I've actually got a novel from 1990s called "The Talisman Deception", two of the ships in that are oil tankers that have been modified with re-inforced bows, sandbag armor around the bridge and afterhouse, relocated steering, and every free space (eg not the crew accommodation) has been filled with buoyant materials (e.g. Table-Tennis Balls, Kapok, Cork, etc.) and used in a quasi Q-ship role.

I've also seen a comic book from the 50s that does something similar, save they fill all available hull space with pine logs and fit concealed 5 inch guns.

Graham

On Wednesday, 16 May 2018, 11:50:40 am AWST, Richard Aiken <xxxxxx@gmail.com> wrote:

ISTR that the Brits required merchant ships built between the wars to have bolt holes pre-drilled to accept (and decks reinforced to withstand the recoil forces of) the mounting of deck guns, in the event of hostilities.

So - had the British government been sneaky and foresighted enough - they could have ordered "tankers" which were actually unarmed (but armored) capital ships built to support the carraige of oil between Venezuela and the western U.S. The commerce would have at least defraying the operating costs . . . and the existence of several extra "not-quite-battewagons" might have given Hitler pause.

Richard Aiken