One of the benefits of modelling a secondary mainline is that the trains tend to be shorter than those on the major routes - no Cornish Riviera Limited or Torbay Express - so they are easier to accommodate, not to mention to model! The main train of the day from London - the 12.30pm PDN/WEY - left London with 12 coaches but most of them came off at Westbury so by the time it reached Maiden Newton it had only 5 coaches. The train was regularly strengthened though so I shall add an extra all 3rd to make it look a little more impressive. Local trains to Westbury, Chippenham or Bristol were usually the normal 4-coach M set so again easily accommodated. I was able to obtain the two documents shown below and these give the details required to represent the trains quite accurately. Of course they show what the GWR planned and were often amended but they do give a good indication of what happened and the make up of trains.
One feature of steam railway operation that is perhaps not so well recognised at this distance in time is the amount of 'tail' traffic handled by passenger trains often on an ad hoc basis. A look at some of the John Huntley 'Steam on 35mm' videos shows that additional vans, etc. were regularly added to trains and it should also be remembered that 'tail' traffic could also run at the front of trains - all depending on where the vehicle was to be detached I guess.
Freight trains were subject to alteration depending on the amount of traffic presented but in 1947 most goods still went by rail so the trains were usually well loaded. I shall be limited on the length of freight trains by the storage sidings. Going back many years now I was inspired by the long goods at Pendon Museum with the train comprising 80+ coal wagons behind a 28xx. I had thought such a train would not be seen at MN but the Service Time Table revealed that the 'Rogerstone coal train' ran through on a Tuesday evening - with the return empties on a Thursday - so I can run a coal train of 22 coal wagons plus Toad behind a ROD - although a 28xx will appear in due course.
Gerry