"Hitting at Extreme Range, Part 2: Torpedoes" Topic

We've had an interesting discussion on the theoretical vs. realistic ranges of naval guns:

TMP link

Now I'd like to pick your brains on torpedoes.

Has anybody done any studies on the chances of very, very long-range torpedo hits?

I'm particularly interested in things like the Japanese Type-93 "long lance", which is so greatly feared for (among other things) its phenomenal range. And I know that once in a blue moon, it did actually hit something at those ranges.

But just as the gunnery tables people found in our earlier discussion rarely gave more than a 3-4% chance of hitting at extreme range, would it be realistic to assume that a torpedo hit beyond a certain range would be a pretty wild stroke of luck?

If we could assume atmospheric and oceanic factors as constants…. What would that range be?

Raizo Tanaka ravaged a US Cruiser formation in excess of 14 miles with Long Lances during WWII. Admittedly Tanaka was a tactical genius, but still. I'll find the report I read on it and post it.

I think you're talking about Tassafaronga, right? My understanding was that the torpedoes were launched about 7-10k yards from their targets. (@ 4-6 miles)

no, it was another night battle. I think I have a book with it.

At any rate, usually the Japanese launched at 17k to 20k yards (roughly 1/2 the range of the Long lance at 49knots) meaning a 10-12 mile attack distance) I can think of several engagements at this range (1st battle of Savo Island springs to mind)

IIRC it's in this Book (Which I highly recommend):

link

War At Sea by Nathan Miller.

"at 0130, Chokai's lookouts sighted the Southern Force, and the Northern Force thereafter, 17,000 yards distant. A minute later, Chokai's first torpedo left its tube, and five minutes into its run, the eerie silence over the sound was broken by the rolling thunder of Chokai's first eight-inch volley, aimed at Canberra."

At java Sea: "At 1633 Naka launched four long lance torpedoes at a range of 15,000 yards. The six destroyers of his division followed suit between 1640 and 1645 sending another 27 torpedoes toward the Allies from ranges between 15,000 to 13,000 yards. Haguro initiated a torpedo attack of her own at 1652, launching another eight at a range of 22,000 yards. "

I meant 38 Knots, not 49 Knots for the long lance. Don't know what i was thinking.

Okay if you're talking about Java Sea they launched something like 80 torpedoes, total, and scored… I think only one hit, right? Sinking the Dutch destroyer Kortenaer from a range of 12.5 miles.

It was Japanese gunnery that won that battle: they fired nearly 1300 rounds.

Later that evening the Japanese made another torpedo attack at long range (21k yards) – 24 torps fired… no hits. Then two more long-range torpedo attacks (15k yards and 18.5k yards)…. no hits.

So it seems that the odds of scoring a hit with a torpedo at that range was pretty much close to nil. The only hits they scored that night were fired later, from much closer ranges: @12k yards; those are the ones that hit the De Ruyter and Java.

(I'm getting this info from Paul Dull's Battle History of the Imperial Japanese Navy, pp. 80-90.)

There was something I recently read about analysis on the Japanese Long Lance torpedo hits. It is somewhere out on the web. But other than one battle where several US ships where taken out from great range the statistics on Japanese torpedo attacks and the percent of hits was very low.

But that's about all that I remember.

The real question is did the Allies change their tactics in response to the Long Lance?

In Hara's book "Japanese Destroyer Captain" he stresses the importance of pressing home a torpedo attack to very close range, 3000 meters if possible. Also it is preferable to fire from more than one angle to ensure success. An enemy under torpedo attack will take evasive action. In writing rules there are a few factors about the Long Lance that make it useful at long range.
Firstly, the LL was a well kept military secret and a total surprise to the allies. At Tassafaranga the allies took no evasive action because they assumed they were out of effective range. They maintained line ahead formation to maximize their firepower and presented a broadside target. When the cruisers began to take hits they assumed they had sailed into a mine field.
When firing at static targets (dead in the water), or near static targets (Savo Island), they had a better chance of hitting at extreme range, because it was easy to plot a solution.

The value of the Long Lance was most effective against an unsuspecting enemy who maintained a predictable course and speed, plus the larger warhead. At Tassafrongo, the Allies did not know the enemy was present and did not vary course or speed. They presented very easy targets for both torpedoes and gunnery. Against a better prepared enemy, the torpedo had to be used en-mass to score an occasional hit. The skill of the Japanese night lookouts was phenomenal and crucial to using the torpedoes' range. There are several instances where the lookouts spotted targets beyond radar range in 42 and 43. Once the US Navy got out of their pre-war set piece battle mentality, and actually began listening to their radar operators, the extreme range became almost useless.

Then again, USS Strong got picked off from a range of almost 11 miles.

So it sounds as if we're all in broad agreement that the extreme theoretical range of the Long Lance was rarely put to the test, simply because the odds of scoring a hit at such ranges were so minuscule, and had more to do with luck than with tactics.

I would guess that 8-10,000 yards was the limit for anything more than luck – against a manouvring target, anyway.
-Kle.

Quite assuredly and i would not argue against that at all.

What I WOULD say is that the Long Lances had two Tactical applications-Long Range "Ambush" attacks against surprised targets and shorter ranged conventional applications.

Plus firing 80 Torpedoes to destroy a Cruiser before it reached combat range is still a good tradeoff.

Plus firing 80 Torpedoes to destroy a Cruiser before it reached combat range is still a good tradeoff.

Certainly worthwhile coming from destroyers but the value of the IJN using those oxygen fueled monsters on higher value units such as their heavy cruisers has to be weighed against the cost of hits taken on those mounts with devastating results. Of the 14 IJN heavy cruisers used in WW2, 6 were heavily damaged or sunk by the explosion of a 24" torpedo mount.

Ooops, typed too fast. Make that 18 IJN heavy cruisers used in WW2. I left out the Mogami class in my first count.

Well, the 80 torpedoes I was referring to didn't hit a cruiser. They hit a Dutch destroyer that was apparently in the wrong place at the wrong time.

The torpedo hits on the allied cruisers were all from much closer ranges.

check out this article, and about halfway down is an analysis of hits to # of torps fired.

link

Great article, thanks.

The 61cm Type 93 M1/2 had a speed of 48 knots at a range setting of 22,000 yards. Assuming the target is roughly perpendicular to the line of fire and makes no change of course from the time the torpedo is fired, it would take about 14 minutes for the torpedo to reach the target. That is a very long time and that is a very big assumption. Even a ship moving at 24 knots is capable of being in a position more than 10,000 yards from the calculated point of impact in that amount of time.

If you are interested in exploring the possibilities of torpedo hits at long range (any range, actually), have a look at NAVAL OPERATIONS ANALYSIS (US Naval Institute, 1968). A simplified version of the formulas presented in this work can be found in SEEKRIEG 4.

Once the US Navy got out of their pre-war set piece battle mentality, and actually began listening to their radar operators, the extreme range became almost useless.

You mean, "Once the radra got reliable enough that it didn't report anywhere for 0 to 500% of the Japanese ships in the vicinity, if it was working at all"?

The early radar sets were both inefficient and unreliable, and their usefulness went way down when landmasses were nearby – like in the Slot. The real problem was that US lookouts depended too much on the 'electronic wonder', and didn't keep as sharp a watch as they should have.

Stepping away from direct strikes – how much effect did these waves of Long Lances have in forcing evasive manoeuvres that threw of the targets' gunnery and allowed the IJN ships to make the most of their gunnery.

A weapon doesnt have to kill something to have a significant tactical benefit.

Would the Long Lance fit into that category?