German Torpedo Crisis in WW2

[kyle9154]

This is a very good read on how u-boat commanders for the first 3 years of the war especially the 1st year where they had constant torpedo issues that would affect performance and outcomes as a whole and probably was the cause of the allies surviving the shipping losses in the 1st year of the war.

Torpedo Crisis - https://digitalcommons.georgiasouthe...99&context=etd

To simulate these statistics in Silent Hunter 3 (I use Onealex compilation) I change the hsie.ini file values to these:
magnetics should always have harder chance of success as they cause double the flooding damage in GWX then impact hits
; Torpedo Failure Fix.
;---------------------
; Failure rates (assuming torpedo set to depth = 0.4*windspeed or deeper)
; Impact Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.25
Val3=0.50 - large failure rates (duds bouncing off hulls/surface runners veering off course/running too deep under hull) though was still more reliable then magnetic pistol
; Impact Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.15
Val4=0.25 - issues were largely solved with impact pistols though a report of one third of torpedoes were failures of some sort ie. duds, premature explosion, surface runner
; Impact Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.03
Val5=0.05
; Magnet Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.20
Val6=0.60 - abysmal failure rates, so many factors were contributing to failures (premature explosions/running too deep under hull/surface runners veering off course)
; Magnet Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.10
Val7=0.35 - to simulate TI order of not using magnetic pistols as there were still many issues with magnetic pistols until late 1942
; Magnet Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.02
Val8=0.10

Legend:
TI = Torpedo Inspectorate
Calm Seas = 0-5m
Average Seas = 6-10m
Rough Seas = 11-15m windspeed

Torpedo Firing Solution:
4 x Windspeed/10 or .4 x Windspeed

I also follow these rules when playing a campaign:

Torpedo Firing Rules
Impact Pistol
1. Min firing depth of 3m(2m in calm seas). - TI historical rule
2. Set depth at least 3m less then target's keel depth. - TI historical rule
3. Never fire in rough seas if target keel is less then 7m, shadow and wait for better sea conditions as magnetics will be unreliable in this weather also.
4. Never fire G7a at fast speed (TI rule Germans used in WW2, greater chance of unreliability at that speed)
5. When firing multiple torpedoes, fire in 6 second intervals to avoid explosions setting off nearby running torpedoes. -TI historical rule

Magnetic Pistol
1. Min depth of 4m(3m in calm seas) - TI historical rule
2. Set depth 0.5-1.5m under keel depending on windspeed(add .01m for each m in windspeed), ex. 1.5m for 10m windspeed, 0.5m for flat calm sea.
3. Never fire in rough seas (11-15m) because of high chance of bouncing off hull or going too deep under the hull and not exploding from target bobbing up and down on the waves.
4. Never fire G7a at fast speed (TI rule Germans used in WW2, greater chance of unreliability at that speed)
5. When firing multiple torpedoes, fire in 6 second intervals to avoid explosions setting off nearby running torpedoes. -TI historical rule

Torpedo Amount Determination to ensure sinking and not damaging a vessel:
Impact Pistol
Under 4500 tons, one torpedo
4500-10000 tons, two torpedoes
10000-15000 tons, three torpedoes
Over 15000 tons, four torpedoes

Magnetic Pistol
Under 7000 tons, single torpedo
7000-15000 tons, two torpedoes
15000+ tons, three torpedoes

U-boat Torpedo Attack Angle:
This mainly affects impact pistols but is a good practice to use for magnetic shots as well.
1. Angle your boat when firing broadside at target so that your angled slightly and firing at say 15 or 345 degree bearing depending which way target vessel is approaching from.
2. Then go to standard speed and turn the boat to 30 degrees(while observing first torpedo result) to port or starboard. This allows you to fire at a good angle another impact pistol at target if first torpedo was a dud or failure or you can choose to fire two torpedoes at once in case one or even both fail (Sept 39-May 40 they had over half of their torpedoes historically fail)

[John Pancoast]

I doubled all of the values in the Hsie.ini as the default are to easy. Like the look of your numbers though; have to give them a try.

[kyle9154]

Originally Posted by John Pancoast

I doubled all of the values in the Hsie.ini as the default are to easy. Like the look of your numbers though; have to give them a try.

If you want to go even more hardcore and historical then use these values that I've been recently trying out:

; Torpedo Failure Fix.
;---------------------
; Failure rates (assuming torpedo set to depth = 0.4*windspeed or deeper)
; Impact Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.20
Val3=0.60
; Impact Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.10
Val4=0.30
; Impact Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.03
Val5=0.10
; Magnet Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.25
Val6=0.75
; Magnet Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.15
Val7=0.45
; Magnet Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.05
Val8=0.15

[John Pancoast]

Originally Posted by kyle9154

If you want to go even more hardcore and historical then use these values that I've been recently trying out:

; Torpedo Failure Fix.
;---------------------
; Failure rates (assuming torpedo set to depth = 0.4*windspeed or deeper)
; Impact Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.20
Val3=0.60
; Impact Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.10
Val4=0.30
; Impact Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.03
Val5=0.10
; Magnet Pistol, until June 1940. Range: [0.00 - 0.99]. Default: 0.25
Val6=0.75
; Magnet Pistol, June'40-June'42. Range: [0.00 - 0.99]. Default: 0.15
Val7=0.45
; Magnet Pistol, after June 1942. Range: [0.00 - 0.99]. Default: 0.05
Val8=0.15

Perfect; I was thinking of tripling them anyway.

[kyle9154]

These are all personal preference and you may not notice the failure rate changes over 1-2 torpedoes but you will on your entire payload over your whole patrol. In my May-June patrol, I fired all 14 torpedoes out of my VIIB during the whole patrol and scored 6 hits, 7 were failures, 1 was a human error - miss due to my miscalculation (this is during the time of the highest failure rates in hsie, sept 39-may 40 and it works as intended). Sh3 simulates failures in three ways either premature explosion before hitting target, running too deep or bouncing off hull - hard to do unless you have bad angle with impact shot or you use a magnetic shot that hits the side of hull instead of going near bottom of hull. I have to resort a lot to using my deck gun early war to finish off a merchant because of damage or take one out due to failures as was historical, they achieved better success with the deck gun then their lousy eels in first year. If I can tell she's unarmed and if there's no other contacts around I may not even waste a torpedo and just use deck gun- provided its not more then 7m/s seas.

[John Pancoast]

Originally Posted by kyle9154

These are all personal preference and you may not notice the failure rate changes over 1-2 torpedoes but you will on your entire payload over your whole patrol. In my May-June patrol, I fired all 14 torpedoes out of my VIIB during the whole patrol and scored 6 hits, 7 were failures, 1 was a human error - miss due to my miscalculation (this is during the time of the highest failure rates in hsie, sept 39-may 40 and it works as intended). Sh3 simulates failures in three ways either premature explosion before hitting target, running too deep or bouncing off hull - hard to do unless you have bad angle with impact shot or you use a magnetic shot that hits the side of hull instead of going near bottom of hull. I have to resort a lot to using my deck gun early war to finish off a merchant because of damage or take one out due to failures as was historical, they achieved better success with the deck gun then their lousy eels in first year. If I can tell she's unarmed and if there's no other contacts around I may not even waste a torpedo and just use deck gun- provided its not more then 7m/s seas.

Right. I've been using my changes for awhile now. Don't ever bother with the deck gun myself; I'd rather have the crew in their gear and have no interest in the deck or aa guns anyway.

[John Pancoast]

Btw, if you're not familar with rudewarrior's Just Follow Orders (JFO) mod, I highly recommend it.
Has a torpedo section too.