Amazing underground flying crossover junctions
 

Afternoon all,

The subject line is the title of the cutaway in the centre pages of the
Eagle of 13th of October 1950, which shows Camden Town junction. I have a
book of Eagle cutaways (got it for free at Portobello Road market for
helping a trader out with his son's unicycling, but that's another story),
and one of them is a diagram of this junction. There's nothing you have't
seen before [1], but the caption says something interesting:

"The Junction at Camden Town, London, where the Northern Underground
railway lines meet is a wonderful example of flying and crossover
junctions. Trains pass under or over each other without conflicting tracks
in either direction in an ingenious layout, thus allowing traffic at peak
periods to reach a maximum frequency of 110 trains an hour."

Before you get excited, i assume that 110 tph is counting all trains
passing through, so both directions on both lines. But still, that's 27.5
tph. When we were discussing splitting the Northern line, the figures we
were kicking around were 22.5 tph in the current setup, and 30 tph with
the split. Was 27.5 tph ever achieved? If so, could it be now? If not, why
not?

tom

[1] eg at:

http://www.geocities.com/Athens/Acro...9/ltcamden.jpg

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Amazing underground flying crossover junctions
 

"Tom Anderson" wrote in message
h.li...
Afternoon all,

The subject line is the title of the cutaway in the centre pages of the
Eagle of 13th of October 1950, which shows Camden Town junction. I have a
book of Eagle cutaways (got it for free at Portobello Road market for
helping a trader out with his son's unicycling, but that's another story),
and one of them is a diagram of this junction. There's nothing you have't
seen before [1], but the caption says something interesting:

"The Junction at Camden Town, London, where the Northern Underground
railway lines meet is a wonderful example of flying and crossover
junctions. Trains pass under or over each other without conflicting tracks
in either direction in an ingenious layout, thus allowing traffic at peak
periods to reach a maximum frequency of 110 trains an hour."

Before you get excited, i assume that 110 tph is counting all trains
passing through, so both directions on both lines. But still, that's 27.5
tph. When we were discussing splitting the Northern line, the figures we
were kicking around were 22.5 tph in the current setup, and 30 tph with
the split. Was 27.5 tph ever achieved? If so, could it be now? If not, why
not?


Interesting - initial thoughts are that that is the throughput possible with
some theoretical, but no longer possible, station dwell times, and all
trains arriving from the extremities as timetabled?

Paul

Amazing underground flying crossover junctions
 

On Aug 29, 5:46 pm, Tom Anderson wrote:
Before you get excited, i assume that 110 tph is counting all trains
passing through, so both directions on both lines. But still, that's 27.5
tph. When we were discussing splitting the Northern line, the figures we
were kicking around were 22.5 tph in the current setup, and 30 tph with
the split. Was 27.5 tph ever achieved? If so, could it be now? If not, why
not?

I presume the 27.5 tph figure is the planned maximum when everything
goes to plan, and so only attempted during the peaks, and 22-25 tph
(not 22.5) is the realistic sustainable throughput.

U

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http://londonconnections.blogspot.com/
A blog about transport projects in London