Scotrail Class 385 Discussion

[hexagon789]

Alex Hynes said this in Parliament this week:-

“It is my aspiration that we do some line speed enhancement on that route, to cut the journey time even further, because those brand new electric trains reach 100mph in half the time of a diesel train and the drivers are having to throttle back—so the train performance is outstripping that of the infrastructure. I say, let us be bold and ambitious and see what can be done to exploit the full performance of the train, because it is impressive.”

Could it be that the new trains have more oomph than anticipated?

http://www.parliament.scot/parliamentarybusiness/report.aspx?r=11520&i=104550

Presumably 110 mph upgrades if Hynes is alluding to linespeed increases.

I don' think so, it sounds more as if the trains are hitting restrictive speed limits whilst accelerating up to 100mph, and so they want to raise those lower speed limits so that they can accelerate through to 100mph in one go. For example, if there is a section of track that goes 30mph>60mph>100mph, the example 385 is hitting 60mph before it reaches the 100mph board, and so if they can raise the section that is 60mph to 70 or 80mph, then they can keep on accelerating up to the higher speed limit.

In general there are many significant drops in permitted speed between Bishopbriggs and Haymarket. It's 50 up Cowlairs, then up to 60, 70 past Eastfield then up to 85. The maximum of 100 applies from Bishopbriggs to the Falkirk Tunnel, then 95 through the tunnel, back up to 100, 90 over Polmont Jcn and through Polmont, back to 100 for a bit, then down to 90 again. 100 through Linlithgow, 80 MU 90 from Winchburgh Jcn to the tunnel, up to 90 all trains through the tunnel, 80 SP 90, then up to 100 right through Newbridge Jcn, through Edinburgh Park to just before Haymarket West. Down to 80/90 there, then 40 into Haymarket station.

So perhaps some of the 90 sections could be increased to 100, I'm not sure you could increase the limits out of Queen Street that easily.

 

[gordonjahn]

Presumably 110 mph upgrades if Hynes is alluding to linespeed increases.



In general there are many significant drops in permitted speed between Bishopbriggs and Haymarket. It's 50 up Cowlairs, then up to 60, 70 past Eastfield then up to 85. The maximum of 100 applies from Bishopbriggs to the Falkirk Tunnel, then 95 through the tunnel, back up to 100, 90 over Polmont Jcn and through Polmont, back to 100 for a bit, then down to 90 again. 100 through Linlithgow, 80 MU 90 from Winchburgh Jcn to the tunnel, up to 90 all trains through the tunnel, 80 SP 90, then up to 100 right through Newbridge Jcn, through Edinburgh Park to just before Haymarket West. Down to 80/90 there, then 40 into Haymarket station.

So perhaps some of the 90 sections could be increased to 100, I'm not sure you could increase the limits out of Queen Street that easily.

The design speed of the new units is 100mph so potentially a whole heap of work to move to 110.

Incremental improvements seems more likely!

 

[gingertom]

In the other direction Queen Street tunnel is the 20mph crawl, not much can be done there for fear of brake failure.

 

[D365]

The design speed of the new units is 100mph so potentially a whole heap of work to move to 110.

Siemens have done it. But as you say not a priority for ScotRail at this time.

 

[NotATrainspott]

There's really not any point doing 110mph in Scotland. Small increases in speed only make a meaningful difference over long distances of max-speed running and the 385 routes just don't have enough. Useful average times are limited more by pathing constraints at major junctions. Grade-separation at Greenhill, the Almond Chord and lifting lower speed restrictions are far better investments which would benefit all services, rather than the ones running fast.

 

[hexagon789]

The design speed of the new units is 100mph so potentially a whole heap of work to move to 110.

Incremental improvements seems more likely!

Quite possibly, but then the linespeed has been upgraded several times. It went from 75 mph to 90 in 1972, to 100 with HST boards in 1979 (though the 47/7s were limited to 95 until 1984/5). The next logical increase is to 110.

Though I would agree that increasing the 90 sections to 100 where possible seems more likely.

 

[Agent_Squash]

The design speed of the new units is 100mph so potentially a whole heap of work to move to 110.

Incremental improvements seems more likely!

The design of the class 350 was 100mph and it involved minimal work to uprate to 110.

 

[hexagon789]

The design of the class 350 was 100mph and it involved minimal work to uprate to 110.

I think it's very possible to uprate the 385s to 110, but whether that will happen soon considering, as others have mentioned, that ScotRail's safety case is for 100 mph running and thar might prove harder to get changed.

 

[gingertom]

I think it's very possible to uprate the 385s to 110, but whether that will happen soon considering, as others have mentioned, that ScotRail's safety case is for 100 mph running and thar might prove harder to get changed.

110mph running might be possible east of Edinburgh towards Drem. Doesn't help the E&G though.

 

[hexagon789]

110mph running might be possible east of Edinburgh towards Drem. Doesn't help the E&G though.

Provided the traction can manage it, there is plenty of 100 mph+ running between Musselburgh and Drem.

I concede your point though, it's a nice idea but perhaps one for the future?

 

[gingertom]

Provided the traction can manage it, there is plenty of 100 mph+ running between Musselburgh and Drem.

I concede your point though, it's a nice idea but perhaps one for the future?

over to Mr Hynes.

 

[hexagon789]

over to Mr Hynes.

Very much, he hasn't been particularly precise about his proposals.

 

[InOban]

Eastbound surely trains should be able to accelerate to 100mph as soon as they clear Cowlairs. Westbound, we must ask whether the limit in the tunnel is unduly restrictive in this day and age. After all we have approach control, and two braking systems - regenerative as well as disc.

 

[gingertom]

Eastbound surely trains should be able to accelerate to 100mph as soon as they clear Cowlairs. Westbound, we must ask whether the limit in the tunnel is unduly restrictive in this day and age. After all we have approach control, and two braking systems - regenerative as well as disc.

I can perhaps see a dispensation for units equipped regenerative braking. Trouble is what happens if the regenerative system fails and the unit has to revert to the "normal" brakes? Overheating and potential reduced braking efficiency just when you need those brakes the most. I think we need to err on the side of caution here otherwise the result could be an unplanned platform extension...

 

[hexagon789]

Eastbound surely trains should be able to accelerate to 100mph as soon as they clear Cowlairs. Westbound, we must ask whether the limit in the tunnel is unduly restrictive in this day and age. After all we have approach control, and two braking systems - regenerative as well as disc.

I can perhaps see a dispensation for units equipped regenerative braking. Trouble is what happens if the regenerative system fails and the unit has to revert to the "normal" brakes? Overheating and potential reduced braking efficiency just when you need those brakes the most. I think we need to err on the side of caution here otherwise the result could be an unplanned platform extension...

I don't believe the Regen braking will give a better deceleration. As far as I'm aware it's designed so the friction (in this case disc) brakes give a slightly higher retardation level because they are the emergency braking system and the fail-safe braking system in the event of Regen failure.

 

[Highlandspring]

Linespeed is governed as much by signal spacing and sighting as it is by geometry or formation. It’s not as easy as saying “this bit of track is straight so lets’s make it 110mph”

 

[hexagon789]

Linespeed is governed as much by signal spacing and sighting as it is by geometry or formation. It’s not as easy as saying “this bit of track is straight so lets’s make it 110mph”

True, if the signal spacings are the same as in the '80s I don't think you could get away with 110 mph. The route is fairly straight as it is for the most part.

 

[gingertom]

I don't believe the Regen braking will give a better deceleration. As far as I'm aware it's designed so the friction (in this case disc) brakes give a slightly higher retardation level because they are the emergency braking system and the fail-safe braking system in the event of Regen failure.

friction brakes of whatever flavour causes heat build up. Use of regen reduces the dependency on friction brakes. Coming down the Cowlairs incline at 50mph without regen could be problematic. Byt hte time you discover

True, if the signal spacings are the same as in the '80s I don't think you could get away with 110 mph. The route is fairly straight as it is for the most part.

increasing the signal spacing would permit higher speeds but at the expense of capacity. The electrification was all about capacity so we can't go giving with one hand and taking away with the other.

 

[hexagon789]

friction brakes of whatever flavour causes heat build up. Use of regen reduces the dependency on friction brakes. Coming down the Cowlairs incline at 50mph without regen could be problematic. Byt hte time you discover

True bit discs are less prone to heat fade than treads and the 170s manage the descent on discs only without much complaint, though that is only at 30 mph.

increasing the signal spacing would permit higher speeds but at the expense of capacity. The electrification was all about capacity so we can't go giving with one hand and taking away with the other.

Without going to cab signalling, though I understand Scotland is not intially being included in the ERTMS rollout whenever it comes.

 

[Chuggington21]

I think the components on the 385 are the same as the class 800 so it could do over 100 easily

 

[InOban]

RTT is now showing a light engine movement tomorrow night from Tyne yard to Newton Aycliffe, followed by a trip to Craigentinny. Maybe the 385 with experimental windows? If it runs!

 

[John R]

I think the components on the 385 are the same as the class 800 so it could do over 100 easily

If I recall, reading the description of the work needed to ensure that the Class 350s were able to run at 110mph they were by no means simple, though worth it given the long distances of sustained running they can do and the way it eased pathing with faster services. Given that you need 18 miles at sustained 110mph running to gain 1 minute over 100mph, (and remember just accelerating from 100mph to 110mph will eat up a few of the available miles) then I can't imagine there would be a business case for it on the E&G. Easing lower speed restrictions will have much more of an impact, as not only does it mean faster passage through the area affected, but means the subsequent speed is faster as you then accelerate, thus reaching higher speeds earlier.

 

[gingertom]

If I recall, reading the description of the work needed to ensure that the Class 350s were able to run at 110mph they were by no means simple, though worth it given the long distances of sustained running they can do and the way it eased pathing with faster services. Given that you need 18 miles at sustained 110mph running to gain 1 minute over 100mph, (and remember just accelerating from 100mph to 110mph will eat up a few of the available miles) then I can't imagine there would be a business case for it on the E&G. Easing lower speed restrictions will have much more of an impact, as not only does it mean faster passage through the area affected, but means the subsequent speed is faster as you then accelerate, thus reaching higher speeds earlier.

the 385's traction equipment comes from the 140mph Javelin so there can be little doubt that the 385 can go significantly faster that 100mph. The AT200 family platform is advertised as up to 125mph yet our 385s are 100. Whether that 100 is hard and fast or an easy tweak to say 110 is a moot point. Whether we should be looking at running them above 100 is a different thing altogether. There's little scope in the E&G to exploit 110+ mph running and as explained above the time savings would only be marginal to not be worth the effort. Different story on the run out to North Berwick though. As you rightly say, easing speed restrictions would have a much greater impact and it is good that Alex Hynes and his team are looking to see if any restrictions can be eased relatively simply (=cheaply) to trim a further couple of minutes off the end-to-end journey time.

 

[InOban]

Ie, if it were possible to relax the limit in the QS tunnel it would save more time than any marginal improvements elsewhere.

 

[Highlandspring]

It's already 60mph through the tunnel, having been raised after the slab track was renewed. The speed is entirely achievable for electrics in the Up direction.

 

[92002]

RTT is now showing a light engine movement tomorrow night from Tyne yard to Newton Aycliffe, followed by a trip to Craigentinny. Maybe the 385 with experimental windows? If it runs!

Assuming that there is no delay, that's exactly what it is.

Delivery of another 385 with the experimental windscreens for testing. One end fitted with the Belgian sourced ones and the other fitted with the Italian sourced ones.

 

[InOban]

There's a duplicate path on Friday if tonight's doesn't run. But here's hoping.

 

[scotraildriver]

In the other direction Queen Street tunnel is the 20mph crawl, not much can be done there for fear of brake failure.

The speed was raised to 30mph in the down direction after the closure dropping to 20mph just before the crossover. Entering an empty buffer end platform has just been increased from 10 to 15 mph too.

 

[YorkshireBear]

Assuming that there is no delay, that's exactly what it is.

Delivery of another 385 with the experimental windscreens for testing. One end fitted with the Belgian sourced ones and the other fitted with the Italian sourced ones.

Excellent, seems quicker than we anticipated.

 

[gingertom]

The speed was raised to 30mph in the down direction after the closure dropping to 20mph just before the crossover. Entering an empty buffer end platform has just been increased from 10 to 15 mph too.

wasn't aware of that change. i was aware of an increase across the crossings themselves in the up direction, which is quite significant for an 8 car train.