Hi!
http://www.airvectors.net/avbrtn.html
"The Brabazon was derived from proposals for a "100 Ton Bomber" submitted to the Air Ministry in early 1943 from Bristol and other British aircraft companies. The requirement was for a very heavy long-range bomber, comparable to the American Convair B-36 of the immediate postwar period. The Bristol submission for the 100 Ton Bomber featured four pusher contra-rotating propellers, each driven by twin 18-cylinder air-cooled 18-cylinder two-row Bristol Centaurus radials. In early concepts, the aircraft featured top, bottom, and tail turrets, each with four 20-millimeter cannon, and an internal bomb-bay; defensive armament was later dropped, altitude being used for defense"
Maveric-san's post is more large and clean.
http://www.secretprojects.co.uk/forum/index.php?action=dlattach;topic=2298.0;attach=19148;image
Bristol Centaurus sleeve valve engine.
https://en.wikipedia.org/wiki/Bristol_Centaurus