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Comment made yesterday at TravelWatch SouthWest:

"How big a bottleneck is Reading?  Stand in Paddington and realise that every one of the HSTs that leaves there [with passengers on?] will be calling at the same single platform at Reading"

I'm not a Reading expert, but I thought that the HSTs that are headed for Oxford sometimes call at the platform further across, rather that 4 7.  Can someone confirm that? 

Thinking about it I've only ever seen HSTs at Reading going away from London on platform 4, but i'm guessing they use other platforms.

Grahame not sure what you are getting at.

The statement is true for most long distant HSTs except maybe some for the Oxford and the Cotswold line, although if there is conjestion the signalmen always had the option of using other platforms rather than the booked old 4.

Are they implying that it's not bottleneck because they follow each other on the same platform or that is the sole reason for the bottleneck.

There are imo several other factors. Reversing/terminating Cross Counties, flat junctions with the West of England/Basingtoke line both ends of the Reading West triangle. Which means all trains other than those terminating in 1 to 3 have to cross the Down Main and at the West end the Up Main as well. Unless the old 4 is used for Up West of Englands which occasionaly happens. But then they are blocking the Down HSTs from Padd.

Then there are of course quite a lot freight trains crosing to and from the Up and Down Reliefs. Heavy stone trains to Acton and freightliners at the West end. Then there are the down terminating stoppers which use to use 6 or 10 which have to cross the UP/Down relief on their way in or out.

It's a pretty busy station most of the day and I would say a bottleneck. Hopefully the flyovers will eliminate many of the conflicting moves and the extra platforms give more capacity.

So I would say Reading was (still is) a bottleneck.

The old 4A/B bottleneck has I assumme been sorted out with the new track layout and platform.

Hmm.  :-\

My understanding of the point Patrick Hallgate was making at TravelWatch yesterday was that his way of explaining, in very simple terms, just what a bottleneck Reading is, was to say that you could be at Paddington and know that every one of the HSTs you could see standing there would have arrived through the same platform at Reading.

Does that make a difference?

Occasionally, but 7 is the preferred platform as it avoid having to either use the up main line (platform 8) or having to cross the up main line (platform 9). In the peaks there are HSTs that use the relief line platforms, but they are the ones which are running on the relief lines calling at more stations. If the train is running main line all the way from London-Didcot, as the Oxford fast trains usually do, platform 7 is the best to use.

I understood the statement to be in relation to departing HST trains all calling at a single platform at Reading, rather than arriving trains (where much more commonly they've called at both sides of the island, and there is also at least one non-stop service inbound).  And my concern, I suppose, is that the statement made (yes, by Patrick), is dumbed down / simplified the scenario to make a nice soundbite (or perhaps "something that the passenger can understand") but in simplifying it made his comment plain wrong ... witness the comment about the HSTs that run on the local lines, confirming that it's not actually every HST. 

If the statement had been "when you're in Paddington, it could be that all the HSTs you see are going to be calling at that single platform in Reading", I wouldn't have questioned it.  But - alas - I heard "every" on departing HSTs, and will not could.  Perhaps I'm a bit of a pedant.  And perhaps I've been programming for too long.  But I like the right story, not one worded so that it's embellished.

I may come back / comment more later;  I'm on a very busy day as we have Apple Pressing in the garden, and a Python course in the training centre ... (Yes, I know it is Sunday.  Sunday is just a day of the week now!!)

In my experience what was said is true.  I cannot recall ever being on an HST out of Paddington that did not call at platform 4/7 at Reading unless there was major disruption.  However I do not catch trains to Oxford so there could be some I don't know about.

I am not sure what the minimum headway is for trains on the Down Main from Paddington, but say it is in the order of three minutes in theory it would make sense for all of them to be booked into Platform 7 at Reading.  If everything is running well they should be able to be accomodated onto 7 rather than incur a time penalty crossing over onto one of the other platforms.  However that falls down when there is disruption, or a train is delayed at Platform 7 for longer than usual. Thankfully the new flexibility of the re-modelled layout should make things easier, particularly in times of disruption.  It won't however fit more trains coming in on the Down Main from Paddington as such will it?

Coming the other way the various routes meeting at Reading means time can be saved if one train is brought in on, say 8, and then a following train in on 9.  The latter train can be loading while the former sets off on the Up Main.

Patrick dumbing down statements  :o when I worked for him never knew him to do that (sic) to be fair to him he is a good senior manager with quite a lot of railway experience, it is possible that he simplified the scenario to have covered every nuance of Reading's operation would perhaps not added anything more to what is overall message was about.

In theory it will allow more trains to come down the main line from Paddington - but it would require calling points to be altered and also the removal of Heathrow Express services. One such example will be that at the moment in peak xx00, xx03 and xx06 departures all operate, the first 2 are fast to Reading, with the last calling at Twyford. The extra platforms at Reading will allow the xx03 to have an uninterrupted run into Reading, and could potentially allow the xx06 to also run fast to Reading - and because of the extra platforms this stop skipping will make it more worthwhile, this with adjustment of paths out of Paddington, could allow another following departure 3 minutes later, however this is not possible at the moment because of Heathrow Express.

At the end of the day, when services run even 5 minutes apart from Paddington to Reading, they will always have to slow to wait for the platform, however this extra time allowed for this can be removed and allow services to depart Paddington closer together and because of the extra space at Reading they will still get a decent run non-stop to Reading because of the lack of slowing down to wait for the platform.

Something similar was done at Milton Keynes a couple of years ago, when an extra down main line platform was built. By enabling a second train to have a clear entry whilst the first one is still in the station or departing it does effectively increase the capacity of the main line (and hopefully avoid the delays and additional time already built into the schedules). No doubt as Louis 94 mentions it's not that simple and timings will need to be adjusted, but it removes one of the key constraints on the route out of Paddington.

So probably a slightly simplified comment by the speaker, but sometimes you have to make such compromises to avoid taking much longer to say what you want to say.