The Southern Railway was the only one of the "Big Four" British railway companies that did not operate sleeping cars other than those brought in from the continent on the 'Night Ferry'. This was because the short distances meant that such provision was not financially viable. The Southern Railway also undertook the practice of converting inherited carriages into electric stock, a cheaper alternative to constructing brand new EMUs. Bulleid initiated an unusual project that attempted to address the problem of overcrowding on suburban services. The answer to the problem was Britain's first double-deck carriages, which were eventually built in 1949. Two sets of four cars were completed and saw use until the 1970s, powered by electric in the same way as the EMUS. However, further orders for these trains were not placed due to cramped conditions inside which were dictated by the restrictions of the loading gauge.