Trains which will never reach top speed.

[MK Tom]

Class 172/0 - 100 mph train. 45 mph line speed.

Any others please ?

I thought 172/0s had a 75mph top speed, with just the /1s, 2s and 3s being 100mph?

 

[D6975]

Quote:
Originally Posted by fgwrich
SWT's 455s would surely hit 75MPH on the runs to Bournemouth & back. Almost same going for the Junipers.

Ah yes forgot about that! Don't know about Southerns lot though..
__________________

When do 455s go to Bournemouth??
I spent a full day at Eastleigh in the summer and the only 455 I saw was on the works.
Is it a very early or very late working?

 

[Eagle]

455s only go to Bournemouth for maintenance. They never get anywhere near the coast in service.

 

[Lrd]

Ah yes forgot about that! Don't know about Southerns lot though..

They've been to Brighton before and also been on the Gatwick Express.

 

[D365]

I thought 172/0s had a 75mph top speed, with just the /1s, 2s and 3s being 100mph?

There was a bit of a misunderstanding over this. Wikipedia claimed 75mph for LO 172/0 like you say, but it's now been established (with the article in question having been edited) that all are geared up for 100mph. Top speed is something different altogether - there's been debate over the (former) state of the (former) 460s.

 

[Eagle]

As has been discussed multiple times recently, the speed they're geared for is not necessarily their top speed.

Gearing something for a higher speed makes the gears more efficient, whether or not the train can actually o the maximum geared speed or not.

 

[HSTEd]

More modern AC motors are also making 'gearing' far less important because they can generate huge torques at huge rotational speeds.

Unlike older DC motors where the commutator will rapidly dissasemble itself if it overspeeds.

 

[notadriver]

As has been discussed multiple times recently, the speed they're geared for is not necessarily their top speed.

Gearing something for a higher speed makes the gears more efficient, whether or not the train can actually o the maximum geared speed or not.

Class 172s are unique in that they are the only units fitted with a ZF 6 speed transmission.
I think it is only heresay that class 458/460 (or whatever class it was) were geared for 125mph.

 

[CarltonA]

The 92 tube stock on the Waterloo & City run somewhat under their maximum speed.

 

[A-driver]

Quote:
Originally Posted by fgwrich
SWT's 455s would surely hit 75MPH on the runs to Bournemouth & back. Almost same going for the Junipers.

Ah yes forgot about that! Don't know about Southerns lot though..
__________________

When do 455s go to Bournemouth??
I spent a full day at Eastleigh in the summer and the only 455 I saw was on the works.
Is it a very early or very late working?

Southerns 455s regularly run at 75 between dorking and leatherhead on fast trains not stopping at box hill. It takes a while but they can get to 75. Plus the peak hour 455/6s to Horsham can just about reach 75. They just take an age to get above 60.

Not quite full traction speed but both 455s and 6s regularly run at 70 on fast London bridge-Norwood / east Croydon runs to Tottenham off peak and caterham/dorking peak and I think some run fast line west Croydon-Vic in the mornings only stopping at clapham-they certainly used to when I was there. You could just about make 70 with a good unit.

 

[notadriver]

Southerns 455s regularly run at 75 between dorking and leatherhead on fast trains not stopping at box hill. It takes a while but they can get to 75. Plus the peak hour 455/6s to Horsham can just about reach 75. They just take an age to get above 60.

Not quite full traction speed but both 455s and 6s regularly run at 70 on fast London bridge-Norwood / east Croydon runs to Tottenham off peak and caterham/dorking peak and I think some run fast line west Croydon-Vic in the mornings only stopping at clapham-they certainly used to when I was there. You could just about make 70 with a good unit.

I've seen them things tanking on the up london bridge fast. I bet the downhill 1/100 grade after Forest Hill helps them achieve 70 mph +

 

[Sunbird24]

Do the class 67s ever reach 125 mph anywhere on the network?

Many years ago I was on a Charter train to York from KX. I joined at Potters Bar and it arrived very late behind a thunderbird 67. The run to Peterbourough appeared very fast, some say it was timed at well in excess of 100. Rumour later had it that the driver was reminded at Peterborough that although the loco was permitted to run at 125 the Mark II coaches were not. True or not, it is likely that when used in place of a class 91 they would indeed do 125 with Mk III (or is it IV?) stock.

 

[notadriver]

I'm inclined to believe this. Whilst the professionalism of full time drivers in TOCs is undoubted, I worry about the so called zero hours drivers doing charters etc especially after Stafford.

 

[Wivenswold]

I'm sure I read years ago that Class 321's struggle to get up to 100mph. The Desiros certainly seem to run faster but that may be down to the different ride on them. Maybe a driver can put me right on that.

 

[DXMachina]

I'm sure I read years ago that Class 321's struggle to get up to 100mph. The Desiros certainly seem to run faster but that may be down to the different ride on them. Maybe a driver can put me right on that.

20 July 1990 - 322481 first of five Class 322 EMUs for Stansted Express delivered from BREL York in a ceremonial high-speed run to London King’s Cross, achieved in 123.5min net with a 112mph maximum; this and the other ‘322s are put into service during 1990 on existing London Liverpool Street - Cambridge services awaiting opening of the Stansted Airport branch (see 19 March 1991).

http://www.networksoutheast.net/jan-1990-to-dec-1990.html

321 & 322 are identical I understand, presumably the same speeds are achievable.
--- old post above --- --- new post below ---
As an aside without proof, I used to live in a town on the WCML southern section. 321s once run in made some pretty decent speed. I'm sure I've been to 100mph between Hemel & Watford on them a few times

 

[IanXC]

I'm sure I read years ago that Class 321's struggle to get up to 100mph. The Desiros certainly seem to run faster but that may be down to the different ride on them. Maybe a driver can put me right on that.

If the 321/322s are that bad I dread to think what the 333s are like - I've heard from a couple of sources that the 333s are generally confined to the Airedale and Wharfdale lines as the limits up there are max 90mph. The 321/322 fleets make use of higher speeds between Leeds and Doncaster.

 

[notadriver]

From the performance logs I've seen a 321/322 struggles beyond 90 mph and indeed on climbs out of Euston and Kings Cross 85-90 is the best speed on climbs. By contrast a 350 with almost double the installed power can climb up towards Tring at 110 mph. AC motors tend to maintain their power into the high speed range where DC motors fall off.

 

[A-driver]

A 321 is pretty much as powerful as a 317. 317s have a slight edge but not much in it. On a fast Finsbury park- Stevenage a 317 and 321 will both reach 100 by Hatfield on greens. Both will also do the ton between Huntingdon and Peterbourgh by about woodwalton.

On the up a 317 departing potters bar on the up fast will reach 100 by between barnet and oakleigh pk. A 321 may be slightly after that, closer to the tunnel although I have had 321s which don't get above 95 on that stretch.

But there really isn't much difference in acceleration of top speed running between a 317 and 321. 321s are far harder to start in poor adhesion though.

 

[D7666]

A 321 is pretty much as powerful as a 317. 317s have a slight edge but not much in it. On a fast Finsbury park- Stevenage a 317 and 321 will both reach 100 by Hatfield on greens. Both will also do the ton between Huntingdon and Peterbourgh by about woodwalton.

On the up a 317 departing potters bar on the up fast will reach 100 by between barnet and oakleigh pk. A 321 may be slightly after that, closer to the tunnel although I have had 321s which don't get above 95 on that stretch.

But there really isn't much difference in acceleration of top speed running between a 317 and 321. 321s are far harder to start in poor adhesion though.

On the Thameslink side I noted 317/319 related in the same was as what you say about 317/321.

I have had it suggested to me - but cannot prove this : when BedPan was announced it was a 90 mph project and the EMU ordered. During the course of the project it was altered to 100 mph after the project started, after building work on EMU stared but some time before delivery.

The suggestion is that 317s gearing had already been ordered when 90 mph was specified, with only bits like suspension and springing then altered for 100 mph.

OTH, 319 and 321 were specified and ordered new as 100 mph and more appropriately geared at construction.

I do not know if any of this is true. I keep an eye out for technical documentation on all of 317/319/321 over many years but never found any in this detail.

Traction motor ratings on 317/319 are the same, they are all GEC motors of EE lineage. But 321s are Brush. There is possibly some characteristic within the motors, or within the traction packs, that causes differences. However, BRB procurement policy at that period was one of micro managed dual sourcing, and the two should have been identical.

But gearing differences is supported by evidence from observation, a 317 in the lower speed ranges has better acceleration than a 319/321, both get to 100 mph in the same time, but in the higher speed ranges a 317 loses out and 319/321 acceleration is better.

And your comment about harder to start 321s in poor adhesion also fits with lower geared 317s.

PS
I have no idea how 318s and 320s fit in with these theories, what with some 75 mph units, etc, i.e. I do not know if the 75 mph is done by gearing, or is a paperwork limit for units that are really 90/100 mph.


Does anyone know the actual gear ratios for any of these units 317-321 ?


--
Nick

 

[notadriver]

I'm also sure 317s were geared for 90 mph from the outset. They are only rated at 1000hp. Class 319s are more powerful and 320/321/322 have slightly greater installed power which might explain the differences.

 

[Deepgreen]

I'll lob in a cheeky one - pretty much all main line-certified steam traction is not pushed to anything like their top speeds (bearing in mind, though, that their maxima are somewhat theoretical)!

 

[southern442]

There used to be a small part of the Brighton main line cleared for 100 mph but in any case class 377s of FCC reach 100 under AC power north of the Thames.

376s can hit their top speed on Sevenoaks journeys and don't forget 375s can hit 100 between Sevenoaks and Tonbridge too

The fast lines at Gatwick are 100mph, and I believe the line through Hassocks is too.

This would mean the 460's would never reach 100 unless on a rare Brighton trip.

 

[Bald Rick]

The fast lines at Gatwick are 100mph, and I believe the line through Hassocks is too.

This would mean the 460's would never reach 100 unless on a rare Brighton trip.

Brighton Main Line is max 90.

 

[Trainfan344]

I'll lob in a cheeky one - pretty much all main line-certified steam traction is not pushed to anything like their top speeds (bearing in mind, though, that their maxima are somewhat theoretical)!

Yes, but IIRC someone mentioned before about if they achieved it at some point during their life time, however as an extension I'll add on Tornado.

 

[Starmill]

321s are far harder to start in poor adhesion though.

A Northern driver once told me he could push a 321 more than a 333 because although the 333 had more power and would get going quicker, the brakes on a 321 were loads better! Seemed very odd to me.




This isn't directly related to your point, but it made me think Hope I haven't mentioned it on here already. That would be dumb!

 

[A-driver]

Brighton Main Line is max 90.

Unless it's changed in the last few years it is 100 through gatwick. It definitely was when I worked down there. Southern 377s were never cleared to run above 90 though. They only cleared them for 100 on the WCML after limiting them to 90 for many years.

 

[Eagle]

Latest sectional appendix shows it's 90 through Gatwick on the fast lines (p4 and p5).

 

[notadriver]

A Northern driver once told me he could push a 321 more than a 333 because although the 333 had more power and would get going quicker, the brakes on a 321 were loads better! Seemed very odd to me.




This isn't directly related to your point, but it made me think Hope I haven't mentioned it on here already. That would be dumb!

It's true - older traction can have better braking. For example a class 319 is vastly superior to a newer networker in terms of braking capability.

 

[W230]

Unless it's changed in the last few years it is 100 through gatwick. It definitely was when I worked down there. Southern 377s were never cleared to run above 90 though. They only cleared them for 100 on the WCML after limiting them to 90 for many years.

There is a section of 100mph* running on the fasts between Gatwick Airport and Balcombe Tunnel Junction. No signage or anything to suggest it at these locations. Never known any driver manage it in a unit though. I've been told by several old school that this was only specially authorised by BR to allow the 319 to beat the London - Brighton time. No idea if it's true - sounds a bit unlikely to me!

*The Sectional Appendix states "Trains other than those composed entirely of Class 319 units must not exceed 90mph".
--- old post above --- --- new post below ---

It's true - older traction can have better braking. For example a class 319 is vastly superior to a newer networker in terms of braking capability.

Interesting. Never driven a Networker but a lot of the Ex-SE drivers reckon a Networker has better brakes than a 319? No idea myself though!

 

[Eagle]

There is a section of 100mph* running on the fasts between Gatwick Airport and Balcombe Tunnel Junction. No signage or anything to suggest it at these locations. Never known any driver manage it in a unit though. I've been told by several old school that this was only specially authorised by BR to allow the 319 to beat the London - Brighton time. No idea if it's true - sounds a bit unlikely to me!

*The Sectional Appendix states "Trains other than those composed entirely of Class 319 units must not exceed 90mph".

Again, that's out of date. My copy of the SA (last updated 02-02-2013) shows no such differential, and it's a blanket 90.