In article , Jonathan Morton
writes
A recent
photo
shows a second set of lines on the south west side of the station.

That could of course have been the BR (ex-GCR) lines. South of and including
Harrow-on-the-Hill they are on the south-western side of the formation,
giving Harrow three island platforms (from south to north Marylebone
down/up, Met down and Met up). I can't remember whether this arrangement
continues north of Harrow Junction.

No: the six platform tracks at Harrow are connected thus:
Northwards Southwards
1 Northbound fast Down ex-GCR
2 Southbound fast Up ex-GCR
3 Northbound slow Northbound fast
4 Northbound Uxbridge Northbound slow
5 Southbound Uxbridge Southbound slow
6 Southbound slow Southbound fast

The Uxbridge pair cross under 1-3 through the diveunder. There are
various other connections; in particular, the fast lines north of the
station connect to 3 and 6 as well and 1 and 2, and there are scissors
between the 3/4 and 5/6 pairs south of the station.

Clive's UndergrounD Guides web pages say "Traffic on the Metropolitan
was
heavy enough that it was quadrupled from Finchley Road to Kilburn in
1913,
Wembley Park in 1915, Harrow in 1932, Northwood Hills in 1961, and
Croxleyhall Junction (north of Moor Park) in 1962." I am right in
understanding this to mean that the second pair of lines were built in
1961.

Does any one have information on this second set and/or any images of
their
construction.

Sorry, no images, but the dates would be right, co-inciding roughly with the
intoduction of the A59 and A60 stock (IIRC, "A" for Amersham and the years
'59 and '60).

A60 and A62, actually.

Not sure if the reference to "second pair" of lines is
strictly correct.

All the doublings involved a second pair of tracks but some reshuffling.
It was never as simple as just adding a second pair alongside.

Certainly the Met south of Harrow is paired by direction

But only since some date around 1938; before then it was paired by
speed. The rearrangement (including new signals for two tracks) was done
in two weekend (Sat pm to Mon am, I think) blockades; between the two
dates, there was a flat crossing between the centre pair of tracks
somewhere around Dollis Hill.

(very efficient use of space, with the slows in the middle, because you can
use a single island platform where there are no fast platforms,

But this arrangement has disadvantages, including requiring a wobble in
the fast tracks and problems at junctions.

I think this continues north of Harrow,
but I can't remember exactly.

No, north of Harrow the pairing is by usage.

So I would guess that quadrupling was achieved
by a new track on each side, BICBW.

You are, I'm afraid.

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Clive D.W. Feather, writing for himself | Home:
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