3rd Rail 100 mph stretches

[Chris172]

I was wondering as many 3rd rail EMUs have a max speed of 100mph, is there any stretches of line were the max speed is 100 mph for these units to obtain?

 

[fkofilee]

Not any on the BML if I remember rightly. Altough mostly 90 MPH limits/

 

[swt_passenger]

Not any on the BML if I remember rightly. Altough mostly 90 MPH limits/

Presumably you’re referring to the Brighton line (VTB), because the Bournemouth line (the actual BML) does have 100 mph sections, albeit mostly east of Southampton…

 

[fkofilee]

But isnt that because some of them have DMUs on them (Voyagers etc) which dont need 750v 3rd rail?
And yes I mean the Brighton ML

 

[alf]

I may be wrong, but I seem to remember 100mph on either side of a 90 mph limit through Gatwick station fast lines.

 

[swt_passenger]

But isnt that because some of them have DMUs on them (Voyagers etc) which dont need 750v 3rd rail?
And yes I mean the Brighton ML

The sectional appendix has a caveat that the 100 mph sections only apply to 442, 444, 450, 701, 707, but also anything that counts as an HST. Which would be 220/221 in this area.

 

[LNW-GW Joint]

I think the 3rd rail routes passed for 100mph (for certain stock types) are:
- the SE former Eurostar route from Sevenoaks to Sandling (before the Eurotunnel/Dover routes separate) - about 40 miles
- the SW main line between Byfleet and Eastleigh - about 50 miles

There are lower limits through major stations/junctions (eg Tonbridge, Ashford, Basingstoke-Worting Jn).
On the SW route the 100mph is not always on both lines.

 

[Ken H]

Presumably you’re referring to the Brighton line (VTB), because the Bournemouth line (the actual BML) does have 100 mph sections, albeit mostly east of Southampton…

Cl 442 were 100mph capable.

 

[Fincra5]

I may be wrong, but I seem to remember 100mph on either side of a 90 mph limit through Gatwick station fast lines.

Used to be a Stretch on the BML near Three Bridges on the Fast Lines, was put in for 319s I believe. Since Removed.

 

[swt_passenger]

Cl 442 were 100mph capable.

yes, I included them in the follow up post.

 

[Ken H]

Didn’t I list them?

Yes you did. Sorry

 

[swt_passenger]

Yes you did. Sorry

They probably no sooner added them back in the SA than they were withdrawn again. Probably keeps someone in an office busy.

I suppose though, given they all use similar shoe gear, any other suitable third rail EMU would manage 100 mph along there, they’ve just never been needed to be cleared yet.

 

[Ken H]

They probably no sooner added them back in the SA than they were withdrawn again. Probably keeps someone in an office busy.

I suppose though, given they all use similar shoe gear, any other suitable third rail EMU would manage 100 mph along there, they’ve just never been needed to be cleared yet.

Really dredging my brain here but didnt the Cl442 pioneer some new Brecknell Willis shoegear to make sure current collection was Ok at 100mph?

 

[swt_passenger]

Really dredging my brain here but didnt the Cl442 pioneer some new Brecknell Willis shoegear to make sure current collection was Ok at 100mph?

It may have done, I wasn’t aware at the time, but I think it’s been posted here before.

 

[AM9]

I was wondering as many 3rd rail EMUs have a max speed of 100mph, is there any stretches of line were the max speed is 100 mph for these units to obtain?

Raising a speed limit from 90 to 100 is largely a waste of money unless the section it is clear of any speed restrictions for at least 20 miles. Allowing for 1 mile to accelerate to 100 and a similar distance to decelerate, that would save about 80 seconds, but would cost a considerable amount to set up and get clearance, and then there's the increase in energy costs and maintenance costs of both rolling stock and infrastructure.
Even in good times it would be a very poor return on funding, and a totally irresponsible proposition for the next few years.

 

[cjmillsnun]

Presumably you’re referring to the Brighton line (VTB), because the Bournemouth line (the actual BML) does have 100 mph sections, albeit mostly east of Southampton…

Isn’t the line down to Bournemouth the South West Main Line.

 

[swt_passenger]

Isn’t the line down to Bournemouth the South West Main Line.

publically yes, but internal documents such as the sectional appendix it’s the “Bournemouth Main Line”.

 

[bramling]

Raising a speed limit from 90 to 100 is largely a waste of money unless the section it is clear of any speed restrictions for at least 20 miles. Allowing for 1 mile to accelerate to 100 and a similar distance to decelerate, that would save about 80 seconds, but would cost a considerable amount to set up and get clearance, and then there's the increase in energy costs and maintenance costs of both rolling stock and infrastructure.
Even in good times it would be a very poor return on funding, and a totally irresponsible proposition for the next few years.

One wonders how worthwhile the 100mph section around Three Bridges / Gatwick was for the 319s, given how the 1980s EMUs tend to die once past 80-85 mph. I vaguely recall the 319/2s may have had modifications, but this would presumably only improve things by a nominal amount.

 

[kermit]

Which were the first "heritage" Southern 3rd rail emus to be allowed at 90mph, then 100mph?

 

[Bikeman78]

One wonders how worthwhile the 100mph section around Three Bridges / Gatwick was for the 319s, given how the 1980s EMUs tend to die once past 80-85 mph. I vaguely recall the 319/2s may have had modifications, but this would presumably only improve things by a nominal amount.

It's downhill from Earlswood to Gatwick and also Balcombe tunnel to Gatwick so 319s would have had no problem getting to 100 on those sections. I doubt they'd have got anywhere near 100 going the other way though. It was a PR stunt by Connex. Assuming instant acceleration and ignoring the 90 through Gatwick station the 100 mph section saved around 40 seconds.

 

[fgwrich]

publically yes, but internal documents such as the sectional appendix it’s the “Bournemouth Main Line”.

All bridge / structure plates are listed as BML XX too.

There the REPs ever allowed to do 100? Not that there was probably little to stop them from doing it at the time.

 

[43096]

All bridge / structure plates are listed as BML XX too.

Those are the Engineers Line References. BML is Waterloo to Bournemouth (Bournemouth Main Line) and VTB is Victoria to Brighton.

So if we're going by the official sources, BML is the Bournemouth line.

 

[AM9]

One wonders how worthwhile the 100mph section around Three Bridges / Gatwick was for the 319s, given how the 1980s EMUs tend to die once past 80-85 mph. I vaguely recall the 319/2s may have had modifications, but this would presumably only improve things by a nominal amount.

I think the only mods that the 319s had that affected their performance was the raising of the braking of the early batches from 9% to 12%, (a standard for express trains in those days). The gradual change of AMBR pantographs to Brecknell-Willis high-speed types would have had a very minor speed impact in terms of their performance (under wires of course) but pointless south of the river.
Not exactly a mod, but the 319/2s had their pantographs removed and stored whilst in the Brighton Express role to reduce clutter from overhanging vegetation and birds, which might also have given them a small aerodynamic drag reduction.

 

[craigybagel]

Raising a speed limit from 90 to 100 is largely a waste of money unless the section it is clear of any speed restrictions for at least 20 miles. Allowing for 1 mile to accelerate to 100 and a similar distance to decelerate, that would save about 80 seconds, but would cost a considerable amount to set up and get clearance, and then there's the increase in energy costs and maintenance costs of both rolling stock and infrastructure.
Even in good times it would be a very poor return on funding, and a totally irresponsible proposition for the next few years.

If you need an entire mile to get from 100 to 90 there's something seriously wrong with your brakes......

I do get your point though - at those speeds a 10mph speed improvement isn't going to make much difference - unless it's part of an overall package, and/or increasing the limit is more a paperwork exercise then something requiring much capital investment.

 

[30907]

Which were the first "heritage" Southern 3rd rail emus to be allowed at 90mph, then 100mph?

If you mean SR, then none; if you mean BR(S) then 90mph was permitted between Tonbridge and Ashford from electrification, so it would be CEP/BEP/HAP/MLV. The regional limit was lifted to 90 from then.
IIRC some EPBs were regeared for 90, but I think that was slightly later.

 

[brad465]

I may be wrong, but I seem to remember 100mph on either side of a 90 mph limit through Gatwick station fast lines.

Used to be a Stretch on the BML near Three Bridges on the Fast Lines, was put in for 319s I believe. Since Removed.

Yes I recall there being a rather small distance able to do it that seemed almost pointless to have. Presumably much more of the route could do 100mph were it not for the heavy traffic flows?

I think the 3rd rail routes passed for 100mph (for certain stock types) are:
- the SE former Eurostar route from Sevenoaks to Sandling (before the Eurotunnel/Dover routes separate) - about 40 miles
- the SW main line between Byfleet and Eastleigh - about 50 miles

There are lower limits through major stations/junctions (eg Tonbridge, Ashford, Basingstoke-Worting Jn).
On the SW route the 100mph is not always on both lines.

I believe its also possible to do 100mph on the old Eurostar connection from the SEML at Dollands Moor, which is third rail for a stretch while the transition to OHLE is made (seriously doubt anything does that now though there). Interestingly 90mph can be achieved all the way through Ashford on the through lines, but I do wonder how much that capability is utilised, as the freight that runs through won't do it, and every passenger service calls there.

On the SWML I believe in the down direction the 100mph running doesn't start until Farnborough, then runs through to Basingstoke, then after a pause through to Worting Jct resumes at 100mph to Eastleigh as you describe. I believe Basingstoke is 65mph on the down, but I'm sure 100mph is possible through the station on the Up fast (or certainly was in the past), while further up 100mph running carries on through to Byfleet or somewhere in that area, although I'm not sure how much of Farnborough-Woking is 100mph in the up direction. I'm not sure why this up/down difference exists in the latter stretch, through Basingstoke I expect curvature is the reason through the station.

 

[Recessio]

Cl 442 were 100mph capable.

Really dredging my brain here but didnt the Cl442 pioneer some new Brecknell Willis shoegear to make sure current collection was Ok at 100mph?

Didn't the 442s hold the 3rd rail max speed record? Presumably that must have been set on a section of line rated for at least 100 mph?

 

[AM9]

If you need an entire mile to get from 100 to 90 there's something seriously wrong with your brakes......

I do get your point though - at those speeds a 10mph speed improvement isn't going to make much difference - unless it's part of an overall package, and/or increasing the limit is more a paperwork exercise then something requiring much capital investment.

Not necessarily, the whole train needs to be clear of the start of the 100mph before increasing speed and fully down to the succeeding speed limit before passing the 90mph start (or whatever it is). So given that a mile only takes 40 seconds at 100mph, that's putting a load on the driver if it is any tighter.

 

[pompeyfan]

Basingstoke has had a TSR over the diamond on the up fast for as long as I’ve worked on the railway. It keeps bobbing between 30mph and 50mph.

on the SWML if you wanted to speed up journey times rather than trying to get up to the magic 100mph marker you’d be better off finding a way for all Desiro stock to draw 100% power, rather than the 59% that a 450 can pull and 85%ish a 444 can pull. That’s without any additional power reduction modes being implemented.

 

[colchesterken]

I have a DVD of a publicity high speed run to Brighton. Lines kept clear but speed limits
enforced. I think they did it by a couple of mins ) must find it and rerun )
The driver made a couple of P A announcements " we are doing 100 mph"