Question about train capacity on lines e.g. Thameslink core

[jas_sl]

Forgive what may be a very noddy question but I recently received my copy of the excellent London Railway Atlas and something stood out to me - the sheer quantity of tracks in some areas versus others.

In particular, I know that the Thameslink core section is planned to have 24 tph through just a doubled section which seems a pretty impressive figure.

Then we I look at sections such as:

- Vauxhall-Waterloo = 8 tracks
- New Cross Gate - London Bridge= 12 tracks!

I wanted to understand exactly why they have so much more infrastructure. Do they have a correspondingly large difference in the number of trains they service than Thameslink's 24 tph? How many trains go through both those sections?

If not, I imagine the differences in infrastructure would be done to a combination of the following: less efficient signalling, avoiding conflicting train movements, the funnelling of several lines, age or legacy of sections. Others?

Could, for example, better signalling and junctions mean that tracks good be freed up for other services?

 

[starrymarkb]

Forgive what may be a very noddy question but I recently received my copy of the excellent London Railway Atlas and something stood out to me - the sheer quantity of tracks in some areas versus others.

In particular, I know that the Thameslink core section is planned to have 24 tph through just a doubled section which seems a pretty impressive figure.

Then we I look at sections such as:

- Vauxhall-Waterloo = 8 tracks
- New Cross Gate - London Bridge= 12 tracks!

I wanted to understand exactly why they have so much more infrastructure. Do they have a correspondingly large difference in the number of trains they service than Thameslink's 24 tph? How many trains go through both those sections?

If not, I imagine the differences in infrastructure would be done to a combination of the following: less efficient signalling, avoiding conflicting train movements, the funnelling of several lines, age or legacy of sections. Others?

Could, for example, better signalling and junctions mean that tracks good be freed up for other services?

In the case of Waterloo peak is something like 60tph... Also trains are fanning out onto seperate routes (rather then just following each other as on thameslink) it avoids the need for a mass of flyovers at Clapham junction by having 4 tracks for the SWML and 4 tracks for the Windsor lines

 

[yorksrob]

In addition to Starrymarkb's answer I would add that the wide sections such as the approaches to London Bridge and Waterloo are due to historical Legacy, for example the approach to London Bridge includes both the London, Brighton and South Coast Railway's main line to London Bridge and the South Eastern Railway's main line to Cannon Street and Charing Cross, both of which were independantly built, owned and operated. Also typically on the approaches to the terminals, you get a mixture of suburban, stopping and express services which use the multiple lines to overtake eachother. I suspect that all Thameslink trains on the central core will stop at all of the stations on this section and travel at the same speed.

 

[tbtc]

I suspect that all Thameslink trains on the central core will stop at all of the stations on this section and travel at the same speed

That was my understanding too - meaning Thameslink's central section is essentially a "tube" level of service, every three/ five minutes or so.

However, whilst the London Underground cope with those high frequency levels on the Victoria Line etc, they are dealing with a uniform service (and not trains running from Bedfordshire/ Cambridgeshire to the south coast).
On most tube lines *everyone* gets on the first train that turns up. However, you're going to have people hanging back from a Cambridge train because they are wanting a Bedford/ Peterborough one, meaning some messy queues.

I'm not sure rail services will cope with those tight deadlines - any slip up in the central tunnel will have repercussions fifty miles away. It's going to be tigther than air craft controll over Heathrow...

 

[yorksrob]

That was my understanding too - meaning Thameslink's central section is essentially a "tube" level of service, every three/ five minutes or so.

However, whilst the London Underground cope with those high frequency levels on the Victoria Line etc, they are dealing with a uniform service (and not trains running from Bedfordshire/ Cambridgeshire to the south coast).
On most tube lines *everyone* gets on the first train that turns up. However, you're going to have people hanging back from a Cambridge train because they are wanting a Bedford/ Peterborough one, meaning some messy queues.

I'm not sure rail services will cope with those tight deadlines - any slip up in the central tunnel will have repercussions fifty miles away. It's going to be tigther than air craft controll over Heathrow...

Lets hope they're building the platforms nice and wide

 

[mackenzie_blu]

Forgive what may be a very noddy question but I recently received my copy of the excellent London Railway Atlas and something stood out to me - the sheer quantity of tracks in some areas versus others.

In particular, I know that the Thameslink core section is planned to have 24 tph through just a doubled section which seems a pretty impressive figure.

Then we I look at sections such as:

- Vauxhall-Waterloo = 8 tracks
- New Cross Gate - London Bridge= 12 tracks!

I wanted to understand exactly why they have so much more infrastructure. Do they have a correspondingly large difference in the number of trains they service than Thameslink's 24 tph? How many trains go through both those sections?

If not, I imagine the differences in infrastructure would be done to a combination of the following: less efficient signalling, avoiding conflicting train movements, the funnelling of several lines, age or legacy of sections. Others?

Could, for example, better signalling and junctions mean that tracks good be freed up for other services?

The one thing not being said is the fact all trains will be driven in auto through the core and will have their doors open for 37secs before going off to the next station. Anyone who knows the services will realise this isn't going to happen. It takes alot longer now for people to get off and despite what the train manufactures do to make it easy people will still want to get off from one set of doors. Anyone watching a peak City Thameslink train in the morning will have seen this where people file out one by one from one door only. They are in for a rude shock with the new system.

Basically the infrastructure (track, signalling) of the Core will be all new along with a new fleet of trains. The hope is that they will be able to create the desired targets. But the singalling system hasn't even been worked out yet.

I don't understand this tube references they keep making. Most services aren't in line to get extra services, just longer ones. As it said this creates huge crowds on the platforms but this isn't an issue as much as we think. Currently at Blackfriars we have resistive platforms widths but yet after an hours suspension of services its takes three to four trains to empty said platform. So new longer trains will do this just as well.

 

[The Planner]

The hope is that they will be able to create the desired targets. But the singalling system hasn't even been worked out yet.

It will be ERTMS, last I heard.

 

[Mcr Warrior]

...Currently at Blackfriars we have resistive platforms widths...

:? Interesting! What exactly is a "resistive platform width"?

 

[mackenzie_blu]

:? Interesting! What exactly is a "resistive platform width"?

Sorry that should have been restrictive!

 

[Mcr Warrior]

Sorry that should have been restrictive!

Thanks for the clarification!

 

[jas_sl]

Thanks to all posters for the info - very interesting.