Third Rail - Possibility of raising speed of South Western Mainline to 110mph?

[Prestige15]

Just two questions

Is there anywhere on the 3rd rail through out the southern region other than the South Weat Mianline that has line speed of more than 90mph?

Isit possible the South West Mainline can increase its line speed upto 110mph in some section like Woking - Basingstoke - Eastleigh? I kinda think so as class 442 almost proved that but not without some serious work on the infrastructure, Would be interested to see the Desiros (potentially being the worlds fastest DC units, beating the 442 by 1mph) and Voyagers traveling that speed.

 

[zwk500]

Just two questions

Is there anywhere on the 3rd rail through out the southern region other than the South Weat Mianline that has line speed of more than 90mph?

There's 100mph on the Kent region from a point around Tonbridge (think it's between Tonbridge and Sevenoaks) to Saltwood Junction, from when 373s used to use the route but it's been maintained for 375s.

There was formerly a section of the Brighton Mainline around Gatwick cleared to 100mph for 319s but that's now back to 90mph for all trains as the gains were not enough to justfiy the extra maintenance.

Isit possible the South West Mainline can increase its line speed upto 110mph in some section like Woking - Basingstoke - Eastleigh? I kinda think so as class 442 almost proved that but not without some serious work on the infrastructure, Would be interested to see the Desiros (potentially being the worlds fastest DC units, beating the 442 by 1mph) and Voyagers traveling that speed.

SWML is 100mph max for 442s, 44s and 450s (HSTs and IIRC Voyagers can also use the 100mph speed but of course aren't 3rd rail). The 442 reached 110mph on proving runs as testing requires a 10% overspeed demonstration for a safety margin. AFAIK they were never authorised to work above 100mph in service.
100mph starts at Byfleet and runs to around St Denys, I think. I can't remember off the top of my head if there's any 100mph sections between Southampton and Bournemouth.

 

[Tio Terry]

Just two questions

Is there anywhere on the 3rd rail through out the southern region other than the South Weat Mianline that has line speed of more than 90mph?

Isit possible the South West Mainline can increase its line speed upto 110mph in some section like Woking - Basingstoke - Eastleigh? I kinda think so as class 442 almost proved that but not without some serious work on the infrastructure, Would be interested to see the Desiros (potentially being the worlds fastest DC units, beating the 442 by 1mph) and Voyagers traveling that speed.

If you lift linespeeds above 100MPH anywhere then you have to look at lineside safety clearances for staff - need to be 2M - or some way of restricting speeds if staff are working lineside.

 

[jfollows]

There's 100mph on the Kent region from a point around Tonbridge (think it's between Tonbridge and Sevenoaks) to Saltwood Junction, from when 373s used to use the route but it's been maintained for 375s.

There was formerly a section of the Brighton Mainline around Gatwick cleared to 100mph for 319s but that's now back to 90mph for all trains as the gains were not enough to justfiy the extra maintenance.

SWML is 100mph max for 442s, 44s and 450s (HSTs and IIRC Voyagers can also use the 100mph speed but of course aren't 3rd rail). The 442 reached 110mph on proving runs as testing requires a 10% overspeed demonstration for a safety margin. AFAIK they were never authorised to work above 100mph in service.
100mph starts at Byfleet and runs to around St Denys, I think. I can't remember off the top of my head if there's any 100mph sections between Southampton and Bournemouth.

Sectional Appendix at https://sacuksprodnrdigital0001.blob.core.windows.net/sectional-appendix/Sectional Appendix full PDFs March 23/Kent Sussex Wessex Sectional Appendix March 2023 .pdf shows where 100mph is allowed; it also notes

Trains other than those composed entirely of Class 442, 444, 450, 701, 707 units or HST's must not exceed 90mph

There's no 100mph beyond Southampton, no. Furthest from London seems to be at 73m 20ch north of Eastleigh. Closest to London is 20m 60ch in the up direction between West Byfleet & Byfleet and New Haw.

 

[43066]

There's 100mph on the Kent region from a point around Tonbridge (think it's between Tonbridge and Sevenoaks) to Saltwood Junction, from when 373s used to use the route but it's been maintained for 375s.

Yep. There’s also a shortish stretch on the down between (IIRC) Sevenoaks and Dunton Green.

If you lift linespeeds above 100MPH anywhere then you have to look at lineside safety clearances for staff - need to be 2M - or some way of restricting speeds if staff are working lineside.

There are specific signs to this effect on the SEML - I had intended to upload a photo of one but sadly the file is too large!

 

[zwk500]

Isit possible the South West Mainline can increase its line speed upto 110mph in some section like Woking - Basingstoke - Eastleigh? I kinda think so as class 442 almost proved that but not without some serious work on the infrastructure, Would be interested to see the Desiros (potentially being the worlds fastest DC units, beating the 442 by 1mph) and Voyagers traveling that speed.

Theoretically possible but for what purpose? You will simply add the time gained back in waiting for trains to cross at Basingstoke, Eastleigh or Southampton. If you want a Desiro at 110mph you can bash the WCML. It's nothing particularly special.
Woking to Eastleigh is 50 miles, you can gain at most 2.5minutes and that's if every single inch of that was currently 100mph, which is not the case. Much better things to be spending money on with the SWML, such as Remodelling Eastleigh or building some kind of freight relief line at Basingstoke (flyover or bypass P5).

 

[Snow1964]

Technically possible to go above 100mph on third rail. For the rail need longer run in ramps to avoid shoes bouncing. For many years (and still on slower sections) the ramps were just bent (kinked downwards) at end of conductor rail

Shoe technology has also moved on from a bit of cast iron bolted to a wooden plank, shoe beam was literally the wooden beam shoes hung from. Things have moved on in 110+ years and can make better shoes and power pick up at speed nowadays.

Commercially the distances aren't big enough to save more than couple of minutes, and by time also factor in better quality track, signalling, and others like trackside safety isn't worth doing, as never going to make journeys so much quicker revenue flies up to cover extra expense.

 

[Mikey C]

Would the electrical infrastructure cope with the extra power demand of regular 110mph running anyway?

 

[islandmonkey]

Technically possible to go above 100mph on third rail. For the rail need longer run in ramps to avoid shoes bouncing. For many years (and still on slower sections) the ramps were just bent (kinked downwards) at end of conductor rail

Shoe technology has also moved on from a bit of cast iron bolted to a wooden plank, shoe beam was literally the wooden beam shoes hung from. Things have moved on in 110+ years and can make better shoes and power pick up at speed nowadays.

Commercially the distances aren't big enough to save more than couple of minutes, and by time also factor in better quality track, signalling, and others like trackside safety isn't worth doing, as never going to make journeys so much quicker revenue flies up to cover extra expense.

1hr15min from Southampton Central to London Waterloo is still a very good time.

 

[Meerkat]

The max speed isn't the problem on SWR due to the short distances.
Where more speed would make a difference would be on the Portsmouth Direct, but unless that is a weak power supply its going to need some serious engineering to straighten it out a bit!

 

[Snow1964]

1hr15min from Southampton Central to London Waterloo is still a very good time.

Even if it is 7% slower than 90mph REPs and 4TCs in late 1970s and early 1980s (when timings were 70 minutes).

Higher frequency, loss of non-stop, but slower and now below the mile a minute which used to be threshold for getting people out of cars on a motorway

 

[zwk500]

The max speed isn't the problem on SWR due to the short distances.
Where more speed would make a difference would be on the Portsmouth Direct, but unless that is a weak power supply its going to need some serious engineering to straighten it out a bit!

Fair to assume that anywhere not already 90mph on the Portsmouth Direct would need to be realigned to get there.

 

[HOOVER29]

Surely then if you wanted to speed up services on 3rd rail you’d have to make the units accelerate quicker.

The 444/450’s on the SWR don’t seem that quick off the mark compared to a 350 I’ve noticed or was that just my imagination

 

[zwk500]

Surely then if you wanted to speed up services on 3rd rail you’d have to make the units accelerate quicker.

The 444/450’s on the SWR don’t seem that quick off the mark compared to a 350 I’ve noticed or was that just my imagination

Yes, raising the floor is so much better than trying to raise the ceiling.

 

[pompeyfan]

Surely then if you wanted to speed up services on 3rd rail you’d have to make the units accelerate quicker.

The 444/450’s on the SWR don’t seem that quick off the mark compared to a 350 I’ve noticed or was that just my imagination

Desiros are restricted on 3rd through the TMS to only draw ~60% on 450s and ~85% on 444s. In my opinion you’d be better off spending the money on the electrical sections so they can draw max power and accelerate quicker. That would give you faster journey times I would have thought.

 

[alf]

I agree the Portsmouth line that needs speeding up.

In the 1960’s the wooden bodied 4 cor units ran hourly non stop from Haslemere to Havant. That allowed them an 80 mph attack on the gradient up to the tunnel south of Petersfield.
Now everything stops at Petersfield & then brakes to a 40 mph crawl through the tunnel. The Nelsons (4 Cors) used to blast though the tunnel at 70 mph. Why the 40 mph limit now?

Southern Railway publicity paintings issued to promote the Portsmouth Direct electrification in 1937(?) show a 12 coach 4COR train hammering through the woods at the Buriton tunnel entrance with sparks flying from the third rail shoes.

Now 88 years on the best Network Rail can do is a 40 mph crawl through the tunnel & a Portsmouth harbour Waterloo journey time far longer than 1937.

 

[zwk500]

Now everything stops at Petersfield & then brakes to a 40 mph crawl through the tunnel. The Nelsons (4 Cors) used to blast though the tunnel at 70 mph. Why the 40 mph limit now?

Perhaps there's a problem in the tunnel? I don't think the tunnel was within the scope of the speed uplifts for the F2P resignalling, but there were a couple of spots with some 10mph bumps up.

 

[Deepgreen]

Just two questions

Is there anywhere on the 3rd rail through out the southern region other than the South Weat Mianline that has line speed of more than 90mph?

Isit possible the South West Mainline can increase its line speed upto 110mph in some section like Woking - Basingstoke - Eastleigh? I kinda think so as class 442 almost proved that but not without some serious work on the infrastructure, Would be interested to see the Desiros (potentially being the worlds fastest DC units, beating the 442 by 1mph) and Voyagers traveling that speed.

Heavily-cropped view of Woking, with a 100mph sign to the left of the loco.

 

[zwk500]

For Completeness, the sections of 100mph running are:

DOWN FAST: 33m43ch to 45m00ch (9m37ch), DOWN SOUTHAMPTON: 50m70ch to 73m20ch (22m30ch)
UP SOUTHAMPTON: 73m20ch to 53m00ch (20m20ch), UP FAST 47m40ch to 20m60ch (26m60ch)

The Down is 100mph from Farnborough to Basingstoke and Worting Jn to Eastleigh, the Up from Eastleigh to Worting JN and Basingstoke to Byfleet, there's approximately 15 miles additional 100mph running for Up trains than down.
Down trains run at 100mph for just over 30 miles of a 40mile distance, Up trains run at 100mph for 46 miles of a 53 mile distance.

London to Southampton is about 80 miles.

 

[yorksrob]

Did Ashford to Tonbridge in 23 mins a couple of years back. Was very speedy

 

[Prestige15]

There's 100mph on the Kent region from a point around Tonbridge (think it's between Tonbridge and Sevenoaks) to Saltwood Junction, from when 373s used to use the route but it's been maintained for 375s.

There was formerly a section of the Brighton Mainline around Gatwick cleared to 100mph for 319s but that's now back to 90mph for all trains as the gains were not enough to justfiy the extra maintenance.

SWML is 100mph max for 442s, 44s and 450s (HSTs and IIRC Voyagers can also use the 100mph speed but of course aren't 3rd rail). The 442 reached 110mph on proving runs as testing requires a 10% overspeed demonstration for a safety margin. AFAIK they were never authorised to work above 100mph in service.
100mph starts at Byfleet and runs to around St Denys, I think. I can't remember off the top of my head if there's any 100mph sections between Southampton and Bournemouth.

Southern (or South Central at the time) did use a 377 for its record running non stop from London to Brighton and it did went to 100mph through Gatwick



90mph is the max between Southampton and Bournemouth and 85-90 from there to Weymouth as shown here

 

[Wychwood93]

I recall a Solent and Wessex performance meeting at Overline House in Southampton - probably 1992 - when the possibility of raising the speed of the 442s up to 110 was raised. Keith Bowden, who was then the Bournemouth depot manager, said that whilst they could comfortably manage 110, he had enough going on with them running up to 100.

 

[pompeyfan]

I agree the Portsmouth line that needs speeding up.

In the 1960’s the wooden bodied 4 cor units ran hourly non stop from Haslemere to Havant. That allowed them an 80 mph attack on the gradient up to the tunnel south of Petersfield.
Now everything stops at Petersfield & then brakes to a 40 mph crawl through the tunnel. The Nelsons (4 Cors) used to blast though the tunnel at 70 mph. Why the 40 mph limit now?

Southern Railway publicity paintings issued to promote the Portsmouth Direct electrification in 1937(?) show a 12 coach 4COR train hammering through the woods at the Buriton tunnel entrance with sparks flying from the third rail shoes.

Now 88 years on the best Network Rail can do is a 40 mph crawl through the tunnel & a Portsmouth harbour Waterloo journey time far longer than 1937.

The 40 isn’t actually NRs fault, the tunnel isn’t wide enough for 23m stock (444s). Due to the risk of drivers forgetting 444s are in the consist the decision was made to reduce the speed from 70 to 40.

 

[Wychwood93]

The 40 isn’t actually NRs fault, the tunnel isn’t wide enough for 23m stock (444s). Due to the risk of drivers forgetting 444s are in the consist the decision was made to reduce the speed from 70 to 40.

IIRC the speed restriction was the same for the 442s.

 

[Mikey C]

The 40 isn’t actually NRs fault, the tunnel isn’t wide enough for 23m stock (444s). Due to the risk of drivers forgetting 444s are in the consist the decision was made to reduce the speed from 70 to 40.

The answer clearly is to remove the 444s from the Pompey line altogether, as it'll help speed up the service

 

[Prestige15]

Theoretically possible but for what purpose? You will simply add the time gained back in waiting for trains to cross at Basingstoke, Eastleigh or Southampton. If you want a Desiro at 110mph you can bash the WCML. It's nothing particularly special.
Woking to Eastleigh is 50 miles, you can gain at most 2.5minutes and that's if every single inch of that was currently 100mph, which is not the case. Much better things to be spending money on with the SWML, such as Remodelling Eastleigh or building some kind of freight relief line at Basingstoke (flyover or bypass P5).

Well how it was done on the midland mainline where theres been a number of line speed increase especially in the Market Harborough, Leicester, Derby and St pancras bottleneck area each of those section saved about 1-2 minutes, Adding all that together can make a difference.

If similar thing can be done on the SWML like increase line speed around Wimbledon to 80-90 and 90-100 between there and Woking, all adding up could make a better result. Then again Pathing and infrastructure says hello once again.

 

[edwin_m]

Well how it was done on the midland mainline where theres been a number of line speed increase especially in the Market Harborough, Leicester, Derby and St pancras bottleneck area each of those section saved about 1-2 minutes, Adding all that together can make a difference.

Each of those had a major (not quite so major in the case of Leicester) remodelling to allow higher speeds in a particular small area, so not really comparable with the OP suggestion of increasing the line speed on large parts of the SWML.

 

[Economist]

It sounds like what they'd be best doing is improving the conductor rail supply so that Desiro units aren't restricted to reduced power settings. It would help improve pathing as well as timekeeping since at the moment a Voyager, especially a 220, will easily out accelerate a Desiro on that route.

 

[D6130]

In the 1960’s the wooden bodied 4 cor units ran hourly non stop from Haslemere to Havant. That allowed them an 80 mph attack on the gradient up to the tunnel south of Petersfield.

The 4-COR/BUF/RES/GRI units were officially limited to 75 mph, as were all Southern electric units in the 1960s, with the exception of the Kent Coast express units from about 1960-62 onwards and the Bournemouth line units from 1967 onwards. However, in the case of the pre-war wooden-bodied units on the PDL, it was difficult to enforce accurately due to their absence of speedometers. Anecdotally, the COR stock trains frequently exceeded their 75 mph limit on the downhill sections of the line.....which made up for their relatively feeble uphill performance.

The Nelsons (4 Cors) used to blast though the tunnel at 70 mph.

Any down train blasting through Buriton Tunnel at 70 mph would have had to slam the brakes on pretty hard for the 45 mph permanent restriction around the almost two miles of the Ditcham reverse curves. These were relaid and recanted in the late 1970s, IIRC, and can now be taken at 60 mph.
An Up train coming uphill off the curves would have had absolutely no chance of reaching 70 by the tunnel mouth.

 

[HamworthyGoods]

Even if it is 7% slower than 90mph REPs and 4TCs in late 1970s and early 1980s (when timings were 70 minutes).

Higher frequency, loss of non-stop, but slower and now below the mile a minute which used to be threshold for getting people out of cars on a motorway

SWR did a consultation for Dec 2018 to make one Weymouth an hour fast to Winchester again all day and that went down like a total lead ballon - connectivity seemingly being more important than journey time on this route.