tubechallenge.com

I have noticed, from looking at Steven Knight's track diagrams (http://www.chesapeake.net/~cambronj/lu/ ... adilly.jpg), that train reversal at Heathrow Terminal 5 will be via sidings. Why is that?

The only reason I can think of is maybe for plans to extend the line further to a 6th terminal that might want a previously defined 'northbound' and 'southbound' platform.

I could imagine that they feel it will easier for the travellers. By reversing in the sidings it will always be the same platform for arriving trains and the same for departing. After all, a substantial part of the travellers to/from Heathrow are visitors and not regular users and this method would certainly be simpler than one with alternating platforms...

I think that the arrangement at Heathrow T5 is good because loads of times I've been to T123, I've left on one platform in the morning and arrived back on the same platform in the evening.
Also, as I go down to the platforms from the ticket hall, I always look at the display to see what train is leaving next because you dont know which train is going when.
Last time I went to T123, there was only one train in the platform but becaue of previous times, I automatically looked up at the board to see what train was going to leave next.
So in my opinion, I agree with the layout at T5.

I see, I hadn't actually thought about the passenger's side of things!

This is a stupid layout. What happens if due to delays there are two T5 trains a minute or two apart? The second train will have to sit outside the station while lots of tourists get off with lots of heavy bags, then the platform staff will have to check everybody is off the train and go along the train closing all the doors, then finally the train goes off into the siding. With the normal terminal layout the second train can just go straight into the other side of the platform.

And if a train happens to break down in the arrival platform then the T5 service will have to be completely suspended, while with a normal layout they can still run trains into the other platform.

The lines from T123 - T5 could be signalled to allow reversible operation, meaning that - in such circumstances - a less frequent single line service could be run.

The way it is set out is as follows -

Heathrow service, every 4th train will go to Terminal 4. If one HT5 train is directly behind another, it will be transformed into a T4 train OR held at Heathrow 123 as T123 will become a through station (one platform for T5, one for town). Trains will be held at T4.

At T5 the staff will be employed by BAA but trained by LUL and there *will* be a member of staff for each carriage to ensure that each train is despatched very quickly.

The reason for the layout is that trains can hit the platform at FULL speed (45mph) rather than having to slow down for end of tunnel.

What do you mean by your last remark about the speed?

Are you talking about the approach speed to T5?

Yes.

The approach speed to the platforms at Terminal 5 will be full line speed.

But that goes against all of LU's safety rules for approach speed to terminii.

It has to be 10mph everywhere else, so why 45mph there?

Won't T5 have Moorgate control then?

BTW what speed do trains arrive at Waterloo on the W&C as they go through the sidings to the departure platform?

Moorgate control was introduced only to prevent trains running into tunnel walls at the ends of platforms. without tunnel walls, Moorgate Control will not be required.

so wait, when they open T5 will the T4 trains go the other way round the loop (hatton cross, then T1,2,3 then T4 then hatton cross), or will there be two platforms at T1,2,3 which both have trains going to central london? cos that would be confusing...

also, i like how boston manor has no name on this diagram. nice one!

I think from what I've heard and what I can gather is that there will be two platforms, one for trains to T5 and the other for trains to Central London. Correct me if I'm wrong please!

Moorgate Control will not be required.

The crossovers are beyond the platforms and the tunnels I believe continue for about 600m which is plenty of time for a tripcock to kick in.

T123 will have 2 platforms as per now.

P2 for Central London.
P1 for HT5.