|Now viewing: 1|
A few note and ideas about building your own track
Why build your own track when there are many clubs around? It involves a lot of time, effort and money, and it may be better to just consider joining a local club. But this doesn’t suit everyone for a whole variety of reasons. Building your own track is a B-I-G task, however, if you want to do your own thing and do decide to build your own track, below are a few notes and guidelines from those who have done it before. There are some which are DO this, and others which are DO NOT do this, and others which are just guidelines to think about. The notes are equally applicable to anyone building a new club track, or a private track.
You also probably need to decide on what you want achieve
It is best if your track is constructed on your own property so you do not have to rely on a neighbour, or others, for the required space. Whilst it may start off all well, a task of this nature can put stresses on the best of friendships. There is also the possibility that either you or your neighbour may decide to sell up and the chances are that the new owners may not want a railway running through there new property.
The site does not have to be flat, or even nearly so. It can be quite steep, and in fact hills add significantly to the appeal of the final operation if there are a few grades and curves. However, hills, and a smaller-than-desired available area, all mean there will be gradients, and curves. The main aim is to keep these within bounds.
It is also desirable to have a visual obstruction from one part of the track to another as this adds to the illusion of distance and the feeling of being a ‘real’ railway. Not being able to see where you are heading or where you have been gives a better impression of your railway being a bigger size than it really is. Visual obstructions could be cuttings or tunnels, existing (or future) trees/shrubs, mounds of earth/rock - either natural or manufactured, buildings, longer grass, etc.
In general the bigger the better, but unless you have a very large available property (and budget), there will undoubtedly be some restrictions. A larger size means larger curves (desirable) but also means more maintenance (less desirable). But if space is less than you would like to have, it is surprising what can be accomplished in a smaller area by clever track layout design and making full use of the visual obstructions available.
When building your own railway or loco it would be wise to consider building it to a commonly used standardised gauge – 3½", 5", or 7¼" gauge - and to follow the track and wheel standards set out by the Australian Association of Live Steamers (AALS). Even though your own equipment may normally only run on your system, this may not always be the case. You may want to take your loco to another track (and probably will) and be confident that it will run on their rails without issue. Similarly it also means that you can have visiting locos and know that they can run on your track trouble free.
Of course, budget also has to be considered, as this too is usually limited. You may well be amazed at the vast quantities of materials that are going to be needed to build your railway.
Write down a list of materials to get an idea of what you are going to need. Some of the things you will need as a minimum are:-
This is not an exhaustive list, and there should undoubtedly be more things on the list, but it gives you some idea of what may be required. Remember too that if you your boundary size is doubled, then the area (and the cost) will be increased about 4 times.
Almost invariably, some earthworks will be required when building a track so consider
Consideration should be given to the possibility of the future expansion of your railway. It may not be practical or financially viable to build your desired railway complete in one major project. It could however be built in stages or sections that can be extended at a later stage when time or budget allows. Design the layout with this in mind, even if some bits are "missing" in stage 1.
Plan beyond "now". You may be quite happy now to build a small track to suit a small loco, but what if the bug bites and you decide in a few years that you want to build yourself a larger more powerful loco? Stranger things have happened! You may well find that the track you have built restricts you to only running 0-4-0 or small bogie type locos. You may also want to consider visiting locos as well when you design your track layout.
Bridges and tunnels are both fantastic features to have on any railway, be it a full size railway, a table top model layout or your miniature ride-on sized railway. They may be an absolute necessity due to local terrain, or may be deliberately ‘designed-in’ to add interest to the track, or enable a ‘figure-8’ type track configuration to permit a longer running track.
But due consideration must be given to both the financial and engineering aspects of either a bridge or tunnel. Bridges and their foundations must be designed and engineered to carry substantial loads with a suitable safety factor, and consider the associated costs like excavations, cranes, etc.
Consider too, not just the loco/rolling stock currently owned or in use, but also the future, or visiting locos, which may be substantially heavier. Design for heaviest load imaginable, then double it! Dynamic loads, even a person walking on the structure, can impose significant transient loads.
Bridges above a certain height may require hand rails etc, to comply with the AALS Codes of Practice, or the local council regulations, just as the raised deck on a house would.
Tunnels have their own associated problems as well. What method of construction, type of construction material, drainage, long term deterioration and maintenance, will all have an impact on tunnel design? Consider too the roof loading from vehicular or pedestrian traffic overhead. Methods of construction could include: Timber, steel or pre-cast concrete pipe, brick-by-brick or block-by block, formwork and pouring concrete, or prefab sections, etc, all have been used successfully.
Side and overhead clearances of permanent way structures from the trains need to be considered. The AALS Codes of Practice give good information on these aspects. A passenger on your train should not be able to reach out and grab anything from a moving train. You may think “no one would do that” but you might well be surprised! When the track goes through a tunnel, or under bridge or structure, any passenger, including the driver(!) should not have to duck to avoid a head strike.
There is no simple answer to the maximum grades which you can build for your track. Grades are relative to your motive power and the loads you intend to pull. However, there are some good practical guidelines which have been shown to work satisfactorily. For the ‘main line’ try to keep the gradient to a maximum of say 1:50 (2%) if possible. Anything steeper than this will substantially restrict the train loads on the entire system.
Steeper gradients are certainly possible but not recommended. Do not exceed 1:30 (3%), and then only on short straight sections in say the lead up to a service area where engines are nearly always ‘light engine’. Avoid steep grades on the main running track wherever possible. Regard 1:30 as the maximum practical gradient.
Remember too that curves create drag for a train, and the gradient does also, so it is preferable to have larger radius curves on gradients if possible to compensate a bit. Having sharp curves on a steep grade requires much more tractive effort than a straight climb on the same grade. A small amount of gauge widening on curves can reduce the drage due to the curve.
Minimum radius is more often than not set by the boundaries of the available land area, and the size (or more accurately the rigid wheel base) of any locomotive or vehicle running on the track. Quite large locomotives can traverse tight curves IF they utilise bogies or some form of articulation, provided the rigid portion of the wheelbase is sufficiently short. For example a Shay or Climax type steam locomotive can negotiate incredibly tight curves but nothing else much can run on that track. Conversely, a large (long) 8-coupled express passenger type steam locomotive will require a larger minimum radius.
Another factor which can limit the minimum radius a locomotive can negotiate might not be limited by the wheelbase alone, but by the sideways movement (swing) of leading or trailing trucks, or bogies, which can foul parts of the locomotive superstructure or chassis. Consideration should be given what size locomotives the track can handle, or be prepared for either track or locomotive damage.
As a general rule the smaller the gauge, the tighter the curves, so a 5"g track can have sharper curves than a 7¼"g one, all else being equal. For 5" gauge, and good working minimum radius is 10m (33ft) with gauge widening of say 1mm on the curves, or 12~15m radius with no widening. This gives a good compromise between trouble free operations, and able to handle both NG and most mainline type locomotives.
For 7¼" gauge, and good working minimum radius is 15m (45ft) with gauge widening of say 1.5mm on the curves, or 20m radius with no widening. If smaller radius curves are required, widening the gauge a small amount to say 2mm (max) for 5"g or 3mm for 7¼”g will greatly assist reducing the friction and permit longer wheel base vehicles to negotiate the curve (but remember those swinging trucks!). A radius tighter than 7m (5"g) or 10m (7¼"g) would restrict operation to NG style equipment. For any particular situation it is possible to approximately calculate the minimum radius a vehicle will negotiate with this minimum radius calculator.
If all you want to do is put a small loop of track around your house or shed to run only your 0-4-0 with a couple of 4-wheel short wheelbase wagons, then go ahead! With the tighter radius curves [7m (5"g) or 10m (7¼"g) minimum radius] some gauge widening on curves is suggested. The gradients should still be less than 1:50 (preferred) and 1:30 (max) as above.
The alignment of the track is quite important, whatever the curves etc. There should be no kinks or sudden changes of direction, and all track should be smooth to the eye when viewed from rail level.
Transition curves are highly desirable when going from a straight to a curved section of track. Even 2m of transition will enhance operations.
It is also very important (almost a must) to have some superelevation on curves. Make sure the roadbed is angled appropriately, and the track laying gang do the right thing.
Wherever possible leave a short straight section before a set of points, so as the locos and rolling stock can align themselves up for the turnout into the curve.
In situations where the track changes from a left hand curve to a right hand one (or vice versa), make sure there is a straight section of track between the curves to take care of the alignment of the chassis, and reduces the stresses (and possible derailments) as the superelevation direction change tends to twist the frames of any vehicle – locomotive or carriage. Without a straight section, the truck or loco will want to twist in two directions at once. Make the straight section as long as practical. If only a small straight is possible, reduce the superelevation on the curves in this area.
Some form of signalling will probably be required, except on perhaps the simplest of circular tracks, but a full-blown automated or computerised signalling is not required either, just sufficient to notify drivers of track conditions ahead. For example, even with only one siding at a track, if another train is coming along the ‘main’ line, and the points are set for the siding, an indicator signal can easily be connected and operate when the points operate. A simple switch on the moving parts can accomplish this.
It is highly recommended that some signalling, no matter how basic, be installed. It also provides a more prototypical experience as well as performing a functional purpose.
Full size practice uses track circuiting where the rails are insulated from one another and the presence of a vehicle with metal axles and wheels (i.e. a typical rail vehicle) completes the electrical circuit and is used to operate the signals. This is the most fool proof way of operating signals, but also requires care in track construction to prevent short circuits from say metal sleepers welded to the rails. Detecting the presence of a train can be done in various ways, but a track occupancy detector circuit can be quite simple.
It is also possible to detect when a train passes a known point, and another detector sense when it passes a second known point, usually at the section of track. This method also works well, but is not as fool proof.
The most important thing about any signalling is that it can reliably detect the presence or passage of a train, day or night, wet or dry, summer or winter, and therefore be relied upon.
Any signalling is better and safer than none!
All tracks require maintenance! And the bigger it is, the more required. Don't forget this important topic in your planning, as poor maintenance can stop you running. Make sure things work properly (e.g. points) by performing inspections on a regular scheduled basis, and lubricating if required. Check the condition of bridges, embankments etc for corrosion, rotting wood or washaways. Check signalling circuits for proper operation, that turnables etc work properly, etc etc.
Debris from nearby trees is often a problem, particularly leaves and twigs that invariably drop, these can be sufficient to cause a derailment. It pays to take a walk around the track, or use a 'fettlers car' type vehicle, before a run and clear/repair anything found amiss. Grass, and other vegetation, also has a habit of growing where you don't want it. Trim and clear as required to maintain clearances.
Weeds can be a problem too, particularly in the right-of-way. They grow quickly in poorest of soils and just about anywhere. Consideration should be given to spraying regularly with a long-lasting weed killer to slow down any re-growth. Another and recommended way to reduce the number of weeds is prior to laying the track and the ballast, to install the black weed control matting available from the hardware stores. It is intended for gardens and is about 1m wide and sits nicely under the track and ballast, and helps control the weeds. Make sure it not just plastic, as it has to be porous to let water seep through to the underlying soil, and also prevent washaways during heavy rain periods.
Safety is an extremely important issue, and often overlooked at the planning stage, and covers a wide scope. Things to consider are
A fail-safe default is the best option.
There also other things you may need to consider when building your dream railway. They may not be high on the priority in the early stages, but may stop you running in the future, so it is best to address these issues as early as possible
There are probably other factors as well, but the above covers most of the things you may encounter and should consider. Unfortunately, it may not be as simple as just building a track around the house, in most cases some of these other factors need to be taken into account. But whatever you do, have fun!.
[Updated: 27 Jan 2013]
|Text and photos Copyright © 2006-2017 SMEX, All rights reserved.|