Why is Marlow a nightmare to electrify?

[SouthEastBuses]

Hopefully they'll be electrified too - albeit in this control period. Henley & Windsor should be simple enough - Marlow is still a nightmare.

Why is Marlow a nightmare to electrify?

 

[SouthEastBuses]

I'm not sure Bourne End is a nightmare; (from the cl230 thread discussion) IIRC First Group people think that 3x20m units are feasible on the branch... Plenty of 3x20m AC EMUs around.

Can you reconfigure a 387 to 3 car for use on the Marlow line whenever it gets electrified? I mean, 3 car Electrostars do exist - just look at Southern's 377/3 and Southeastern's 375/3.

If not, the alternative is an order for new 3 car 385s, or get some 3 car EMUs from Scotrail (the latter could order more 385s for older EMU replacements).

 

[JN114]

Why is Marlow a nightmare to electrify?

The issues are less with the electrification itself, which would be quite easy IMO, and more around the configuration of the junction at Bourne End - currently the practical limit is 2x23m vehicles in the Down (Marlow) platform. Rebuilding for anything longer would be difficult, albeit not impossible. No manufacturer has anything in their current ranges that fits that bill, and even then it’d be a similar deployment level to the Stourbridge Shuttle - 2 units for 1 diagram. Not at all efficient.

Case could perhaps be improved if there were a bunch of these units, and they could be doubled or even tripled up on Henleys and Windsors; it might make for a more viable fleet. Even more so if the same argument then led to the similarly 2-car infrastructure limited Greenford branch.

So I wouldn’t say the actual process of electrification would be a nightmare - objections from local residents aside. It’s more all the other work that would have to come with it. Never say never though!

 

[clagmonster]

How heavy do the passenger loadings get at Marlow? Could something similar to the Stourbridge solution work, with half hourly services Maidenhead - Bourne End and Bourne End - Marlow, the doubling of off peak service compensating for lack of direct service. Maidenhead - Bourne End would be sparked and worked by a conventional EMU.

 

[JonathanH]

There was a previous comment about the Marlow line that you wouldn't really want a unit dedicated to the route as the flange wear on the curve out of Bourne End would be excessive.

 

[HSTEd]

Looking at aerial photography it would seem that the primary problem is overlaps/buffer stop distance rather than actual physical space between the end of the track and the actual start of the pointwork.

Could you maybe come up with a derogation solution that used ETCS and very slow approach speeds to reduce the overlaps enough to get a standard 3 car unit in?

 

[JonathanH]

Could you maybe come up with a derogation solution that used ETCS and very slow approach speeds to reduce the overlaps enough to get a standard 3 car unit in?

Seems unlikely - the approach speed into Bourne End platform is already 15 mph for DMUs (10 mph for anything else) and the platform length is only 47 metres.

https://sacuksprodnrdigital0001.blob.core.windows.net/sectional-appendix/Sectional%20Appendix%20full%20PDFs/Western%20Sectional%20Appendix%20February%202021.pdf

[Picture shows except from page 143 of the Western Route Sectional Appendix showing line speeds of 15mph into the Marlow platform at Bourne End]

 

[SouthEastBuses]

This will be the most expensive and ambitious solution - but I think there should be a complete rebuild of Bourne End station, relocated underground with two tracks as a through station, with a tunnel then curving to eventually rejoin the current branch line. Electrified from the outset with potential for 8 cars, this could solve the problem of the current turn back. Otherwise, the only other solution is either a dedicated 2 car EMU for the line, or a battery powered 230.

Now the one big question - would the extremely big cost of this rather ambitious project be justified for the amount of passengers that the Marlow line gets? Basically would the potential benefits outweigh the cost disadvantage?

Seems unlikely - the approach speed into Bourne End platform is already 15 mph for DMUs (10 mph for anything else) and the platform length is only 47 metres.

https://sacuksprodnrdigital0001.blob.core.windows.net/sectional-appendix/Sectional%20Appendix%20full%20PDFs/Western%20Sectional%20Appendix%20February%202021.pdf

View attachment 95016
[Picture shows except from page 143 of the Western Route Sectional Appendix showing line speeds of 15mph into the Marlow platform at Bourne End]

Correction: if you are on about the platform where trains reverse to go to Marlow, then it is actually 85m.

 

[SouthEastBuses]

And yes a 3 car 387 for the Marlow line is actually possible - the Electrostar carriage is 20.3m long, and with the platform at Bourne End being about 70m long (not 85m as I thought in the earlier post), I can see the Marlow line shouldn't be too much of an issue to electrify.

Maybe my expensive idea of a complete remodelling of Bourne Hill won't be needed, who knows.

 

[popeter45]

The issues are less with the electrification itself, which would be quite easy IMO, and more around the configuration of the junction at Bourne End - currently the practical limit is 2x23m vehicles in the Down (Marlow) platform. Rebuilding for anything longer would be difficult, albeit not impossible. No manufacturer has anything in their current ranges that fits that bill, and even then it’d be a similar deployment level to the Stourbridge Shuttle - 2 units for 1 diagram. Not at all efficient.

Case could perhaps be improved if there were a bunch of these units, and they could be doubled or even tripled up on Henleys and Windsors; it might make for a more viable fleet. Even more so if the same argument then led to the similarly 2-car infrastructure limited Greenford branch.

So I wouldn’t say the actual process of electrification would be a nightmare - objections from local residents aside. It’s more all the other work that would have to come with it. Never say never though!

at some point we will need 2 car EMU/BMU's so maybe a fleet of 2/3 car Aventra's with end gangways as a combined thames valley fleet could make sence

 

[Whistler40145]

at some point we will need 2 car EMU/BMU's so maybe a fleet of 2/3 car Aventra's with end gangways as a combined thames valley fleet could make sence

An order of 2/3 carriage Class 717 Desiro City EMUs a possible option.

 

[NSEFAN]

This will be the most expensive and ambitious solution - but I think there should be a complete rebuild of Bourne End station, relocated underground with two tracks as a through station, with a tunnel then curving to eventually rejoin the current branch line. Electrified from the outset with potential for 8 cars, this could solve the problem of the current turn back. Otherwise, the only other solution is either a dedicated 2 car EMU for the line, or a battery powered 230.

Now the one big question - would the extremely big cost of this rather ambitious project be justified for the amount of passengers that the Marlow line gets? Basically would the potential benefits outweigh the cost disadvantage?

If you're spending all that money, then can you spare an extra few quid to reopen the route to High Wycombe, too?

 

[SouthEastBuses]

If you're spending all that money, then can you spare an extra few quid to reopen the route to High Wycombe, too?

That could also be a good idea - depends if there is enough demand for this to happen

But anyway, a much cheaper solution as I said above would be a 3 car 387.

at some point we will need 2 car EMU/BMU's so maybe a fleet of 2/3 car Aventra's with end gangways as a combined thames valley fleet could make sence

A 3 car 387 could do too as I said.

 

[JamesT]

And yes a 3 car 387 for the Marlow line is actually possible - the Electrostar carriage is 20.3m long, and with the platform at Bourne End being about 70m long (not 85m as I thought in the earlier post), I can see the Marlow line shouldn't be too much of an issue to electrify.

Maybe my expensive idea of a complete remodelling of Bourne Hill won't be needed, who knows.

Although there are 3-car Electrostars in class 377/3, is the equipment in a 387 such that you could lose a carriage and it all still work?

 

[Bald Rick]

Now the one big question - would the extremely big cost of this rather ambitious project be justified for the amount of passengers that the Marlow line gets? Basically would the potential benefits outweigh the cost disadvantage?

What do you think?

 

[The Planner]

And yes a 3 car 387 for the Marlow line is actually possible - the Electrostar carriage is 20.3m long, and with the platform at Bourne End being about 70m long (not 85m as I thought in the earlier post), I can see the Marlow line shouldn't be too much of an issue to electrify.

Maybe my expensive idea of a complete remodelling of Bourne Hill won't be needed, who knows.

I would re-check, the up platform at Bourne End is 125m, which does not connect to the Marlow branch. The down platform which does is 47m as previously described.

 

[Ianno87]

I would re-check, the up platform at Bourne End is 125m, which does not connect to the Marlow branch. The down platform which does is 47m as previously described.

The picture from Wikipedia shows a 2 car Turbo in the Down platform, to give an idea (picture shows 2 car turbo in platform, with small amount of length remaining at each end)

Bourne End railway station - Wikipedia

en.m.wikipedia.org

 

[swt_passenger]

The picture from Wikipedia shows a 2 car Turbo in the Down platform, to give an idea (picture shows 2 car turbo in platform, with small amount of length remaining at each end)

Bourne End railway station - Wikipedia

en.m.wikipedia.org

Using Google’s aerial view there’s 240 ft (73m) between buffer stop and the point machine. There really must be a practical solution, they haven’t got to gain much length. Can’t they move the buffers by dispensation against standards for a start?

 

[The Planner]

Using Google’s aerial view there’s 240 ft (73m) between buffer stop and the point machine. There really must be a practical solution, they haven’t got to gain much length. Can’t they move the buffers by dispensation against standards for a start?

Looking at street view, you aren't moving that buffer stop far.

 

[swt_passenger]

Looking at street view, you aren't moving that buffer stop far.

But as Tesco would say, every little helps...

 

[Ianno87]

Using Google’s aerial view there’s 240 ft (73m) between buffer stop and the point machine. There really must be a practical solution, they haven’t got to gain much length. Can’t they move the buffers by dispensation against standards for a start?

Looking at street view, you aren't moving that buffer stop far.

Looks like the length isn't quite there.

The only other option might be to re-align the whole platform track into where the present buildings are - though that might require some land purchase in the 'vee' of the junction. Though if you're spending that kind of money, you'd be wanting it to be 4 car-capable.

 

[SouthEastBuses]

What do you think?

I've never been on the line so I don't know. Hence why I'm asking all of you whether the huge cost is beneficial or not.

I would re-check, the up platform at Bourne End is 125m, which does not connect to the Marlow branch. The down platform which does is 47m as previously described.

Using Google satellite measurement, the actual length would be between 70 and 80m. It is possible to run a 3 car Electrostar on the Marlow line - you just need to extend the buffer towards the actual end of the track.

 

[SouthEastBuses]

I've never been on the line so I don't know. Hence why I'm asking all of you whether the huge cost is beneficial or not.



Using Google satellite measurement, the actual length would be between 70 and 80m. It is possible to run a 3 car Electrostar on the Marlow line - you just need to extend the buffer towards the actual end of the track.

Also I forgot to say, a 3 car Electrostar would be 60m long. So yes it's doable.
Plus the third carriage can potentially have the benefit to increase capacity too.

 

[popeter45]

Looks like the length isn't quite there.

The only other option might be to re-align the whole platform track into where the present buildings are - though that might require some land purchase in the 'vee' of the junction. Though if you're spending that kind of money, you'd be wanting it to be 4 car-capable.

if doing that would it just make more sence to re-site the station to be on a direct curve rather than being a terminal station?

 

[Ianno87]

if doing that would it just make more sence to re-site the station to be on a direct curve rather than being a terminal station?

That would be quite considerably more land take and environmental impact.

 

[Non Multi]

Knowing that the branches are unlikely to be wired, I'd look at a fleet of gangway ended 23m 2 car modular DEMU/BEMU/HEMUs for the long term for GW 769, 165/166 and Sprinter replacement at the start of the 2030's. Ideally with a modular design that caters for diesel-hybrid, battery or hydrogen fuel cell.

 

[JonathanH]

Knowing that the branches are unlikely to be wired, I'd look at a fleet of gangway ended 23m 2 car modular DEMU/BEMU/HEMUs for the long term for GW 769, 165/166 and Sprinter replacement at the start of the 2030's. Ideally with a modular design that caters for diesel-hybrid, battery or hydrogen fuel cell.

That sounds like a lot of spare cabs being moved around the system just to allow for 2-car units for Marlow and Greenford.

 

[Non Multi]

That sounds like a lot of spare cabs being moved around the system just to allow for 2-car units for Marlow and Greenford.

Splitting a 2 car set for 3 car formations is an option with a gangway ended units.

 

[JonathanH]

Splitting a 2 car set for 3 car formations is an option with a gangway ended units.

...provided they have suitable couplings at the inner end and there is a gangway translator plate available. There has been a trend towards more permanent couplers in the middle of units and wider gangways so it isnt certain that units of the 2030s could be formed that way.

 

[Ianno87]

Knowing that the branches are unlikely to be wired, I'd look at a fleet of gangway ended 23m 2 car modular DEMU/BEMU/HEMUs for the long term for GW 769, 165/166 and Sprinter replacement at the start of the 2030's. Ideally with a modular design that caters for diesel-hybrid, battery or hydrogen fuel cell.

Dare I say it, but a Parry People Mover running 2tph or 4tph between Marlow and Bourne End, connecting into a Class 387 Maidenhead-Marlow shuttle running 2tph.