British Rail, as part of its dieselisation scheme, contracted Clayton Equipment Ltd to supply eighty-eight diesel-electric locomotives (what would later be known as the BR Class 17), and other orders were fulfilled for international customers from nations as diverse as Australia, Korea, Cuba and Poland. A£5 million contract by British Railways for 88 mainline diesel electric locomotives followed during the same year, supplemented by 1.75 million order for ten models that were exported to Cuba was obtained whilst, at the time, the company sales, particularly of mining and tunnelling locomotives, which were primarily for the export market, also continued to rise. The Cuban locomotives were based on the Brush Type 4 locomotives also been built at the same time. In 1962, a decision was made by British Coal that all pit ponies were to be removed from mines in the United Kingdom. British Coal expressed an interest in using small locomotives to help remove material from their pits. Clayton Equipment supplied a number of these machines which were put into service, before being asked to develop a locomotive that could negotiate steeper gradients. Clayton Equipment designed and manufactured a special rubber-tyred locomotive of especially small size to work in mines, and this became one of its most popular products. It was mainly supplied to British mines, but as the British mining industry went into sharp decline, Clayton was required to promote its product heavily to international customers to retain a sustainable level of business. A major marketing drive to expand into overseas territories and diversification into the tunnelling and construction sectors was essential. This provided to be a huge success, and today over 90% of equipment is produced for the export market.