On Jul 13, 11:41*pm, Jamie Thompson wrote:
On 13 July, 21:52, Andy wrote:

Provision of the passing loop at Bricket Wood would have had nothing
to do with the costs of the units needed to run the service. The class
350s, used by LM, cost a similar amount to the new LO class 378 units,
although it is hard to compare the costs to the train operating
company, as the rental cost of units seems to be much harder to find.
What would be cheaper is for LM to run the branch with the class 321s
that they are retaining, rather than switching to any form of new
unit.

I was led to believe that the point of the loop would be that you
could have two trains on the line at once, and due to them needing to
be 377s (or as you suggest 350s - like I say, I don't really care
about the trains themselves!), the economics didn't add up. More
juice, heavier, higher leasing...can't say I remember or indeed ever
knew the details.


Indeed, the loop would allow two trains at once, but there is really
no way to increase the frequency to every 30 mins without a loop. The
old timetable (in immediate post-electrification days) had a train
every 40 mins during the peak, but the time keeping fell off a bit
towards the end of the rush hour and there was a gap in service to
allow for this. Current frequency is a train every 42 mins at the
start of service, then 45 mins for most of the day but 45-50 mins in
the evening peak. The journey takes 16 mins end-to-end which doesn't
leave sufficient turn around times to run a reliable service every 40
mins (this would only allow 4 mins at each end).

On 13 July, 21:59, (Neil Williams)
wrote:





On Mon, 13 Jul 2009 13:25:23 -0700 (PDT), Jamie Thompson

wrote:
Yup, but one of the main reasons the passing loop got deferred is
because one of the franchise commitments that came in when LM took
over was to harmonise their fleet or some such, meaning that the line
can only be worked by a hugely excessive new 377, when a much smaller/
cheaper non-standard unit would suffice ( I believe a Silverlink Metro
unit used to operate the line before the franchise change).

It was a 313[1]. *But IMO it makes no sense to add it to the
incredibly slow DC lines. *Better use of the loop, if built, would be
to attach it to a self-contained AC Euston-Harrow-Bushey-Watford
shuttle, with most stops south of Watford being removed from existing
LM services. *This would make better use of units, as there are quite
a few LM trains that are quite quiet north of Watford but full and
standing south of either there or Harrow.

The problem is that for services north of Watford to run fast to
Euston, they need clear lines, which they won't have if St Albans
services are sitting in the platforms at Bushey, H&W, Wembley, etc.
You might have something if you were to stick a loop or two at those
stations, but that's even more unlikely than my dodgy flyover/under. I
did think about them once though, Bushey has nasty drainage issues in
the subway, so if you took advantage of a rebuild to move the
platforms further south (also enabling you to provide disabled access
via ramps a-la Carpenters Park), then you may have room for a loop or
two before the Bushey arches. At Harrow one loop would be easy by
reusing the old Belmont platform, though you'd need to fit a lift from
the eastern ticket office to the overbridge if you wanted to maintain
the existing disabled access. Two would require quite a rebuild of
most of the platform area to shuffle things around (probably
sacrificing fast line platforms in the process, not to mention that
the proximity of the road bridge's supports would limit your options).
At Wembley there's no chance. If anything were to happen I'd imagine
it'd be easiest to knock through the parcels platforms...but well.
Hmm. Adding platforms at Willesden Junction with loops from the outset
would by comparison be easy


But there is actually plenty of capacity off-peak to do this and
London Midland are planning have these relief services running from
Watford Junction anyway during the peaks anyway. If you look between
17.00 and 18.00 or between 18.00 and 19.00 there are currently 6
trains leaving Euston on the slow lines, add in the Southern service
and there are 7 passenger trains per peak hour leaving London. The
time penalty for the current Harrow / Bushey stoppers is 4 mins to
Watford Junction at non-peak times although often less during the peak
as many trains are Harrow or Bushey not both. For an easy example,
removing the Harrow and Bushey stops from the xx.04 and xx.34 off-peak
services would allow xx.10 and xx.40 services calling at Queens Park,
Wembley (ok the first two are 'extras'), Harrow, Bushey and Watford
Junction to run without impacting on the following service which uses
the slow lines (xx.24 and xx.54). Compared to many other routes out of
London, the WCML slow lines are not at capacity, even allowing for the
freight which runs during the peak. Platform loops don't really add
capacity whilst allowing for a reliable timetable, as there is a very
narrow slot for the fast train to run through whilst the slow is
stopped in the loop.

...which is why something extending every other slow DC service on a
40 minute timetable (shame they won't up the DC frequency to 4tph,
that would give a handy 30 minute every-other option) and letting
people connect to the existing AC services makes more sense for me.
That way you get less stopping at H&W/Bushey/etc. leaving more line
capacity for outer AC services.


But you'll have the same stopping at Harrow and Bushey whatever train
run on the AC lines, as the existing service will have to retain their
calls. Currently the DC services have a 16 min turnaround at Watford
Junction which allows plenty of recovery time (and this is often
used). You would turn this into 4 mins at St. Albans for every other
train, with maybe a couple of mins stand at Watford Junction in each
direction to adsorb late running / power switch over when coming onto
or off the DC lines.

This kind of thing has already started with some peak services, and is
likely to expand. *Ideal stock for it is to use LM's retained 321s.
If the branch platforms are too short for 8 cars (as I think they
are), one set could be left at Watford while the other one does the
branch - if it can work at Northampton it can work there.

I was under the impression that all the 321s would eventually be on
their way elsewhere.

Current plans see 7 x class 321 units retained by LM (unit 411 and 412
have already been repainted in LM livery) and originally it was to be
10.