This standard is a proposal by the original Manual Group. It has not been adopted by the Guild, but is available to groups of modellers who choose to use it, or to follow the principles described here.

It is common practice in the smaller gauges, but less so in gauge O, for groups of modellers to agree on a standard baseboard module for joining layouts together to produce a larger system either for use at a club or exhibition. A notable British example is the East Kent Group module.

Most of these standards specify the overall dimensions of the baseboards, the distance of the first track from the edge and the track centres but not all specify the number of tracks. None use the Guild fine standard running line centre spacing of 80mm which was first published in 1950 and some specify more than one standard board width.

It is impracticable to standardise an overall width of baseboard and number of tracks because there is an infinite arrangement of the ends of layouts to be joined, but a standard interface has been developed which will allow layouts using it to be joined together either directly or with intervening sections forming main lines. Any number of tracks can be joined providing that the dimension between track centres is a multiple of the Guild standard for running lines (80mm). It is not practicable to cater for other track spacing by a universal interface.

The minimum width of the baseboard will be determined by the number of tracks. Provision has been made for 'bolt on' edge sections to give a continuous baseboard edge but these will be made to suit individual combinations of layouts. Figure 1 gives the dimensions of the standard interface.


Figure 1. Standard layout interface dimensions.

Twelve through wires terminate in 2 ampere terminal blocks to permit any type of plug and socket or direct wiring to be easily connected. Terminal 1 is allocated to the common return and 2 onwards are track feeds starting from the left facing the interface. A second block is provided for other connections. The use of terminal blocks with through wires rather than pre-connected plugs and sockets allows wiring to be easily matched between layouts and avoids problems arising if a plug and socket becomes obsolete.

Layouts with the standard interface can also be joined by standard sections of double track main line having interface dimensions shown by Figure 2. These have a width of 150mm and can be used side by side to provide multiple through tracks as shown by Figure 3. Provision has again been made for 'bolt on' edge sections incorporating, for example, fencing.


Figure 2. Double track joining section interface. Extension unit is the same both ends. Adaptor unit has the other end to suit a non-standard layout end.


Figure 3. Four track main line connected by two standard joining sections.

The length and radii of joining sections can vary to meet particular requirements but it is suggested that for maximum flexibility of application the lengths of straight sections should be in multiples of 300mm and curved sections should have not less than eight segments to a circle with a minimum radius of 1.5m (in other words the equivalent of the classic 'train set' of bygone gauge O years).

Layouts with non-standard interfaces can be connected using specially made adaptor sections having one end matching the layout and the other terminating in a standard interface.

Written by the Technical Committee for the Gauge O Guild Manual. Rewritten and adapted for the GOGWiki by Nick Baines.