"Niklas Karlsson" wrote in message
...
In article , David B wrote:
The best way to measure the speed is get a good GPS receiver - although
its
use is obviously limited to surface sections. AFAIK the Picadilly line
1973
stock has a top speed of 45 mph. 60 mph on A60/62 Metropolitan line
stock is
only achievable west of Harrow on the Hill.

I tried to do this on the Met line the other day, but couldn't seem to
get sufficiently good GPS reception (yes, this was in the surface
sections).

I've also tried doing the same on the SWT Reading line, which seems to
work well on the Junipers, but not very well at all on the 455s and
421s/423s, for some reason.

Perhaps there are GPS receivers with better sensitivity than my basic
eTrex, though?

Niklas
--
"The cod distributed to chip shops throughout Britain will generally first
have
been sent to Battersea for dipping."

You have my sympathies. My GPS is a Garmin and an old one and can have a lot
of trouble locking on (tracking) satellites. Maybe the more expensive makes
are better and can achieve a 'lock' a lot faster. Try moving about the train
(both sides) and if possible get a 'lock' before boarding the train so the
GPS gets a headstart once the train is moving. It takes longer to get a lock
once on the move. One other thing, make sure you have good line of sight to
the sky, ie near a window.