In 1941, massive refortification works were carried out by men of 930 Port Construction and Repair Company of the Royal Engineers. Two concrete gun batteries were built, each housing two six inch naval guns. Searchlight posts were added together with their attendant generator houses. Nissen huts sprang up all over the island to house the garrison. A huge metal jetty projected from the island’s quay into the Channel and a narrow-gauge railway transported supplies and materials from the jetty to the island plateau.