Train Length and Tonnage

[peach james]

SWL & BWU question:

 

OK, I know this is S&C specific, even if a prototype question- (I will put it in prototype questions too).

SWL= Standard Wagon Length
What was the SWL length restriction for the S&C


& the other part of this one-

What is the BWU rating for various engines (3F, 4F, 5MT, 8F, 9F  for the S&C?

(Basic Wagon Unit- the "weight" of each wagon)

I'm playing a bit with Long Marton, and are at ~43 16 ton minerals, which would be 86 BWU if what I understand is correct (a 16 ton mineral = 2 BWU loaded). That's the practical limit for the 8F on the head of the train, but I'd like to try and get it right, rather than modelling on what I think looks right.

James

[The Johnster]

Most main line railways in the UK as a very general rule limited train lengths to 60 SWL, or SLU (Standard Length Units) as we called them in the early 70s.  The length of refuge siding and loops is based on this, as is the clearance distance of signals, the actual distances being calculated to include two locos and a brake van as well.  For the purposes of estimating the train's length, we were told that mineral wagons on 9' wheelbases counted as 1 SWL in the same way as one on a 10' wheelbase such as a vanfit.  

 

So far as loading is concerned, beware of taking the rating on the side of the wagon as gospel.  For example, the 16 tons on the side of a mineral wagon refers to the medium gross (load plus the weight of the wagon, not the net which is the load without the wagon that the customer is charged for) loading; full gross load was 21 tons, and these wagons ran full loaded most of the time.  Confusing when a train of 21 ton hoppers is considered.  This again is the medium gross load, almost never carried as the full gross load for these wagons, which incidentally were 1 and a half SLW, loaded 28 tons full gross.

 

These are generalised comments and there were many exceptions, and I know little of the Settle and Carlisle in that sort of detail, but would be a good basis to work on until you get better information.  If you can get hold of a Sectional Appendix (to the Working Timetable) for the route during the period you are modelling, it should give the loads allowed for each loco power class, not to mention any restrictions on locos using particular sidings and so forth.  They make fascinating reading!  46 full loaded 16 ton minerals at 21 tons a go for an 8F on the S & C sounds like a bit of a pull for the loco; 46 x 21 + 20 tons for the brake van = 986 tons trailing, 1052 including the loco, which is probably more than an 8F could manage on a 1 in 100 gradient without assistance.  Block coal trains usually ran to the full paying load, which would be determined by the steepest gradient on the train's route, the 'ruling gradient', both in terms of haulage ascending and braking on the descent, and occasionally further limited by the length restrictions  Thus, it may be the case that a train running over the S & C but routed via Copy Pit would be loaded with Copy Pit as the ruling gradient, therefore having no great difficulty with the S & C.  

 

As a guard at Canton in the early 70s, one of my regular trains was the 03.15 Cardiff (Long Dyke)-Carlisle 7M49, which was routed via Todmorden and the S & C because part- or un- fitted trains were not allowed over the WCML north of Carnforth in those days, but for which the ruling gradient was the 1 in 90 Llanvihangel bank between Abergavenny and Hereford, on my part of the run.  IIRC, and there is no guarantee that I do, the load for this train was 960 tons, but that included a 117 ton Class 47 diesel.  It was what would now be called an intermodal service, and there was enough traffic for it to take it pretty close to it's loading most nights.

 

Not a definitive answer, but I hope it is of some help!

[Dagworth]

Never come across SWL meaning Standard Wagon Length, Google only finds it twice, once is this topic and the other is a SimSig reference. Normally SWL means Safe Working Load and I cannot imagine the railway would ever re-purpose such an important safety related meaning.

 

Andi

[Fat Controller]

Never come across SWL meaning Standard Wagon Length, Google only finds it twice, once is this topic and the other is a SimSig reference. Normally SWL means Safe Working Load and I cannot imagine the railway would ever re-purpose such an important safety related meaning.

 

Andi

I remember seeing SWL on those self-adhesive labels that started to be applied to wagons from the 1960s; the base unit was the 16t Mineral. Repetitions of abbreviations and acronyms occur quite often in the various railway lexicons I've seen.

Apologies; after reading the Stationmaster's typically well-informed posting, I realise it was 'SLU', not 'SWL'.

[The Stationmaster]

I remember seeing SWL on those self-adhesive labels that started to be applied to wagons from the 1960s; the base unit was the 16t Mineral. Repetitions of abbreviations and acronyms occur quite often in the various railway lexicons I've seen.

 

Or was it HML?

 

The standard descriptive unit of wagon length is an SLU = Standard Length Unit = 21ft and that has been the case for many decades.  From 1968 a nationally standard system of freight train loads was introduced which changed everybody over to a system based wholly and solely on tonnage (UK Long tons of course but later altered to metric tonnes) and depending on their state of lading wagon types were given a tonnage based on being either 'Heavy', or 'Medium' or 'LIght' or Empty  and this information was shown in the Working Manual (White Pages) and, later, TOPS.  The wagon was labelled according to what was in it and the wagon label was them either H, M or L for a loaded vehicle  - so for example a Bogie Bolster D, Air Braked in the 1987 metric tonnage situation was quoted as 80 tonnes Heavy, 66 tonnes Medium, 38 Tonnes Light, and 23 tonnes empty.  the different weights also affected its Route availability (basically based on axle loading so when H the RA was 6, 4 at Medium, at 1 for Light and Empty.   Also because it was over 21 feet long it was given a number of Excess Length Units (in its case 7) which are used as additions to SLUs when calculating train length.

 

Thus when putting together a train it has to comply with certain basics - which mostly contained within thew White Pages of the Working Manual for Rail Staff.  This (and not the Sectional appendix) will set out the Length Limit (in SLUs for each route) plus the maximum tonnage limit for various types of traction likely to be used on trains over that route.  Nowadays all the addition of load and length is done within the TOPS system (but it can still be done manually when occasion demands) and TOPS will even flag up if any vehicle is not compliant with the Route availability code for the route the train will take.

 

The only information contained in the Sectional Appendix will be the length of loops (expressed, again in SLUs) as the loading and Route Availability etc is not relevant to the information in that document.

 

So if you want to study a particular route at a particular time you are likely to need the relevant Working Timetable (WTT) especially as in earlier years that publication contained most of the freight train loads information on some Regions; if it's post 1968 you need to get hold of the relevant (for the route) Loads Book or sections of the WMRS White Pages and you need the HMLE details for the relevant wagons.  Or you can do it thew simple way and dig out loads of photos of trains on the route and look at the traffic on them.

[caradoc]

In Scotland the standard maximum train length is 71 SLUs, with variations; For example, the West Highland Line is (IIRC) 37 SLUs max, due to the length of the passing loops. This is not to say that longer trains cannot run, on the West Highland one overlength train at a time can run as it can still cross other trains, albeit with potential delay. On the WCML some very long container trains are authorised to run, around 100 SLUs, these are too long for most if not all of the loops and are therefore scheduled not to be overtaken. Which is fine until any out-of-course running occurs, either of the freight itself or the other trains around it, in which case delays are inevitable. 

[TheSignalEngineer]

Route clearance is nowadays shown in the Sectional Appendix available here http://www.networkrail.co.uk/aspx/10563.aspx

 

A couple of examples  for locos and coaching stock

 

 

 

Some tables also show the RA number as in the loco example.

There are more tables for loading gauge clearance of each route throughout Network Rail included. For those who do today's railway just pick your location in the relavant zone document on the NR website and it will tell you what you can and can't run.

[The Stationmaster]

Route clearance is nowadays shown in the Sectional Appendix available here http://www.networkrail.co.uk/aspx/10563.aspx

 

A couple of examples  for locos and coaching stock

 

Route clearance NWa.JPG

 

S-RC table.JPG

 

Some tables also show the RA number as in the loco example.

There are more tables for loading gauge clearance of each route throughout Network Rail included. For those who do today's railway just pick your location in the relavant zone document on the NR website and it will tell you what you can and can't run.

 

Yes - an important point is that the location of some information is date dependent (and varied between Regions!).

 

Another good point made in Caradoc's pst is in respect of Length Limits where although the limit is officially set down (usually based on the length of the longest loop/refuge (lie by) siding limits can be exceeded under special authority.  thus on  the Western we regularly ran the Merehead stone trains up to 120 SLUs (and I believe some still are) in order to achieve the contract tonnage.  Back in the steam age exactly the same would be done - for whatever reason - either authorised by notice or in exceptional circumstances authorised by Control but doing so on a route like the S&C was probably unusual most of the time.

[The Johnster]

Stationmaster, you may be confusing HMLE, which refers to the loading of wagons for the purpose of estimating total tonnage.  The figures were, in the early 70s, given on a yellow stickybacked  notice on the wagon side left hand end above the information panel. H was heavy, M medium, L light and you will be astonished when I reveal that E was empty.  So, for a '16 ton' mineral wagon, H was 21 tons, M was 16 tons (and what do you get, another day older and deeper in debt), L was 10 tons and E was 6 ton IIRC.  You read the actual loading of the wagon off the label, where it was given in one of those letters by whoever had been responsible for loading it and labelling it.

[TheSignalEngineer]

There were plenty of wagons running around without sticky load labels even at the time of the TOPS cut-over. In 1969 details of what was on the labels for each type of wagon were in the 'White Pages' - Part 6 of the Working Manual for Rail Staff, see http://www.barrowmoremrg.co.uk/BRBDocuments/BR30054_6_Issue.pdf, to be used in the case of wagons without the labels.

[The Stationmaster]

Stationmaster, you may be confusing HMLE, which refers to the loading of wagons for the purpose of estimating total tonnage.  The figures were, in the early 70s, given on a yellow stickybacked  notice on the wagon side left hand end above the information panel. H was heavy, M medium, L light and you will be astonished when I reveal that E was empty.  So, for a '16 ton' mineral wagon, H was 21 tons, M was 16 tons (and what do you get, another day older and deeper in debt), L was 10 tons and E was 6 ton IIRC.  You read the actual loading of the wagon off the label, where it was given in one of those letters by whoever had been responsible for loading it and labelling it.

 

As I said - albeit quoting an example in metric tonnes (and it's now 48 years since I went on the course for the new loads system  ).

[peach james]

I'd like to thank everyone for the answers given- and apologize for the confusion about SWL vs SWU.  (I got it from Clive, in Tony's thread, which I copied over to Long Marton so I would know where to find the answer when I forget in a few years...)

 

 

Thanks,

 

James