Performance of Regeared Pendolionos (390s)

[BelleIsle]

Mulling over world events with a Euston driver t'other day in a local hostellry the subject of the Pretendalino (90+Mk3 rake) came up. He was saying how the performance difference with a 390 was not as much as some people think as the 90s have superior acceleration in the lower speed ranges. This is partly due to the 390s being designed for 140mph operation.

This got me thinking. Assuming that 140mph is never going to happen you could regear the 390s for a top speed of 125mph to give them some more grunt lower down. What sort of time savings would this realise? The odd minute or something worth doing cost wise?

 

[notadriver]

I think 140 mph is an eventual goal for WCML operations when ETCS is implemented. Also (just my opinion) the class 90 is a obviously geared for 110 mph for the mixed work that it does (sleeper trains). I wonder if it has the same gearing as the class 87s - which were geared for 100 mph when built. As i understand when their top speed was increased officially to 110 mph the gearing wasn't changed so I assume the class 90s have the same gearing as the 87s. Maybe the Pendolinos could do with more distributed traction to increase acceleration?

 

[pablo]

The 390s could do with lower gearing because they spend a lot of time at a speed a good deal less that 125 mph.
If so then could the Voyagers keep up?

 

[The Planner]

There is little in it between a 221 and 390 on the WCML, they'll end up with the same running times eventually.

 

[driver_m]

There is little in it between a 221 and 390 on the WCML, they'll end up with the same running times eventually.

I'd beg to differ. If you had 221s on Manchesters, you'd notice the difference immediately. The timings are tight as it is with 390s, a 221 would always be late. A 221 is initially good at getting going but takes a while to get to 125 and that's assuming its on all engines.

The pendo has been slowed down a bit from when they come in as 8 cars. Back then they were like rockets without the eco mode too. But they are still a decent powered train considering the weight on them. They don't need altering at all in my opinion. Taking them out of eco mode helps too. The xx00 07 30 and 40 services out of euston all have an average speed of over 100mph in the first hour so they do spend a lot of their time at 125mph.

 

[contrex]

Also (just my opinion) the class 90 is a obviously geared for 110 mph for the mixed work that it does (sleeper trains). I wonder if it has the same gearing as the class 87s - which were geared for 100 mph when built. As i understand when their top speed was increased officially to 110 mph the gearing wasn't changed so I assume the class 90s have the same gearing as the 87s.

According to "British Rail Main Line Locomotives Specification Guide" by Pip Dunn, classes 86, 87 and 90 all have 32:73 gear ratio.

 

[The Planner]

Possibly should have been a bit more detailed, they'll end up the same south of Rugby at some point, would have a cheeky fiver on that.

 

[sprinterguy]

I wonder if it has the same gearing as the class 87s - which were geared for 100 mph when built. As i understand when their top speed was increased officially to 110 mph the gearing wasn't changed so I assume the class 90s have the same gearing as the 87s. Maybe the Pendolinos could do with more distributed traction to increase acceleration?

The class 87s were limited to 100mph due to being fitted with GEC cross-arm pantographs as built: These were replaced by Brecknell Willis High Speed pantographs in the mid eighties, allowing the locos to be cleared for 110mph operation with no re-gearing necessary, as you say.

 

[Ash Bridge]

The class 87s were limited to 100mph due to being fitted with GEC cross-arm pantographs as built: These were replaced by Brecknell Willis High Speed pantographs in the mid eighties, allowing the locos to be cleared for 110mph operation with no re-gearing necessary, as you say.

That's just got me thinking, back around 1970 (give or take) class 86 E3173 which was the first of the class to be fitted with Flexicoil secondary suspension, was involved in trials on the Southern part of the WCML running at speeds of up to 130mph. Would this have been regeared for this purpose ?

 

[notadriver]

What would be interesting is the Pretendino vs a Pendolino at non EPS speeds (limited to 110 mph). The 90 seems to have poor hill climbing performance above 100 mph so perhaps north of Preston it could march the Pendolinos ?

 

[455driver]

I think 140 mph is an eventual goal for WCML operations when ETCS is implemented. Also (just my opinion) the class 90 is a obviously geared for 110 mph for the mixed work that it does (sleeper trains). I wonder if it has the same gearing as the class 87s - which were geared for 100 mph when built. As i understand when their top speed was increased officially to 110 mph the gearing wasn't changed so I assume the class 90s have the same gearing as the 87s. Maybe the Pendolinos could do with more distributed traction to increase acceleration?

The 87s were geared for 110mph from the start but when they were introduced the maximum speeds of the stock and line were 100 so why have a train which has to be maintained for a higher speed than they can go?

86/2 were geared for 125mph but limited to 100mph.

 

[sprinterguy]

According to "British Rail Main Line Locomotives Specification Guide" by Pip Dunn, classes 86, 87 and 90 all have 32:73 gear ratio.

Only the 86/1s (the class 87 test-beds, so it stands to reason) are geared as such: The rest of the class 86 fleet (with the exception of the unique re-geared 86/5) have a gear ratio of 22:65.

 

[pablo]

What would be interesting is the Pretendino vs a Pendolino at non EPS speeds (limited to 110 mph). The 90 seems to have poor hill climbing performance above 100 mph so perhaps north of Preston it could march the Pendolinos ?

When the Pretendalino did the 13:33 FO Lancaster a few years ago, it matched the Pendolino's timings to Crewe by just cutting out the stop at Rugby IIRC.