wrote:

I think this discussion has grown out of all proportion. In the off
peak when things are not quite running to time, the line controllers
will often just send the odd train in 4 to MHE, which is in effect the
same service as a shuttle (15 mins). The shuttles are set up currently
in times of severe disruption, but from what I can see, I don't quite
grasp the reason for the mass debate?

Introducing a shuttle service is a good idea, but the way they're
planning to do it isn't, and has triggered speculation about whether
they're running the service down prior to closure.

Whats the current interval off peak anyhow?

The other flaw in the main arguments are a "through service", a
"through service" to what exactly? Camden? Change. Bank? Change.
Euston? Change.

Only the second of those examples would require a change.

The Tube is unlike the rest of the railway where
changes can be painstaking and frustrating. The tube network is a whole
series of walks, transfers and interchanges. So a few dozen people at
Finchley Central are left waiting an extra 2 minutes for a MHE train,
whats the major deal?

The big deal is that they're worsening the service, whereas it would be
so easy for them to improve the service.

The notion of reducing train lengths incidentally to save costs is
ridiculous in this instance because there would have to be customised
rolling stock for a branch line. Commonality of fleet breeds reliable
trains, fact.

The notion that it is a ridiculous notion is itself ridiculous! Firstly
it's commonality of modular components and equipment layout that gives a
reliability advantage - not how far the back cab is from the front cab!

Secondly, the rest of the fleet's big enough to gain a commonality
advantage. Having one train different is unlikely to impact on the
reliability of the rest of the fleet, even if the reliability of the
train that's different is adversely affected.

And thirdly, shorter trains are cheaper to maintain because there's less
of them to maintain! Supposing a 2 car train was sufficiently different
from the rest of the fleet that the maintenance cost per car km was
doubled. That still leaves you ahead of where you'd be if you ran a
6 car train.

Anyone know whether the change is borne from TfL or a TubeLines
infastructure related cost?

Not for certain, but it's more likely to be TfL.

--
Aidan Stanger
http://www.bettercrossrail.co.uk