A file of correspondence concerning a plan to install radio sets in British consulates in various Spanish cities to transmit reports of Axis shipping movements. The letters discuss the details and intentions of the scheme, which was intended to help the Royal Navy catch Axis blockade runners; an objection from the British ambassador to Spain, Sir Samuel Hoare, arguing that the plan would complicate relations with the Spanish; arrangements for transporting and installing the radio sets; and reports of technical difficulties, and the need for trained operators.