Post by mrjrt on Jan 10, 2014 2:07:46 GMT
In a discussion elsewhere on the various merits of the announced alterations to the arrangements at Turnham Green and potential options for the Ealing Broadway and Uxbridge services, I once again began musing on the strange arrangement by where the smaller tube stock provides the express services and the larger, arguably more suitable (if operated with A stock back in the day had the infrastructure been upgraded to match the potential uses and in more modern times, with S8s, for example), District line provides the local service. By way of analogy, it's like the Jubilee running to Amersham and Uxbridge and the Met running to Watford and Stanmore. Just seems strange given the more "mainline" nature of the routes (with 4 tracked sections, etc). Anyway, I was wondering if anyone was aware of the actual justifications for the current arrangements...
There's an obvious reason why things are that way now - the Heathrow tunnels were short-sightedly only built to tube gauge - but the track arrangements pre-date that mistake by quite a fair margin. The only conclusion I can come to that makes sense for me is that when the Piccadilly was diverted at its western end to take over the duty of the deep-level-District between Hammersmith and South Kensington, it also inherited the track arrangements intended for the District's surface section - The DLD would most likely have been the outer "expresses" from the extremities at Hounslow and Uxbridge, so it figures those would be the routes the Piccadilly would serve once it surfaced.
Where this theory falls down of course is the arrangements when the Piccadilly first surfaced at Baron's Court - it was to one side so it could run segregated to the Hammersmith terminus. The post 1933-era changes saw the District using the path of one of the Piccadilly's previous links to the surface District route to Lille Bridge with the Piccadilly slewed into the central position it should probably have occupied originally for better cross-platform arrangements at Hammersmith when it terminated there. But I digress. When the opportunity to extend the Piccadilly over the disused LSWR tracks arose, the cheap option of a new side platform at Stamford Brook seems to have been the choice, requiring the stopping service to serve the outside lines, and thus be operated by the District, not the Piccadilly. It makes sense for the Richmond branch to be served by the stopping service, but given the position of the junctions and the desire to adopt the LSWR route as cheaply as possible, again, it points to the choice for the District to serve it, and thus be forced into the local role.
So far the infrastructure seemingly cut is reconstruction of Stamford Brook to give the Piccadilly both platforms, and the flying junctions at Turnham Green to give the Piccadilly access to Richmond. We can look perhaps that planners may have had an eye on the Central Line's aspirations to reach Richmond, so perhaps not wanting to invest in new junctions would make sense in that context. Perhaps the District was to be the stopgap until then. However, beyond Turnham Green you have Chiswick Park, where the reconstruction for the Piccadilly's extension once again unfortunately used flanking platforms, probably to save reconstructing one of the existing ones. Strangely though, the Piccadilly extension through to Hounslow was built with island platforms, presumably because you would have had so many services heading east and west when the Piccadilly and District both served this section that having separate platforms made this easier.
Anyway, I was just wondering. Doubt anyone alive knows the real reasons...
There's an obvious reason why things are that way now - the Heathrow tunnels were short-sightedly only built to tube gauge - but the track arrangements pre-date that mistake by quite a fair margin. The only conclusion I can come to that makes sense for me is that when the Piccadilly was diverted at its western end to take over the duty of the deep-level-District between Hammersmith and South Kensington, it also inherited the track arrangements intended for the District's surface section - The DLD would most likely have been the outer "expresses" from the extremities at Hounslow and Uxbridge, so it figures those would be the routes the Piccadilly would serve once it surfaced.
Where this theory falls down of course is the arrangements when the Piccadilly first surfaced at Baron's Court - it was to one side so it could run segregated to the Hammersmith terminus. The post 1933-era changes saw the District using the path of one of the Piccadilly's previous links to the surface District route to Lille Bridge with the Piccadilly slewed into the central position it should probably have occupied originally for better cross-platform arrangements at Hammersmith when it terminated there. But I digress. When the opportunity to extend the Piccadilly over the disused LSWR tracks arose, the cheap option of a new side platform at Stamford Brook seems to have been the choice, requiring the stopping service to serve the outside lines, and thus be operated by the District, not the Piccadilly. It makes sense for the Richmond branch to be served by the stopping service, but given the position of the junctions and the desire to adopt the LSWR route as cheaply as possible, again, it points to the choice for the District to serve it, and thus be forced into the local role.
So far the infrastructure seemingly cut is reconstruction of Stamford Brook to give the Piccadilly both platforms, and the flying junctions at Turnham Green to give the Piccadilly access to Richmond. We can look perhaps that planners may have had an eye on the Central Line's aspirations to reach Richmond, so perhaps not wanting to invest in new junctions would make sense in that context. Perhaps the District was to be the stopgap until then. However, beyond Turnham Green you have Chiswick Park, where the reconstruction for the Piccadilly's extension once again unfortunately used flanking platforms, probably to save reconstructing one of the existing ones. Strangely though, the Piccadilly extension through to Hounslow was built with island platforms, presumably because you would have had so many services heading east and west when the Piccadilly and District both served this section that having separate platforms made this easier.
Anyway, I was just wondering. Doubt anyone alive knows the real reasons...
