>Или подскажите более узкоспециализированный ресурс.
google.com
гугль, великий и ужасный, выдаёт если не искомые "картинки", во всяком случае рассказы о таких конструкциях - видимо, дело рутинное. нет необходимости упирать на то, что "он так сказал".
...during January, 1942, in an effort to make Esso Baton Rouge look more fearsome than she was, Captain Poche suggested his crew build gun \"tubs\" fore and aft like the armed merchant vessels carried. His crew carried out the plan. A realistic looking but fake 4-inch gun was built and put aft, while a fake 3-inch gun was mounted on the foc\'sle head forward. Each was painted war gray. Staged gun watches were maintained in the hope that this ruse might keep a U-boat at periscope depth, rather than surfacing to shell the ship. If nothing else, at least the circular wooden \"gun tubs\" would offer some shelter from the fierce wind whipping off the winter North Atlantic.
The fake gun constructed by the Troop aboard Masaya was made of coconut tree logs. There are no known photographs of the Masaya sporting her new armament.