There are various reasons why this may seem, initially, to be a bad idea. Most notably:
- The District Line will have only just been resignalled and now it looks like the branch to Ealing Broadway will need resignalling again.
- Some journeys such as Richmond to Ealing Broadway would involve going all the way to Hammersmith to change.
- Chiswick Park station would need to be added to the Piccadilly Line, which would mean platform height alterations and new points so the Piccadilly Line would call there. This would not be a popular move with most station users who would probably see their daily journey involving a change back onto the District Line at Hammersmith or Barons Court.
- Ealing Common depot is the depot for the District Line on the west side of London. If the Piccadilly Line goes to Ealing Broadway instead, then the District Line depot will not be on the line it serves
- The Piccadilly Line serves Heathrow. One would not want additional branches on the Piccadilly Line if it meant lowering the proportion of trains serve this busy transport hub.
- The Piccadilly Line effectively already has three ultimate destinations in the west (Heathow Terminal 5, Heathrow terminal 4 and Uxbridge). A fourth would make operating the line even more difficult.
The counter arguments, however, put this proposal in a different light:
- Given that this is a long term plan there is no need to re-signal the Ealing Broadway branch twice. For example, knowing the long term plan, one could continue to have District Line trains driven manually between Acton Town and Ealing Broadway until the Piccadilly takes over.
- Subsequent to this the strategy being adopted it now actually looks more and more likely like that either the same signalling system will be used for both lines or at least there will be a higher level of compatibility making this less of an issue.
- The problem of longer journeys involving a change at Hammersmith and doubling back could be eliminated by stopping all Piccadilly Line trains at Turnham Green. This would also eliminate the current situation when Piccadilly Line trains only stop at Turnham Green at certain times.
- The platforms for Chiswick Park could be relocated on the Richmond branch. Furthermore, by diverting all former District Line Ealing Broadway trains to Richmond the service from Chiswick Park would be much better than previously with double the number of trains.
- The fact that the depot isn’t on the line doesn’t really matter. In west London many drivers book on and off at Earls Court so many shifts would be unaffected. There would be some “dead running” but this cannot be avoided.
- One can only send a limited number of trains to Heathrow. Due to passengers typically being unfamiliar with the tube, possibly jetlagged and also having a lot of luggage you are never going to be able to run that many trains to Heathrow anyway as the dwell times have to be longer. Even if the Piccadilly only runs a maximum 32tph there are plenty of trains to serve Uxbridge and Ealing Broadway.
- In 2023 the concession for Heathrow Express expires. It is not currently clear what will happen then, but presumably the mayor would be free to run more Crossrail services to Heathrow – and without charging a fares premium. If that were to happen, and given that there is little chance of any significant capacity expansion at Heathrow in the short to medium term, then it could reasonably be expected that the number of passengers on the
- Heathrow branch of the Piccadilly Line would actually go down.
The number of trains required to serve Ealing Broadway will not be that great if passengers transfer to Crossrail, so it wouldn’t take many trains to provide an adequate service.
- The fact that the branches of the Piccadilly line are imbalanced is irrelevant. If you run 32tph through the central area then you need the facility to turn round 32tph on the western branches regardless of what is happening on the east side of the line. You are not going to need more than 8tph for Uxbridge and they need to dovetail in with the 16tph on the Metropolitan Line to Uxbridge. There is a limit to what you can run to Heathrow so in practice you can also serve Ealing Broadway without other branches suffering.
The main advantages of Piccadilly Line trains serving Ealing Broadway instead of the District Line are:
- It makes the Piccadilly Line completely independent of the District Line for normal daily working.
- The District Line can run 16tph to Richmond in the peak period instead of the currently inadequate 8tph.