** An outstandingly rare WW2 Restricted military intelligence report, every distributed copy with its own unique security number, this being 'Copy No 247'.
Very few examples of this classified and security-numbered report have survived. Because of the report's extreme rarity, few collectors know these documents exist; only a tiny handful actually owns one.
An 'ordinary' version of this restricted CIOS intelligence report was subsequently authorised for issue. The later version was given the same title but had the HMSO name as publisher on the front cover and lacked the security classification and unique identifying security numbering.
WW2 RESTRICTED report Copy No 247 Disc Valve Engine Junkers Torpedo Engine Model Jumo, KM8
CIOS Intelligence Report. XXXI-61. Combined [British/US] Intelligence Objectives Sub-Committee (CIOS). 1945.
** RESTRICTED Copy No. 247 of the WW2 military intelligence report by CIOS on a torpedo engine with rotary disc valves designed by Felix Wankel.
CIOS 'Black List of targets for urgent investigation' category: Torpedoes
Duplicated typewritten report in English, 10 x 7.5 inches, 25 x 19 cms. 13 pages text, plus 34 photographs on 18 pages, plus further large foldingdiagrams and text at the end.
Very good in original stapled card wrappers. Protected in a modern clear archival jacket.
The Junkers KM8 torpedo engine is of particular note in that its rotary disc-valve assembly was designed by Felix Wankel, later of rotary engine fame. The report makes especial mention of the potential for this valve arrangement.