J J Seekings & Co was founded at some point between 1870 and 1875 by Joseph J Seekings, with the purpose of manufacturing stationary steam engines. It was taken over by W Sisson & Co Ltd in 1889.

William Sisson & Co Ltd were based in Gloucester and specialized in the design and development of high-speed launch and marine engines and boilers. They also designed vessels of all types, used initially on the Thames, Severn and Lake Windermere. The company was established by William Sisson in 1889 when he took over the small marine engineering works of J J Seekings and Co, situated near the Gloucester Docks. In 1896 the company built the engine for the SS Henley; by 1901 the company was manufacturing stationary steam engines for marine use and by 1904 the business became a limited liability company, with new works built at Barnwood, Gloucestershire. The company also supplied steam power units to the Cardiff railway in 1911 and built an engine for Swindon Gas Works in 1939. After the Second World War, Belliss and Morcom Ltd. began to take a financial interest in the company, ultimately acquiring full control of the company in 1958.