meridians and Voyagers.

185s on two engines accelerate similar to a 158 which isn’t fast enough for current timings on some sections.

 

[HSTEd]

Ultimately removing engines that will weigh a couple of tonnes each isn't going to solve anything.

The simple reality is these trains simply aren't well suited for ongoing operation on British railways.