It's a dud - again!

[bcarter3]

So I upped my difficulty a little from easy so that I now get dud torpedos, and boy did I get some duds. I fired off 10 torpedos, all ten hit the mark, 7/10 were duds! Is this normal? How many duds should I expect to get? This seemed a little high to me. Heck, if 7/10 are going to be duds every time I might as well surface the dang boat and pop off deck gun shots, I might even hit something then!

[nfitzsimmons]

On my current patrol (late 1942-early 1943) the first 7 torpedos I fired worked, the next 9 were duds. Waiting to find out how many of the rest are bad. Playing with normal difficulty and TM 1.7.6.

[seafarer]

Not out of line with real world experience either. Read some of the patrol reports that are available online, and you'll hear of skippers firing 4 or more duds in a row, at least in 1942. Especially frustrating when they either saw or heard the fish clearly strike the target, but fail to detonate (such shots were officially recorded as misses too, which must have just upped the frustration the captain's were feeling about the mark 14).

[Wilcke]

Perfect!

[Capn_Sinky]

I have basically found that in the default SH4 and playing on Normal skill level that I have a 50%-70% failure rate for the Mark 14s. In WWII from 41 early 43 it was about this high. Most commanders have more duds than think but dont realize it. The Navy Ordinance Dept in 1942 basically told the Sub Commanders that either they were dumb or didn't take care of their torps. In some cases sub commanders had their torp crews field strip each torp before firing so they could verify that the torps inner mechanics were functioning. Course when they reported this to the Ord Dept they basically said "well that eliminates the torp, so you must be an idiot." Navy Ord Dept officials were not the most liked individuals at parties. There were several recorded instances of Jap freighters making it to their destinations with unexploded torps sticking out of the hull. Nothing ticks a sub commander off more than to risk life and limb to sneak in undetected, fire a full spread of fish, escape back to port and be called an idiot by a know nothing desk jocky.

Basically there are 3 types of failure actually 4 if you count the dreaded circle back (aka Tang killer) The game actually only informs you of one type, the dud warhead. In this case the torp strikes the target and if you are watching and it is running shallow enough you can actully see a splash on the side of the target. To compensate for this make sure the torp is set to slow speed and that it strikes the target at an angle of 70 degrees or less. basically this failure was due to a bad exploder firing pin that was crushed or bent on impact. This was eventually corrected by late 42 early 43 interestingly enough by using stronger firing pins made from jap props from aircraft shot down at Pearl. Talk about the benefits of recycling. "Hey and its even a "Green Torpedo" take that that Tojo."

The most common failure that I have seen and the computer didn't tell me it was a dud was the mag exploder failure. Basically the earths magnetic field causes the mag exploder to detonate before the torpedo impacts the target. I have on several occasions had the fish explode less than 100 yrds from exiting the tube. I thought the escorts were shooting at my periscope, until I went to the tactical map and saw only two fish headed toward the target and I knew I had fired three fish. To combat this set the exploder to contact only. Yes its against the regs, but hey my hand slipped oh-kay.

The third failure was because of a last minute redesign to the Mark 14. This resulted in the fish running on avg 11 feet too deep. This also is not reported as a dud. You just think you missed, untill you flip over to the tactical map and see a spread of fish swim harmlessly under a Isa BS. This combined with the reg stating to set the exploder to mag and the run depth set to 5 feet below the keel of the target basically meant a zero chance for a kill. To combat this find the depth of keel in the manual, multiply by 3.25 (got to do the metric conversion thingy) then subtract 12 and set to contact only. You may still have a run under every now and then in rough seas, but combine this with an angle of impact of less than 70 degrees and speed set to slow and you will see some drastic changes in torp performance.

The last and rarest failure is the circular run torp. This one basically circles around and spanks you on your backside. OUCH! As Bart S. would say "While I thought that it was physically impossible, this both sucks and blows at the same time!" Have not had to opportunity to experience this wonder as of yet (knock on the XO's skull) my best guess would be "Ahead Flank! Crash Dive!" Followed quickly by a few propositions to a higher diety that one's choices regarding women and drink will change if the boat can pass through 100ft before the fish completes its turn.

The other thing to assist you in your mission prior to mid 42 is to swap out some Mark 14s for some older Mark 10s before you go on patrol. I make it a habit of replacing about half of my Mark 14s with Mark 10s before leaving port. I have yet to return from patrol empty handed. It takes a little cognative re-assessment when planning your attack, but it will be well worth the effort.

Good Luck and Good Hunting!

Capn_Sinky (aka Stinky)
O.I.C.I.C.
Officer In Charge of Ice Ceam

USS Drum

[bcarter3]

Awesome post Cpt. Sinky, thank you so much.

If the failure rate is so high on the Mk. 14's why would you even carry any? Why not swap out the full inventory for Mk. 10's instead. Yes I know they are steam, have a slightly shorter range and only one speed setting (as far as I can tell), but wouldnt you rather have reliability vs. range?

I know when I set up for an ambush I sit 1000-2000 yards away. It seems that the Mk 10's would still work in this scenario, or am I missing something obvious here?

[Capn_Sinky]

Thanks, Sorry about the length, Im a bit of a technical nerd.

Good question, why not all Mk10s. Well it seems that when I refit and select Mk10s that the next time I return to port there are not as many Mk10s left. So I am assuming (and we all know what that means) that the supply is limited. Dont want to use them all up at once. Plus you might tick off the pig boat capns, and remember they DON'T have ice cream makers so there always in a bad mood

True the Mk 10 is more reliable but it also has a smaller warhead (500lbs) the Mk 14s have, and my mind is failing me either 800 or 900lb warhead. So a Mk 10 is a little over half as powerfull.

Now here is where "Stinky Logic" comes in:

Gato sub can carry 24 fish. So if you carry only mk 14 you are carrying a little over 19,000 lbs of explosive. Now if you go with avg failure rate of 50% you are really only delivering about 9500 lbs of explosives to Mr. Tojo. Could be more or less depends on batch of fish. But 12 duds can really be a morale breaker, and a bad day at the office if it happens at the wrong time .

Now if you carry half and half, 12 mk 10s = 6000lbs of explosive force. 12 Mk 14s are about 9500 lbs, then avg out the 50% failure your delivering about 4800lbs. So now with a half and half load your only avering about 6 dud vs 12 duds and your delivering almost 11,000lbs of trouble for the imperial navy vs 9500lbs with the Mk 14.

Also Mk 14s can be handy little fish if you can see the bad guys in the harbor but can't get in close enough to use a Mk10. Set em to run slow and they will go all day. (actually 9000yrds which gives you almost 9 minutes to get somewere safe.) Wake Island is a good example, to use the Mk 10s you got to get right up under the bulldogs nose. But with the Mk14 you can stand back across the street and toss a few his way and be at a safe depth by the time he figures out what is going on.

Hope that helps.

Good Luck and Good Hunting!

Capn_Sinky (aka Stinky)
O.I.C.I.C.
Officer In Charge of Ice Cream

USS Drum

[swdw]

Originally Posted by bcarter3

Awesome post Cpt. Sinky, thank you so much.

If the failure rate is so high on the Mk. 14's why would you even carry any? Why not swap out the full inventory for Mk. 10's instead. Yes I know they are steam, have a slightly shorter range and only one speed setting (as far as I can tell), but wouldnt you rather have reliability vs. range?

I know when I set up for an ambush I sit 1000-2000 yards away. It seems that the Mk 10's would still work in this scenario, or am I missing something obvious here?

MK 10's have a smaller warhead and require more hits. In real life they could not be set by the TDC and I ran across a reference to the fact they had more problems with the azimuth gyro (stability) than the Mk14. So once the fish was in the tube you needed to keep a constant AOB, not close the range, and hope the target didn't change speed before firing. Azimuth gyro problems result in more frequent problems like circle runners. They also ran deeper than the depth setting used.

We're doing some digging, but some mods may not even have had a gyro angle setting, but not sure yet.

They sufferedd from duds too but not quite as high a number as the Mk14. This was because of the slower speed and less mass.

[Sailor Steve]

Originally Posted by bcarter3

If the failure rate is so high on the Mk. 14's why would you even carry any? Why not swap out the full inventory for Mk. 10's instead. Yes I know they are steam, have a slightly shorter range and only one speed setting (as far as I can tell), but wouldnt you rather have reliability vs. range?

I know when I set up for an ambush I sit 1000-2000 yards away. It seems that the Mk 10's would still work in this scenario, or am I missing something obvious here?

The main reason I can see for not carrying all Mk 10s is hindsight. They didn't have that option, primarily because they didn't know what the problem was. I play to replicate the same experience they had, so I keep the loadouts they had historically.

But that's just me.

[bookworm_020]

Originally Posted by Capn_Sinky

Basically this failure was due to a bad exploder firing pin that was crushed or bent on impact. This was eventually corrected by late 42 early 43 interestingly enough by using stronger firing pins made from jap props from aircraft shot down at Pearl.

The pin was also too heavy, so that it would also get jamed, causing a dud. A quck fix done was to put the pins in a lathe and turn them down, reducing their weight and increasing the success rate!

If the failure rate is so high on the Mk. 14's why would you even carry any? Why not swap out the full inventory for Mk. 10's instead. Yes I know they are steam, have a slightly shorter range and only one speed setting (as far as I can tell), but wouldnt you rather have reliability vs. range?

The mark 10 torps had there own problems. Skippers running out of Brisbane reported that the mark 10's were slow to imput data (tought when you need to do a snap shot of a BB!), had major reliablity issues due to parts that were worn out due to excessive use. The torps had been used pre-war, but to save money they were programed to float at the end of the run, so that they could be reused over and over again. They were also slower than more modern fish, giving the taget a better chance of spoting them (they were steam powered, so they left a trail) and getting out of the way.

[CCIP]

I remember designing the mod for the Mk.14 failure rates, and indeed that's close to where I was aiming for! From what I could gather, the failure rate in early war was around 60-70% due to various reasons (which includes not just duds per se but also depth problems, gyro problems and premature detonations). So what you're getting is pretty much what you should expect!

[SuperCavitation]

Originally Posted by Capn_Sinky

The third failure was because of a last minute redesign to the Mark 14. This resulted in the fish running on avg 11 feet too deep. This also is not reported as a dud. You just think you missed, untill you flip over to the tactical map and see a spread of fish swim harmlessly under a Isa BS. This combined with the reg stating to set the exploder to mag and the run depth set to 5 feet below the keel of the target basically meant a zero chance for a kill. To combat this find the depth of keel in the manual, multiply by 3.25 (got to do the metric conversion thingy) then subtract 12 and set to contact only.

Sinky,

Are you saying the torp depth gauge in the US subs is metric?



This gauge? Even though I'm set to use "Imperial" in my game settings?

[FIREWALL]

I never tic dud anymore. I miss enough as it is with manual targeting. :rotfl:

[skwasjer]

I usually have quite a few duds when I set the torps to deep with impact pistols, even at 90 degrees, as they just bounce of the bottom of the hull. I prefer to run torps at low speed, reducing the chance of faulty pistols or prematures. Either I use magnetic (but they often run to deep) or with impact pistols set them relatively shallow (at no more than 1/2 the draft, less with warships). Duds are so annoying, especially when you see a big BB sail by. *** klunk *** Torpedo is a dud, sir! arrrghhh...

[SuperCavitation]

Originally Posted by SuperCavitation

Sinky,

Are you saying the torp depth gauge in the US subs is metric?



This gauge? Even though I'm set to use "Imperial" in my game settings?

I swear I'm not as dumb as (I hope) I appear.... but my torps are still running deep.

I just completed an encounter with a Kongo, 27.9 draft. Multiplied, that's 90.6.. Minus 11 = 79.6.....

Soooo... I set the torp depth at 15 per the US gauge illustrated above. That's a give of, what? 13? And three of them just flew right under her.

Then, I decided to divide.... 27.9/3.25=8.6 rough. Cant take 11 away from that unless you consider the deck gun. :p

*Lost on patrol with torps that he can't program* MAN TEH DECK GUN!!1