In article , PhilD
writes
As I understand it, the "mileage" (what is the correct term for metric
units?) counts up along the route

from Ongar at 0.00 to Mile End, across to the District, then

through Monument, Victoria to Earl's
Court, then counts backwards around the western curve to High Street
Kensington.

Platforms 3 & 4 only, yes.

From Earls Court, this gives:

Earls Court 46.27
High St Kensington 45.65 (and 50.97 on Circle line)

45.65 is the buffers of platforms 3 and 4 (in fact, the latter, ISTR).
50.97 is Metropolitan mileage to the midpoint of platforms 1 and 2. That
mileage is calculated by following the District and then the Piccadilly
to Rayner's Lane, then backwards along the Metropolitan to Baker Street,
then forwards again via Notting Hill Gate.

South of High St Kensington is a connection between the Circle and
District routes, and both sources of information give this as 45.34.

Correct; this is on the HSK-EC curve.

This clearly does not tie up with the Circle line scale, but appears
to me as though the figure should be greater than 45.65 (i.e.
somewhere between the High St Kensington and Earls Court figures) for
the District scale.

Coo, you're quite right. I'd never noticed that before.

Other sources suggest that 45.01 is the correct figure for HSK buffers
and 45.03 for the midpoint of the through lines. Though that doesn't
feel quite right.

On the other hand, one source suggests that the kilometrage stops
decreasing at 45.34 and starts increasing again. I can't think why it
would, though.

Thanks for pointing this out. I have corrected the relevant bits of
CULG.

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