PT boats

Factual Questions
41

HMS King Edward VII, HMS Irresistible, HMS Ocean, and Bouvet all sank with one mine reported-. To be fair, they were all Pre dreadnought battleships.

List of sunken battleships - Wikipedia.

I thought the HMS Royal Oak was sunk with one torp, but it took maybe 3.

However, wiki says the HMS Triumph was sunk by one torp, along with the HMS Majestic. So was the French battleship Suffren, and the French battleship Gaulois.

It took two to sink the HMS Cornwallis, same with the SMS Szent István, which was sunk by two Italian Torpedo boats. The Japanese battleship Asahi took two torps, and so did the Japanese battleship Kongō,

The SMS Kurfürst Friedrich Wilhelm, renamed the Barbaros Hayreddin was sunk by one British torp.

42

Fair enough, I’m wrong again.

43

You would probably be correct if you excluded pre-dread battleships.

44

HMS Marlborough was in rough shape after Jutland, where she was hit by 1 torpedo.

45

Additionally, and much more pertinent to the issue, is that the single smallish torpedo absolutely wasn’t the cause of the loss of Manchester. The commander issued the orders to scuttle because he feared repairs would not be affected before Manchester was in danger of further attacks, not because she was in any danger from the sinking from the single torpedo hit. The commander issued orders to scuttle at 0250, and the initiation of the scuttling charges couldn’t be stopped when he was informed 5 minutes later that power had been restored to one turbine and steering - and had actually been restore at 0202, 45 minutes before he gave the order to scuttle, so she wasn’t ever actually in danger of further attacks.

46

Oh, I agree. The ship was damaged, not sunk, by the torpedo. She was lost thru poor damage control.

47

Yeah, looking back I probably worded that weirdly and in a way that could make it sound like I was in some disagreement with what you wrote, I only meant to emphasize what you said. If I had it to do over again, I’d drop the “and much more pertinent to the issue, is that” from the first sentence. Apologies.

48

No offense was meant or taken.

49

Centerline bulkheads did for a lot of those older pre-dreadnoughts, also that torpedo warheads had become much bigger than the earlier ship designers had made provision for.

50

I’m not disputing you, but can you expand on what you mean by this? What was different about the different eras’ ship designs and how did that increase vulnerability?

51

They thought a centreline bulkhead down the middle of the machinery spaces of the ship would limit flooding to one side of a compartment, but torpedo warheads had grown bigger and the explosive in them more powerful, the resulting weight of water, all on one side, affected stability until the ship capsized. This danger had been foreseen by naval architect Sir Edward Reade as long ago as 1871.

Irresistible, which sank slowly, with only a small list, had the centreline bulkhead damaged causing free flooding across the whole compartment.

52

Marlborough was hit at 1854hrs by a torpedo from Wiesbaden; initially she was able to maintain her place in the battle line, and the powerful pumps reduced flooding to manageable levels. About 0100 the following night it suddenly increased, perhaps due to worsening weather, after the Admiral transferred his flag she made for the Humber at 14kts and arrived there under her own steam, 37hrs after being hit. The damage was much worse than prewar tests, on the old Hood, had suggested.

53

It’s surprising how much improvement there was in flooding control. A 10,000-15,000 ton pre-dread might sink after being hit by one torpedo with a ~400 pound warhead. A 25,000 ton WW1 batttleship might handle 2 torpedo hits with 600-800 pound warheads. By the 1930’s there were 10,000 ton cruisers that could do the same. The cruiser Minneapolis survived 2 hits with 1100 pound warheads.

54

It’s true that the USN torpedoes were shite, but there were other problems as well.

How much more success would there have been only changing the torpedoes but not fixing the other issues is the premise for a good debate.

First, while the issues with the Mark 14 torpedo is well known, early PT boats were outfitted with the older Mark 8 torpedoes which had their own set of issues, including their smaller warhead of less than 500 lbs.

Another problem was with the black powder charge for launching the torpedoes from the launchers, where the humidity of the South Pacific caused frequent misfires. Sometimes flashes from the charge or burning oil in the tubes would give away the PT boat position to the enemy. Dry runs and other malfunctions also occurred.

In 1943, the Mark 8 were started to be replaced by the Mark 13, designed as aerial torps. They weren’t ideal for PTs but their lighter weight while having a larger warhead, combined with the ability to be dropped from launching racks rather than requiring torpedo tubes saved more than 1,400 lbs each.

For the question of given better torpedoes, how much more effective would they have been? Obviously, they would have had some more successes. There were a number of attacks, especially on destroyers, which possible torpedo failures may have contributed to unsuccessful results. Other attacks were broken up when the enemy discovered their position from the flashes.

However, there were other issues which may have been more significant. One of the obvious flaws was the lack of radar for many boats. In the sea battles around Guadalcanal, the USN lacked the resources to maintain a constant presence in the immediate vicinity at night. The US ruled the seas during the day because of the air superiority, but lacked the number of ships to control the nights.

PT boats were brought in to help with the coverage. This could have been the perfect opportunity to have made an even more significant contribution to the war. The appropriately nicknamed Iron Bottom Sound could only be approached from narrow channels to the east and around Savo Island to the west. The reinforcements to the IJA and supplies were delivered to a limited geographical area not far from the PT base.

The lack of radar, bad coordination, inferior radios, inadequate training and insufficient numbers all contributed to limiting the results from the PTs.

The PT program just wasn’t advanced enough to take advantage of the perfect opportunity. In a classical would’ves, could’ves, should’ves, had there been two squadrons of better trained, fully radar equipped boats, more of the shellings of Henderson Field and the reinforcements and supplies would have been prevented.

55

Excellent post. Thanks for the info.