4' 8 1/2''? Or, how to annoy the pub quizmaster.

[Nimbus]

"What is Britain's 'Standard Gauge'?" Four foot eight and a half inches? Er, no! In fact the track gauge was reduced from 4' 8 1/2" to 4' 8 3/8" in 1967 in an effort to alleviate severe 'hunting' problems with the wheelsets of Mark I carriage bogies. These problems must have been considerable for BR to have to go to the extreme of physically changing the railway gauge? Ah! But in 1999, presumably with the near demise of Mark I coaching stock, the gauge reverted to 1435mm ( 4' 8 1/2" ). But! In that same year, 1999, a new type of rail was introduced, known as NR 60, which required yet another new national gauge being introduced, this time 1438mm, or 4' 8 5/8". All three gauges are said to remain on various parts of the network today. Does anybody know which is where? Is the ECML now laid to 1438mm? Anyway, when 'mine host' asks the question at the start of this piece, you can now 'enlighten' him! ( I'll get my coat... )

[thesignalman]

I am sorry but I can't be convinced that the entire railway network changed gauge.

It is possible newly laid track was to those new dimensions but the thought of adjusting existing track would be another kettle of fish altogether.

John

[Rlangham]

The old theory about 4 foot 8 and a half deriving from the width of a horses backside doesn't hold much water either - waggonways were of varying sizes, such as Tanfield being four foot, and the first steam railways were of differing sizes too, Wylam being 5 foot for example

[Mickey]

The p.way probably deserves a whole topic thread to it's self anyway when I was at a signal box that had amongst several other running lines a fairly heavily used line of 'joined track' that was mainly used by Freightliner trains as well other block load freight trains and some ECS trains it was quite a common practice maybe once every 6 months for a p.way gang to go out on that length of track and 'pull back' several lengths of rails because apparently some rail lengths would creep forward and would then need pulling back if you can believe it. It seems strange that a certain length of fixed ridged things like rails would occasionally need 'pulling back' but it did use to happen I saw those guys doing it.

[thesignalman]

Yes, I remember that too, Mickey. I think the need was often driven by track on curves being pushed outside their line by heavy/fast traffic which in turn pulled the straight sections towards it.

John

[Mickey]

You remember that practice as well John of the the p.way 'pulling back' the rails as well. Yes that was usually on the Down Primrose Hill branch between Camden Road Junction and passed the area of the old Hampstead Road Junction box (Camden Lock market below) or further onwards towards Primrose Hill station. Yes the Up & Down Primrose Hill branch does twist and turn a bit around the Hampstead Road Junction area.

[Nimbus]

I seem to recall that the distance of 4' 8" ( Imperial ) was said to be the average width of Roman cart wheels? ( Roman feet and inches were smaller than later Imperial ones, but the physical distance was 4' 8" using the later measurement system ). I think this was confirmed by the archaeological discovery of buried cartwheel rut-marks leaving a known Roman stone quarry, in Northumberland possibly? The loaded carts were clearly leaving the quarry on the left hand side of the road, which is interesting too - but indicative of nothing but local usage, of course.

[JonR]

There was a conference on Friday about the Willington waggonway, this was a rare surviving section of wooden waggonway found on Tyneside that is the earliest surviving example of standard(ISH) gauge line measuring in at 4'8". It likely influenced the choice of the killingworth waggonway and the adoption by Stephenson on the Hetton, Stockton and Darlington, Canterbury and Whitstable and Liverpool and Manchester. (The half inch was added in sometime later) here's the article from Tyne & Wear Museums http://blog.twmuseums.org.uk/the-willin ... programme/