Why do Richmond and Ealing BW trains not run to Edgware Road

"because we've always done it that way"

Back in the mists of time (before 1933) the section from High St Ken to Edgware Road was part of the Metropolitan Railway, and it was only after the formation of London Transport that District trains ventured further north (except on the jointly operated Circle). Because of short platform lengths on that section, full length (eight car) District trains couldn't operate there and as the Wimbledon branch could support a higher frequency than the other two -three until the District ceased to run to Hounslow - because they shared track as far as Turnham Green, it could more easily bear some trains being shorter.

As all trains are now run by S7 stock more complex service patterns could be used - e.g Wimbledon,Edgware Road, Aldgate, Victoria, Richmond; or Hammersmith H&C to Upminster via a complete circuit of the Circle, but it ain't broke so why try to fix it?

I don’t think the east end drivers are trained on the road past High St Ken

Chris is spot on. One train every ten minutes to Earl's Court where you can change for all other destinations is much better than one train every thirty minutes each to Wimbledon, Ealing or Richmond.

If you send trains to all three branches, a delay on one puts the trains out of turn on their return run, which causes problems for crew reliefs etc, which will then ripple across the service as a whole.
While the same issues still exist for the existing Edgware Road to Wimbledon service, because they're all going to the same destination, they all get affected, and it's possible to reform the service after disruption more easily, rather than having two thirds of your trains on time and the remaining third late.

Has it also got something to do with the fact trains from HSK can only arrive at platform 4 at Earls Court? From there anything going to Ealing Broadway or Richmond blocks a departure from platform 3 while it crosses the points. If instead the train is going to Wimbledon, no such blocking. Its not uncommon to see two trains depart platform 3 and 4 at Earls Court simultaneously, one from 4 to Wimbledon and one from 3 to Ealing Broadway / Richmond. Trains from platform 4 to elsewhere rather than Wimbledon reduces the station throughput?

The Wimbledon branch frequency is about twice Richmond or Ealing branches, allowing half to take the Edgware Road branch, and the others to provide even frequency to all branches through the City.

Unfortunately the layout on the eastbound side is the opposite - trains from Wimbledon can only reach platform 2, and thus if going on to HSK or beyond have to cross the path of any ex-Ealing or ex-Richmond train in platform 1 heading for the City. The recent demolition of Earl's Court exhibition centre, which sat above the burrowing junctions, was a missed opportunity to sort this out.

Sorry, I was sloppy with my wording and intended this to mean the Praed Street Junction to Edgware Road platforms 'system' - trying to keep the explanation short(ish).

In any case to be stricly accurate, with upgraded signalling already commisioned at Edgware Road, the area would have extra capacity for the moment (although that may be subject to the completion of any further planned work). It probably would be possible to introduce another 'leg' of the service to the Richmond or Ealing Branches on top of the current services. This however, would be at the expense of firstly unbalancing the service pattern to a different number of trains to / from HSK compared to the Hammersmith Branch; possible but likely to be much less reliable. More importantly, this would make some of the other service increases across much of the rest of the H&C and Circle and elsewhere planned for the upgrade infeasible. Overall, this would sacrifice improvements which will bring considerable relief to a selection of the key already congested passenger flows (at least in normal times), to improve a much less significant traffic objective.

And currently its not working

lt's "because"

Because:

That's the way it was always done
.
"If it's not broke, don't fix it" applies

Innovative ideas are always stifled, just in case they don't work
Innovative ideas are always stifled, just in case they do work and are superior to what went on before, then other people are blamed for not thinking of it earlier

Nobody remembers those that didn't try, so keep your head below the parapet, carry on and collect your pension - it's too good to risk
People do remember those who came up with ideas that didn't work.

Any change would be deemed to be "too complicated" for 'customers' as a reason not to implement them.
The unions might not like it

New ideas require other people to think, and it's not always what they want to do.

i.e. innovation stifled by the "we've always done it this way" brigade approach - which is back to what I posted above.

Innovations are rarely tried.

The statement by Chris L ignores the fact that currently, eastbound trains have to cross paths with Wimbledon - Edgeware Rd services. Look at the Carto Metro map, and go figure.
There are so many things that could be tried, but with the "Innovations don't always work" mentality always prevailing, we get nowhere

It is not my intention to get into an argument, so this is my LAST posting on this (unless seriously provoked).

Again, I say look at the Carto Metro map

Ealing - Upminster cross on level grade with Wimbledon - Edgeware Road trains at Earls Court. But that is NOT the case with the return trip.
SO, thinking outside the box, here's a spur of the moment 'off the wall' idea for a working - not a recommendation

1- Ealing to Edgeware Road
2- Edgeware Road to Wimbledon
3- Wimbledon to Upminster
4- Upminster to Ealing

No cross pathing required.

Other ideas are also available. They need to be. Clockwise and anti-clockwise "LOOP" services around the Circle are an idea. You just have to THINK about them, rather than simply dismiss them because you cannot be bothered to consider any change.

I now think that A60 stock and d7666 have made a good and valid point after all.

It is almost like you have two separate lines quite literally when comparing the Edgware road to wimbledon service to the Richmond/EBW to Upminster service.

I'm not sure how long the edgware road service has only gone to Wimbledon but I'm pretty sure it's been longer 50 years?

Now I agree that sending all three western destinations to Edgware road would be tough, but surely you can have two of them going to ER. It's kind of like how the Met used to only have Amershams (and for a brief period Chesham too), not serve certain stations all day everyday, making it impossible to do say a direct North Harrow to Amersham journey (bar like one or two trains in an entire day). Ofcourse they sorted this out on the met now by being rid of fasts off peak.

On the district, I appreciate you may not be able to increase the service on the route and overall district line to be able to maintain the 10min service to Wimbledon - ER frequency and also send another branch there too, so naturally, i expect that it would be half Wimbledon, half EBW or Rich going to ER. Therefore 3tph Wimbledon to ER would now have to go to upminster instead whilst 3 of the EBW or Rich to Upminster trains now go to ER. The end result.......? The mainline and therefore a lion's chunk of the line will lose what is basically a frequent service to either EBW or rich (20 mins does not sound good enough for central London passengers heading west).It would also mean the mainline has an odd 9tph to Wimbledon, 6tph to one of the others and 3tph to the final one. So three different frequencies might not make much sense and sound confusing.

I think the above result of the mainline getting just 3tph to one of the destinations west is seen as a much worse loss than simply having ER get no other service. To allow 30 more stops to gain, 4 must be inconvenienced. Seems to make more sense now.

THe ER branch is a strange one, it's like a long version of a siding which serves a couple of stops. There is no other line where there is such a huge size disparity between two branches, let alone those branches splitting within zone 1 (northern line two branches through the core are not comparable to this so please don't use that as an example). I can therefore see that the ER branch may be seen as more of a line which can be used to take away some pressure from the mainline (you can also reverse trains much quicker as ER is also closer than Upminster.

Now if frequencies along the entire line can generally be increased, that changes the entire context of this conversation. Perhaps there are plans to change service patterns post resignalling.