Japanese Type 93 versus US Mark XIII torpedo.

[windhund116]

Why at the beginning of WW2, was the Japanese Type 93 "Long Lance" a more reliable torpedo than the US Mark XIII? What was done to finally make the Mark XIII more reliable?

Thanks!

 

[SaparotRob]

Testing, I'm guessing. The Mark 13 and 14 weren't tested because of expense.

 

[fastmongrel]

Testing, I'm guessing. The Mark 13 and 14 weren't tested because of expense.

I think a lot of hubris was involved. There seemed to be an attitude that we are so good we don't need to test we know it works.

It's not an attitude unique to the torpedo department it's a common problem among design teams. The Boeing 737 is a classic example.

 

[Peter Gunn]

A point rarely touched on for Japanese torpedo development was the Washington Naval Treaty and the 5 : 5 : 3 ratio. The IJN was held to fewer ships than either the U.S. or G.B. and gun size was also limited to 14" main batteries for new construction in all navies. Torpedoes on the other hand were NOT size or weight restricted. The Japanese realized early on, read mid 1920's that with extensive training for night tactics and development of a reliable and powerful torpedo, they expected to get the better of the larger USN in an attrition battle across the Pacific when the hammer dropped.

Consequently, the IJN spent a lot of time and yen developing said torpedo's and tactics that would give their fleet the edge against the American's as the USN moved west. Senior planners knew they couldn't build enough big gun ships to compete on a one to one basis vis a vis Battleships BUT, DD's and Cruisers loaded with large, long ranged and powerful torpedo's should even things up for them.

Once they had a reliable unit extensively tested, (unlike the Mark 14) they put them on everything afloat except battleships whereas the USN only put torps on DD's, one can see the wisdom of this in for example, ANY engagement in the Solomon's in 1942-43.

As for the American Mark 14, there was a long bitter battle with arrogant a$$hats that developed it and refused to admit there were ANY flaws with it. When one reads the arguments going back and forth and what was done and more importantly what was NOT done, you can almost make a case for either sabotage or treason for the S.O.B's at Naval Torpedo Station Newport R.I.

And that is not hyperbole, they were so pig headed they were actively hurting America's war effort in the Pacific.

 

[R Leonard]

ummm, perhaps because the Type 93 "Long Lance" (a name imposed on it postwar by S E Morison) was a ship-borne weapon found on destroyers and cruisers and not carried by Japanese aircraft, or submarines for that matter. The US Mk 13 was an aircraft delivered weapon that, at least up until the modifications of 1943 and 1944, required a very narrow, and dangerous, delivery window. These restrictive delivery parameters of speed and altitude were well known because they DID test it. One naval aviator of the period of my close acquaintance, originally trained in scout-bombing in 1940 and transitioned to fighters (along with his entire VS squadron) in March 1941 once described the VT business in the early part of the war as "the most self sacrificing job in all of naval aviation," because of the mission restrictions.

Improvements to the Mk 13 included a breakaway barrel shroud over the nose/warhead which cushioned the impact on the water, a breakaway box shielding over the fins for cushioning, and ring shrouds on the fins which improve directional control. These greatly improved/enlarged the delivery window.

 

[SaparotRob]

The original post asked about the MK XIII. I added the Mark XIV because of the same issue. The Mark XV belongs in there as well.

 

[Peter Gunn]

Seems I suck at reading Roman Numerals...

Well ONE of you mentioned the Mark XIV so

 

[MIflyer]

Suggest you get the book "Hellions of the Deep" US torpedo development was a total disaster before WWII. The USN decided to have their own torpedo factory rather that rely on industry and that produced a team of civilian "feather merchants" that were devoted primarily to making sure they kept their jobs. Each torpedo was produced as an item made by "craftsmen" rather than using mass production methods. Testing was limited due to funding being reserved for civilian pay. The RI delegation intervened to make sure that no harm came to "their" torpedo factory and that no others were built to compete with it. When WWII began they boasted they could really knuckle down and get production up to 50 a month. The actual wartime requirement was 1500 a month.

The UN captured some German electric torpedoes and gave them to the RI Torpedo Factory to be duplicated. That went nowhere. They then gave the electric torp job to Westinghouse, who got the job done, US electric torpedoes being deployed on subs in 1944.

The USN organized a team of academia and industry to build an acoustic homing torpedo, completely separate from the RI Torpedo Factory. That air dropped weapon killed a U-boat on its very first combat use (giving the USN the place of first combat user of guided missiles). Then the USN gave that same team the job of fixing the crappy torps the RI factory was turning out, and they handled that very well, too. By the end of WWII the USN had actually reduced employment at the RI Torpedo Factory and they sold the place off after the war.

By the way, dif you ever notiece that PT boats dispensed with torpedo tubes late in WWII? They switched them to lighter air dropped torps. Dropping them off a boat is not as stressful as dropping them out of airplanes.

This whole experience with a government owned torpedo factory was such a delightful success that it was duplicated in the 1970's for something called the Space Shuttle, with similar results.

 

[SaparotRob]

Great post M MIflyer . I have wondered why tubes were dispensed with on PT boats. Crewmen just shoved the torpedoes over the side?
Nice follow up info on the torpedo story.

 

[MIflyer]

The interesting thing is that at the start of WWII the USN assumed that you had to very delicately deliver torpedoes into the water, very low and slow. That was the belly-flop approach. Now which hurts more, belly flopping into the water or diving in head first with your arms in front of you? Actual experiments showed that dropping the torps higher and faster subjcted them to axial stress when they hit the water like a bomb, which they could take better than a "belly flop" sideload. They added wooden breakaway fins to make sure the torp went into the water nose first.

 

[The Basket]

Torpedo are very complex so yeah.

Maybe the submarine captain is at fault. Or the pilot.

And the Type 93 is just propaganda so I would not bother with such nonsense. So closing with enemy cruiser or destroyer formation is fine.

 

[MIflyer]

By the way the secret of the long Lance, asdie from being made by people who gave a crap about their work, was very simple. Rather than a tank of compressed air to power the engine the IJN used a tank of compressed O2. That meant the torpedo had more room for fuel and hence could run longer and faster than US torpedoes.

But the dummies at the USN torpedo factory never thought of doing that. Instead they put their efforts into things like making the contact fuse work through a 90 degree angle, which means it was not strong enough to go off with a direct right angle hit.

 

[The Basket]

The secret is in the sauce.

The IJN used hydrogen peroxide which is not ideal.

Works nice but created a shed load of issues.

So it's not a simple case of this and that. Hydrogen peroxide and pure oxygen have issues. So it's not straight forward choices. It's whether you can live with them.

 

[windhund116]

When reading Theodore Roscoe's Submarine Operations in WW2, torpedo duds in USN subs was a great morale issue with the crews. His chapter on Torpedoes is enlightening (finally re-read it). Magnetic exploder device issues. Always random duds. Deep running. Premature exploders. Runaway and circling torpedoes.

US Submarine Operations in WW2

David Hoerl's essay on torpedoes is also very good.

Torpedoes and the Gun Club.

Nice article on the Long-Lance.

Long-Lance torpedo.

 

[swampyankee]

This whole experience with a government owned torpedo factory was such a delightful success that it was duplicated in the 1970's for something called the Space Shuttle, with similar results.

Last I had heard, neither Thiokol (the contractor for the SRB) nor Rockwell (the builder of the Shuttle, and prime contractor for the STS) were government-owned enterprises. The Challenger Disaster was because of a design flaw (Thiokol's responsibility) compounded by a management culture at NASA which put schedule above all else.

There were alternatives to the Thiokol SRB design, and there are O-rings that are made of elastomers that don't become brittle at normal ambient temperatures.

For the STS design history, start here: Aircraft Systems Engineering

 

[MIflyer]

The Shuttle was designed by NASA for NASA, to be operated by NASA, and all other launch systems were to be phased out to prevent competition with it. They ran over 25 Atlas boosters using bulldozers in the early 70's since we would not need them, over a billion dollars worth of perfectly good launch equipment trashed. Detail design and manufacture of the Shuttle components was done by private companies. Cost per launch was supposed to be $14M; actual cost has been calculated at $1.5B per launch. 50 flights a year were promised; they never got more than 9 and most of the time less than that.

 

[SaparotRob]

Ouch.

 

[cherry blossom]

Interestingly, the German Navy also started WW2 with very poor torpedoes. The errors were totally different so that, for example, American torpedoes ran deep because the designers had forgotten Bernoulli's Principle and assumed that they were measuring the water depth from a stationary torpedo whilst the Germans assumed that they could balance the water pressure with air at atmospheric pressure in a tank but the tanks tended to slowly leak and the pressure in a submarine was higher when diving. One difference was that the German officers responsible were court martialled and imprisoned.

 

[windhund116]

Interestingly, the German Navy also started WW2 with very poor torpedoes. The errors were totally different so that, for example, American torpedoes ran deep because the designers had forgotten Bernoulli's Principle and assumed that they were measuring the water depth from a stationary torpedo whilst the Germans assumed that they could balance the water pressure with air at atmospheric pressure in a tank but the tanks tended to slowly leak and the pressure in a submarine was higher when diving. One difference was that the German officers responsible were court martialled and imprisoned.

Was the WW1 version of the U-boat torpedo much different than the WW2 version?

Thanks!

 

[MIflyer]

The US ended WWI with the best torpedoes in the world, combining features of US and foreign designs. But the USN decided that having fought the war to end all wars there would not be enough business to support private industry.

Torpedoes could vary a great deal in design. One pre-WWI type even used a spinning flywheel to power the screws rather than an engine.