Layout design for realistic operation
by Harry and the late Ivor C. Marshall.
© Harry Marshall 2006
The right of Harry Marshall to be identified as the Author of the Work has been asserted
In the first part, we looked at the reasons for thinking about the track design for an intended station layout with some care, introducing the premise that such design is essentially dependent on two groups of factors. These are the services the passengers and other customers would expect from their railway transport company, and the railway and general transport technology available at the period modeled.
Beginning with the matter of ‘period’, it is not only the question of correct vehicles, locomotives and buildings that we must consider. There are ‘outside’ matters as well, such as the degree of mechanisation on the roads, and in the transfer processes. Indeed, the very existence of certain kinds of freight on rail depends critically on the period modeled, and therefore the need to provide for its movement by rail. It usually took some time after a traffic ceased to be carried for all signs of its existence to disappear from the railway, though. More subtly, the cost of human labour has been a steadily rising factor in railway operation, certainly within the last century, and this has influenced operating and handling methods, and hence track layout to a considerable degree.
As to ‘traction’, steam of course reigned supreme up to the second world war or did it? A very significant part of the Southern system was electrified by the end of the thirties, and there were limited examples elsewhere e.g. Southport and Liverpool.
Above photographs courtesy of Electric Traction Supplement, The Railway Gazette June 24 1938
The introduction of unitised trains without detachable motive power had a profound influence on track layouts, which continues to this day. The use of steam, however, did require more localised facilities for the provision of coal and water, as well as overnight storage. The need to turn steam locomotives, even some of the tank types supposedly designed not to need it should not be forgotten. For those to whom the management of steam power is not even a memory, I will include a section later. The introduction of diesels had only a marginal influence on track design, other than for the servicing resources. We still had main-line machines and shunters, so all that really changed generally was the smell and the sound! One should not forget however that the Merry-Go-Round (M.G. R.) non-stop services to power stations and steelworks only became practicable with diesel traction, the huge increase in range available between pauses for refueling and servicing being the critical factor.
The ‘geographical’ issues are twofold. There is the large-scale matter of the operational difference between, say, East Anglia and the highlands of Scotland, in terms of motive power, i.e. provision of banking or pilot power, and the track layout needed to permit its attachment or removal. More locally, there is the immediate environment of a station area, in which for example the sidings may have to be placed in inconvenient locations to reach the rail- served customers, or the loco. depot may be crammed into a hole in the ground of limited size and no possibility for expansion, e.g. Guildford, or the whole station clings to a hillside, creating a width restriction that enforces less than economical operation. The possibilities, both on the real thing, and even more for fictional situations, are legion, and the impact of them needs to be thought through so that the essential operational character of the place represented can be brought out.
Under the heading of ‘nature of traffic’ we should look at both freight and passenger matters, and their interaction, as it is all too easy for instance to provide only one run-round loop at a place when the activities there entail running-round both passenger and freight trains. The consequent clashes and grid-locks as an essential loco release from a passenger train gets blocked by a freight shunting move can be very frustrating, especially if the real place never had that sort of problem! On the other hand, if it did…
So far as purely freight considerations go, we must be able to cut trains up such that all vehicles are placed at their loading and unloading points with the minimum of shunts, and equally to re-assemble them efficiently. Some of these locations will require the train or individual vehicle to be run through the facility, others merely need placement. Either way, access to each area will need sufficient length up head-shunts or other sidings to permit shunting clear of adjacent passenger movements, and the use of barrier vehicles when dealing with “Locomotives must not pass this point” situations. (A Bullied pacific once famously damaged the station roof at Ilfracombe by ‘blowing off’ at the wrong moment. What it would do to the average goods shed I leave to your imagination!) It also helps local business relations if the customer who has three deliveries a day is not at the remote end of a siding otherwise populated by small coal merchants. Think about it!
Ideally, there should be somewhere for incoming traffic to arrive before processing, and departing trains to be assembled, but this is really a counsel of perfection, and only seen at large stations with no geographic limitations. It does however allow separation between local shunting activities and the main-line locomotives that bring and remove complete trains. Designers contemplating fictional or examining real locations for exhibition layouts ought to bear this consideration in mind, in the interests of continuous activity.
‘Seasonality’: sometimes described as the best excuse for more and different freight models ever invented! Also something of a pain in the real world, where special-to-purpose vehicles for seasonal traffics had to be stored and maintained, expensively, for limited periods of revenue earning use during the year. Banana vans (steam heated) are the best example, perhaps, particularly in the early days of the traffic. Also the dilapidated rakes of pensioned-off carriages that lurked at Mitcheldever and other places waiting to move race-goers to Ascot, Epsom and elsewhere. For the modeller, though, seasonal traffic is an opportunity to ring the changes with the vehicles shown on a layout, and to vary the services run, both passenger and freight. This is where knowledge of such things as the farming patterns of an area at a period is important, so that we are not ‘moving calf traffic’ at the same time as the ‘summer perishables’ vans move into and out of the goods shed (on the same siding, but next to the yard gate)! For passenger workings, the transition from the winter two-coach one-an-hour pattern to a station heaving with holidaymakers off long rakes of corridor coaches from a railway with a different livery, or race traffic (including horse boxes, and the handling problems that go with them) will certainly prevent boredom! Obviously, everyone will have their own local situations to consider, but this is a dimension that has quite a bit to offer in terms of operating interest.
Train handling at stations
So far, we’ve looked at little more than the variety of external aspects that will influence our original track design, or the adjustments we might make to something from reality. Turning now to ‘internal’ matters, it is possible to distinguish three quite different forms of station, and to notice a number of significant stages in the development of railway engineering, each of which altered the methods of operation, and hence the layouts of stations in some degree. Of station forms, we have the terminus, the junction and the through station, each with or without freight facilities. Certainly there are hybrids around, and some junctions are barely distinguishable from through stations, but in terms of operation each presents its own problems.
Once we start looking at the engineering history, though, the interest expands to meet the horizon, as a one-time colleague used to say. Rail ways (two words, deliberately) were powered at the beginning by horses, humans and the occasional winch. Wagons were usually moved one at a time, and point-work was supplemented by small turntables at the end of the besidings, to return the waggons to the main roads. This approach persisted into the dawn of the steam age, it being common practice to separate the locomotive engine from its attend(er)ing wagon and pass it across to a release road piecemeal, as it were, at terminal stations. See early drawings of Nine Elms, Euston and other places if this strains your credulity. The intensity, or lack of it, of services in the early days meant that this was a tolerable approach, but matters soon changed, the coming of larger engines, many more trains, and the odd accident each having an influence. Increasing traffic density meant that much slicker means of releasing locomotives were required. Locomotives became more reliable, and feasible daily mileages increased.
In parallel, methods of operation of train services started to evolve, a movement away from one return journey per train per day over the longer distances being noted. This had an effect on the way sets of stock were managed at terminals, such that rather than removing a rake for servicing at a depot, it would be cleaned, lamped and (in course of time) toileted in the platform. A useful reduction in shunting moves into and out of the station resulted, offering more pathways for more service trains. Perversely, some of these were lost to light engine moves to and from the loco yards, as machines came and went for ‘requirements’. Local turntables and strategically placed water supplies eased this situation, but were not universally available.
Passenger Train workings
In amongst this, the method, particularly for shorter-haul trains, and especially at rush hours, of putting the next outgoing loco straight on to a set, and departing it quickly after arrival emerged. This enables release of the arriving train engine to shed, to be ready for the next incoming service on the particular route served. The classic application of this technique was the famous “jazz” service using high-powered tank engines in and out of Liverpool Street, pre-war. The longer-haul services still required the removal of the stock from the incoming loco, even if it was placed by the shunter in an adjacent road, and both these practices persisted well into the diesel age. Retention of locomotive release crossovers at the buffer stops of terminal stations in this country has never been common, the logic being that the approximately three coach lengths of platform lost to the point-work was more valuable for passengers to step on to than for engines to run past. There are or have been notable exceptions outside London, however.
The particular circumstances of traffic, or a special operational need could justify this otherwise inefficient arrangement. Inefficiency in this context refers to more than just platform length, however. The penalty for omitting the release crossover at a terminal station is the mandatory provision of a motive power unit of some kind to remove the stock from each successive incoming train. This is usually but not always a dedicated station pilot loco.
Another machine to maintain and fuel, one or two sets of men to pay… If, however, there is other work about the place for this loco then the cost incurred could be justified.
It should be appreciated that not all the coaches of an arriving train necessarily went out on the next outgoing service. Dining vehicles, for example, for most of their history have been detached for re-provision and cleaning outside meal service times. Reduction of train length outside busy times also became a feature, especially once servicing and maintenance routines got more sophisticated, around a hundred years ago.
The exception to all this was in fact the precursor to the unit working we see today, i.e. the push-pull train. This could operate into a simple terminal platform, theoretically in total isolation from the rest of the network. Shades of the “Titfield Thunderbolt”!
In practice, of course, both the locomotive and the rolling stock require to be fuelled and serviced, and would probably share running lines with other trains for part of the route served anyway. It is very easy to forget to include a detachment for coal or exchange of loco in the daily timetable for a push-pull set!
This brings us to the question of junction station working, and here, you have to know the habits of the particular company you are modeling, as practice varied considerably. The Southern, for example, would provide a train that started from London for all points west, so constructed that bits could be detached at a succession of junctions down the line, each forming complete trains in themselves. This had the commercial advantage that passengers could board at Waterloo, with luggage, and stay in their seats undisturbed (except for a meal in the dining car) to any of eighty-one destinations west of Exeter. Because the train physically stopped at the junction stations, it was possible for passengers to join the train also. Another organisation covering similar territory provided ‘slip’ coaches which were detached at speed by a guard, and brought to a stand at the junction station for which they were intended.
Fine, but there was no access to the dining accommodation, and a probable change to a separate branch line train at the junction. The non-stop nature of the main train gave a fast service out to the various slip locations and the remote terminus, but potential joining passengers at the intermediate stations were not served. As an aside, I’ve never seen this procedure modeled; have any of you? I wish I could describe the other companies’ practices, but have no experience of them personally, so its back to your own research, I’ m afraid.
To produce the Southern’s arrangement, all that is required is a platform or short siding in which the branch engine stands while the main train occupies the through platform for detachment and passengers joining/ leaving the continuing portion. Once this has gone, move on to the detached portion, run the branch service with it, come back ahead of the returning main train, run round and stand aside, (bay platform?) and attach to rear for return to London. Or, place in London-facing bay, remove branch engine, main line engine to collect and attach to front of its train. This preserves the sequence of portions for the next day….. but I digress! I have no personal experience of the Great Western practice, but it must have involved several shunt moves to get the slip coach(s) on to the return workings in the right order, with consequent cost in time and resources. The other method, of course, is simply to call the main-line train at your station, passengers for the branch to change to another train, either waiting in a separate platform, or to follow in from a siding.
Once we turn to consider freight workings, the situation becomes slightly more complex. Every line and station in the country has or had its own particular needs and problems, and this is where study of the local traffic patterns through the years portrayed is so vital. Once we know what has to be moved where and when, then it is possible to provide the necessities, albeit on a reduced scale. Taking a typical (if there is such a place!) country station which might also be a junction, or for that matter the terminus of some bucolic branch line, we might expect to encounter some or all of the following; coal, livestock, perishables, machinery, timber or other bulky, heavy commodities, maybe vehicles of some kind, fluid products such as milk or oil, parcelled goods and possibly grain. Each of these requires its own specific line-side facilities, and each will have its own patterns of delivery or dispatch, on a daily basis, as well as the seasonal effects. The physical layout of the yard will also be influenced by the local geography, and, (depending on period,) safety and access considerations. From a railway management point of view though, we need to be able to work it efficiently, i.e. with the reasonable minimum of arrivals, departures and shunt moves.
As an aside, it is noticeable that modellers who, to add to operational interest as they see it, make life difficult for themselves by design of yard layout, get quite frustrated with their creations and usually re-design to something more practicable.
Taking each of the above traffics in turn, coal mostly comes to such a place in side-door wagons, some or all of which might be local private owners. Correct truck to correct merchant’s staithe, please! Importantly, once placed, they should not be disturbed for the 24 hours it usually takes to empty them by hand. Livestock vehicles want placing at the cattle platform, of course, but this is not an every day traffic, and it may be found that coal is not delivered on market days, when the cattle movements are occurring further down the same siding. Perishable traffic would, for most of railway history, pass through the goods shed, though delivery straight to a van in the open was more common as the motor age progressed. This also applies to a lot of parcelled traffic, such as hardware, small quantities of raw materials for local trades etc. The vehicles involved, if the area freight manager’s staff are ‘on the ball’ will be in and out the same day, if there are two freight trains in the timetable. Heavy or bulky things need the yard crane, are not likely to need ‘action this day’ and would merit a dedicated siding if at all regular. If modelling a period before about the mid-thirties, vehicles including farm machinery would be dealt with this way also, end loading banks not being that common, even after the war.
Once we consider the fluid traffics, matters become more period dependent. Milk handling by rail changed from churns in vans to glass-lined tankers in the thirties, but not universally even then. Small stations could still despatch a few churns per day, even if only to a station just up the line, right up to the fifties. Churns would usually go through the goods shed, and of course a twice-daily drop and pick-up was mandatory, dictating absolutely the freedom of rail access to the shed. Milk tank traffic, as for fuel oil, would be in or out of a dedicated siding, probably on customer’s premises, and for milk the twice-daily routine with attendant clear access to the siding was necessary. Fuel oil, however might be only once or twice a week, but remember the need for the barrier vehicle each end, “locos. must not pass…” etc. and the consequent length requirement. As to grain, milling tended to be a rather seasonal activity until the advent of effective rot and rat-proof storage, so it is not impossible to treat this as an alternative with sparse summer coal traffic, when the grain is ripe, and vice versa. Access could therefore be shared on a seasonal basis down the same siding.
In Part 3 we shall look at some of the techniques of track design, and “layout editing”.