15X Fleet State and Replacements?

[Anonymous10]

Personally I would go for 90+mph units which have good acceleration mainly for flexibility so they can do some of the faster services, something like a bimode 3 car aventra with connecting doors would be good imo.

Sounds good but also be good if class 170s which are already being used in those services to be regeared

 

[Energy]

Sounds good but also be good if class 170s which are already being used in those services to be regeared

I don't think 170s are used for those services, and more 170s are rare so the chances of GWR being able to get 170s is low.

 

[Anonymous10]

I don't think 170s are used for those services, and more 170s are rare so the chances of GWR being able to get 170s is low.

Ah I thought this was a general 15x replacement forum

 

[Mikey C]

Why were the 158s and 166s only 90mph units, seeing that they operated on express routes, and most EMUs operating such routes can do 100? Were the engines available back then lacking grunt?

 

[Energy]

Ah I thought this was a general 15x replacement forum

Sorry it is, I'm just getting confused! The point still the point remains that not many 170s are going free.

 

[Anonymous10]

Sorry it is, I'm just getting confused! The point still the point remains that not many 170s are going free.

Granted but tfw are going to Cascade them internally and no doubt other operators might do so so surely regearing would be good for them

 

[Jozhua]

However as previously said most routes the 150s operate are commuter routes which have frequent stops and require higher acceleration I personally would aim for a train no slower than a class 150 and can accelerate as fast if not faster if we can get a higher top spead that's nice but let's focus on acceleration

Tbh, I'd of thought they would go hand in hand. Obviously you've got gearing ratios which might make some difference, but it mostly comes down to the engine performance. I have a feeling that 15X's (excluding 158) were limited to 75mph due to constraints on engine performance at the time. I guess while the frames might have coped with it, no point giving it a higher speed designation if it can't reliably obtain it. If pacers can do 75, I would be surprised if the 15X rolling stock wouldn't be capable of safely doing 90mph. I know the MK3 based 319 EMUs can do 100, even if the last 10-15mph comes quite slowly.

In the case of the 230's, due to their past lives on the underground, I assume this is why the trains have such a low top speed, as the original stock was never designed for much more than 50mph...

Hybrid technology is presumably becoming cheaper too, so some electric motors to give the trains an extra kick out of the station could be useful!

 

[Anonymous10]

I mean that the 170s are less fuel efficient at low speeds ect and regearing has been suggested to correct it

 

[hooverboy]

Tbh, I'd of thought they would go hand in hand. Obviously you've got gearing ratios which might make some difference, but it mostly comes down to the engine performance. I have a feeling that 15X's (excluding 158) were limited to 75mph due to constraints on engine performance at the time. I guess while the frames might have coped with it, no point giving it a higher speed designation if it can't reliably obtain it. If pacers can do 75, I would be surprised if the 15X rolling stock wouldn't be capable of safely doing 90mph. I know the MK3 based 319 EMUs can do 100, even if the last 10-15mph comes quite slowly.

In the case of the 230's, due to their past lives on the underground, I assume this is why the trains have such a low top speed, as the original stock was never designed for much more than 50mph...

Hybrid technology is presumably becoming cheaper too, so some electric motors to give the trains an extra kick out of the station could be useful!

the 150/3/5/6's were primarily designed for operation on local and regional branch lines,most of which is still 75mph or below, so there was no need for more power most of the time, although they would still run on bits of mainline.

Back in the 1980's a significant chunk of mainline "slows" were either 75mph or 90mph running,meaning one of these would not interfere that heavily with pathing .
A lot of mainlines are now rated at 90mph/100mph for the slows,so even these units now need the capability to run at high enough speed not to block the services running behind it.

I think it would have been feasible for sprinters running at 90mph with tweaked engines!, 156's have on occasion been clocked around 85mph, and 158's nearly 100mph.

 

[Jozhua]

I mean that the 170s are less fuel efficient at low speeds ect and regearing has been suggested to correct it

Yeah, the 170's were always aimed at intercity services on Express routes, so it's less like a regional unit that has the capability of doing more than 75.

the 150/3/5/6's were primarily designed for operation on local and regional branch lines,most of which is still 75mph or below, so there was no need for more power most of the time, although they would still run on bits of mainline.

Back in the 1980's a significant chunk of mainline "slows" were either 75mph or 90mph running,meaning one of these would not interfere that heavily with pathing .
A lot of mainlines are now rated at 90mph/100mph for the slows,so even these units now need the capability to run at high enough speed not to block the services running behind it.

I think it would have been feasible for sprinters running at 90mph with tweaked engines!, 156's have on occasion been clocked around 85mph, and 158's nearly 100mph.

Yeah, this makes sense! The speeds on UK rail have creeped up over the last couple of decades, plus there has always been a decent amount of higher speed running for a decent bit of the fleet.

Areas that spring to mind are the now 100mph section between Bolton & Salford, which shares with TPE 350's/397's. 319's can get about 90mph, whereas 150's are stuck at 75mph for the majority of the leg.

There's also the 7/8ish mile 110mph section between Derby and Long Eaton, where 156's share the track with 170's and 222's. The :13 156 leaves less than 10 minutes before the :21 222 I believe. So if that 156 is late, 90mph running could definitely clear up the tracks quicker. That along with the 100ish mph between Derby and Ambergate too.

Then there's Hope Valley, which I guess could benefit more from both Acceleration than speed, but I feel they go hand in hand for a large part.

 

[Meerkat]

Rather than directly replacing the 15x with new trains shouldn’t the plan be to move the CAFs to replace them, whilst correcting the CAF purchase mistake by replacing those with electrification and bi-modes (battery or OHE)?

 

[JonathanH]

There's also the 7/8ish mile 110mph section between Derby and Long Eaton, where 156's share the track with 170's and 222's. The :13 156 leaves less than 10 minutes before the :21 222 I believe. So if that 156 is late, 90mph running could definitely clear up the tracks quicker. That along with the 100ish mph between Derby and Ambergate too.

You say that, but 7/8 miles isn't really that far and the route has rather slow bits at the junctions at Derby and Trent so 90mph doesn't necessarily make a lot of difference against 75mph and faster acceleration.