tubechallenge.com

Yes, I can hear you all now - "you're mad", "history has proven the Amersham start to be the only realistic way of doing it", but without going into the finer points of it now, I've got a small hunch that it *might* just possibly make sense to go out to Amersham and then come back into Marylebone on the Chiltern train.

One reason for this is that, according to the ever-reliable TFL journey planner, tubes arriving from Chesham (via C+L) arrive at Amersham at 25 and 55 past the hour, and trains to Marylebone depart at 26 and 56 past the hour.

A couple of questions:

1. What's more likely - tubes arriving late from C+L and trains running bang on time on the Chiltern service (disaster), or the opposite?

and

2. What's the change like from the tube to a London-bound Chiltern Express (or whatever they're called)? Is it a quick cross-platform affair, or does it involve a mad dash through the tunnels underneath the platforms?

Where are you getting those Amersham - Marylebone times from? I can't find anything in journey planner that matches this? If it is possible then the one minute connection could be tight and a huge gamble. You would need to be towards the back of the tube around carriage 4 or 5, and then it's a dash up and over a bridge to get the Chiltern service to Marylebone.

Soup Dragon wrote:Where are you getting those Amersham - Marylebone times from? I can't find anything in journey planner that matches this? If it is possible then the one minute connection could be tight and a huge gamble. You would need to be towards the back of the tube around carriage 4 or 5, and then it's a dash up and over a bridge to get the Chiltern service to Marylebone.

I based it on general mid-morning times, and using 1st April as the date (using a more current date seemed to create some problems elsewhere in terms of work going on, so as it's just a rough guide anyway, that's the date I picked for working-out purposes).

The chances of mid-morning trains arriving on time at Amersham going into London are very high.
The chances of Metropolitan trains arriving on time at Amersham from London are only moderately high.

Starkey7 wrote:The chances of mid-morning trains arriving on time at Amersham going into London are very high.
The chances of Metropolitan trains arriving on time at Amersham from London are only moderately high.

The chances of a Met signaller putting one of theirs out ahead of a Chiltern, which will then run on yellows all the way to Ricky, are extremely high.
The chances of said Met signaller then telling the Network Rail Delay Attribution Team that the Chiltern service in question was running under clear signals is even higher.

Of course, the fun bit will come when the Met is resignalled if it turns out that their ATP system (which, IIRC, is proposed to be the latest version of SELCAB) isn't backwardly compatible with Chiltern's.

I can see it now...First train from Aylesbury in the morning gets to Mantles Wood, hits the first Met ATP loop, and promptly sits down and sulks because it can't understand the signal.

Cheers,

Barry

Its a huge Gamble with 30 min frequency At Amersham I have looked at it but ruled it out as to risky for a GWR

Fifteen or twenty minutes, surely? There's a Chiltern and a Metropolitan every half an hour, and both go to London fairly fast.

Actually, for most of the day there are four Metropolitan trains and two Chiltern trains leaving Amersham and heading into London - so a mean frequency of ten minutes.

Unless it's changed a lot since I left, that is.

TheFatBuoy wrote:Yes, I can hear you all now - "you're mad", "history has proven the Amersham start to be the only realistic way of doing it"

Watch January 12th attempt that is not starting at Amersham.But wont tell u where.

So far as I can see, "Changing at Amersham" means neither starting nor finishing in the top left corner - are the only remaining realistic start or end points for a GWR then Heathrow T4 or T5, Epping, or Upminster (probably the ideal finish if you just want to get round)?

It could mean a start/finish at Chesham, Jbom1.

jamesthegill wrote:It could mean a start/finish at Chesham, Jbom1.

In principle, yes, but then I wouldn't be taking the fast train to Marylebone

Hasn't history shown that a Chesham start is asking for trouble too?

Or have timetables changed since "my day"?

palkanetoijala31 wrote:

TheFatBuoy wrote:Yes, I can hear you all now - "you're mad", "history has proven the Amersham start to be the only realistic way of doing it"

Watch January 12th attempt that is not starting at Amersham.But wont tell u where.

Morden? Possibly involving a Wimbledon to Vauxhall SWT train later on in the day?

Never rely on a Chiltern train!! Not sure what that part of the line has been like but Gerrards Cross to London has been up shits creek for about the past month in the mornings, not great