On Wed, 10 Jan 2007, Dave A wrote:

Tom Anderson wrote:
On Tue, 9 Jan 2007, asdf wrote:

On Tue, 9 Jan 2007 13:07:54 -0000, John Rowland wrote:

Personally I dont see why the Met line has to run to Barking?

Because at the moment, the Met trains empty out in one direction and
fill up in the other. It's better to have them filling up with new
people as the old ones get out.

And by swapping the eastern destinations of the Met and H&C, exactly
the same thing happens with the H&C...

But the Met east of Baker Street has 120 carriages per peak hour, whereas
the H&C has something like 48 carriages per peak hour.

But if 15 Met tph are to head through Aldgate East, some Districts will
have to be cut back to Tower Hill (and/or Mansion House) to make room,
which just shifts the same situation onto those Districts.

No, because the Mets replace H&Cs.

asdf has a point - the current H&C service is only 8tph. If all 15tph Met go
to Barking, then 7tph will have to be removed from the District service

Allowing another 7tph of Hammersmith trains to be Teacups rather than
Aldgates - by jove, Holmes, we've cracked it!

Assuming they reverse somewhere like HSK or Edgware Road, rather than
Tower Hill, of course.

- I imagine that demand for services along the southern Circle is higher
than for the northern Circle.

Ah, but between where? If the demand is along the actual circle bit
(Charing Cross to the City, say), then heavily pruning some Districts back
to a western point and replacing them with Teacups would be fine; if the
demand is actually from the western District suburbs to the south side of
the circle, it wouldn't, and the admittedly far more sensible idea of
reversing some Districts at Tower Hill would come into play. The only case
where you need to preserve the full District service beyond Tower Hill is
if there's much more demand for trips from the eastern end of the
District/H&C to the south circle than the north.

Hmm. I think i'm in knip there.

Anyway, yes, there you, all fun and games until someone loses a peak-time
through train.

Perhaps 7tph from the Met will terminate at Aldgate alongside 8tph from
the new H&Circle service.

Well, or that. So now we have both the Met and the H&C having half Aldgate
and half through trains. What fraction of District trains reverse at Tower
Hill rather than running through? ISTR it's actually quite a lot.

Trying to get my head around this service pattern is as difficult as the
multitude of proposals for the North London Railway.

I had a look at the service patterns on the railway south of the river the
other day.

*shudders*

tom

--
Curse me, God, for making you this way!