The Louis class was the culmination of three events. The Royal Navy 'WAIR' type conversions which the Lemurian Navy then copied to its older destroyers. Then the RN sent out the plans for the Hunt class Destroyer Escorts. The plans for the Hunts was something the Lemurian Navy was interested in. The original RN design had a 280 foot ship, armed with six 4", in three twin mounts, a bank of torpedoes with a 28 knot speed. The design looked very cramped. Even in 1939 when the design was ready for production, electronics and new weaponry would have overloaded an already tight design. The first RN units delivered in 1940 lost a twin 4" mounting early to allow for upgraded equipment. The Lemurian design was 20 odd feet bigger and a few feet wider. It had already lost the aft most twin 4" in favour of enhanced depth charge capabilities.
The final design was put into production in late 1939 with completion of the first two units expected in 1941. The other War Emergency Destroyer Class (Henri) was plagued with the availability of the twin 4.5" turrets which were required for the carriers, battleship and cruisers, also in production, which had priority. The same call on twin 4" was not there, and a steady flow of armaments for the class aided production. Eventually 32 units were delivered, the last eight ordered in 1944 were cancelled in early 1945. The last four units were completed in 1945 and went straight to being escorts to the Fleet Train for the Commonwealth Pacific Fleet. Twenty five of those units survived the war and were incorporated into the post war Fleet.
The seven ships lost were three in the Mediterannean, two in the Atlantic, one in the Arctic, and one in the Pacific. The most interesting loss was the HMLS Louis which was escorting a convoy from Liverpool to Nova Scotia, which was being tracked by the first operational type XXI U-boat. Two dummy attacks were made on the convoy, which drew no response from the escorts. The escort on the Type XXI's side of the convoy was the Louis. The Type XXI's Kommandant decide that sinking the Louis would open up that side of the convoy for further attacks. The Type XXI had six forward torpedo tubes which the Kommandant decided would have two fired at the escort then two each on the largest ships it could see. It would then withdraw and reload the tubes for another run on the convoy. The six torpedoes were on their way, these torpedoes were electric and did not have any giveaway bubbles. The first the Louis new of the attack was when two torpedoes hit the ship. Boom, boom, and that was it. The Louis was sinking. Another escort came up and dragged off survivors, then went hunting for the U-boat. The Type XXI was way outside of detection range and reloading. Three more hits on ships in the convoy, then 30 seconds later a fourth hit. The fourth torpedo hit had missed its first target and run through to the next column where it hit another merchantmen.
The Type XXI, having reloaded, easily overtook the convoy. The Type XXI could make over 20 knots underwater to the convoys 12 knots. The Type XXI took a slight lead on the convoy so that when it fired its torpedoes the convoy would run on to them. Again the Kommandant targeted the escort that had replaced the Louis, and then another two ships behind it. The convoy looked like a 'steel wall' to the Kommander through his periscope. Torpedoes away. The escort though, is on full alert, and hears the torpedoes screws on hydrophones. The escort turns towards the torpedo track and goes hunting. Too late, the Type XXI has exited the battle area at full speed and the Flower Class escort is way behind. Five of the torpedoes fired find targets on the wall. Four more merchantmen either sunk or crippled. A very good return.
