METRICATION:  20% complete
Metric Non-metric
Loads, capacities, and tare weights Speed limits imperial-only on most lines
Brake force

Drawings and bills of quantities

Drawings and the issuing of bills of quantities have been in metric units since 1971.

Rail Traffic

On 5 May 1975, rail traffic switched to metric measurements for loads, capacities, tare weights and brake force.

Rail Traffic metrication leaflet – 1975


On the traffic side of the railway we are chiefly concerned with distance and weight. As to distance, no metrication is planned for the time being. Unless the Government decides to change from miles to kilometres on the roads, we too will go using miles, chains and yards – and of course speeds in miles per hour.

With weight measures the situation is different. Already the railway sales people have for some time been quoting rates for freight in metric weights, because so many of our customers are dealing in them, Now it is time for them to come into use on the operating side as well. From 5 May next, metric weights will become the standard for loads, capacities, tare weights and brake force.