Railway distances

[Zoe]

In sectional appendecies the chain is the highest resolution. When imposing a TSR does this have to start at the nearest chain or can yards within a chain be specified?

 

[Tomnick]

Wherever I've seen yards used in railway mileages generally, it has always been in the form of 'X miles, Y yards' - never 'X miles, Y chains, Z yards'. In that case, finding the nearest full chain would involve a conversion from yards to chains, not just a simple rounding operation.

 

[Zoe]

I was also thinking in terms of signal locations. Using miles and chains would not be that accurate for the position of a signal on a line so would this be specified in miles and yards?

 

[Mojo]

What a nightmare! Glad the Underground uses a real system of measurements. Even the Traffic Signs Manual uses a proper system of measurements when setting out, for example, the distance from roadworks. The signs read in miles/yards, but the distances are all in proper measurements (1 Mile signs should be placed 1600m ahead and 1 Yard = 1m).

http://www.dft.gov.uk/pgr/roads/tss/tsmanual/tsmchap8part2.pdf

 

[Zoe]

Even the Traffic Signs Manual uses a proper system of measurements when setting out, for example, the distance from roadworks. The signs read in miles/yards, but the distances are all in proper measurements (1 Mile signs should be placed 1600m ahead and 1 Yard = 1m).

Yes, I believe the 100 yards to roadworks signs you get are actually places at 100 metres.

 

[Ploughman]

TSRs are specified as Miles and Chains.
Miles and Yards are used for signal measurement.
Structure locations such as bridges may be either, but dependant on length may be recorded as centre of structure if short or start and finish if long. Possibly over 22yd long(1 Chain)
Older records may actually be in Mile / Chain / Link
100 links to the Chain
Link = approx 4 1/2 inch

 

[Soft Mick]

In sectional appendecies the chain is the highest resolution. When imposing a TSR does this have to start at the nearest chain or can yards within a chain be specified?

if you have the 'private and not for publication' sectional appendix then you should be a railway worker and you would know the answer...lol

 

[Zoe]

if you have the 'private and not for publication' sectional appendix then you should be a railway worker and you would know the answer...lol

The National Electronic Sectional Appendix is indeed restricted access but anyone can buy a printed copy.

 

[Soft Mick]

The National Electronic Sectional Appendix is indeed restricted access but anyone can buy a printed copy.

no. Thats not right. At least, the public aren't supposed to get copies! However, I've seen a well known book shop near picc selling the rule book before now....

 

[Old Timer]

The LNW, LNE, East Anglia, Southern and GW Territories use miles and chains.

The Scottish Region Sectional Appendix and WONs use miles and Yards and have done for at least 20 years that I know of.

 

[Zoe]

no. Thats not right. At least, the public aren't supposed to get copies! However, I've seen a well known book shop near picc selling the rule book before now....

Printed copies have been availabe to anyone to buy for a few years now. Printed rule book modules are also available.

 

[Trog]

The LNW, LNE, East Anglia, Southern and GW Territories use miles and chains.

The Scottish Region Sectional Appendix and WONs use miles and Yards and have done for at least 20 years that I know of.

I remember there was a trial of using miles and yards instead of miles and chains for speed restrictions on the WCML I think in the early 1990's. It lasted only a couple of weeks before we reverted to miles and chains, as there were too many problems with wrongly placed boards.

 

[The Barlow Boy]

What a nightmare! Glad the Underground uses a real system of measurements. Even the Traffic Signs Manual uses a proper system of measurements when setting out, for example, the distance from roadworks. The signs read in miles/yards, but the distances are all in proper measurements (1 Mile signs should be placed 1600m ahead and 1 Yard = 1m).

http://www.dft.gov.uk/pgr/roads/tss/tsmanual/tsmchap8part2.pdf

Chains are a real measurement and have been used on the railway for longer than those nasty foreign metre things.

 

[Old Timer]

All work on the Railway Infrastructure nowadays is done in metres and soon I can see that the Imperial system will be withdrawn, simply through the fact that most young people have little clue about anything other than the metric system, and even though distance is still measured by the Imperial system by Law.

Various routes are now being fitted with Km markings and mile posts are no longer being maintained/replaced.

 

[Hydro]

Various routes are now being fitted with Km markings and mile posts are no longer being maintained/replaced.

That will put a pretty big dent on the IM trains then, they run completely and utterly off of mileposts for synchronisation of the measurement systems. Even the new real time positioning and mapping system has the mileposts on the map and runs in miles/chains/yards. A change to KM would put the whole train borne test systems back to square one.

 

[jopsuk]

Isn't the new ERTMS system in Wales entirely in sensible metric units?

 

[Zoe]

simply through the fact that most young people have little clue about anything other than the metric system, and even though distance is still measured by the Imperial system by Law.

Is that really the case? I'm under 30 and understand the imperial system. It was even briefly covered when I was at school in the 1990s.

 

[Ploughman]

That will mean a major headache for the keepers of the structures records as these are all in Miles and Chains / yards.
All those tiny culverts that everybody forgets about until you dig one up or block it and the local farmer complains that his fields are now flooding.

 

[Marklund]

The Scottish Region Sectional Appendix and WONs use miles and Yards and have done for at least 20 years that I know of.

Sadly, not any more. They've been converted to chains. :roll:

 

[Mojo]

Chains are a real measurement and have been used on the railway for longer than those nasty foreign metre things.

Imperial is not a real system of measurements, it's a random collection of units. And there's nothing foreign about the metric system, the concept was thought up by a British person and been the official system of measurement in this country since the 1960s.

In any case, I'll carry on working in proper measurements as will everyone I work with, as will most industry (most technology, cars, etc. are all made using proper measurements and then converted into rounded imperial units). It's far easier to work out all of the calculations!
--- old post above --- --- new post below ---

Is that really the case? I'm under 30 and understand the imperial system. It was even briefly covered when I was at school in the 1990s.

I haven't got a clue. It makes no sense to me, although I admit people might understand it.

 

[PaulLothian]

As someone who spent far too much of my primary school years working out how to do additions, subtractions, etc. of imperial units, I have no doubt that metric measures make more sense, and always use them where possible. It is interesting that people are now quite selective about which imperial units they use, depending on the context, and that some of the measurements have practically disappeared - quarters (as in 2 stones = 1 quarter), quarts, furlongs (and of course chains) are almost never used in day-to-day activity.

Thank goodness...

 

[Zoe]

Are signals placed at exctact chainages then? If the distant is a sempahore then the Inner Home signal can be placed 440 yards (20 chains) in advance of the Home signal as this is the clearing point distance. If the distant is a colour light however the this is 200 yards (9.09 chains). In this case would the signal actually get placed at 10 chains rather than 200 yards?

 

[jopsuk]

the americans still use farrenheit- even in technical papers. I weep when I stumble across these. Damn prussian unit...

 

[The Barlow Boy]

Are signals placed at exctact chainages then? If the distant is a sempahore then the Inner Home signal can be placed 440 yards (20 chains) in advance of the Home signal as this is the clearing point distance. If the distant is a colour light however the this is 200 yards (9.09 chains). In this case would the signal actually get placed at 10 chains rather than 200 yards?

Signalling distances as you describe are in yards, as is (or was until the metric facists took over) detonator protection distances. It's so much easier to pace out yards than metres - especially if you're a bit on the squat size!

 

[ralphchadkirk]

Signalling distances as you describe are in yards, as is (or was until the metric facists took over) detonator protection distances. It's so much easier to pace out yards than metres - especially if you're a bit on the squat size!

:roll::roll: So people who use metric are now facists... :roll:

 

[cyclebytrain]

There's nothing wrong with using an appropriate unit of measurement, that's not metric. Take for example where there are two trains on a platform. Do you hear announcements that the front x metres of train are going to xyz or that the front y carriages are going to abc? Which one would you find more useful???

 

[ralphchadkirk]

There's nothing wrong with using an appropriate unit of measurement, that's not metric. Take for example where there are two trains on a platform. Do you hear announcements that the front x metres of train are going to xyz or that the front y carriages are going to abc? Which one would you find more useful???

Are you joking? The number of carriages going somewhere is not a unit of measurement. Hence why it wouldn't be measured in feet, yards, metres, centimetres or chains.

 

[cyclebytrain]

Are you joking? The number of carriages going somewhere is not a unit of measurement. Hence why it wouldn't be measured in feet, yards, metres, centimetres or chains.

I think you're a bit confused here. In the example, you are measuring a distance along a platform. You could do it in metres, or in carriages. Both are valid, even if you don't like it.

 

[Mojo]

I think you're a bit confused here. In the example, you are measuring a distance along a platform. You could do it in metres, or in carriages. Both are valid, even if you don't like it.

Well I think they're different ways of measuring something for a different purpose. If I have 4 help points that should be located equally along a 108m (or 6 car) platform it wouldn't be very accurate (or wise!) to say that the help points should be placed one and a half cars apart.

 

[Old Timer]

Imperial is not a real system of measurements, it's a random collection of units. And there's nothing foreign about the metric system, the concept was thought up by a British person and been the official system of measurement in this country since the 1960s..

Not sure where you got this information from old chap but I regret to say it is incorrect.

The metric system was developed in France under the leadership of Louis XVI, and principally a Frenchman called Antoine-Laurent de Lavoisier, in the late 18th Century.

That alone is sufficient excuse for anyone to keep to Imperial measurement

Despite your views on the Imperial system, like the rest of the world, it was based upon units derived from measurements associated with the body, and all the important historic buildings were built using these systems worldwide.

Remembering Imperial is easy too, as 22 yards (the length of a cricket pitch), is one chain, 80 chains are in a mile