Underground Fuel Reservoir, Inchindown

The Underground Fuel Reservoir at Inchindown, built between 1938 and 1943, consists of an extensive network of six rectangular underground fuel storage tanks. These tanks are accessed through operational and maintenance tunnels, as well as valve chambers that have been carved out of the hillside bedrock and are predominantly lined with shuttered concrete. At the beginning of the operational piping tunnel, there is a small square-plan fan room, and at the end, the six underground fuel tanks are located. The tunnel measures approximately 350 metres long and 3 metres wide. Inside the tunnel, two pipes are laid beneath the concrete floor, which can be accessed through metal inspection covers, connecting each underground reservoir to the tank farm in Invergordon. The reservoir tanks vary in size due to the local geology, but they generally measure 9 metres wide, 237 metres long, and 13.5 metres high, with a total capacity of about 5.6 million gallons of fuel.