text: The outbreak of war focused minds. Apart from the AA armament issue concerns started to be raised about progress generally. By February 1940 the two factors led to a proposal to change the design of four of the 'L's and fit a main armament of 4-inch (102 mm) Mark XVI* guns in Mark XIX High Angle/Low Angle (HA/LA) twin mounts as used as secondary armament in the s already in service and main armament in the  of sloops then under construction. Associated changes were provision of two quadruple 0.5-inch (12.7 mm) machine guns. All ships of this class except Lightning and Laforey carried a four-barrel 2 pdr pom-pom.
  The lessons of the Norwegian campaign and at Dunkirk drove home the need for this change and it was agreed in July 1940 that there were also to be four of the twin mounts instead of the originally proposed three. The fourth was to be at the forward end of the after superstructure which cut down on the fire arcs of both mounts but ensured the fourth would still be available for use in heavy weather.
  Not all senior officers were in favour and some openly expressed opinions that it would mean the ships could not successfully fight their foreign equivalents. Experience in the Mediterranean, especially that of Force K which contained two of the 4-inch (102 mm) 'L's, showed that the loss of gun power against surface targets was balanced against a higher rate of fire.
  Review of AA armament continued and in October a decision was taken to remove the after bank of torpedo tubes and fit a single 4-inch (102 mm) HA gun instead and that is how the  gunned ships eventually went to sea, although some surviving ships, including Matchless and Marne, had the after tubes replaced later in the war.