Pearl Harbor WI: the U.S. Navy had put torpedo netting around their battleships?

[Carl Schwamberger]

It isn't that simple, to take an enemy ship intact requires it to be in port and you to hold the port long enough to get the ship under way, the enemy to surrender the ship intact for some reason, or to capture the ship fast enough for the other side not to scuttle it. The Japanese would not do the first at Pear Harbor, though they did capture some minor allied ships that way.

Mostly cargo ships, tho a gun boat or two and one US destroyer were used by the Japanese. In the case of the destroyer it took about a year to put the vessel back into operation and train a crew. It was occasionally spotted in the South Pacific in 1943-44 by US aircrew, who were confused about what "..one of our destroyers was doing so far north." Possiblly as much as 800,000 tons of cargo ships were captured and put to use by Japan. Training crews was a problem as the steam, electrical, and other mechanical systems were not much like the ships the Japanese engineering crew were used to. Even where the technical document came with the ship they still had to be translated and the engine room gang learn to operate the power plant and other machines without wrecking them. It was a process similar to a crew training up on a newly launched ship.

That all bears directly on anyone capturing a enemy warship. it takes years for the engineering officers and chiefs petty officers to know the mechanical system forwards and backwards. A newly formed crew cannot step aboard a strange ship and steam directly off to battle. If the ship is in perfect condition it could easily require a year to reach a minimum skill standard. If repairs or major maintinance is necessary two years may very well be necessary.

Post war the USn took a number of Japanese and German submarines back to the US. That was accomplished with weeks of training under the supervision of the original crew, key German or Japanese engineering personnel aboard, and not the slightest thought of anything than heading to port in a straight line. In the case of the Japanese submarines the combined US/Japanese crew never dived the boats on the voyage from Japan to Oahu.

 

[zert]

Come now. You know wiley Americans can get the gist of anything within minutes and go into battle to defeat their enemies with their own ships.

 

[mcdo]

I could be completely wrong here, but I had thought that the reason there was no torpedo netting in Pearl was because the US was convinced the harbor was too shallow for air-dropped torps to work?

I know that the IJN had to specially modify the fish they dropped with wooden fins, as otherwise they would have just dived too deep and gotten stuck in the mud. Pearl Harbor is VERY shallow, with only so many spots deep enough to anchor big ships. Even today, I'm told subs that come into port often have to scrape mud and other filth off of their keels, because parts of the harbor are only 30 feet deep or so.

 

[Carl Schwamberger]

You are most correct. I have several books on the shelf that mention the torpedo depth problem, and the Japanese solution. John Costellos 'The Pacific War' mentions this, and how the Japanese converted armor piercing naval cannon projectiles into bombs for the PH attack, as their existing bombs would have seldom penetrated the BB armor. This does not entirely obviate the usefullness of torpedo barriers. The USN was aware of the japanese mini subs, and the Italians sucesfull use of small submersables in the Mediterranean. Which is why there was a barrier and ASW patrol at the Pearl Harbor channel entry.

 

[Captain Jack]

If gas is used against ships they would be essentially unussuable afterwards. I read in Friedman's U.S. Battleships: Illustrated Design History In the early 20's the USN conducted some experiments with ships and gas and came to the conclusion that if the gas actually got into the ship it would be impossible to decontaminate it sufficiently to be put back into service.

 

[katchen]

If gas is used against ships they would be essentially unussuable afterwards. I read in Friedman's U.S. Battleships: Illustrated Design History In the early 20's the USN conducted some experiments with ships and gas and came to the conclusion that if the gas actually got into the ship it would be impossible to decontaminate it sufficiently to be put back into service.

The vesicant gasses of the 1920s, yes. But the military utility of organophosphates such as tabun, sarin and soman are that they break down after a few weeks and decontaminate themselves And are realtively easy to decontaminate a place from, unless an oil based formulation such as VX or cyclosarin that IS long lasting is used. .
So if the Japanese towed a ship that they had gassed back to Japan, the sarin used to secure it would almost all have broken down by the time it got there. And the rest could be readily cleaned away with agents such as water and hydrogen peroxide (which is how the US is breaking down and decontaminating the Syrian chem weapons).
In Japan's case, it was never a question of the Japanese having any qualms about using chemical or biological weapons. The Japanese used both against the Chinese. The reason that the Japanese never used either against US targets is that the Japanese harbored hopes that the US would finally negotiate with Japan right up until Hiroshima.
From n.wikipedia.org/wiki/Sarin
The most important chemical reactions of phosphoryl halides is the hydrolysis of the bond between phosphorus and the fluoride. This P-F bond is easily broken by nucleophilic agents, such as water and hydroxide. At high pH, sarin decomposes rapidly to nontoxic phosphonic acid derivatives.[13][14] The initial breakdown of sarin is into isopropyl methylphosphonic acid (IMPA), a chemical that is not commonly found in nature except as a breakdown product of sarin. IMPA then degrades into methylphosphonic acid (MPA), which can also be produced by other organophosphates.[15]
Sarin degrades after a period of several weeks to several months. The shelf life can be shortened by impurities in precursor materials. According to the CIA, some Iraqi sarin had a shelf life of only a few weeks, owing mostly to impure precursors.[16]
Its otherwise-short shelf life can be extended by increasing the purity of the precursor and intermediates and incorporating stabilizers such as tributylamine. In some formulations, tributylamine is replaced by diisopropylcarbodiimide (DIC), allowing sarin to be stored in aluminium casings. In binary chemical weapons, the two precursors are stored separately in the same shell and mixed to form the agent immediately before or when the shell is in flight. This approach has the dual benefit of solving the stability issue and increasing the safety of sarin munitions.

 

[Heisenberg2013]

What if the U.S. Navy, in the aftermath of the British raid at Taranto, were worried the same thing might happen at Pearl Harbor, and placed torpedo netting around their ships? Would it save the Oaklahoma, West Virginia, and the California from being hit by torpedo's?

Well, we know now that its not that they weren't worried. They very much were. An attack on Pearl was often discussed, but negligence and the belief that it would come as some sort of sabotage operation was what they were geared for.

 

[Grand Admiral Thrawn]

Sarin and the other nerve gasses need to be invented by the Japanese or shared from the Germans. And they did not use gas since it was a MAD situation: any gas use at Pearl Harbor means the PI and Singapore use gas on the IJA, stopping the Japanese assault short of the Dutch Indies. They used the gas on the Chinese, who could not retaliate.