Longbridge to Barnt Green: why no longer 4 tracks?

[59CosG95]

Hi all,

I was looking at the Cross-City line earlier today, and wondered why some of the existing tracks south of Longbridge aren't as heavily utilised as others.

Take for example the Up Gloucester Slow (UGS); it runs all the way from Barnt Green, parallel to the Up Glos. Fast (UGF) and could easily be used by northbound Cross-City line services from Redditch/Bromsgrove if it were to be electrified (like the UGF/DGF). Cross-City Line services cross onto it at Longbridge Junction anyway, so it seems very strange that they don't use it already.

The Down Gloucester Goods (DGG) runs parallel to the DGF as far as Cofton Jct, where they merge, giving a 3-track railway from there to Barnt Green. However, it used to be 4-track (OS maps from the 1970s confirmed this), and, given that the uprights for the OLE headspans sit approximately on the former alignment, it must've been removed during the early 90s.

Does anyone know why this was the case, and why it hasn't been upgraded since?

Thank you very much in advance.

 

[Dr Hoo]

As Longbridge to Barnt Green is a fairly short and easily graded section with no intermediate stations all types of train can get along fairly quickly. There are nearby regulating opportunities in both directions at either end.

Why would it be necessary to have four tracks (especially if they had to be electrified)?

Things have rather moved on from when unfitted freight trains crawled along and this section was quadrupled originally.

 

[59CosG95]

As Longbridge to Barnt Green is a fairly short and easily graded section with no intermediate stations all types of train can get along fairly quickly. There are nearby regulating opportunities in both directions at either end.

Why would it be necessary to have four tracks (especially if they had to be electrified)?

Things have rather moved on from when unfitted freight trains crawled along and this section was quadrupled originally.

I'm sure the planned increase in service frequency of 3tph (Longbridge terminators extended to Bromsgrove) would be cause for using more than just 2 tracks for passenger services.

For example, if the Up Gloucester Slow were to be electrified, with linespeed raised to 90mph, Cross-City services could then use either Up Gloucester line, thus reducing the pressure on the Up Gloucester Fast. Similarly, if the Down Gloucester Goods were to be electrified, and line speed raised (not necessarily to 90mph), southbound Cross-City services could continue down it to Cofton Jct, rather than crossing onto the DGF as they currently do, causing less of an impact on the regional and intercity services which use them all the way from Kings Norton. Of course, the DGG doesn't have to be extended all the way to Barnt Green.

 

[The Planner]

You don't need it, it works with whats there. Up Gloucester raised to 90mph would be pointless, you would never reach that. Putting things out at Cofton is just moving deckchairs, you still have to get it out before or after an XC.

 

[Dr Hoo]

Well over £100m has been spent at Bromsgrove, sorting the layout out. One might hope that the re-modelling has been done with a view to accommodating the post-electrification timetable south of Longbridge.

 

[MidnightFlyer]

Well over £100m has been spent at Bromsgrove, sorting the layout out. One might hope that the re-modelling has been done with a view to accommodating the post-electrification timetable south of Longbridge.

I believe the new layout at Bromsgrove routes the terminating services into the central faces of the two islands, and sends the traffic to / from Stoke Works around the outside, removing any conflicts to the main line. I believe only one of the three per hour are booked to call at Barnt Green too, which I'm presuming relieves another constraint.

 

[Chris125]

I believe the new layout at Bromsgrove routes the terminating services into the central faces of the two islands, and sends the traffic to / from Stoke Works around the outside, removing any conflicts to the main line. I believe only one of the three per hour are booked to call at Barnt Green too, which I'm presuming relieves another constraint.

Not exactly - from the left in this photo you have the main through route towards Bristol, then a through line which can be used for turning back Cross City services, the through line towards Birmingham and finally a freight/passenger loop.

 

[MidnightFlyer]

Not exactly - from the left in this photo you have the main through route towards Bristol, then a through line which can be used for turning back Cross City services, the through line towards Birmingham and finally a freight/passenger loop.

Thanks for the clarification. The point still stands though that it is designed so as not to cause conflict with northbound services upon arrival of the extended local services, or southbound ones upon departure.

 

[ChrisHogan]

You don't need it, it works with whats there. Up Gloucester raised to 90mph would be pointless, you would never reach that. Putting things out at Cofton is just moving deckchairs, you still have to get it out before or after an XC.

My recollection of a cab ride on a 323 back in 1993 was that 90 mph is just about reached approaching Longbridge from a standing start at Barnt Green before starting to brake for the Longbridge stop.

I suspect that Barnt Green to Longbridge stretch will become another Coventry corridor with 6 323s, 3 long-distance services and the Hereford each hour when the Bromsgrove service starts in May 2018. It only needs the slightest delay to XCity services to cause significant reactionary delay. I suspect WMSC will give priority to Class 2s over this section in the future.

 

[Old Hill Bank]

Wiring all four lines from Longbridge (or even King Norton) to Cofton/Barnt Green was discussed during the development of X-City Electrification but no one would fund it. Shoving the up class 2s onto the "slow line" may now make sense but again it's money.

 

[deltic08]

Not exactly - from the left in this photo you have the main through route towards Bristol, then a through line which can be used for turning back Cross City services, the through line towards Birmingham and finally a freight/passenger loop.

Compared to platform 2, platform 4 is a bit of a dogleg. Has there been a reduction in linespeed on the new down fast through this platform since remodelling?

 

[The Planner]

My recollection of a cab ride on a 323 back in 1993 was that 90 mph is just about reached approaching Longbridge from a standing start at Barnt Green before starting to brake for the Longbridge stop.

Which shows you don't need it to be 90 if you can only attain it for a tiny amount of time.

 

[The Planner]

Compared to platform 2, platform 4 is a bit of a dogleg. Has there been a reduction in linespeed on the new down fast through this platform since remodelling?

No it hasn't reduced

 

[Ianno87]

My recollection of a cab ride on a 323 back in 1993 was that 90 mph is just about reached approaching Longbridge from a standing start at Barnt Green before starting to brake for the Longbridge stop.

I suspect that Barnt Green to Longbridge stretch will become another Coventry corridor with 6 323s and 3 long-distance services each hour when the Bromsgrove service starts in May 2018. It only needs the slightest delay to XCity services to cause significant reactionary delay. I suspect WMSC will give priority to Class 2s over this section in the future.

A plus point of the 'new' loop at Alvechurch is that extends the typical turnround time at Redditch from 6 minutes (previously) to around 15 minutes (today), to help mitigate some of the issues you describe (so a late runner Down to Redditch has a much better chance of returning on time)

 

[edwin_m]

A plus point of the 'new' loop at Alvechurch is that extends the typical turnround time at Redditch from 6 minutes (previously) to around 15 minutes (today), to help mitigate some of the issues you describe (so a late runner Down to Redditch has a much better chance of returning on time)

But won't a late runner Down to Redditch delay an Up service at the Alvechurch loop?

 

[59CosG95]

But won't a late runner Down to Redditch delay an Up service at the Alvechurch loop?

The loop doesn't just do Alvechurch station; it actually extends quite a way down until Weights Lane (roughly halfway between Alvechurch and Redditch), so there's a larger recovery margin.

 

[Ianno87]

But won't a late runner Down to Redditch delay an Up service at the Alvechurch loop?

The re-occupation of the single line at Alvechurch (from and back towards Barnt Green) seems to vary between 2.5 to 5.5 minutes in the timetable; although technically in practice it can probably be as little as 1 minute between arrival into the Down platform and departure from the up platform. So there is some allowance to absorb small lateness to a Down train before it knocks an Up train.

In the event of very late-running, there is always the option of turning back short at Longbridge, using the turnback siding that will soon have very little using it.

 

[headshot119]

The re-occupation of the single line at Alvechurch (from and back towards Barnt Green) seems to vary between 2.5 to 5.5 minutes in the timetable; although technically in practice it can probably be as little as 1 minute between arrival into the Down platform and departure from the up platform. So there is some allowance to absorb small lateness to a Down train before it knocks an Up train.

In the event of very late-running, there is always the option of turning back short at Longbridge, using the turnback siding that will soon have very little using it.

Or at Barnt Green (Assuming the turn back signal was left in)