Photograph
by
Andy Leitch
Avro
Vulcan B1 XA901 was broken up at RAF Cranwell in 1972. The engine is a
Bristol Olympus 101. 901 was delivered with Olympus 101s with 11000lb
thrust. Before deliveries commenced, Bristols anticipated that the first
Vulcan B1 deliveries would be with the Olympus 101, being replaced in
production and by retrofit with the improved Olympus 3. In the event,
uprating the Vulcan B1 engines took another route by evolving the 101.
The improved 102 of 12000lb thrust which soon replaced it in production
(XA904 onwards) had an extra LP compressor stage and trimmers in the jet
pipe. By raising the turbine entry temperature enabled even more power
of 13500lb thrust (104). This was achieved by the use of redesigned burners
and turbines. 102s were modified to the later 104 standard during overhaul.
The Olympus 104 had the same take-off power as the proposed Olympus 3.
Though many texts state that most 101-engined B1s were ultimately reengined
with 104s, it appears that this may not have been the case. The engine
above is confirmed as a 101 by its enormous intake bullet, once described
as 'the biggest heated pitot in the world.' This feature demonstrates
why the Olympus had so much development potential. By reducing the size
of the bullet and internal spool diameter, air mass through the engine
could be increased without a significant (if any) increase in external
diameter.