On Tue, 2 Dec 2008, Mr Thant wrote:

On 2 Dec, 16:30, 1506 wrote:
Yes! *In this instance the cost of conversion of the Hammersmith
branch would be a very small part of the overall cost of Crossrail.

As would giving me a million pounds. That's no reason to tack it onto
the scheme unless it has benefits that justify the cost.

Indeed. For instance, you could get exactly the same benefits for
significantly less by giving me half a million pounds. I will be writing
to the minister to urge him to take forward this vital cost-saving
measure.

It would be mitigated by saving the cost of the reversing sidings at
Paddington. *The main issues would be platform widening and platform
geometry. *There might also be a need for additional ingress and
egress at stations. *Conversion to AC electrification would be
consideration.

Lots of expensive infrastructure changes to save one measly reversing
platform and probably offer a worse service than the H&C will have by
the time this could happen (trains every 5 minutes),

Is that definite? What allows the H&C to run this currently impossible
frequency? Is this a T-cup thing?

plus whatever the benefits to Circle Line operation you'd get. I don't
see the sums adding up.

If the works needed were just what 1506 suggested - a bit of platform
lengthening and shaving - it might not be too expensive. Although it would
need all-new signalling, which is not so cheap.

Are Crossrail trains going to support third rail anyway for the Abbey Wood
bit? If so, you wouldn't even need to OHLEfy Hammersmith.

But the point is that that isn't a politically viable programme. This is
Crossrail, which means the stations have to be revamped and upgraded and
made all singing and at least 60% dancing. Lifts, bigger passageways,
shiny metal everywhere. And that means bags of cash. The benefit to the
rest of the SSL might be significant, particularly for people in the
southwest who could gain single-seat rides into the northern edge of the
City, but i'm doubtful that demand on the Hammersmith branch itself is
enough to make it worthwhile. It's no GEML. Although neither is the GWML,
of course - but that's another story.

tom

--
I could tell you a great many more particulars but suppose that you are
tired of it by this time. -- John Backhouse, Trainspotter Zero