With that I suggested that I put a post on my blog & he will also post it on his blog, this may help others as well in regard to this topic. For non followers & followers of my blog, I refer you back to my post of 26/4/2013 that has some Teleprinter loads & other details on train composition to save repeating what was said there.
To begin with it really is not possible in the modelling scene to be totally prototypically correct, at least that’s my opinion if for no other reason than the constraints placed on us regarding layout space, & the many compromises needed to be made. Looking at loads, who would have a big enough layout with say a long enough grade of 1:40 that would allow you to run a train that ran almost daily from Sydney to Port Waratah (PTW). That was 58 empty S trucks & Brake Van for a load of 486tons, which was hauled from Gosford by a garratt. The load is 170 under the full load for a garratt, but over the load for all other steam loco’s unless double headed. The problem is not as far as a model garratt may not have any problems pulling it but, no one that I know has layout that even comes close to the short Fassifern bank in distance wise, but also on an HO layout, it would look out of place & far too long.
How can the modeller work out what to do with obtaining a prototypical load? In the end each individual will do his own thing, & work on more than likely what looks right in his eye’s which is not too bad of an idea at least to start with anyway. For the modern era modeller, I have no idea of the way things work these days, loads length & even running times, so I will leave that to others. I model as most would know a limited era time frame 1955 – 1957, a bit before my time but one that I know was not much different than the middish 60’s & pre the Mk2 44, & 48’s, except for big engines I worked on most steam in service in my chosen era.
The issue of load & lengths really only comes into play for the modeller who has grades on his layout, I have one section of 1:40 on a 28” radius curve facing up trains, thus it is the limiting load factor for my loco’s. The benefit of course is that it by its grade & curve is a limiting factor for modelling purposes, & each should look at his layout & any grades on it & make allowances for them.
The basic length is based on the humble S truck (those from the current Austrains releases are the same as an S truck for length purposes) all train loads & compositions (again see my previous blog post) were governed by that length, to complicate things, wagons like the K were 1.2 in length, some early bogie wagons were 2 while others such as the BD was 1.8, while later from the BDL onwards they were 2.3, a notable exception being the CG wagon that was only 1.7 in length.
To simplify, the length situation, remembering that I model an earlier period, I make the K & RU & equivalent wagons as being 2 = 3 S wagons, for those modelling periods with the longer than 2 equivalent bogie wagons, a similar idea could be adopted such as 2 bogie wagons = 5 S trucks.
Some photo's here indicate the difference of loaded & unloaded trains working over 1:40 grades. First loaded & where short trains can look ok behind steam & 1st generation diesels. Even when empty, a model train does not have to be long & loaded to look right.