"D7666" wrote

through the core - 24x12=288; (20*12)+(4*8)=256; 256/288=0.888888etc.

ITYF it should be 272, so a reduction of a little over 5%.

Thus it is very important to understand this issue, and very important
they get it right.

Exactly.

The Catford Loop stopping service only gets 2 tph in the evening peak (plus
one extra shoulder peak train), so it will be difficult to justify the cost
of extending platforms at these stations, especially as Elephant & Castle,
Peckham Rye, and Bellingham (if the sidings are retained) look difficult to
extend to full 12 car.

Peter

On Nov 17, 11:58 am, "Peter Masson" wrote:

through the core - 24x12=288; (20*12)+(4*8)=256; 256/288=0.888888etc.

ITYF it should be 272, so a reduction of a little over 5%.

Oh yes, sorry, added the 16 to 240 instead of taking it off the 288
d'oh.


Thus it is very important to understand this issue, and very important
they get it right.

Exactly.


Having just tripped over myself there ) even 5-6% in the core is
still significant, and it still gets to be bigger when looking only at
Midland services.

--
Nick

On Nov 17, 11:58 am, "Peter Masson" wrote:

Bellingham (if the sidings are retained) look difficult to
extend to full 12 car.

I'm puzzling over St.Albans for similar reasons.

The south end is already extremely narrow on the island platforms 2/3
- it is so narrow it would never get through safety rules if this were
a new station today. So if extending that way they would need to
significantly widen as well as lengthen ... and I think that option
has effectively been cut off by the new building work outside the
railway on the Up side.

The north end has the present 8car turnback siding in immediately off
the north end of the platforms. For the turnback to be retained to be
of any operational use it too would need extending to 12 cars ... and
as reported in uk.railway previously it is only just dead 8car now, so
probaly needs extedning by 4-and-a-bit for SPAD mitigation. So if the
platforms are extended north by 4car, the buffer stops at the extreme
end of the turnback needed shifting north by a bit more than
equivalent to 8 car lengths, and here you are well into a deep
cutting.

Even staggering the extended platforms does not work for combinations
of the above reasons.

I am assuming therefore that St.Albans loses its turnback facility ???

--
Nick

On Mon, 17 Nov 2008 05:01:55 -0800 (PST), D7666 wrote:

Bellingham (if the sidings are retained) look difficult to
extend to full 12 car.

I'm puzzling over St.Albans for similar reasons.

The south end is already extremely narrow on the island platforms 2/3
- it is so narrow it would never get through safety rules if this were
a new station today. So if extending that way they would need to
significantly widen as well as lengthen ... and I think that option
has effectively been cut off by the new building work outside the
railway on the Up side.

The north end has the present 8car turnback siding in immediately off
the north end of the platforms. For the turnback to be retained to be
of any operational use it too would need extending to 12 cars ... and
as reported in uk.railway previously it is only just dead 8car now, so
probaly needs extedning by 4-and-a-bit for SPAD mitigation. So if the
platforms are extended north by 4car, the buffer stops at the extreme
end of the turnback needed shifting north by a bit more than
equivalent to 8 car lengths, and here you are well into a deep
cutting.

Even staggering the extended platforms does not work for combinations
of the above reasons.

I am assuming therefore that St.Albans loses its turnback facility ???

Surely the turnback siding doesn't have to be immediately outside the
station? It could, for example, be moved a few hundred yards down the
line.