On Nov 17, 9:06 am, Mizter T wrote:

From that answer...

quote
Brighton to Bedford [not 'Thameslink route'] trains rarely call at
Kentish Town and Cricklewood other than in the late evening or early
morning. Instead they are served by the Wimbledon loop trains that
will remain a maximum eight carriages in length due to the road bridge
at Tulse Hill and complex track layouts near other station platforms.
/quote

I don't understand what the 'not Thameslink route' bit in square
brackets is supposed to mean?

Yes ... in their reply to me they used the same words ... but
amazingly to my surprise they followed this up without me promptng
them 2/3 days later with a correction saying that is not what they
meant ... but were supposed to be referring Brighton/Bedford trains at
that point. It is actually clear what they meant as they refer to
Wimbledon loop trains later on.



In a more detailed response to myself I asked about possible SDO
because my thoughts were if Kentish Town is limited permanently to
8car how much impact will that have overall i.e. will there still be 4
TPH 8car trains in the long term. They replied that SDO is not ruled
out ... but no decision has been made on this yet ... and IMHO does
not need to be made for some time.

As we know the plan is for the (principal) suburban Thameslink service
south of the Thames to switch from being the Wimbledon loop service to
being an Orpington or Sevenoaks service via the Catford loop (i.e.
Peckham Rye). So, how easy would it be to sort this route out for 12
car trains?


The switching of the Loop trains away from TL core is not yet decided.
This is proposed in one of the RUS (Brighton? South London? ) - it is
not a TLprogramme suggestion and loop trains remain in their version
of the 2015 network map.

True, RUS proposals have a habit of turning out to be correct, and it
seems to me the RUS reasoning is valid, but at the moment, but in the
mean time it is not certain, again, read the FAQ at

http://www.thameslinkprogramme.co.uk...ex#question_41


Given that Kentish Town and Cricklewood are only normally served by 8
car Wimbledon loop (to be Sevenoaks/ Orpington) services, I don't
understand why there is a specific interest in whether they are
getting platform extensions that they would appear not to need?.

Because if the loop trains *are* diverted away it would impose a cap
on any service that does call at Kentish Town unless SDO is
implemented. And it would be a permanent cap, way into long term
future past 2015 and way beyond. ((I assume that if the replace
Cricklewood by new Brent Cross idea does not go ahead then the
existing Criclewood would be extended to 12car.))

Leaving just Kentish Town at 8car north of Thames without SDO would
have a very great impact on capacity on the whole core route e.g. if
*all* peak hour 24 TPH trains could otherwise be 12car, the effect
alone of 4 TPH 8car (the current Kentish Town pattern but no matter
where it comes from) compared with all 12 car is an 11% reduction
through the core - 24x12=288; (20*12)+(4*8)=256; 256/288=0.888888etc.
It has a much bigger impact on the Midland side when you do that sum
for only Midland trains after remoiving GN-bound trains.

In turn, once one 8car station has been conceded, the whitehall bean
counting mandarins can move in and suggest cost cutting by allowing
other 8car station to be kept.

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

--
Nick

"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.

On 17 Nov, 09:47, D7666 wrote:

On Nov 17, 9:06 am, Mizter T wrote:

From that answer...

quote
Brighton to Bedford [not 'Thameslink route'] trains rarely call at
Kentish Town and Cricklewood other than in the late evening or early
morning. Instead they are served by the Wimbledon loop trains that
will remain a maximum eight carriages in length due to the road bridge
at Tulse Hill and complex track layouts near other station platforms.
/quote

I don't understand what the 'not Thameslink route' bit in square
brackets is supposed to mean?

Yes ... in their reply to me they used the same words ... but
amazingly to my surprise they followed this up without me promptng
them 2/3 days later with a correction saying that is not what they
meant ... but were supposed to be referring Brighton/Bedford trains at
that point. It is actually clear what they meant as they refer to
Wimbledon loop trains later on.


Thanks. Yes, it can indeed be deciphered when in context but it's a
really stupid mistake for them to make - it only succeeds in adding
confusion where there is already enough befuddlement!


In a more detailed response to myself I asked about possible SDO
because my thoughts were if Kentish Town is limited permanently to
8car how much impact will that have overall i.e. will there still be 4
TPH 8car trains in the long term. They replied that SDO is not ruled
out ... but no decision has been made on this yet ... and IMHO does
not need to be made for some time.

As we know the plan is for the (principal) suburban Thameslink service
south of the Thames to switch from being the Wimbledon loop service to
being an Orpington or Sevenoaks service via the Catford loop (i.e.
Peckham Rye). So, how easy would it be to sort this route out for 12
car trains?

The switching of the Loop trains away from TL core is not yet decided.
This is proposed in one of the RUS (Brighton? South London? ) - it is
not a TLprogramme suggestion and loop trains remain in their version
of the 2015 network map.


'Twas proposed in the South London RUS.


True, RUS proposals have a habit of turning out to be correct, and it
seems to me the RUS reasoning is valid, but at the moment, but in the
mean time it is not certain, again, read the FAQ at

http://www.thameslinkprogramme.co.uk...es/public_inde...


Very interesting. Some intriguing wording used in that answer:

"The view of the team that compiled the South London Route RUS was
that the success of the 24 trains per hour operation [through the core
Thameslink route] will depend upon a very high level of operating
performance."

Surely this should also be the view of the TL Programme team! Unless
they've subcontracted their thinking out to others, perhaps after
being lobotomised by DfT Rail.

I find it hard to believe that anything other than the RUS's
recommendation will come to be - the logic behind it is pretty solid
after all. The talk of decisions being left until later so "they will
be made with the benefit of the most relevant and contemporary
analysis possible" sounds good but unless someone's going to build a
flyover or diveunder somewhere south of Blackfriars then the physical
facts won't have changed.

I wonder if putting this official decision off (when it seems to have
essentially been decided already) can at least partially be explained
as being a bit of quasi-politically expedient procrastination? After
all there's going to be a good number of users of the Wimbledon loop
who're going to be properly cheesed off that they're losing their
through Thameslink service and are being relegated to a plain-vanilla
suburban service, especially given all this exciting talk they've
heard about the new all-singing all-dancing super-duper Thameslink
which is on the way which they previously assumed they'd be part of.

Personally I think they should just get it over and done with, confirm
the changes officially and get on with singing the praises of the new
Blackfriars station and the easy interchange that will be available
there with the frequent new Thameslink services come 2015 (or whenever
it is). But of course this is DfT Rail, the masters of
prevarication...


Given that Kentish Town and Cricklewood are only normally served by 8
car Wimbledon loop (to be Sevenoaks/ Orpington) services, I don't
understand why there is a specific interest in whether they are
getting platform extensions that they would appear not to need?.

Because if the loop trains *are* diverted away it would impose a cap
on any service that does call at Kentish Town unless SDO is
implemented. And it would be a permanent cap, way into long term
future past 2015 and way beyond. ((I assume that if the replace
Cricklewood by new Brent Cross idea does not go ahead then the
existing Criclewood would be extended to 12car.))


Understood - but as I state downthread Kentish Town is far from the
only place where the issue of short platforms pops up, there's all the
other stations south of the Thames on the proposed routes up through
the Elephant. Unless of course some of the Brighton trains might
become stopping trains north of the Thames...

(snip calculations)

In turn, once one 8car station has been conceded, the whitehall bean
counting mandarins can move in and suggest cost cutting by allowing
other 8car station to be kept.

I certainly see your point - but my recollection of the South London
RUS is that the routes they recommend for 12-car trains are not those
proposed for the 'metro' Thameslink services that run through Elephant
& Castle. The RUS places the demand for 12-car trains elsewhere.


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


Which is that the trains should have SDO, right?

I think this discussion is perhaps particularly illuminating in one
respect, which is the different perspectives with which the Thameslink
Programme can be approached from - put simply, from the north or from
the south. It's illustrative of the challenge of Thameslink - the
meshing of somewhat distinct suburban railways both north and south of
the Thames.

(Perhaps that's a rather banal comment!? Perhaps I'm putting words
into your mouth too?!)