Frequently Asked Questions

A "live steam" engine is one which is actually driven by steam which has been produced by heating water until it boils, just like the real thing.

Water is heated inside a sealed container (the boiler) until it boils and produces steam. It is kept boiling while ever steam is required. Because this process is contained within the boiler, the pressure of the steam increases to a pre-determined limit and it is this pressurised steam that is drawn off as required to power the cylinders.

A safety valve is fitted to the boiler to prevent the steam pressure rising above its normal operating level. On ROUNDHOUSE models, this is 40 psi (pounds per square inch) which is about 2.7 bar. When the steam pressure reaches this level. the safety valve opens and allows excess steam to 'blow off' to atmosphere. Both the operator and any spectators must be aware the engine is very hot when being operated and emits very hot steam both through the chimney and the safety valve.

All our standard locomotives are all gas fired using mixed propane-butane gas which is the simplest method of heating the water. The gas is stored in a special tank mounted on the locomotive and fed, via a gas regulator valve, to a burner mounted either outside the boiler (externally fired) or inside a flue which passes right through the boiler from one end to the other (internally fired). Whichever the method, when ever the burner is lit it is heating the water to produce the steam. The rate at which steam is produced is controlled by the gas regulator. Turning it up increases the heat at the burner and thus the amount of steam produced whilst turning it down has the opposite effect.

Steam drives the loco as it passes from the boiler through a regulator valve and down to the cylinders. In the cylinder it pushes a piston from one end to the other; first one way then the other. The piston is mounted on a rod (piston rod) which is attached by a special swivelling joint (the crosshead) to a second rod, (the connecting rod) which in turn is connected to the wheel or crank. As the piston is pushed backwards and forwards, it causes the wheel to rotate. The steam has to be sent to each end of the cylinder in turn and the used steam must exhaust up the chimney. This is taken care of by a valve in the valve chest mounted either on top or at the side of the cylinder. It must also do it at the right time on every stroke of the piston and this is accomplished by means of the valve gear. The amount of steam passing to the cylinders is controlled by the steam regulator.

There is a simple routine to preparing a loco for operation on ROUNDHOUSE models.

Certain ROUNDHOUSE locomotives are fitted with a water top up systems and water gauge so that you can keep topping up the water level in the boiler as it is used. In this way it is possible to keep the engine in steam for long periods.

Radio control is a standard option on all ROUNDHOUSE 'classis series' locomotives. This gives full control direction and speed from a distance. Standard 2.4 Ghz three or four channel radio control equipment is used. One channel operates the reversing valve gear and another operates the steam regulator. A radio controlled locomotive is supplied complete with coupled handheld transmitter.

The 'basic series' locomotives can be fitted with radio control by the owner using a fitting kit that is available as an accessory. On these models, because they are fitted with slip-eccentric valve gear, the r/c is only operative on the steam regulator to control the speed. Reversing still has to be done manually on this loco series.

Like any machine, regular lubrication is very important. For all other moving parts, a medium grade general lubricating oil (20w50 motor oil or similar) or Steam Oil is required and should be applied as follows:

Before each operating session. - Axles, axle bushes, crank pins on each outside crank, all valve gear pins, expansion links and pivot bush's, crosshead/slide bar, piston rod, valve rod, valve rod fork end, lifting links and weigh shaft.

Once each month when loco is used regularly - pony truck axles (if fitted), pony truck pivots, radio control linkages to both reversing gear and regulator, reversing lever on manual models, tender axles and bogie pivots, roof hinge screws, gas regulator spindle, steam regulator spindle.

Periodically, a general check round for loose screws or nuts and simple adjustment to cylinder glands (adjustable seals round the moving piston and valve rods) is required due to the constant heating up and cooling down of the engine.

Insulated wheels are fitted as standard on certain models and are an optional extra on others, but not 'basic series' models, so you can operate ROUNDHOUSE steam locomotives on the same track as your electric trains without shorting out the system.

Because a working steam engine exhausts a certain amount of water and oil from underneath the chimney, track cleaning may be required a little more frequently.

If you ask this question of a dozen garden railroaders, you will probably get a dozen different answers as there are many ways to tackle the task of creating a railway for your loco to run on. The best way to tackle this is to look at what other people have done, see what options there are, how each may be applied to your own garden and see which suits your own needs best.

The minimum radius needed to run one of our smaller locos (i.e. Billy, Lady Anne, Katie) is 2 foot meaning you can start out with just one circle 4 foot in diameter!

As a start to building listed below there are several national associations and multiple publications that can help with ideas and practical information on basic construction of your railway.

16mm Narrow Gauge Modellers
The G Scale Society
Garden Railway Magazine

The final decision on which gauge to choose has to be yours, but here are a few points you may like to consider.

32mm gauge pro's and conns.

45mm gauge pro's and conns.


Narrow gauge is a mix and match of styles and sizes in the real world, and the same can apply to your model railway without anything looking too out of place. LGB continental style coaches for instance, would be perfectly at home behind a typical British outline tank loco - just visit the W & LLR in Wales to see this.

The kit form British outline stock can often be fitted with either 32 or 45mm gauge wheel sets so you can still run them on 'G' scale track.

One often asked question is, 'is the wider 45mm gauge more stable than 32mm gauge'. The answer is no, there is very little difference. Because we are dealing with narrow gauge rather than 'main line', the running speeds are not high enough to cause a problem if the train is under proper control.

The whole essence of 'G' scale and SM32 is to create a narrow gauge line that meanders through, and is integrated into, your garden. As it is your railway, it can take on whatever style you prefer and if it looks right to you, then it is right. Some prefer the narrow look of 32mm gauge, but again it's all down to personal preferance. Have a good look at what rolling stock, track and accessories are available for both gauges and see which appeals to you most.

Roundhouse Engineering Co. Ltd., Doncaster, UK. 2018. Click Here To Return To The Homepage