When the Tank Corps was first formed each Company had its own workshops, and this system lasted to the end of 1916. Then in the course of the winter reorganisation, Company Workshops were abolished and Battalion Workshops were substituted. By the autumn of 1917 the experiment was tried of centralising still further and merging Battalion into Brigade Workshops, and early in 1918 it was decided to take the last step and to concentrate all repairs in the Central Workshops. This system, which achieved a great economy of skilled men, was made possible by a very clear line of demarcation being drawn between Repairs and Maintenance, a principle which had been laid down by Colonel F. Searle, D.S.O., the chief engineer of the Corps and the head of the whole mechanical side of the Tanks. No damaged part was ever to be repaired on the field; mechanical efficiency was to be maintained by the broken bit of mechanism being immediately replaced by a complete new part. This replacement was carried out by the crew, whose efficiency as mechanics was enormously increased by being thus made responsible for their own machines. One point had, of course, to be carefully attended to in carrying out this system. There had to be a very efficient supply organisation by which the necessary spares were quickly available in the field. When the crew had removed the damaged part from the Tank, it was sent back to the Central Workshops to be repaired. Here a specially skilled man would be always employed upon damages to one particular part. [48]“For example, broken unions of petrol pipes commonly occur in all petrol engines, and if a small unit workshop exists, the brazing out and repair of such broken unions can be carried out there. But in order to do this a coppersmith must be kept at the unit workshop, and only part of his time will be employed in this work of brazing petrol unions. If now, however, all broken unions, from every unit, are sent back to a Central Workshop for repair, there is a sufficient amount of work of this description to keep one man, or possibly two or three men fully employed all their time. “These men become absolute experts in brazing broken unions, and before very long can do in a few minutes a job which would take a coppersmith with the unit workshop an hour or two to carry out.” It is interesting to trace what might have been the itinerary of a Tank from the time it left the manufacturers in about Midsummer 1917, till after going into action in, say, the Third Battle of Ypres.