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“Equal to” loading quotation to driver?


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Come on someone, refresh my memory (what’s left of it!);  I’ve searched online but seem to come up with a load of garbage!!!

 

I remember my late father, an ex SR and later BR driver, relating how the goods guard would inform him of the train’s loading with something akin to “40 equal to 75”. This would refer to the the number of actual vehicles whether all loaded or some not in relation to a train consisting of loaded vehicles only.

 

What I would like to know is to what were the “standard” vehicle unit weights referring to; for instance, would it have been 20T per loaded vehicle? Would the guard have calculated the empties’ weights, dividing their total (tare) by 20T and added them to the total loaded wagon’s weights?

 

interestingly, was there a “universal” unit weight used on all BR Regions in the years 1948-68.

 

Thanks for any replies.

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This could be referring to two possibilities, train weight or train length. I would expect the train weight to have been advised in tons, as that would be meaningful in terms what the locomotive is permitted to haul (and stop) over the routes concerned. The train length matters in terms of loops and sidings, and is usually given in SLU or Standard Length Units. 1 SLU equals a typical 17' 6" wagon, and plainly there are many wagons that are significantly longer than that. These are listed in multiples of SLUs; a 20T mineral wagon would be 1.5SLU, A 62' bogie bolster would be 3 SLU. So a 40 wagon train with a whole crop of bogie bolsters might equate to 75 SLU, critical information to both the driver, whose route knowledge will include the lengths of every loop and refuge siding on the route, and the signalmen. 

 

Jim

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Jim is correct; it is shorthand for '45 vehicles equal to 75 SLU (standard length units, previously BWU, basic wagon units, which I think went out of use in the 60s).  75 SLU is a long train; most UK main lines were restricted by the length of loops and distance between signals to 60 SLU.  There were plenty of exceptions; the SWML between Severn Tunnel and Pengam Junctions was allowed up to 90 SLU, but only on the relief roads and trains had to have a clear route through Newport High Street. 

 

Weight was given to the driver in tons, inclusive of the loco in the case of freight trains but not in the case of passenger or NPCCS.  When you are adding up weights of loaded wagons do not be  misled into using the tonnage printed on the side, 16ton for a steel mineral for example of 10ton for a vanfit.  These were for the guidance of those loading the wagons and showed the load the vehicle could carry, thus a 16ton mineral carried 16 tons and weight 5 tons empty, so the fully loaded weight was 21 tons; a 21ton double door mineral was 28 tons fully laden.

 

Then there was Brake Force, a figure denoting how many tons of the load could be held by the vacuum brake, plus of course the loco weight.  It was given in the load books, along with the weight each class of loco was allowed over each route.  This is where the term 'ruling gradient' comes from; it is the steepest uphill gradient on a trains entire route, and limits the weight the loco can haul without stalling; 'ruling downhill gradient' similarly limits the minimum amount of brake force needed for different loads for class 6, 7, and 8 trains.  

 

Maximum permitted speed is that of the slowest speed restricted wagon, usually 45mph because that was the speed allowed for 9 or 10 foot wheelbase 4 wheel wagons.  But a class 8 consisting entirely of bogie bolsters could be allowed 60mph, and quite interesting in a brake van.

 

This was the core of the information on the 'load slip', the certificate signed by the guard to give to the driver before starting the journey, and handed by driver to driver at relief points en route. As well as this information, it certified that the train had been examined (either by the guard or by C & W staff who had in their turn given a Train Preparation Certificate to the guard.  It was still the guard's responsibility to examine the train and perform the brake continuity test

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Does this lot help?

 

Episode 1 (I must have scanned at too high a resolution but I'm not going to do it again!), from a 1957 Freight Train Loads Book:

 

1957-1.jpg.70ca76f70fe18eab739c31b7027fd411.jpg

 

1957-2.jpg.8caee98ccc6ce3bbb491c03809561113.jpg

 

Edit to say I've scanned some pages of a 1964 FTLB but, having reached my upload limit with this post, I thought I could do a second post but computer still saying I can only do 10megs when I try.

 

Edit 2 - Perhaps tomorrow.

 

Edited by Poor Old Bruce
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1 SLU is 21 feet. Is that a 17'6" wagon plus buffers?

We still use SLU to this day, every siding length is known in SLU and the trainlist has the length in SLU. Multiply the number by 21 and that's your length in feet. Longest I've dealt with was around 120 SLU.

 

Jo

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I’m still amazed that an SLU was set at 21’ and not 22 being as the entirety of the railway has used chains as a measure since railways were invented and three lots of 22’ is one chain. 
 

Andi

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22 minutes ago, Dagworth said:

I’m still amazed that an SLU was set at 21’ and not 22 being as the entirety of the railway has used chains as a measure since railways were invented and three lots of 22’ is one chain. 
 

Andi

 

Ah but if you think: siding 10 chains long, that gives you 30 SLU with another bit of length for luck.

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An interesting area and one of many languages prior to 1968 when the National Freight Train Loads system was introduced.  Before I go any deeper into that the '40 =75' was almost certainly =75 for length.

All routes had Length Limits, expressed in SLUs (21 feet as already posted by Jo) and these were a standardised figure certainly post 1948 and maybe earlier.  The length limit of a route is basically governed by the length of loops but occasionally other features such as standage space between signal on curves or other connecting lines and were published in Loads and Marshalling Books - the latter usually being the source for the permitted length for various trains.  Length Limits exclude, and always have the loco and brakevan  - they are solely in respect of the wagons being conveyed by the train.  On the GWR freight train length limits or restrictions were published in Marshalling Instructions as 'XX (number of) wagons'  - the post war Service Timetable load calculations explained that the length of a wagon was 21 feet (with suitable allowance being made to increase that figure for longer vehicles) but a figure is not defined in Pre-War STTs 

 

Traditional and longstanding Length Limit on BR was less that 100 SLU and even 100 was exceptional.  But from the 1970s onwards trains of up to 120 SLUs became increasingly common although in most cases they exceeded the normal Length Limit for the route they were running over and required carefil timteabling.  But by the 1980s various loops etc were being constructed or upgraded to accept 120 SLUs or more.  It had however becoming an interesting task where - for example on the Western, we were running trains of 120 SLUs over routes where the Length Limit was much less than that and the loops were nowhere near that long .  Nt too bad at night of course but we had a regular train of stone empties running back from Acton for Merehead during the middle of the day/early afternoon and it was permitted to convey up to 120 SLUs - and there was nowhere (including Reading) capable of holding it for regulating purposes between Acton and Ufton Crossing.  Fortunately it could outrun a stopping DMU between most stations east of Reading but at Reading it was long enough to simultaneously block every running line route and platform line route except the Up Relief Line/Platform No.9 and No.10 bay, or the Up Goods, to the Up Relief Line.  No wonder somebody at long last was able to afford to build a diveunder:blink:

 

 

 

Loads in tonnage terms are a very different matter.  Prior to 1968 the various BR Regions were basically using their former Company systems for calculating freight train loads.  '[Poor Old] Bruce' has posted something which is clearly of LMS origin.  Similarly the GWR categorised wagons as No.s 1 (heaviest), 2, or 3 if they were loaded or as 'empty' and load calculations were based on the equated number of  Class 3 loaded wagons.  It was a complicated system but oddly the 1968 BR system did use an equivalent of the old idea by classifying loaded wagons as Light, Medium, or Empty but unlike the GWR etc systems the 1968 system took into account the differences in tare weight and capacity of all the more common types of wagon whereas under the e.g. GWR system a loaded wagon was at a set tonnage irrespective of the type and tare weight of the wagon.  The LMS system would appear to have been similar.    Further under the 1968 system empty wagons had a weight, by type, equal to their tare weight rather rather simply being counted as an 'empty'.  

 

But from 1968 it was all based on using tons and calculating a load became a lot simpler - you just went through the train noting the category of load on the wagon label and reading off the tonnage relevant to that load from the wagon data panel (or looking it up in the Working Manual if the wagon didn't have a data panel).  The other change made at that time was the move to calculating Brake Force by tonnage instead of simply by the number of power braked wagons - so another column of numbers plus taking the loco brake force off its data panel (or looking it up in the book).  Two columns of numbers and add them up to get the train load, in tons, and the Brake Force, also in tons, with the latter determining the category (headcode) under which the train could run and hence its maximum permitted speed.  The data panel also recorded the length, in SLUs and that too could be toalled to give the total length.  All of this information, once complied, was then given by the Guard to the Driver of a form called the 'Driver's Slip'.  No longer any need to say '40=75'  because that information was now on the Driver's Slip.   So some maths involved for Guards and Train Preparers  (but now simpler than it had been because it just became straight addition instead of working out proportions of 1s, 2s, & 3s and counting the number of fitted wagons).  But it did need accuracy in noting the data panel information and it was all fully and carefully explained on a special one day training course (well it was a one day training course on the Western).

 

The next really useful step was when TOPS came along in 1973/74 onwards and all the data panel information was in the TOPS system on the wagon files.  All the system needed to be told when a wagon was consigned was the weight of the load to put it into the correct H, M, L category on the data files (or it was empty).  When a train was prepared all that was now needed was to list the wagon numbers (plus, of course,  the usual train preparation tasks) advise it to the TOPS office who - before cardless TOPS - simply put the wagon cards into the correct order and ran off a Train List together with the loco and including the brakevan.  TOPS also had the necessary information on the loco files to use the loco data plus the train List to produce a Driver's Slip so the manual task of calculating load and Brake Force etc was no more.

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IIRC, or at least I was told during my guard's training course at the University College of Cardiff West Box before Charlie McCarthy demolished it with an 08, that the loop/refuge siding SLU lengths allowed for double heading and an assisting lock, and the brake van of course.  The locos were not included in the SLU on the driver's slip.  Thus Miskin up and down loops, 120 SLU in length, were in fact longer than that by the length of 6 possible locos if two 60 SLU trains were put inside one behind the other, for which calling on signals were provided.  The distance was between the outlet signal and the clearance point for the spring loaded catch point at the entrance to the loop, and allowed for full buffer decompression, several yards over 120 16t minerals and their vans and locos.

 

Thus, when the triple headed Port Talbot-Llanwern Iron ore trains came into operation, Miskin was the only loop in the up direction long enough to hold the trains; Tremains was available in the down direction, but Pencoed was of insufficient length.  These trains had to be given a clear passage between Leckwith and Cardiff East, where they were routed to the relief lines, so pathing them was subject to much head scratching in both Port Talbot and Cardiff Panel Boxes, Port Talbot because once let out on to the SWML at Margam Moors the up loaded trains took some time to clear the summit at Stormy Down before they could work up to running speed, 60mph, after which the only place to pass faster traffic was Miskin, so Cardiff had to ensure that this loop was clear and available.  A guaranteed clear route was also needed between Ebbw Jc  and Llanwern reception, so they were quite a bit of a handful one way and another; originally triple headed with 37s at 27 wagons and later double headed with 56s a 30 wagons, the full 120 SLU.

Edited by The Johnster
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20 hours ago, The Johnster said:

 When you are adding up weights of loaded wagons do not be  misled into using the tonnage printed on the side, 16ton for a steel mineral for example of 10ton for a vanfit.  These were for the guidance of those loading the wagons and showed the load the vehicle could carry, thus a 16ton mineral carried 16 tons and weight 5 tons empty, so the fully loaded weight was 21 tons; a 21ton double door mineral was 28 tons fully laden.

 

This is interesting - in another thread (I can't remember which - possibly something about goods traffic levels)  suggested that the 16 ton (or whatever, depending on vehicle) marker was the maximum weight - that is tare plus load. Somebody specifically stated (with what appeared to be authority) that the "payload" of a 16 ton mineral was around 8 or 9 tons - 16 tons less tare of around 7. I thought that surprising when I read it - not a lot of point in describing a vehicle as 16 ton capacity when it is less. The tare weight displayed on the side of the wagon is so that in (what appears to be an unlikely) event that it is put on a weighbridge, the maximum should not exceed tare plus 16 tons (for a 16 ton mineral).

 

Clarification welcome (then possibly I will find the other thread and make some remark)

 

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23 minutes ago, Derekl said:

 

This is interesting - in another thread (I can't remember which - possibly something about goods traffic levels)  suggested that the 16 ton (or whatever, depending on vehicle) marker was the maximum weight - that is tare plus load. Somebody specifically stated (with what appeared to be authority) that the "payload" of a 16 ton mineral was around 8 or 9 tons - 16 tons less tare of around 7. I thought that surprising when I read it - not a lot of point in describing a vehicle as 16 ton capacity when it is less. The tare weight displayed on the side of the wagon is so that in (what appears to be an unlikely) event that it is put on a weighbridge, the maximum should not exceed tare plus 16 tons (for a 16 ton mineral).

 

Clarification welcome (then possibly I will find the other thread and make some remark)

 

The "plated" capacity of a railway vehicle is exactly what it says it is, the maximum load that the vehicle is permitted to carry. The gross weight is the sum of the load weight and the tare weight.

 

 The tare weight is put on the vehicle so that the weighbridge operator, having measured the gross weight before discharge, can avoid having to measure the wagon again to obtain the empty weight, and thus the actual load.

 

Jim

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4 hours ago, The Johnster said:

triple headed with 37s at 27 wagons and later double headed with 56s a 30 wagons, the full 120 SLU.

Evening!

Whilst I don't doubt the story, were the iron ore trains not a little shorter than that, and presumably so too the loops? 17 O&K boxes (near as damn it the same size as the tipplers) comes in at 36 SLU. 19 Hoppers are 45. I'd expect 30 wagons to come in around 65 SLU? 120 SLU would be around 56 wagons.

Jumbos out the Mendip quarries with 44-47 wagons tend to be around the 105 mark, including loco (s), give or take a couple of SLUs.

 

Jo

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1 hour ago, Steadfast said:

Evening!

Whilst I don't doubt the story, were the iron ore trains not a little shorter than that, and presumably so too the loops? 17 O&K boxes (near as damn it the same size as the tipplers) comes in at 36 SLU. 19 Hoppers are 45. I'd expect 30 wagons to come in around 65 SLU? 120 SLU would be around 56 wagons.

Jumbos out the Mendip quarries with 44-47 wagons tend to be around the 105 mark, including loco (s), give or take a couple of SLUs.

 

Jo

Quite agree.  The 5,000 ton Yeoman's trains were = c.120 SLUs depending on formation, the lighter weight trains running now are shorter as you say.  When we did the 12,000 tonne trial train it was of course considerably longer although I can't remember without checking back through my planning papers and Notice if I actually bothered to publish the length in SLUs although we did need to know the length in feet for for splitting it after arrival at Theale (which it never reached).

 

For information the capacity of length of MIskin loops was not 120 SLUs.  In 1969 the Down Loop was 134 SLUs and the Up Loop was 143 SLUs.  In the 1972 supplement to the Sectional Appendix they were shown as 128 SLUs and 133 SLUs respectively - no doubt a consequence of relaying.  However in 1982 the Down Loop is shown as 122 SLUs - perhaps because the exit signal has been moved back(?).  Pencoed Up Loop was 120 SLUs for years.

 

As far as the length is concerned the allowance was always for the length of the train, in SLUs plus an allowance for the loco plus an allowance for the brakevan.  I've an idea that was published somewhere at one time - possibly in the White Pages of the WMRS (?) but I'm not going to plough through that at this time of night.   But that was the way we always measured them if we needed to check details off the single line diagrams and it is also the way we calculated the required length when giving the Civil Engineer's track designers our minimum length requirements for new and altered layouts or the S&T Scheme Development Engineer the information as it could affect signal siting in some places (read on).   The only one I know of that was specified any differently from that was when I had the Up Relief between Foxhal Jcn and Dicot West End converted into a goods loop line where I needed the equivalent of two loco lengths plus the specified train length so the length I required was specified on that basis (a bit more was needed for signal siting which the S&T sorted when they did a check measurement on site for their design).  The length shown in the Sectional Appendix is however based on the normal method of allowing for one loco.   The new loops I specified between Hanwell Bridge and Southall East were also calculated on the basis of only a single loco plus the required train length (which the design regrettably couldn't entirely deliver).

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13 hours ago, Derekl said:

 

This is interesting - in another thread (I can't remember which - possibly something about goods traffic levels)  suggested that the 16 ton (or whatever, depending on vehicle) marker was the maximum weight - that is tare plus load. Somebody specifically stated (with what appeared to be authority) that the "payload" of a 16 ton mineral was around 8 or 9 tons - 16 tons less tare of around 7. I thought that surprising when I read it - not a lot of point in describing a vehicle as 16 ton capacity when it is less. The tare weight displayed on the side of the wagon is so that in (what appears to be an unlikely) event that it is put on a weighbridge, the maximum should not exceed tare plus 16 tons (for a 16 ton mineral).

 

Clarification welcome (then possibly I will find the other thread and make some remark)

 

 

As others have said already, a 16T Mineral Wagon was designed to carry a payload of 16 tons of coal. The GLW (Gross Laden Weight) system came in with (IIRC) oil tank wagons of 35T (like the Airfix one). We are more familiar with the usage for 45T and 100T tanks and bulk wagons etc.

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1 hour ago, Poor Old Bruce said:

 

As others have said already, a 16T Mineral Wagon was designed to carry a payload of 16 tons of coal. The GLW (Gross Laden Weight) system came in with (IIRC) oil tank wagons of 35T (like the Airfix one). We are more familiar with the usage for 45T and 100T tanks and bulk wagons etc.

It all depends what the 16-tonner is loaded with; if it's large pieces of coal, then it's quite probably 7 or 8 tonnes. If it's fine anthracite duff, often loaded wet, then it'll be close to its maximum load. 

Back in 1974, I spent quite a lot of time going through weighbridge tickets at a large iron-foundry. Many, if not all, 16-tonners loaded with baled scrap, were above their maximum load, in most cases by four or more tonnes.

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1 hour ago, Poor Old Bruce said:

Here we go. 1964 loads book pages:

 

 

 

 

 

 

That is very interesting as it shows the LMR had already moved to HML before the National Freight Train Loads system came in.   The other useful thing is that it shows the Basic Wagon Unit (BWU) although I'm not sure if that was used nationally at that time -  but it looks like it was as I have just managed to delve out a 1964 WR Loads Book I didn't realise I had and it too uses H,M, & L and uses BWUs in the load tables for load calculation purposes  

 

Next step is to see if I have anything which can track down when that system, using BWUs instead of the earlier number system used on the Western, came in.  The GWR system was definitely still in use on the WR in the Summer of 1962 but I can't find any decent 1963 sources so it might have changed then or, as the book is dated 1964 (again no decent sources) it might not have changed until then.  Next change of course was in 1968 with the change to using tonnage for all calculations.   Whatever else can be said about it the system used in the 1964 booklets had a very short life compared with those that went before it and came after it.

 

Incidentally a   i've now dug out some wagon data panel information while back I came across a GWR document which actually gave the tonnages for various categories of loaded wagon -  No.1 = 16 tons, No.2 = 13 tons, No.3 = 10 tons;  empty = 6 tons,

 

As Brian has already said there's no way you could get 16 tons of large pieces of coal into a 16 ton mineral wagon - various invoices I saw over the years were, as Brian has said, about the 7 - 8 tons mark.  I've now dug out some 1987 wagon data panel details although the weights are in metric tonnes, not long tons - the weights for vac fitted 16.5 tonne mineral wagon are 10t empty; 13t L; 17t M; & 25t H.  So when loaded with large coal it would have been labelled Medium but as Brian said wet duff and baled scrap were considerably heavier so would be labelled Heavy. 

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Posted (edited)

Well folks, all these replies have made for very interesting reading, my original query being answered in spades.

Thank you all so much for the help. 
Afterthought. All those sums and pocket calculators just a possible figment in a future “Tomorrow’s World” in the early days.

Edited by Right Away
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As others have said, an interesting read, and one of the reasons that this forum is so useful (as well as being something of a time toilet :-) ).

 

What does surprise me is that the length of trains, in SLU, for loops etc. excluded the brake van and any locomotives, of which there would be at least one.

 

With the exception of the SR Queen Marys, I would have thought that most brake vans were of a similar length, so could be accounted for fairly easily.

 

But locomotives could be a different matter altogether. From memory - of models, with all the implications that has - the type 2s (except the 31 and including the 33) were of similar length, were the type 3s and 4s (except the 33) all of a similar length? The type 5s seemed to be longer. And what happened if you had an unexpected double header due to a failure? It seems an obvious flaw - you would want the train length to be the full train length, not just the consist.

 

[Corollary: I believe that road trucks are measured differently in different parts of the world. I believe that in the UK (Europe?) it is the length of the tractor unit plus the trailer, whereas in other parts it is the length of the trailer only. This is why, in the UK that tractor units tend to have the flat front, with the engine under the cab rather than the long hood units with the engine out front, as often seen in North America and elsewhere.]

 

Large aside: I work with iron ore trains in North West Australia. Out of interest I converted one of those to SLU - 375, of which 11-12 SLU are the three locomotives. I didn't do the weight calculation as the weights are so far above the maximums quoted above it wouldn't be representative.

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1 hour ago, dvdlcs said:

As others have said, an interesting read, and one of the reasons that this forum is so useful (as well as being something of a time toilet :-) ).

 

What does surprise me is that the length of trains, in SLU, for loops etc. excluded the brake van and any locomotives, of which there would be at least one.

 

With the exception of the SR Queen Marys, I would have thought that most brake vans were of a similar length, so could be accounted for fairly easily.

 

The key of course is what you allow for the length of a loco and the length of a brakevan and provided that takes account of the longest loco and the normally longest brakevan there are no problems plus in any event there will be space allowed for signal sighting etc in the design.   Provided everybody who needed to know understood that then there would be no problem.  When my office used length limit informations for train planning purposes, particularly for exceeding them (we were the publishing authority on the WR for freight train lengths) the check was at that stage, all folk 'outside' had to do was comply with what we published.  And similarly Control when authorising a train, or a local supervisor doing the same, all they had to do was understand what the limits allowed and comply with them.

 

In some places we definitely allowed for two locos - for example when i planned the layout for the coal loading terminal at Avonmouth (Bristol Bulk Handling Terminal) all the lengths for sidings and run-rounds was based on being able to accommodate the specified maximum train length (which in turn tied in with the maximum loading rate of the bunker) and the longest loco combination likely to be ever used (2 x Class 37) although no trains were booked to be worked by  that power combination.

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