The Weighing Equipment (Automatic Rail-weighbridges) Regulations 2003

3.3.3.  Automatic rail-weighbridges used for uncoupled wagon weighing shall recognise and indicate the following situations:E+W+S

(a)the passage of two or more coupled wagons;

(b)the passage of two or more uncoupled wagons that is sufficiently close to cause either a malfunction of the instrument or errors exceeding the appropriate maximum permissible errors.