I want to build a crossover [2mm scale] but I don't know and having
difficulty finding out the distance between tracks.
Short of getting in the car and going down to the Spa Valley Railway
[LBSCR/SR Tunbridge Wells] 1960 ish can anyone tell me the distance between
tracks ? OR where to find such information ?
I think it used to be 6 foot on the straight. On the Liverpool Manchester
line they started out with 4' 8.5" so out of gauge loads could run on the
inner rails of both tracks during slack periods, I believe this idea was
dropped after Mr Huskisson got mashed on the opening day.
I did wonder quite a bit on the information that the track distance is
6ft 6in (more or less) and thought that it might be a narrow gauge line.
But the information on a track distance of 4ft 8½in on the Liverpool and
Manchester line toold me otherwise.
Is it really so that you measure track distance between the nearest
rails of two tracks and not between track centres? How odd.
Does this mean that 6ft 6in track distance translates into 6ft 6in + 4ft
8½in + 2½in = 11ft 5in = 3480 mm (appr.) between track centres (on
Well, you can do the same by using track centre distance and measure
from for example the left hand rail on the left hand track to the right
hand rail on the right hand track. On curves you would normally measure
between the outside rails of the curve as gauge widening will change the
position of the inside rails.
Thank you. I was uncertain of if track distance is measured over the
inside or outside faces of the rail head.
It's just one of the measurements.
The other is between centres. But unless you actually have a centre
line, a rail-to-rail distance is easier to measure.
When there was a derailment they would say "dropped into the six foot"
to say there it went.
Not really, in practical terms. You can make a gauge (stick with
two stops on it) to measure the gauge very easily - measuring to
the track centres would be more complex, and not realy necessary.
Any answer is going to be:
a - a generalization.
b - era dependant.
c - situation dependant.
d - probably wrong.
The individual founding railway companies set their own standards. They
probably set different dimensions for mainlines, branches and yards.
Since it is a major job to realign two parallel tracks given that the
sub-bases would have to be rebuilt, the tracks tended to stay the same
distance apart until such time as there was a real need to change them.
An illustration, I was watching a BBC history programme which questioned
why the properties/shop fronts in a street in some town in Britain were
all of precise equal width but to a dimension which wasn't a round
figure in feet and inches. They traced back the subdivision to the time
of Roman occupation and the dimension to a logical dimension in the
Roman mesuring system. My point is, some dimensions remain long after
the logic for their adoption is forgotten.
German track spacing is variously 3.75m on prussian branch lines, 4.0m
on early main lines, 4.25m on 20th century main lines and 4.5m (minimum)
on ICE lines. New Zealand Railways was 11 feet, increased to 12 feet
None of that answers your question but it might help explain
discrepencies in other answers you might get. ;-)
When you're laying full sized track it's a bit complicated to measure to
the center of each track, given that the existing track doesn't have any
markers or stud contacts or third rail! ;-) The track you're about to
lay isn't actually there, which makes it even more difficult!
Given illiterate track laying teams, the simplest method of accurate
spacing is to give the foreman an accurate gauge, probably a big robust
chunk of wood cut accurately to length. Given that this chunk of wood
would be unwieldy, the shortest dimension that would give accurate
spacing would be chosen.
If the gauge had matched the center to center dimension, the track
layers may well have mistaken it for a sleeper and laid it under the
Bear in mind the note about increasing to 10ft way for loops
and sidings alongside running lines.
Assuming rail at 2.3/4" wide and 6ft way, the minimum
centre-to-centre is 11ft-2in = 134"
(72" + 2 x 2.3/4" + 56.5" = 134")
(Note that on the GWR and BR(W) lines the old "00" rail was 3" wide,
so historic centres are 1/2" wider at 11ft-2.1/2in, and the "six-foot"
later 2.3/4" rail is actually 6ft-0.1/2in -- i.e. 6ft-6in to running
All spacings need to be increased on curved track to allow for vehicle
overhangs and superelevation.
It's rather amazing, then, that railway builders and maintainers in this
country are able to measure distances and clearences from the track
centre and has done so for 160 years.
Surely the gauge (bit of wood) can be cut to measure between the inner rails
and simply 'marked' for the centre to centre distance (which woulod be the
distance between the lines plus one gauge width).