Divining speed limits

[dpgibbons]

I have a train simulator route (the steam-era GWR line from Dorchester to Castle Cary) for which I have precise data on curvature, gradients and signal distances but no information on speed limits. So I'm wondering if I can use this data to deduce the latter. Can anyone assist please?

[Phil Bullock]

Dont forget most steam locos did not have speedometers - it wasn't the nanny state of today, train speed was largely governed by the time served experience of the engine crew based on point to point timings and load tables in the working timetable.

 

Cheers

 

Phil

Edited October 23, 2018 by Phil Bullock

[Zoe]

I have a train simulator route (the steam-era GWR line from Dorchester to Castle Cary) for which I have precise data on curvature, gradients and signal distances but no information on speed limits. So I'm wondering if I can use this data to deduce the latter. Can anyone assist please?

Speed restrictions were published in the service timetables, there is a full set of 1949 STTs available on Michael Clemens' site:  http://www.michaelclemensrailways.co.uk/?atk=592 Section 3 covers the route, you will find the speed restrictions for your section of line on page 158.  Note that only specific locations were subject to a speed restriction, elsewhere a 75 mph limit applied.

Edited October 23, 2018 by Zoe

[dpgibbons]

That's just the ticket thanks. So presumably a 75mph speed restriction board would have been placed at the end of each restricted section?

[Phil Bullock]

Can I suggest perusal of a working timetable? An absolute mine of information of this nature for any given line

 

Cheers

 

Phil

[dpgibbons]

Zoe has already obliged with the links above.

[bécasse]

That's just the ticket thanks. So presumably a 75mph speed restriction board would have been placed at the end of each restricted section?

 

The vast majority of permanent speed restrictions were not marked in any way, although the exact practice varied according to the previous owning company, drivers being expected to know speed restrictions as part of their route knowledge. Somewhen c1960 the (ex-LNER) cut-out speed restriction signs started to be adopted BR-wide (and implementation was quite rapid, initially painted white, but later yellow. Even with these there was no "end of restriction" sign, although, of course, there might be a sign for another restriction lower than the norm for the area.

 

Temporary (usually p.w.) restrictions were marked with advance warning yellow fishtail signs which indicated the actual speed limit plus © (commencement) and T (termination) signs - all back lit. The Southern Railway marked a very small number of severe permeant restrictions with boards signs similar to the temporary © (but displaying a pyramid shape rather than a C) and T signs but with no advanced warning.

 

Finally, it wasn't just steam locomotives that weren't fitted with speedometers, until the mid-1970s they weren't fitted to any Southern suburban electric units either. A lack exploited by ASLEF during "work-to-rules" to bring the service to a complete stop while the drivers still had to be paid (as it was the management's fault that there was no way of ensuring drivers didn't exceed the speed limits laid down).

[dpgibbons]

The 1949 timetables referenced by Zoe shows which speed limits had a "Permanent speed restriction indicator provided", and outside station limits these are fairly numerous. 

[jim.snowdon]

The spur to the universal signing of permanent speed restrictions was the Sutton Coldfield derailment in January 1955, after which the stencil pattern sign was adopted. Initially, they were painted white, with yellow not being adopted for many years, probably the winter of 1963-4, when the problem of seeing a white sign against a snow (white) background was accepted.

 

Jim

[The Stationmaster]

The vast majority of permanent speed restrictions were not marked in any way, although the exact practice varied according to the previous owning company, drivers being expected to know speed restrictions as part of their route knowledge. Somewhen c1960 the (ex-LNER) cut-out speed restriction signs started to be adopted BR-wide (and implementation was quite rapid, initially painted white, but later yellow. Even with these there was no "end of restriction" sign, although, of course, there might be a sign for another restriction lower than the norm for the area.

 

Temporary (usually p.w.) restrictions were marked with advance warning yellow fishtail signs which indicated the actual speed limit plus © (commencement) and T (termination) signs - all back lit. The Southern Railway marked a very small number of severe permeant restrictions with boards signs similar to the temporary © (but displaying a pyramid shape rather than a C) and T signs but with no advanced warning.

 

Finally, it wasn't just steam locomotives that weren't fitted with speedometers, until the mid-1970s they weren't fitted to any Southern suburban electric units either. A lack exploited by ASLEF during "work-to-rules" to bring the service to a complete stop while the drivers still had to be paid (as it was the management's fault that there was no way of ensuring drivers didn't exceed the speed limits laid down).

 

GWR warning boards for TROSs (temporary restrictions of speed) were painted green edged in white and did not show the speed, the WR changed over to a yellow, with an illuminated indication of the speed for the TROS, in July 1949.

 

Indicators for PROSs (permanent restrictions of speed) were revised on the WR in December 1958 when LNER pattern signs using cut out numerals, painted white, were first introduced on the Region.  Unlike the GWR pattern of illuminated indicators this type was actually sited at the point were the PROS commenced (the GWR pattern indicators were normally sited in rear of the point where the restriction commenced) and - as was the practice elsewhere - the point where normal linespeed resumed was not marked.  GWR pattern PROS indicators are not mentioned in the 1960 Appendix revision so presumably had either disappeared by then or, more likely, were in the process of being removed as fast as circumstances allowed and were considered to be not worth mentioning.

 

As far as the GWR was concerned the provision of speed indicators for PROSs was more of a rarity than commonplace, for example the September 1948 Section 1 STT (basically the London Division) shows only 15 restrictions out of well over 200 as having speed indicators.  The situation changed after the cutouts were introduced as it gradually became the practice to provide an indicator for PROSs below linespeed but, for example, the 1960/61 WR Section 1 WTT showed virtually no change in the provision of indicators from the September 1948 book.  PROSs were shown in the Sectional Appendix instead of WTTs from the 1969 reissue of the Appendices.

[DCB]

Steam era trains had an audible warning device, a rail joint every 20 yards, and a driver with a decent ear and sense of rhythm could judge his speed by these.     Also all locos have some form of "Beat" from the missing Chuff on a run down V2 to the almighty clang of a run down B1 axlebox.  These are in the 20 foot travelled range for big tank locos and with experience and a chunk of latent ability its not difficult to sense the speed. Some people don't have this ability admittedly, but then again some people can't drive their cars at anything like a constant speed even with a speedometer staring at them from the dashboard.

 

Several books of railwaymen's reminiscences refer to drivers sensing speed from beats.   Howard Gasson wrote of a man who forgot he was on a Hall not a Castle on a London train and lost time due to this.  It took years of experience to become a driver