TRACK

Commercial 'O' gauge track is not recommended because it is too big for tramway standards. The recommended rail is Code 100 solid nickel silver, flat bottomed. Separate rail of this type is produced by Peco and other manufacturers and is recommended. Track and points are usually made using copper clad sleepers and soldering the rail to the sleepers. If a live overhead supply is used there is no reason to insulate the rails. For two rail operation then cutting an insulating gap in the copper cladding is required. Because the track is buried under the road surface the sleeper spacing can be around 50mm (2in) apart on straight track, closer for curves and special work.

WHEELS

The width of tramcar wheels are much less than railway wheels, with a smaller flange width and depth. In 'O' gauge to use exact scale wheels would require very precise track construction and wheel setting. To get reliable running, most modellers use commercially available wheels and track, that is to BRMSB 'OO' gauge railway standards. The wheels and groove are slightly wider than true scale, though visually it is acceptable. Similarly the diameter of tram wheels is generally smaller than railway wheels.

In 'O' gauge there are three main wheel diameters; 16mm, 14mm and 12mm. The 16mm represents 28/31 inch diameter wheels and these are found on most four wheel trams and older bogie trams and the driving wheels of some maximum traction bogies. The 14mm diameter are found on modern low height four wheel trams, modern equal wheel bogies and the driving wheel for some maximum traction bogies. 12mm are found as the pony wheel for maximum traction bogies and on some very modern low floor trams. All three diameters are commercially available under the Romford name. It is usual to use a 30:1 gear ratio.

OVERHEAD

Terry Russell produces ready made traction poles. They are strongly made in brass and steel to the correct standards. They have a length of pole at the base for fixing to the baseboard. Drill a vertical hole in the baseboard just large enough to be a drive fit for the pole. The pole is forced into the hole to the correct depth. In "Distance apart of traction poles on straight track" we recommend that the poles are closer than prototype, as this increases the apparent length of small layouts and makes them look more realistic and interesting.

Terry Russell makes suitable overhead ears, frogs and crossings. These can be fixed to span wires or bracket arm poles. Hard drawn nickel silver wire 0.3mm diameter is available from Terry Russell. This is soldered to the ears.

Terry Russell makes assembled working trolley poles for open top or enclosed top trams. These all have swivelling trolley skids which are appropriate for the overhead system. Working pantographs are available ready made from Sommerfeldt.

POWER SUPPLY

The standard power supply is 12 volts DC, using model railway controllers. The recommended controller is the electronic feedback type and the handheld (HH) from Gaugemaster has been used with great success. It requires a separate 16 volt AC supply from a transformer (also available from Gaugemaster). The controller is very small and can be carried around the layout with ease.

The way tramways are operated in 'O' scale is by using either a live overhead system or a two rail power supply. In the live overhead system the power is fed through the overhead and returns via the rails, just like the prototype. However, there is one major difference between model and the real thing. In the model the overhead is one continuous electrical supply. All sectioning is done through the track. This makes modelling much easier and prevents stalling on overhead dead spots. The two rail system is exactly like that used for model railways.