Mixed Trains, and Tail Traffic

[The Stationmaster]

As the expression 'mixed train' often crops up on RM Web I thought it might be useful to explain something about mixed trains and exactly what they are. This also leads to the far less frequently mentioned subject of 'tail traffic' because it is sometimes the case that something which is actually tail traffic is mistakenly referred to as a mixed train.

 

Mixed trains existed for many years as part of the British railway scene although they were largely confined to the more lightly used branchlines where a separate freight train was either not justified by traffic levels or presented timetabling difficulties. However the penalty of this neat cost saving idea was that any passenger train which was permitted to run as 'mixed' invariably required more time to be allowed both in running and at stations as provision had to be made for it to both convey and shunt freight vehicles. Thus it was best suited to shorter branchlines where speeeds were low and passengers were not going to be too concerned about journey time. But the idea was also used on longer routes - for example Fort William - Mallaig in Scotland, a distance of 40 miles albeit with relatively low speeds and little need in later years to engage in intermediate shunting.

 

The 1955 Modernisation Plan plus the ever increasing number of branch and secondary route line closures gradually brought about the end of mixed trains. The replacement of steam hauled coaching stock with dmus ended the chance of doing anything but the very simplest of shunting and the diesel units had insufficient brakepower to cope with the weight of unbraked waqons shoving them as they tried to stop. A few workings survived and could still be seen at the end of the 1960s if not a little later but the general Regulations applicable to mixed trains were withdrawn in 1972 - an indication, if one were need, of just how unusual such trains had become by that year. But that did not necessarily mean the end of such trains as they could still be operated under Regional Instructions if necessary.

 

I don't know when mixed trains finally vanished from the BR network and I suspect they might have survived in Scotland for as long as there remained traffic to justify them.

 

What Is A Mixed Train?

 

This is relatively simple to define as 'a train for the conveyance of passengers and freight in which the freight wagons are not required to have a continuous brake'. In other words a mixed train could (and did) for example convey loaded 16T mineral wagons or indeed just about any other type of wagon in everyday traffic use.

 

However this freedom came with some hefty restrictions such as the requirement to stop at stations in order to avoid a longer run than 10 miles without stopping (but they were not required to stop between stations should stations happen to be more than 10 miles apart; work that one out - it clicks, after a while ). In addition the total number of vehicles was not allowed to exceed 30.

 

Far more important, and the key way of recognising a mixed train, was the way in which the train had to be formed.

 

Firstly all passenger carrying vehicles had to be marshalled immediately behind the engine and with the cointinuous brake working throughout. Freight vehicles had to be marshalled behind the passenger vehicles and there had to be a freight brakevan ('in which a Guard must ride' to quote the old phrase) at the extreme rear of the train. In fact it might well be that there would be more than one such brakevan as the Regulations as they stood in 1960 required one brake van with a tare of at least 10 tons for every 10 wagons, or one brake van with a tare of at least 13 tons for every 15 wagons, or one brakevan with a tare of at least 16 tons for every 20 wagons, or fractional parts of 10, 15, or 20 wagons respectively!

The simple bit to remember - if it is a mixed train it will have a freight brakevan on the back. Or putting it another way if it hasn't got a freight brakevan on the back it is not running as a mixed train, even if it happens to be shown as one in the working timetable.

 

Tail Traffic

 

Put very simply 'tail traffic' is traffic (i.e vehicles) other than passenger carrying (or there as a Gurad's brake) vehicles attached to a passenger train. It can be formed either at the rear or in front of the passenger vehicles according to a variety of conditions and circumstances (which changed considerably over the years as will gradually be explained if the interest is there).

 

The important thing to recognise about tail traffic is that it could - and often did - consist of freight vehicles, with one stipulation. That stipulation was that such vehicles had to conform with the requirements for being branded 'XP' (in simple terms sufficient length of wheelbase and be fitted with continuous brakes). There were working timetable restrictions on trains being allowed to convey 4, and later 6, wheeled vehicles which obviously influenced the sort of tail traffic they could convey and there were also various braking and speed constraints plus the ability of a train to take a tail load (a critical factor with dmus) which also had to be taken into account.

 

So that's it for a first stab at the subject. If there is sufficient interest I shall try to build up the explantion to cover much more of the ever changing story of tail traffic through to the days when the arrival of HSTs and 'modern' dmus finally killed it off.

[MacRat]

Thank you for explaining.

I'm wondering which rules had to be followed when shunting mixed trains at intermediate stations? Was shunting with passengers on board allowed, to propel a wagon into a siding?

 

Mac

[The Stationmaster]

Thank you for explaining.

I'm wondering which rules had to be followed when shunting mixed trains at intermediate stations? Was shunting with passengers on board allowed, to propel a wagon into a siding?

 

Mac

 

That's one to which you quickly say 'very good question' and then start all sorts of verbal tricks and tell a couple of stories while you think of the answer.

 

In reality most shunting would not have been very practical with more than a couple of coaches in the way and large bogie coaches would have been even more awkward when you are trying to shunt (verbal trick #1 . So for any serious shunting the coaches might well have to be stood to one side if at all possible or - far better - the train would be shunted, if the track layout permitted, by running the loco round and getting to grips with the business end of the train.

 

But the latter would rarely have been possible at many intermediate stations so we come back to your question and give first the official answer which is it would be most convenient and doing it properly to turf out the passengers. We can then get absolutely practical and look at a small wayside station well away from roving officialdom and with minimal passenger facilities on a day when it's raining fit to burst and take an educated guess at what really happened, if you get my gist.

 

The only mixed train I ever travelled on had no freight work to do until it reached Mallaig so there it all worked very nicely because the passengers got off and the wagons were on the rear which was just right for shunting after the loco had run-round (sorry I should have included that in the verbal tricks ).

 

Finally back in the late 1960s I was travelling up a Western Region branch on a very heavily loaded 3 car dmu which had to attach tail traffic at an intermediate station. That shunting move was done without detraining us because, I'm pretty sure, the station staff would have had a riot on their hanbds if they had tried anything else (and the shunting move was done with added safety beyond what the Rule Book required so all was well, except for the huge delay to the train).

 

Hope that has helped sort out what was, I think, always a rather difficult and contentious area.

[jamie92208]

I came across an example of this in research I did for my Long Preston layout. Apparently a local farmer used to regularly buy cattle at Dingwall and have them shipped to Long Preston (At the southern end of the Settle and Carlisle.) This traffic usually consisted of 2 cattle wagons and a signalman who worked the box at the station told me how the traffic was handled.

 

Apparently they would come down from Carlisle on the last southbound of the day with the cattle wagons marshalled behind the coaches. When they got to Long Preston the train was signalled out to Hellifield and set off till the cattle wagonns had cleared the trailing connection to the cattle dock. This meant the train passing the starter signal. The ground frame was then unlocked from the box and the train, with passengers on it, was reveresed into the cattle dock and the cattle wagons removed. The train then continued towards Hellifield, Skipton and Leeds.

 

I was surprised at this method of working but the signalman has confirmed the details on several occaisions. I also found a note in the sectional appendix that allowed up two two fitted wagons to be conveyed on the tail of the train, or three unfitted ones if a brake van was also attached.

 

I have never had the guts to actually try this move on the layout when the public are watching but one day I will.

 

Jamie Guest

[buffalo]

An interesting topic. Mixed trains show up on the S&D branch and in the early days of the Camerton branch -- it's probably one of the things that attracts me to these lines.

 

As to tail traffic, you may remember a recent discussion on the old RMweb about branch line passenger train formations in which someone (it may even have been you) mentioned the rules about not having passenger compartments next to the engine. The use of brake ends as a form of 'crumple zone' was mentioned. Since then, I've been thinking about NPCS such as GWR siphons of the early four and six wheel types, and wondering whether these would have been permitted as a 'crumple zone'. There are many photos showing one or two of these at one end or the other of a train. Would the need for a 'crumple zone' have influenced where they were placed, or would it just be for convenience where they might need to be detached during a journey?

 

Nick

[The Stationmaster]

An interesting topic. Mixed trains show up on the S&D branch and in the early days of the Camerton branch -- it's probably one of the things that attracts me to these lines.

 

As to tail traffic, you may remember a recent discussion on the old RMweb about branch line passenger train formations in which someone (it may even have been you) mentioned the rules about not having passenger compartments next to the engine. The use of brake ends as a form of 'crumple zone' was mentioned. Since then, I've been thinking about NPCS such as GWR siphons of the early four and six wheel types, and wondering whether these would have been permitted as a 'crumple zone'. There are many photos showing one or two of these at one end or the other of a train. Would the need for a 'crumple zone' have influenced where they were placed, or would it just be for convenience where they might need to be detached during a journey?

 

Nick

 

It was indeed me who wrote, and quoted some Instructions, about the marshalling of gurad's/van compartments at the end of trains.

 

The question of marshalling of tail traffic was considerably more complicated in the 1930s than it was in the 1960s but I would be happy to go into the most detailed explanation I can summon for anyone who is interested (based on GWR source material I hasten to add). I can also look at 1920 as a 'snapshot' date as well if you are interested but the general Instruction - certainly for express trains - at that time was that any four or six wheeled vehicles should be placed at the rear of the train and short wheelbase 4-wheelers always had to be at the rear. The reason for the latter Instruction was almost certainly due to consideration of vehicle weight and brake power with the only safety implcation being that under emergency braking it was likely to be overwhelmed by any bogie vehicle marshalled behind it.

 

So is anyone interested in the detail? I would be happy to delve it out as it is both interesting and, I hope, useful but it will take a little while as it is quite complex. Also I can add the 1920 GWR mixed train stuff which answers Mac's question in detail (for the wrong piece of railway in the wrong era, but miracles always take a little longer).

[buffalo]

...So is anyone interested in the detail?

 

Well, I certainly am, and I hope others are too. I'd also be interested in reading anything you or others can add on the extent to which any of these rules might be waived, subverted, or just ignored on the minor branches.

 

Nick

[MacRat]

...So is anyone interested in the detail? ...

I'm too interested in rules and the ... uhm, actual practice.

Mac

[BluenGreyAnorak]

I'd be interested too, please. I've just been reading a little bit about these sorts of trains in Railway Operation for the Modeller by Bob Essery but it was only really an overview. It did have some good examples of when the rule book had apparently been dropped in the firebox though

[The Stationmaster]

Right chaps - I shall for Saturday with the next instalment (family stuff today and Friday is an old boys (& girls) reunion lunch for those of us who dallied in the Mendips at some part of our railway lives (and talking of bending Rules etc we did on one occasion try a Hymek for pheasant hunting on the Radstock branch, unsuccessfully alas ).