[1] The companies were already involved in the transport of many thousands of troops during annual manoeuvres and it was realised that better coordination and planning would be required if the United Kingdom were to enter into a future European war.
In 1911, the companies began to plan for the movement of troops, horses and equipment to the embarkation ports, chiefly Southampton, in case of mobilisation; the main role of the REC was to oversee this work.
[2] Using powers granted to the government by the Regulation of the Forces Act 1871, the REC took control of the national rail network on 4 August 1914, the day that war was declared and mobilisation began.
The basement in Fielden House was unsuitable, so the unused Down Street tube station was converted into bomb-proof underground offices to become the headquarters of REC.
The doors to the new headquarters were fitted with gas locks, and short, secret, platforms were added, where REC members and senior staff could stop a train and travel in the cab to the next station.
[13] The Minister of Transport, Euan Wallace, took control of the railways on 1 September 1939 (two days before Britain declared war on Germany).