Why did the Japanese sink only the Repulse and the Prince of Wales, and not the escorting destroyers?

by zhrmghg

Accompanying the HMS Repulse and Prince of Wales during their final battle were the destroyers Electra, Express, and HMAS Vampire. After sinking the two capital ships, why didn't the Japanese 'finish the job' and sink the remaining destroyers as well to annilate Force Z completely?

thefourthmaninaboat

Force Z also included the destroyer Tenedos, but she had been detached prior to the attack and was returning to Singapore.Tenedos did come under attack from Japanese aircraft, at 10 AM on the 10th December - the Japanese pilots had misidentified her as a battleship. Nine G3M Nell bombers, armed with 500 kg AP bombs attacked Tenedos, scoring zero hits. This attack demonstrates part of the reason why no attack was made on the destroyers with Force Z. Destroyers are fast, manoeuvrable ships. The only aircraft available to the Japanese for an attack were level bombers or torpedo bombers - both of which destroyers could easily dodge. Even the comparatively unwieldy Repulse was able to avoid the vast majority of torpedoes aimed at her, and all but one of the bombs. Trying to attack a destroyer would have just been a waste of ordnance.

Another, key reason why the destroyers were not attacked was that they did not pose as large a threat to Japanese operations as the two capital ships did. Force Z had sailed northwards to destroy the Japanese force landing on the Malaysian peninsula at Singora and Kota Bharu. These were protected by a strong force of two battleships, six heavy cruisers, a light cruiser and twelve destroyers. These were deployed in three separate squadrons - Main Body with the battleships and two heavy cruisers, the Kota Bharu force with the light cruiser Sendai and four destroyers, and Cruiser Division Seven with the remaining four heavy cruisers. Repulse and Prince of Wales could defeat any of these squadrons, defeating the Japanese invasion in detail. However, the four destroyers were completely outclassed by any Japanese squadron, and so were effectively neutralised. Sinking them was unnecessary, as they could make no attack that would not end in them being sunk.

A final reason was that sinking Repulse and Prince of Wales had required a considerable investment in time and sorties. Over 80 aircraft had been committed to attack them - bombers that could otherwise be supporting Japanese troops in Malaysia or bombing Singapore. The first Japanese aircraft had launched at 6 AM, and it took until 11:13 for them to find and attack Force Z. Sinking the destroyers, which was as shown above a difficult and strategically pointless task, would have taken the bombers even more time.