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Marshalling wagons ca. 1980, with regards to braking


F2Andy
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I am curious about running freight trains in the 80's, and how consists were organised with respect to braking. I appreciate there has been a similar thread recently, but it does not quite answer my question.

 

This table comes from Wiki; it is the TOPS codes for various brake types.

 

A    Air brakes
B    Air brakes with through vacuum pipe
F    Vacuum brakes with Accelerated Freight Inshot (AFI)
G    Vacuum brakes with AFI and through air pipe
H    Dual (air and vacuum) brakes with vacuum AFI
O    No continuous brake (unfitted)
P    No continuous brake, through vacuum pipe
Q    No continuous brake, through air pipe
R    No continuous brake, through air and vacuum pipes
V    Vacuum brakes
W    Vacuum brakes with through air pipe
X    Dual (air and vacuum) brakes
Y    No continuous brake (for track machines)


If we suppose a loco with both air and vacuum brakes, I feel these consists would work. 1 is trivial; 2 has one wagon with through vacuum, but presumably no problem if not used; 3 and 4 have one type at the front, but the other piped through for the back. So far so good.

 

 1 (loco)AAAA
 2 (loco)ABAA
 3 (loco)BBVV
 4 (loco)WWAA

 

How about these? If a wagon is dual braked, does that mean you can use as either?

 

 5 (loco)XXAA
 6 (loco)XXVV
 7 (loco)AAXX
 8 (loco)VVXX

 

If some are unfitted, I guess a brakevan is required, but does it depend on the overall weight and combining braking power? Assuming the latter, are these possible? Or do you always need brakes on the last wagon in case it brakes away, so 10 needs a brake on it?

 

 9 (loco)OOOOOOOO(brake)
10 (loco)VVVVVVVO
11 (loco)WVVVVVVV

 

Would you ever see three types of brakes

 

12 (loco)WWAAOOOO(brake)
13 (loco)RRRBBVVV

 

So the Accelerated Freight Inshot...  Does that need to be fitted to the loco? Which locos? Is it compatible with through pipes? Would it be used with unfitted?

 

14 (loco)BBFF
15 (loco)FFOOOOOO(brake)
16 (loco)PPPPPPFF(brake)

 

With regards to coaches, I assume they had a single braking type throughout the consist, either air or vacuum (single heating type too!).

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It would be worth you seeking out a copy of 'Freight Train Formations' by David Ratcliffe, published by Ian Allan. He has lists of formations for many different types of freight train around the period you're interested in.

AFI was wagon-fitted, without any mods to the loco.

Trains would be air-braked, vac-braked or unfitted; I can't think of any case where a normal freight would have both air and vac systems coupled up, and functioning. It was either/or one or the other.

Piped vehicles had to have a certain number of braked vehicles behind them.

 

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The important thing on any freight in that period would be to get the required Brake Force to match the Class under which the train would and TOPS would generate most of that and also the Train Preparation form so all the person doing the shunting had to do was make sure the correct pipes were connected and a Brake Test would also need to be carried out.

 

AFI was fitted to wagons, it basically made no difference to the loco although the way the train brake reacted to an application and release  would vary a bit. Piped wagons were only really relevant when formed in the fitted part of a train and if a train was only partly fitted that section (unless required otherwise) for traffic working reasons would be immediately behind the engine to concentrate the Brake Force and reduce the risk of breakaways.  Trains with unfitted wagons always required a brake van unless there was a specific local exception - for example certain trip workings in the Healey Mills area were at one time permitted to run unfitted without a brake van over short distances but that was very unusual.

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My understanding and someone far more knowledgable than me can give a far more detailed answer is that you form the train according to the brake force required.

 

In the cade of having both Vacuum and Air brakes available you choose whichever provides the required force with the others running with the brake system inoperative therefore you would require a brake van.

 

If a wagon is dual braked you can use it as either and therefore can be used in either portion which is forming the fitted head.

 

Piped wagons when marshalled so that the pipes were in use must have a vehicle with the continuous brake system operational trailing so that is the train splits there is a means of bringing them to a stop.

 

Unfitted wagons or wagons which are fitted but running without the system in operation always require a brake van.

 

Of course there are always exceptions to the rules however for 99.99% of applications they aren't relevant.

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2 hours ago, The Stationmaster said:

The only exception I have heard of involving mixing air and vacuum brakes in a single train was a system used in Scotland for attaching air braked vehicles to what amounted to vacuum braked Mixed Train.  Unusual to say the least.

There were two such workings, IIRC- to Mallaig and Oban. There was another peculiar working, which had a vac-piped Freightliner wagon coupled between loco and first (vac-fitted) coach. The wagon was also fitted with a through steam-piped. This ran from Inverness to the Far North.

There was a case where someone preparing a train (from Ravenscraig to Trostre, I believe) connected all the  through vacuum pipes, instead of the air. It was all right until the train started to descend Beattock- it eventually ended up as a big heap near Quintinhill.

Some information about aspects of freight train formations can be found in Paul Shannon's 'Rail Freight since 1968- Wagonload' He gives an idea how longer-distance trains (pre-Speedlink) would be marshalled. An example might be a Severn Tunnel Junction- Mossend train with both air and vac-fitted traffic :-

Loco; Warrington (AB), Carlisle (AB), Mossend (AB)   Mossend (VB), Carlisle (VB) Warrington (VB) Van

At Warrington, portions might be added for Carlisle and Mossend, and the Warrington portion detached, the process being repeated at Carlisle

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The number of piped vehicles in the fitted portion changed some time around then.

When I started in Bristol TOPS the rule was a maximum of five consecutive piped vehicles, with a minimum of two fitted vehicles (with brakes in working order) on the rear. Around 1980(?) the rule changed to max 3 piped in a row, with min 3 fitted on the rear.

1980 was an interesting time, with many vac and unfitted wagons still in service but increasing numbers of new air braked stock being introduced. The traditional wagon load freight network was in decline, but continued to run until May 1984, the air braked Speedlink network had been expanding since the late 1970s. 

 

From your examples earlier, post 1980 trains 1, 2, 5, and 7 are ok running air braked. Trains 6, 8, and 11 are ok vac braked. Trains 3, 4, and 10 would need a brake van.

 

The most common freight vehicles fitted with AFI braked I can think of are 51t tank cars including those for loco fuel coded TTF, many were later modified with air brakes as TTA.  Also the large fleet of sealion ballast hoppers coded YGH (dual braked air, and AFI vacuum).  

Here is an example of a vacuum braked ballast train dogfish (ZFV), and two sealions (YGH) on the rear.

scan0017.jpg.a651b2be1b7d09c3f55c1ea72f22db26.jpg

37181 at Park Junction, Newport with a ballast train from Machen Quarry. 25/9/86.

 

cheers 

 

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Dual braked wagons were quite rare; most wagons with both air and vacuum bags were piped only for one or the other.  The only visual difference without looking at the equipment beneath the wagon was the colour the brake pipes were painted, red for vacuum and for air brake pipes, yellow for air reservoir pipes, and white for through pipes.  1st generation dmus uses a (very effective) dual piped vacuum system with a vacuum reservoir pipe, but I don't recall what colour it was painted.  The dmu vacuum brake pipe could be used to connect the brakes on a vacuum fitted loco hauled coach or wagon as tail traffic.

 

Unless this had changed by the 80s, where wagons had through pipes and were marshalled in a fully fitted train or in the fitted head of a part fitted one, the wheels of at least 4 axles to the rear of it had to have working brakes.  The same applied to fitted vehicles on which the brakes were not working, and it had to be ascertained by the guard as part of the brake continuity test that this was the case before he countersigned the perparation certificate and allowed the train to depart.  On passenger carrying trains, all brakes had to be working and if not, the train proceeded at reduced speed to a location where the fault could either be rectified or the coach taken out of service.  

 

I do not recall ever working a part-fitted class 7 or 8 train with an air braked fitted head, or a dual braked one.  I do recall working such trains with air braked wagons that had through vacuum pipes in the fitted head, and trains (including fully fitted class 6) with wagons on which brakes were not working, subject to the 4 axles rule and sufficient brake force being available for that class of train, both vacuum and air braked (but not of course simultaneously).  I cannot recall any wagon being fitted with through air pipes, only vacuum through pipes on air braked or unbraked vehicles (the latter being largely brake vans. Fitted brake vans were very rare as of course there is a biological and arguably sentient brake operating mechanism aboard them).  Bauxite livery was carried by any vehicle with a vacuum pipe, irregardless (thank you Donald) of whether it had automatic brakes.

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Here is a train in 1981 with an air braked fitted head. 37255 is drawing out of the Commonwealth Smelting sidings at Hallen Marsh with 7C42 for Severn Tunnel Junction. The train is formed:-

 

37255

VDA (Cov-AB loaded with ingots)

VDA

VDA

HCO (empty coke hop)

HTV (empty 21t hop)

HTV

HTV

HTV

etc etc

CAO (brake van)

 

scan0054.jpg.cb025aa54c24e26115170ca3570ef805.jpg

37255 departs Hallen Marsh 5/2/81

 

 

 

cheers 

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The other dual-braked train I can think of was on the Southern, an MLV with a couple of Southern utility vans. MLV with air/EP brake, vans with vac brake. :)

 

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Thanks for all the replies.

 

FatController, I have ordered that book, it looks good!

 

Stationmaster: "AFI was fitted to wagons, it basically made no difference to the loco although the way the train brake reacted to an application and release  would vary a bit."

 

Would all vacuum braked wagon be AFI? Or could they mix, and the AFI only affected the calculation (and driving characteristic)?

 

The number of piped vehicles in the fitted portion changed some time around then.

 

Rivercider: "When I started in Bristol TOPS the rule was a maximum of five consecutive piped vehicles, with a minimum of two fitted vehicles (with brakes in working order) on the rear. Around 1980(?) the rule changed to max 3 piped in a row, with min 3 fitted on the rear."

 

Good to know it is so complicated...

 

Rivercider: "From your examples earlier, post 1980 trains 1, 2, 5, and 7 are ok running air braked. Trains 6, 8, and 11 are ok vac braked. Trains 3, 4, and 10 would need a brake van."

 

Thanks.

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11 hours ago, Rivercider said:

Here is a train in 1981 with an air braked fitted head. 37255 is drawing out of the Commonwealth Smelting sidings at Hallen Marsh with 7C42 for Severn Tunnel Junction. The train is formed:-

 

37255

VDA (Cov-AB loaded with ingots)

VDA

VDA

HCO (empty coke hop)

HTV (empty 21t hop)

HTV

HTV

HTV

etc etc

CAO (brake van)

 

 

Would I be right thinking the vacuum brakes of the HTVs were not is use as the VDAs and HCO do not have vacuum pipes?

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24 minutes ago, F2Andy said:

 

Would I be right thinking the vacuum brakes of the HTVs were not is use as the VDAs and HCO do not have vacuum pipes?

Correct, this train ran with an air braked fitted head that day. First three VDAs piped up air braked. No automatic brakes or pipes on the HCO, so it and the HTVs are all running unfitted.

Previously there would have been more vac braked stock, so shunters everywhere would generally make up a vac brake head, the odd air braked wagon was treated as unfitted. By 1980 there was often more air braked traffic about, so the fitted head could more easily be made up with air brakes, then the vacuum stock ran with the other unfitted on the rear.

 

cheers

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33 minutes ago, F2Andy said:

Thanks for all the replies.

 

 

Would all vacuum braked wagon be AFI? Or could they mix, and the AFI only affected the calculation (and driving characteristics)

 

Thanks.

Wagons fitted with AFI vacuum brakes were in the minority (as I mentioned there were TTF tank cars and YGH sealion hoppers). They could run mixed up with other vacuum braked stock indiscriminately.

 

Sealion ballast hoppers in particular were often mixed with other vacuum braked wagon types on engineers trains.

Here is a good mixed vacuum braked train passing Lichfield Trent Valley in 1986. The train looks like a catfish (ZEV), dogfish (ZFV), Sealion (YGH),  seven mermaids (ZJV), and three new turbots (YCV) .

scan0017a.jpg.d9ea3b6a8c519e05ad47afaa991a3f0b.jpg

25278 heads south 17/6/86,

 

cheers

 

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