West London Orbital - Alternative layout for London Overground station at Old Oak Common.

[MarkyT]

This is an alternative track and signalling layout for TfL's London Overground station at Old Oak Common, including Mildmay line and West London Orbital platforms. It is a fairly small tweak to proposals detailed in a presentation by the TfL development team to the Permanent Way Institute in early 2025. It differs from that idea mainly by routing all WLO trains via a new island platform on the west side of the Dudding Hill line to the MML, including a north facing terminal bay for short workings, and requiring no platform on the existing southbound line which would become an independent extension of the link line that currently diverges to the WCML at Acton Canal Wharf Jn, becoming a longer, more useful single line joining Willesden No.7 Jn directly to Acton Wells Jn. At ~1km long, the revised llink line could become capable of holding a maximum length freight train (775m) clear of both junctions with free run in to a clear overlap, unlike today's very short link line that can only accommodate a short train, under ~400m, without its tail blocking back over the junction to rear, as now and in the original TfL WLO layout. The current and TfL proposed layout also contain a risk of mutual blocking of long freights due to close proximity of Acton Wells and Acton Canal Wharf Junctions with unavoidable signals between them in the area where platforms are proposed. This revised proposal eliminates that risk and, with the further reduction in conflict it provides, may prove necessary to reliably accommodate the additional proposed passenger services, alongside existing freight flows and future growth in cross London traffic. Having all WLO trains on one island also potentially cuts capital costs in providing facilities and access for another side platform and may also save operationally in staffing.

 

[Mr. SW]

Interesting.

My impression was that they would somehow 'Streamline' the layout to get trains across the pointwork as quickly as possible by adjusting crossing angles, switchblade lengths and moderating curvature. The speed increase would be tiny, but a 5mph uplift is a 5mph uplift and it'll be across a junction where timing would be probably measured in seconds.

But they won't be doing anything for a few years yet. Maybe they'll make few changes in the meantime.

I've been over my notes and pulled up this diagram. It's four and a half years old but it may yet amuse.




GOOD is almost identical to the proposed scheme, but there is no bay on the West London Orbital section and there is a crossover ladder at "Atlas Road Junction", which di not occur to me at the time to label separately.
BETTER involves extending the four track section down as far as Western Avenue to provide extended layover tracks. It would mean throwing a new bridge across the Great Western Main Line. This is probably not going to ever happen.
BEST is just a bit of fun and is never, ever going to happen. A great deal of the North and South Western Junction Railway had passive provision built into it for four-tracking, which was never carried out. There are signs today of double-width bridge abutments and oddly wide boundaries but in many cases these are degraded with time and hard to spot. The proposed layout at Acton Wells I think uses unused abutments and a pier over the New North Mainline although this would result in clipping the back gardens in Wells House Road. Perhaps a little realignment may deal with this.

 

[MarkyT]

Interesting.

My impression was that they would somehow 'Streamline' the layout to get trains across the pointwork as quickly as possible by adjusting crossing angles, switchblade lengths and moderating curvature. The speed increase would be tiny, but a 5mph uplift is a 5mph uplift and it'll be across a junction where timing would be probably measured in seconds.

But they won't be doing anything for a few years yet. Maybe they'll make few changes in the meantime.

I've been over my notes and pulled up this diagram. It's four and a half years old but it may yet amuse.

View attachment 177972


GOOD is almost identical to the proposed scheme, but there is no bay on the West London Orbital section and there is a crossover ladder at "Atlas Road Junction", which di not occur to me at the time to label separately.
BETTER involves extending the four track section down as far as Western Avenue to provide extended layover tracks. It would mean throwing a new bridge across the Great Western Main Line. This is probably not going to ever happen.
BEST is just a bit of fun and is never, ever going to happen. A great deal of the North and South Western Junction Railway had passive provision built into it for four-tracking, which was never carried out. There are signs today of double-width bridge abutments and oddly wide boundaries but in many cases these are degraded with time and hard to spot. The proposed layout at Acton Wells I think uses unused abutments and a pier over the New North Mainline although this would result in clipping the back gardens in Wells House Road. Perhaps a little realignment may deal with this.

Best would be nice but likely impossible now with residential development close to the tracks, especially around stations. Better is a good idea but doesn't provide standage to hold a long freight from Kew waiting to cross Acton Wells clear of a following Willesden-bound Mildmay. A single additional loop line on this approach starting just north of Acton Central station and finishing just south of the GWML bridge could be more useful. The Western Avenue bridge looks like it could take a third track and there are no other under or overbridges structures in this ~1km stretch. An extra parallel crossover at the north end of this loop could allow a Mildmay to run into its OOC platform while the freight is getting under way through Acton Wells. It would also add more comprehensive reversing arrangements at OOC for LO trains:


Edit: a sneaky overtake if there's nothing coming the other way!