18 inch HSWT,  circa 1956

from Gordon Bleasdale
March 2006

Left to right in the control room:  Ken Walker, Ken Hall and Gordon Bleasdale, around 1956.  The model was a 'demonstration' one of no particular project, used for visitors.  The tunnel was powered by two RR Nene jet engines.  The Mach number range of the 18 inch tunnel was -

Transonic: M = 0.4 to 1.10 with slotted walls
Supersonic:
 
M = 1.4, 1.6 and 1.7
 
with sets of fitted liners (top and bottom) to give those fixed Mach numbers.