In 1936, the British Air Ministry issued a specification for a long range heavy bomber under B.12/36. Supermarine responded with its Type 316 which would have projected performance of up to 360 mph with 30,000 ft ceiling and 3000 mile range. Engines would be either Merlins, Hercules, or Daggers. But the project had competition from Short's S.29 and then there were delays with modification requests by the Air Ministry which led to the Type 317. So it took years until Supermarine Woolston could start to construct two modified prototypes with Hercules engines and double rear turret. They were lost in Sept 1940 to a Luftwaffe bombing raid along with the construction plans and all tooling- a total loss. So, the Suffolk saw no action in WW2; instead, the Short S.29 evolved into the Short Stirling and then came the Halifax and Lancaster (the last was best). Had the Suffolk arrived on schedule it would have been up to Lancaster standard much earlier and BC could have hit Germany earlier with more tonnage. In this regard, the Luftwaffe made an early accomplishment with its bombing raids!

I have never seen any photos of the prototypes, but here are two artist depictions: http://www.rjmitchell-spitfire.co.uk/otheraircraft/images/g_b12_b36_bomber_lrg.jpg http://freespace.virgin.net/john.dell/super.JPG