[1] Velox boilers were the first commercially available machines to make use of axial compressors and played a pivotal role in the later development of BBC’s industrial gas turbines.

The great significance of the Velox idea lies in the fact that by means of the increase in pressure and velocities the components are greatly reduced in size, and the processes are accelerated without impairing the efficiency.In a Velox steam generator used for electrical generation, flue gases from the combustion chamber are used to turn a gas turbine which is connected to a compressor which together make up the charging set.

Efficiency of Velox steam generators was generally around 88—90% when burning blast furnace gas and 91—93% per cent with fuel oil.

In 1939, BBC delivered a single Velox boiler to the British Royal Aircraft Establishment in Farnborough for evaluation and testing.

Pulverised coal, fed into the Velox combustion chamber by compressed air, was tried but caused excessive erosion on the gas turbine from flying ash particles.

In 1936, BBC built the world’s first constant flow industrial gas turbine for the Sun Oil refinery in Marcus Hook, Pennsylvania.