Narrow Gauge in the Garden. (Also maybe useful for standard gauges).

[Mountain Goat]

Years ago my first venture into 7mm narrow gauge was track pinned to hardwood creosoted wooden triangles cememnted into a garden path on which track was pinned. It worked well but it was only a single line about ten to fifteen feet long just to test the idea. My thoughts had also strayed into SM32 and I purchased a Mamod loco kit but didn't venture any further as the track was expensive and I would have had to give up on 00 to aford it and back then I wasn't ready for such a change. The Mamod leaked steam everywhere using the rubber O rings supplied, but I did get it working just before I sold it by soldering in the steam pipes instead of using the O rings.
It made me think. While SM32 and G scales are popular, I have only twice (Via youtube) ever seen a 7mm narrow gauge garden railway and I have never seen or heard of a 4mm scale narrow gauge garden railway, yet 00 gauge is popular outdoors and N gauge has been used with success, though it is a little small.
A garden railway is possible in a small scale, though some precautions will be required. The smaller scales are normally electrically driven through track power. This does mean the track needs to be kept clean in the same way it needs to be kept clean with an indoor railway layout. The track needs to be nickel silver or brass. Steel track just is not an option when running outdoors. Depending on where one lives, one may need to solder link wires around the rail joints to ensure electrical current reaches where it is meant to be. Those living in a sheltered inland area may not need to do this as they are less likely to get salty mists like one can get living near the coast.
Controllers.... These need to be kept dry. The trains and the track can get wet, and running in the rain is not a problem as if a short occurs, the controllers short circuit protection will trip just like it does indoors. However, the controller itself and the mains power side of things need to be kept dry, not only for the protection of the controller, but for your safety as well. Hence most garden railways in the smaller scales will run into a shed. It is possible to run an extension lead from ones house or garage into the shed but it is better to have an electrician run a proper supply.
Other options are radio control, or a simple battery loco with an on off switch in the same way a childs toy train works? May not be ideal but it will work. How about clockwork? It was very popular not so many decades ago... The advantage of these are that it won't matter if the track is dirty. As long as the wheels are not obstructed they will run. Radio control is the most attractive option but is it ideal as there are a limited amount of locos which one can run. If one only has a few locos and does not want more then it is a good idea to consider it.
The track base.... Concrete and rubbercrete make good bases. Hardwood does as well, but some softwoods are not ideal. It depends where one lives. Concrete has the advantage that it expansion properties are fairly similar to nickel sliver, so in the past 00 gauge garden railways have been ballasted with a weak cement mix. With wood, it is a good idea to cover it with felt, and pin track down lightly so it can move a little. That way any expansion and contraction of the wood and rail (Which have different expansion rates) will be catered for. The larger scales tend to have less of an issue then the smaller scales when using wood as a mm of expansion in a large scale is not much, but to a small scale it is a lot. Don't forget, wood expands when it is wet as it swells. Rails expand when they are dry and warm while wood shrinks when it dries. Hence track layed on a wood support will need to take this into account.
The height of the railway needs consideration. Railways at ground level can quickly dissapear under weeds especially in the smaller scales, so will need more work to keep them from turning into a jungle. Raised height railways have the advantage here, but raised height railways are more vunerable to the wind. A fence or similar can provide shelter. It also depends on the terrain of the land. Ideally track should be level with a slight uphill section to reach the shed, which will prevent water entering the indoor area. It is also ideal if the track does not need to cross any paths and enters a shed at table height level. However, life is not always like that, but if it can be arranged in this manner, it will be easier.
Generally with a garden railway, the larger scales are easier as if a leaf falls on the line, they are less of an issue, however in small scales they can be a disaster! A spec of soil falling on the line in SM32 or G scale is no problem. But in 009 it is a landslide! A blade of grass in the way in SM32 or G scale is not an issue. The trains just push past as if it wasn't there. In 0-16.5 (7mm narrow gauge) it may push past or may cause an issue depending on the size of the blade and its strength etc. In 009, it is an obstruction. Hence the smaller scales usually need more maintenence before running.
However, a garden railway is well worth the effort and is possible in most scales and gauges with some thought and planning.

[footplate1947]

Hello MG I had a standard OO gauge garden line which had about a 80ft run all around the flower beds. It was built by driving 3 x 2 into the ground and fixing decking to the top of the stakes about 8" above the ground. I used ordinary Peco nickel silver streamline track and some points. There were not many points as there was only one passing loop giving the appearance of a double track station. It worked well and was ordinary 12v DC operation. So garden railways don't have to be large gauge do they. I wired all the track with short pieces of wire so there was not any worry about bad connections from fishplates upsetting power supply. You did have to clean the track often but I did not have a track cleaning wagon then to help.
The advantage with large gauge may be that it would be easier to have battery power and radio control which would eliminate track cleaning outside I would think. I don't know if battery power is practical as for as how long the batteries would last when running. I have never tried that. I would get fed up quickly if you had to spend all day changing batteries every 20 minutes,
If you had battery power I wonder if you can have a recharging siding where you could run a loco in for recharge, switch it on and recharge them with out touching them at all. Now that appeals to me.

[Mountain Goat]

It is feaseable for a sheltered siding in a shed to charge a battery via track power as long as the loco is facing one direction and not reversed.
I have not mentioned another solution to a garden railway where mains current may be out of reach and that is a railway powered from a 12 volt DC battery, e.g. a leasure battery or even a car battery. The only downside to this is one may need to make a simple controller as ready made panel or hand held controllers tend to drop the track voltage a bit if fed with 12 volts DC. Of corse, one could step up from 12V DC to feed a ready made controller which is another alternative. Point and signal control are other issues that will need to be addressed possibly in a similar manner or some sort of manually controlled alternative can be used. Regarding narrow gauge, it is rare to see a 7mm scale narrow gauge garden railway, yet the scale does offer a more realistic look then a smaller scale does in relationship to the outside world, and it still is a relatively cheap alternative to the larger scales which by their very nature tend to be rather costly in comparisson. However, there is one area where using 7mm narrow gauge will need to be addressed and that is in regards to running in windy conditions, as coaches may have the potential to act like sails! A suitable fence or wall or even plant life to act as shelter would be advised. 7mm narrow gauge (In theory) should be ok with track power as one can add weight to the locomotives as the larger bodies should (In theory) have more available space, therefore they provide the possibility of increasing the force applied to the wheels to gain sufficient cuttent from track power to run their motors. However a potential difficulty is that most 7mm narrow gauge locomotives will only have four or six wheels which may slightly limit the potential current collecting ability. Either extra forms of pickup via little skates or having plugs and sockets to connect to rolling stock with additional pickups are both possibilities should the needs arrise, though adding additional weight would be the first option to consider, as this not only increases the electrical contact potential, but also increases traction on damp or wet rails.