The original need for concrete sleepers arose because of shortages of timber during World War Two. Trials took place using reinforced con crete, but these were not very successful. However sleepers using prestressed concrete – at that time, a relatively new method used to overcome the natural weakness in tension of concrete – were installed and tested in the UK in 1943. These trials were successful and the first factory to manufacture prestressed sleepers, using a long line pretensioning system, was established the same year. Initially bull head rail which was then used was held on the sleepers in a “chair”. Later when flat bottom rail was introduced base plates were used. These have now been more or less entirely superseded by direct elastic rail fastenings where a cast iron stem or a plastic insert is embedded into the concrete. Not least, factory production and the installation and maintenance of track have progressed to the methods using the sophisticated plant and equipment in use today.