|
|
| Re: SAS termini questions (126348) | |||
 |
|||
| Home > SubChat | |||
|
[ Read Responses | Post a New Response | Return to the Index ] |
|
||
|
Re: SAS termini questions |
|
|
Posted by stephenk on Sat Aug 13 11:32:36 2005, in response to Re: SAS termini questions, posted by Rail Blue on Sat Aug 13 07:20:36 2005. "I'll have to go and see if they still open up trains on both sides on p3/4. I haven't been there for a couple of months"I think they still do, mainly for the benefit of arriving passengers although departing passengers are directed to platforms 4/5 (assuming everythings working as it should). "Firstly, what's the idea behind it being 35tph? I'd've thought 36tph would have made headways much simpler" I totally agree with you there. 35tph is an odd number. 34 or 36tph would be more sensible. As trains will be revesing in three platforms, then there will probably be uneven headways, as 33% movements conflict. Maybe this results in the 35tph? "Even if all platforms were used to reverse this 35tph, the most efficient way would still have all boarding on p4/5: 1) Train arrives on p1/2. 2) Train arrives on p3/4; train on p1/2 moves beyond station to relay on track 45. 3) Train on p3/4 departs; train on track 45 moves onto p5; train arrives on p1/2. 4) Train on p5 departs; train arrives on p3/4; train on p1/2 moves beyond station to relay on track 45. (repeat stages 3 and 4) " Some of the Paris metro termini with 3 tracks use a similar idea, with some trains relaying in sidings, and some trains reversing in a centre track in the station. It also helps with passenger flow as all passengers arrive on one island, and depart on the other. However, given LULs draconian tipping out rules, and the 4 minute driver end change rule, I think the above would get a bit too complicated to operate. Personally I think it would probably be easier to reverse trains in all three platforms, with drivers stepping back 3 trains (as will happen at Stratford on the Jubilee Line from next January). If Bank vs Charing X trains ran in a 2:1 ratio (as they do in the off-peak at present), that would be even better for stepping back operations. But using all 3 platforms would result in the passenger flow problems that I've mentioned earlier in this thread. |
|
|
|