|
Post by whistlekiller2000 on Mar 14, 2016 10:14:42 GMT
Although I've seen it happen (after the last Christmas Social stood on the platform with tut), today was the first time (just now) where I'd been in a train exiting Woodford towards the city that, using the siding, went around to the left of the parked up Hainault train occupying the mainline.
I sort of recall tut's explanation for this before but it'd be nice to see it in writing! How regular is this move nowadays?
|
|
|
Post by stapler on Mar 14, 2016 16:56:39 GMT
There will be someone who knows the exact answer, but I'd estimate over the years one in thirty or forty journeys Londonward from Loughton.....
|
|
|
Post by superteacher on Mar 14, 2016 19:22:00 GMT
It happens usually when they need to put a train into Woodford sidings or bay platform. The only access to that is via number 21 road, which is usually used to reverse the trains coming from Hainault. When access is needed to Woodford sidings or bay, they have to leave 21 road clear, and reverse the train from Hainault on the mainline. Thus, the train towards Central London goes via 21 road.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 14, 2016 19:49:48 GMT
Don't say I never give you anything This is the layout around Woodford station. Under normal circumstances, the Woodford via Hainault train arrives in westbound platform 2 (WB2) from Roding Valley and terminates. The train is tipped out, everybody gets off, with the train operator and/or platform staff going carriage to carriage and ensuring there's nobody left on the train and closing the doors of each carriage one by one using porter buttons. The train then proceeds straight out of the station turns left and parks in the siding (21 road). Here it is out of the way of the eastbound and westbound main lines and it can layover there until it's time to go back. It will then be cleared out of 21 road and into eastbound platform 3 via both crossovers, from where it can head to Roding Valley, on to Hainault and (usually) into central London via Newbury Park. However, you can also see that the only possible way to get into the bay platform (westbound platform 1 (WB1)) is via 21 road. Also, the only way you can stick a train straight in the sidings from South Woodford is via 21 road. The train will arrive on the eastbound main from South Woodford and go right over both crossovers into 21 road, from where it can go into westbound platform 1 or onto one of the sidings. This means that, if you want to put a train in the sidings to get it out of the way, or reverse a train short using the bay road, or lay a train over in the bay road, you have to leave 21 road clear for that train. What this means is that you can't put the train from Hainault on 21 road and have it wait for its correct departure time like normal, because then the train for the bay road or the sidings will have to wait for it to leave on the eastbound main, with everything else queueing up behind it. So what you do is instead you terminate the train from Hainault in platform 2 as usual, but instead of going left into 21 road, you head straight on and stop on the main line, next to 21 road. 21 road is now clear and trains can access the bay road or the sidings. The train from Hainault can then wait on the mainline until it's due to go back to Hainault, at which point it can be cleared into eastbound platform 3 via the crossover and carry on as normal. What this means, though, is that the Hainault train is now sat on the westbound main. So, of course, all westbound traffic from Woodford into central London must go around it. And it does this by simply leaving platform 2, turning left, running along 21 road and then turning right and carrying on along the westbound main to South Woodford. Of course this isn't ideal as it's really the long way round, and the low speed crossovers means this adds a fair chunk to the journey time to South Woodford. Of course, you also have to regulate your moves quite well because any train wanting to go west via 21 road may have to wait for the train terminating in platform 1/going into the sidings, or vice versa. Another option, of course, is to use the trailing crossover to the east of the station. You can terminate in platform 2, change ends in the platform and then head back to Roding Valley straight out of platform 2 and cross onto the eastbound. This is often done, but the problem is, this blocks the westbound main until the move is complete. It also means shepherding the passengers from platform 3 to platform 2 and there's always gonna be one who wants to go to London who will find themselves scratching their head at Roding Valley 2 minutes later. Nevertheless this move is common if a Hainault train is running quite late, but less useful if it's on time and not due back east for another five or ten minutes, say.
|
|
|
Post by whistlekiller2000 on Mar 14, 2016 20:09:11 GMT
Thank you my good man.
|
|
|
Post by spsmiler on Mar 14, 2016 21:10:57 GMT
I feel sure that many years ago there used to be direct access from the bay platforms to the main westbound line without needing to go via No.21 road. So why would the track layout have been changed to this format?
Simon
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 14, 2016 21:36:32 GMT
I feel sure that many years ago there used to be direct access from the bay platforms to the main westbound line without needing to go via No.21 road. So why would the track layout have been changed to this format? Simon That is correct. The track layout around Woodford used to be a lot "busier", if you will. However 21 road was just a shunt neck and siding and didn't connect to the main lines at the South Woodford end. I think that connection is a good thing, however a lot of flexibility has been lost. But it's rationalisation, it massively cuts down on the number of points you have to maintain and it cuts down on complexity when resignalling. The move from the westbound main into the bay platforms, and the sidings too I believe, was very low speed and, obviously, to protect the move would require some fierce speed control. When the old layout at Woodford was put in, you could get away with a simple trap road and still allow a full speed approach to Woodford platform 2, but when the area was resignalled that wasn't considered good enough. So keeping, or replacing, the old crossovers would've vastly increased complexity and it's a low speed, multiply conflicting move. Moreover, the old layout meant that the departure from platform 1 had to cross to the main line immediately outside of platform 2. The new layout allows you to have a departure from platform 1 and a full speed arrival into platform 2 simultaneously with full safety. I believe the old layout also allowed those moves to be signalled, but using protection that would not be considered adequate today - a simple trap road.
|
|
|
Post by norbitonflyer on Mar 14, 2016 21:38:53 GMT
I feel sure that many years ago there used to be direct access from the bay platforms to the main westbound line without needing to go via No.21 road. So why would the track layout have been changed to this format? Simon 1984 layout # I assume, as always, the layout was simplified to reduce maintenance costs. (see discussion elsewhere about Epping)
|
|
|
Post by whistlekiller2000 on Mar 14, 2016 21:41:42 GMT
I feel sure that many years ago there used to be direct access from the bay platforms to the main westbound line without needing to go via No.21 road. So why would the track layout have been changed to this format? Simon 1984 layout # I assume, as always, the layout was simplified to reduce maintenance costs. (see discussion elsewhere about Epping) Cracking picture Norbo!
|
|
|
Post by stapler on Mar 14, 2016 22:14:45 GMT
Woodford is an awful place to terminate trains. Wouldn't a connection between the up main and the bay, with a connection north of the station, ever have been considered in the past, when electrification was being considered? Obviously with steam trains, the question of running round would have been relevant, but surely a connection from the north into the bay would have been sensible with EMUs? Yes, I know the booking office, subway, and parcels station were in the way!
|
|
|
Post by norbitonflyer on Mar 14, 2016 22:18:58 GMT
Not mine - I just Googled "Woodford sidings" Last time I went to Woodford was to see the 1986 stock exhibited there.
|
|
|
Post by patrickb on Mar 15, 2016 0:18:38 GMT
I often change at Woodford and on many occasions have traveled via the No. 21 Road. Happens occasionally in the evenings. From observation, at times, the whole process of dumping passengers, closing doors and moving into the siding has been slow, and the train behind (often a Northolt train) is seen slowly creeping onto the platform. I always wondered why trains don't start at Hainault and travel through Woodford to Central London instead of the current arrangement. 3 tph surely can't effect services on the Epping Branch
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 15, 2016 0:43:08 GMT
And this, I believe (since I'm in a diagram drawing mood) is a schematic diagram of the layout before modernisation: Drawn with the help of (inter alia) Harsig's excellent signalling diagram showing the state of affairs when the Central line took over, back when the goods yard was still there.
|
|
|
Post by stapler on Mar 15, 2016 7:58:48 GMT
Patrick, the reason is capacity on the main line. The extra gaps which would be caused by pathing loop trains south of Woodford would make the present overcrowding in the peaks north thereof even worse.
|
|
|
Post by stafford on Jun 7, 2018 20:57:47 GMT
I think there may be history behind some of this. I lived in the station buildings in the electrification works period, and whilst the tube terminated and reversed in Platform 1, the steam service East (North) wards terminated and reversed in platform 2. And then years later there was the several years of trials of Automatic trains, research work towards the first Victoria line stock, using 21 to reverse as I recall. In passing, the goods yard buffers were at the end of the garden, and once a 12 ton open was pushed right to the buffers loaded with wooden compartment wall divisions from old stock being scrapped at Stratford, then passed over our fence, and after laborious dismantling used to build a garage, chicken house and domestic coal store. Stratford also charged a battery for us, bless 'em and allowed us to get the pre-war Rover going again.
|
|