Matt Wheeler wrote:
SNIP!

Towards Amersham, from Aylesbury, the trains enter LUL track at,
presumably, 60mph at "Mantles Wood Junction".
Where is the first LUL signal with trip after the junction and before
Amersham station, presumably before the siding line into the main
london bound platform at Amersham... but how close, as the trains will
still be travelling at some speed at that point.


Yep. Signal JW1. Depending on how you drive, you would be doing
anywhere between 60 and about 40 there. You would always be slowing
down for the platform at Amersham, because you are either calling at
the station, or slowing down for the Tripcock Test in the in the
platform at Amersham (its a white light by the side of the signal.
There is a device that looks like a pedal on the track, and you must
pass over that at no more than 10mph. If the white light goes out, the
test is passed, and you can proceed normally, if the light stays on,
the test is failed and you dont go any further) There was a tripcock
tester on exiting Amersham towards Aylesbury on platform 3, where the
vast majority of Chiltern services are routed. This has been removed,
and there now sits a 15mph speed limit through the station. Ive not
been through platform 2 exiting the LUL since the tripcock tester on 3
has been removed, though im fairly certain that the tester is still
there.

The effects of dangling tripcocks striking raised trainstops doesnt
seem to be a problem. Trains have been working like this for years, and
the world is still spinning. Fair enough, its got people talking on
here about it, and some of the comments have been interesting, but the
system works, and LUL, who dont change anything (there are still "off"
indicators at a lot of Met stations!) unless they really have to, arent
going to change something that isnt causing them a problem any time
soon.

As for the maximum speed limit on the LUL, well, there is a very grey
area at Amersham. There is a 70mph speed limit sign between Amersham
station and the Network Rail boundry, beyond the electrified track.
Now im told that the maximum speed anywhere on the LUL is 60mph. Ive
never seen this written down, but ive been told many times by many
different people that it is. But this 70mph sign exists. Can trains do
70mph there, or is this 60mph limit real? I for one keep on acclerating
past 60mph.