Here is a question I've had about naval warfare in WW2 in the Pacific. Was it possible to spot a torpedo headed for your ship and quickly angle a 5" cannon downward to shoot down into the water to destroy or damage the torpedo? I heard that torpedoes were set to run at a depth of 20 feet. Could a 5" shell reach that deep?
The 5"/54 naval gun (typical gun) had an elevation range of −15° to +65°, so they wouldn't likely be able to point at a torp in visual range.
This makes me wonder why navies never developed a "harpoon" to shoot at torpedoes by the time of WW2. There could be any number of harpoon-like tubes, along each side of the ship, that fire long, narrow missiles, down at a very steep angle to hit torpedoes before they can strike the ship, or explode by proximity sensor, or set for a depth, to disable the torpedo? They would be on loose swivels so they can be moved and aimed easily. Oh well, for some reason it never happened.
I wonder, if under perfect circumstances with pre-set charges to go off at 20 feet or so, something like a Hedgehog couldn't be fired in front of a torpedo to detonate it (with great luck) or alter its course? I realize the timing problems, but if you were hunting a sub or a nearby vessel had just been hit and you're expecting it to fire at you next, you have sound and sonar guys on full alert for the sound of a running torpedo... ? Seems like it would be possible, or that something "like" a Hedgehog might have been looked at during the war. .
I've read of a single account in the Battle of Leyte Gulf that a spread of torpedoes, maybe 4 launched by an IJN destroyer at one of the US jeep carriers at maximum distance. The torpedoes slowed a bit and ran closer to the surface, drawing the attention of a passing USN torpedo bomber. I think that it was his carrier the torpedoes were heading for. Anyway, the torpedo bomber strafed and knocked out all but one of them. The single 5" gun on the carrier deck got into action and blasted the last torpedo heading their way. Can't remember the name of the carrier to save my life. Great save though.
Whatever counter measure...it has to be quickly (very) deployed and be immediately effective. My idea was a mesh "skirt" that could be dropped over the sides to pre detonate the torp or even capture it and let its fuel run out...even this "simple" idea is far from ideal or dependable. We know rounds shot into water disintegrate very quickly, after just a few feet...it the rounds were explosive then one might have a chance...but the crews would have to be at battle stations and ready for it to have any chance of moving the gun into position and getting one or two shots off...The torpedo isn't slow. This all predicated on the idea that the torp is even spotted, which many weren't. IMO the use of speed and manoeuvre "if" the torp is spotted is still the easiest and most effective defence.
Torpedo nets were nothing new in WWII. Those slanted lines on the sides of battleships in WWI were net booms.
Rough rule of thumb, one degree of arc is equivalent to one foot (or mile, or whatever) for each 57 feet (units) of distance. 15 degrees of depression would put a shell 15' down just 57' from the trunnion. A shell fired from 30' above the waterline would hit the water just 114' out (discounting gravity, but at that point the trajectory is almost a straight line). The 5"/54 first entered service on the Midway class carriers. WWII 5-inchers were mainly the 5"/38 and smaller numbers of the 5"/25; most mountings had -15/+85 degrees elevation.
The US Navy today is developing an anti-torpedo torpedo. Advances in torpedo technology like wake homing have made evasion or decoying less feasible, so they are turning to the "hard kill".
How far out would they have to engage a torp running at, say, twenty feet submergence? Is that an effective range? Can CIC get guns grouped on such targets? Basic questions I'm wondering about and don't have the skills to answer.
...remember the torpedo is only about what--2 feet diameter?? ...moving at what speed--about 50 knots? - what's that distance/time to ship? ...under water very, very hard to get close to that and very very very hard to hit ..you might get a hit in front of hit--IF it's coming right at the gun--if not, by the time the gun gets the range, game cover-fish is in the ship... ..how fast does the gun traverse/etc? how was it traversed? ...the farther away the fish is, the harder to range in on it ..it's hard to hit a man sized target ---not moving---at 500 yards with a military M16A2 in the prone with sling here --the B target dimensions so the answer is '''possible'''--but very unlikely...
The ship could fire a salvo of counter-torps that would explode at a distance from the hull and create an air pocket that would disrupt the run of the enemy torps?
Nope...keep thinking if we are now talking modern tactics...speed is still key...so much so it should be like the goal keeper, automatically deployed. The problem with an anti torp defence that works well is that the enemy will make the charge bigger and bigger...to damage the ship from a distance...tactical nuclear for example. Also new drone like torps can wait for the ship to come to them and then activate and shoot and high speed toward the ship leaving very little reaction time...
That's what I was thinking with the Hedgehog launchers. It might change the course if nothing else. With today's modern torpedoes you'd have that effect and also a chance of disrupting the electronic guidance. .
How about PBYs with hedgehog racks slung under the wings? Dumbos could fly low and slow, ready to be where needed.
Hedgehogs are contact detonation only. No contact, no BOOM! There is either miss or destruction, there is no course change. Also, it threw a 100 foot wide ring of explosives around the point of aim, so the gunner better be up on his offset so that he hits the torpedo.
good call...that's right ...plus timing of the firing to impact is very difficult, if not impossible = not a direct fire weapon ..and range was about 250 yards? -- sounds like it is even more difficult to hit a torpedo with it than with a 5 incher