Chamberlain had not abandoned his dedication to social reforms designed to help the working man. He was instrumental in adapting Bismarck's German model to set up a system of compensation for injuries on the job. His Workmen's Compensation Act 1897 was a key domestic achievement of the Unionists at the end of the century. It cost the Treasury nothing since compensation was paid for by insurance that employers were required to take out. The system operated from 1897 to 1946. Chamberlain also tried to design an old age pension programme, but it was too expensive to meet with Conservative approval. He came to realize that a new source of revenue, such as tariffs on imports, would be required. Further opposition came from friendly societies, which were funded by their own pension program for their members.