The type 81 general purpose frigate HMS Zulu (1962) in No. 2 dry dock at Govan, Glasgow in December 1963 during the final stages of building. A twelve inch diameter and a five inch diameter gratings in the lower hull.

The type 81 general purpose frigate HMS Zulu (1962) in No. 2 dry dock at Govan, Glasgow in December 1963 during the final stages of building. The photographer is on the floor of the dock looking at a circular twelve inch diameter five slot grating and a circular five inch diameter grating in the hull. Hands are pointing to the gratings and a scale stick is between them.