On Fri, 28 Jan 2011 16:54:06 -0800 (PST), Jamie Thompson
wrote:

I've proposed this several times, as it seems quite a no-brainer to me
to give a totally segregated DC metro service from Watford Junction to
Surrey Quays and the branches following it.

I have to ask where the demand is for such a long service? Would people
really travel on a DC stopping service via East London from Watford to
South London? Surely the imperative is to boost WLL capacity and add a
second Southern service per hour?

I also cannot see hundreds of millions of pounds being spent to change
an alignment on which hundreds of millions have just been spent to
provide sufficient capacity for Overground and freight services over the
NLL.

While there does seem to be a level of demand for a service via Primrose
Hill does it really need to be hugely frequent? Could not a x30 shuttle
from Willesden Junction to Camden Road not suffice? OK people will need
to change but there will be frequent services at both points to allow
that to happen. I may be a tad out of date about platform / turnback
provision at Willesden Low Level and Camden Road (3rd platform) so my
idea might not work.

If more of the freight
could be diverted via the Goblin and Hampstead Heath (or better yet,
via some other route bypassing inner London), then the issue of the
fright loops becomes moot.

And what happens to the GOBLIN service level if yet more freight has to
be pumped along that line? It might be possible to raise line speed a
bit and possibly squash some more signalling capacity out. Network Rail
opted not to fix the decaying bridges, that result in permanent speed
restrictions, during the recent upgrade works so where will the funding
come from to fix them? TfL and the DfT cannot or won't find £250k to
progress design work for electrification so I doubt we will see any more
money being spent on the GOBLIN for a long time - more's the pity as
it's a local line for me.

I also think we need some brave thinking about local North / East London
services linking down to Stratford via Lea Bridge. Again partly local
self interest but a service from Chingford via Low Hall curve and from
Enfield via South Tottenham to Stratford would generate patronage and
aid local mobility. The Enfield proposal would create a potential
capacity problem at South Tottenham given conflicting moves so that
would need some thought.

Heck you can run it with light rail vehicles for all I care - please
just provide the services. They could sensibly be run and marketed as
part of London Overground.

The LO lines are no different to the SSL
lines, and we all know what capacities are possible on those.

Well the SSL lines don't have to cope with freight. They also have far
higher demand levels than the Overground and have trains that are twice
as long. There are other remedies like longer trains on parts of the
Overground that will raise capacity before you start resignalling and
track realignment. Didn't Ian Brown have a vision of 5 car trains on
the NLL, WLL and DCs? Not sure about ELL but that is scheduled to have
16 tph on the core section when the new SLL opens in late 2012. I think
it will take a long time to exhaust the capacity of 16 tph on the ELL
although the southern branches may be fuller south of NXG.

However, this will become impossible thanks to the strange choice of
method chosen to link HS2 to HS1. They are proposing to tunnel a
single-track tunnel from Old Oak Common all the way to Primrose Hill,
then rise up and take over one of the tracks (widened to UIC gauge)
onward to St. Pancras. I suspect the widening required might require
the removal of the other track over the viaducts though. Why they
don't just continue the tunnel a few hundred metres more to St.
Pancras is beyond me. Sure it will save a tiny fraction of the cost,
but you're crippling the LO network's future prospects.

I think you need to define what you the LO network's future prospects
are before you can conclude that a HS2 link tunnel will cripple them.
--
Paul C