open ocean work, being restricted to the North Sea and Mediterranean Sea. This sacrifice was accepted to give any chance of meeting the requirements. The demanding specifications in an overworked Admiralty design department resulted in a major design miscalculation. When the detailed calculations were done the centre of gravity was lower than expected and the beam was increased. As the first ships were being completed it was found that the design was as much as 70 tons overweight, top-heavy, leaving them dangerously deficient in stability. The first twenty ships were so far advanced in construction that it was necessary to remove the 'X' 4-inch gun mount and add 50 tons of permanent ballast. These ships became the Type I group and had the multiple 2-pounder guns relocated from behind the funnel to the more advantageous 'X' position. The design deficiency of the Type I was rectified by splitting the hulls lengthwise and adding a 2½ foot section, increasing the beam to 31 ft 6 in and the margin of stability sufficiently for the designed armament to be shipped. These ships became the Type II group, and also had a revised design of bridge with the compass platform extending forwards to the wheelhouse face. Under the 1939 Emergency War Programme, 36 more Hunts had been ordered; three of these were completed to the original (Type I) design. Depth charge stowage could also be increased from 40 in the Type I to 110. For the 1940 building programme, torpedoes were deemed necessary. The next 27 ships were completed to a revised design, the Type III group, and were intended specifically for Mediterranean work. They sacrificed 'Y' gun for a pair of 21-inch torpedo tubes amidships, the searchlight being displaced to the aft shelter deck as a result. The Type III Hunts could be easily identified as they had a straight funnel with a sloping top and the foremast had no rake. Fourteen of them had their stabiliser fins removed (or not fitted in the first place) and the space used for extra fuel oil. The last two Hunts came from an independent lineage and were built to a private design that had been prepared pre-war by John I. Thornycroft & Company. Submitted to the Admiralty and rejected in 1938, a modified design had been accepted in 1940. They were known as the Type IV. They had a novel hull design, with a