Thermotank Ltd

Thermotank was a Scottish engineering company specialising in heating, ventilation and air conditioning, founded in Glasgow in 1900 by Alexander William Stewart and his two brothers William and Frederick. The business was based on Alexander’s invention, the Thermotank, a system designed for maritime use which could maintain a constant temperature coupled to circulation of air on board ships.

In 1922, Alexander Stewart invented and patented the Punkah Louvre, a device able to control and direct the supply of air as required. The Punkah Louvre became a device recognised worldwide and was fitted in ships, trains, buildings and aircraft.

The Thermotank company became the world leader in marine air conditioning systems with equipment installed in thousands of vessels from 1898 onwards including, most notably, great ocean liners such as the Cunard Line’s RMS Lusitania and RMS Mauretania (1907), RMS Aquitania (1913), RMS Queen Mary, (1934) and RMS Queen Elizabeth (1938) and also the French Line’s SS Normandie (1932), Royal Mail’s RMS Andes (1939) P&O's SS Canberra (1961). The Thermotank system was also adopted by the British Admiralty for installation in many of its warships.

In 1959, the company merged with long standing associates and refrigeration specialists J & E Hall & Co to form Hall Thermotank Ltd.