 Complete the following phrase:  Work in Gibraltar began immediately under Commander Geoffrey Birley and his chief engineer Colonel Fordham. The site chosen at Lord Aireys Battery on the southern tip of the Rock already had an existing tunnelling scheme for a shelter. Extensive trials of the equipment began in January 1942 under the eye of MI6 radio expert Colonel Richard Gambier-Parry. Much thought was also given to the type of men needed for such a strange and demanding task. A member of Scotts ill-fated 