MoD P-Way Design & Maintenance Book

I'm not sure if this is the correct section - if it should be elsewhere, moderators, please feel free to move it.

I came across this MoD publication which goes into great detail about the specification, design, construction and maintenance of P-Way - with masses of formulae for calculating minimum radii for specific lengths of wheelbase, cant, expansion gaps, fitting dimensions for chair ferrules, reclaiming damaged sleepers - and even guidance on inspecting pre-used track components to judge whether they are fit for further use. Bonus - it also covers narrow gauge track, too! It really is a mine of very practical advice and data. Here's the link:

https://www.gov.uk/government/uploa...nent_Way_Design_and_Maintenance_-_issue_4.pdf

 

Some interesting pictures too, including the Shoeburyness turntable.

Sadly, the companion volume on maintaining the strategic reserve of steam locomotives is still redacted.

 

A most interesting and informative document. Would IMO be a useful addiction to any PW Department Bookshelf as a reference/guide, especially any new/embryonic outfit. Really liked the level rail crossing obviously the Welsh Highland narrow gauge line crossing the NR line standard gauge line in Porthmadoc.

 

I would consider this as a guide for industrial standard trackworks.
As far as I can tell most of the Preserved Standard gauge railways in this country work to the higher standards to be found in Network Rail Group Standards.

The use of 75lb rail and MOD Concrete sleepers are one example of the lower standards covered by the handbook.
Most railways will use current or recently withdrawn NWR or BR standard concrete / timber / steel sleepers with BH rail of original 95lb dimensions or FB rail of no less weight than 98lb upto the most recent UIC 60.

 

I agree that the book does cover obsolete rail and the old MoD sleepers, but it makes clear that though these are present on many MoD lines, replacements and new build should not use them. I quote from pp. 67-69:
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Existing Track in BS75R Type Rail

BS75R rail is now obsolete; however there remains a substantial amount still in service at some MOD depots, and still in acceptable condition for lighter traffic use. This rail is usually vertical and is supported on former Ministry of Supply concrete sleepers with clips and screwed stud fixings, or timber sleepers with pressed steel baseplates, AS screws and Pandrol PR401 clips. Older pattern dogspikes and associated base plates should be replaced.



Figure 7.6 Plain line track – obsolete BS75R rail on concrete sleepers
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But for new build track, and track already built with CEN56 rail, it says this:

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New Work and Existing Plain Line in CEN56 (BS113A, RT113A, or equivalent) Type Rail

Plain line is normally inclined CEN56 (BS113A, RT113A, or equivalent) rail with F27 or F40 type prestressed concrete sleepers in hard stone ballast (preferably granite), with Pandrol e1809 clips. Creosote treated softwood timber sleepers with Pandrol baseplates can also be used according to conditions. As an economy and where existing track is to be matched, rails can be vertical and used with pressed steel baseplates, Pandrol PR401 clips and timber sleepers. Pressed steel baseplates should be fixed to sleepers by galvanised AS type short pattern 140mm screws.



Figure 7.5 Plain line track – BS113A rail on concrete sleepers

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To reject the entire book, with its wealth of practical and useful guidance and data, just because it refers to obsolete rail standards (whilst making it clear that they are obsolete), seems like throwing out the baby with the bathwater. It may well be the case that some preserved lines still have such track and sleepers in yards and sidings, so the information in the book on how to set up the ballasting for such track could well save those railways a lot of broken concrete sleepers.

And I would think that the narrow gauge data, with all the detailed formulae for calculating appropriate curve radii, cant, and gauge widening with regards to wheelbase lengths, and the drawings giving dimensions and angles for ballast and drainage, would be most useful to narrow gauge operators, particularly when building new sidings, passing loops and extensions.

 

Note your comments and I do agree that some aspects of this book are useful, but it should be remembered that it is aimed at what is an Industrial system not a passenger one.

If you are going to use new FB rail what length of rail is going to be used?
In the book you will find 4 different lengths quoted. 18.282, 18.288, 18.29 and 18.3m
It may seem a small detail but at 3 in the morning and you need to make an extra unplanned cut or worse try and make a short rail fit a correct gap.
If accuracy is required one only should be used.
Did not see any mention of sleeper installation over 24 per length.
Are Timber strapping rails actually used on any CWR? BH rail or FB rail yes, but I have never seen any Timber ones and they should never be positioned as indicated on the diagram showing the ADJ Switch. How do you tamp it?
Reversible clips, are not a feature of standard railway concrete sleepers.p157

 

How about the purchaser picking a length to match the rail lengths they are already using, and clearly specifying that length on the purchase order form? I'd have thought that was standard procedure even if you're only ordering photocopy paper.

As I used to specify dimensions down to +/- 0.001" on some of the engineering drawings I drew up, I don't call that a small detail at all - especially not if you're talking about a quarter of a mile of track.

Considering the number of times I've known and read about P-Way departments buying in second-hand track from both main line and industrial sources, I find it hard to believe that they would never have come across a situation of having rails of two or more of those lengths - and dealt with them.

In view of the number of instances of railways buying second-hand rails, and having to collect them at very short notice, I'd have said that was a counsel of perfection.

Never having done any more on P-Way work than second-manning on engineering trains, I'm not qualified to comment.

MTA -

I went for a ride on one well-established and sizeable line where bringing the track up to industrial standards would have been a dramatic improvement, and eliminated the need for a lengthy and significant speed restriction.