Air Torpedo (Fido) Mod.

Stiebler · 07-23-12, 10:35 AM

The American acoustic homing torpedo (known as ‘Fido’ because it ‘sniffed out’ the enemy) was deployed from aircraft against U-boats from June 1943.
This innovation was present in the old U-boat simulation ‘Aces of the Deep’, but was omitted by the devs from their creation of Silent Hunter III owing to a false belief that inevitably it sank the U-boat, which would make the simulation unplayable.

In fact Fido was no more infallible than the German acoustic torpedo, fitted to U-boats and intended to sink ships. In both cases the acoustic torpedo was intended to steer towards the nearest loud sound in the water. For a German acoustic torpedo, intended as a defence against convoy escorts, the ‘loud sound’ was expected to be that of a closing warship making about 10-12 knots, and the sound receiver was attuned to the sound of the propellers at that speed.

Fido was even cruder, because it steered directly towards the loudest sound. When a ship moves through water, the rotation of the propellers causes ‘cavitation’, the name given to the popping of bubbles. Cavitation is much more audible when the propellers turn quickly (high speed) than when they turn slowly. A U-boat caught on the surface by an aircraft would crash-dive at full speed in an attempt to get away - thus the propellors would be causing very loud cavitation. Under these circumstances, Fido was an effective weapon, and it has been credited with a hit-rate of some 25%. By contrast, the German acoustic torpedo T-V had a hit-rate of only 10% according to post-war analysis. However, the T-V was aimed only at a difficult target, which would probably be deploying decoys (such as the noise-making device ‘Foxer’, or even by dropping random depthcharges) whereas Fido faced no such distractions.

If a U-boat dived very slowly, then Fido would be almost ineffective. Therefore orders were given to Allied air crews that Fido was never to be dropped under conditions where the enemy could see the presence of an acoustic torpedo. In practice, this meant that it was always dropped onto a U-boat that was already submerged (or in the act of submerging). The idea that a hit by Fido always destroyed the submerged U-boat is wrong. U 256, U 456 and U 333 all survived to return to the surface, where they reported that they had been hit by ‘bombs’ in the region of the propellers. There may have been other examples.

‘Aces of the Deep’ modelled this very well, with a warning to the U-boat commander that the soundman could hear a torpedo approaching. The trick to avoid being hit was then to reduce to slowest speed, when Fido would miss.

I have added the same effect to SH3. The rules of the code are these:
1. If the aircraft would have dropped depthcharges, it is assumed also to have dropped an acoustic torpedo.
2. The U-boat receives a warning from the console of ‘torpedo incoming’, and a spoken warning ‘Torpedo in the water’ from the soundman. Time compression also drops to 1.
3. For the next 10 minutes of game time, the torpedo tries to locate the U-boat. If it has not succeeded after 10 minutes, then the torpedo is lost.
4. If the U-boat is located, a simple test of the U-boat speed is made. A probability factor is also applied. The slower the U-boat is moving at that time, the less likely it is to be hit.
5. If the U-boat is hit, then hit-points are deducted equivalent to 75% of the original maximum U-boat hit-points. (If the result is less than 0, as a result of earlier damage, the U-boat is sunk at once). You will also receive a console message from the Chief Engineer telling of the hit.
6. Fido is not used in this mod before 1 July 1943.

This mod should cause the player to lose enthusiasm to wait around when seen by aircraft. Although it will occur only rarely, you *may* be hit by a torpedo even when moving at slowest speed (2 kts) underwater. In fact, I would advise manually moving the speed on the speed-dial to 1 kt while the torpedo is in the area.

In real life, attacks by a pair of carrier-borne Avenger aircraft on a U-boat were quite common. One of the Avengers would carry a Fido. In order to mimick this, you need to add depthcharges to an Avenger, to replace part of the standard bombs loadout. Special files for this purpose are supplied as part of the mod.

Finally...
Several experienced and talented modders have tried previously to model the effect of an aircraft dropping a torpedo onto the U-boat. None of these attempts has been sufficiently successful to create a mod which could be released.
I lack the skills of these modders, therefore:
No graphic effects will be seen with this mod, it is entirely computational. You will not see the aircraft dropping a torpedo, you will not see the torpedo in the water, and there will be no visible explosion if it hits its target. My objective has been to improve game-play. Besides, since (by definition) the U-boat is submerged when FIDO is dropped, how can they see external events?

Download the mod, with details, from here:
http://www.subsim.com/radioroom/showthread.php?t=196674

Stiebler.

Myxale · 07-23-12, 11:37 AM

Another great feature out of your hat! Kudos mate.

I personally don't care much for graphical representation of certain game-play elements, as long as they are incorporated well and add to the game.
This little mod sounds like it will add lots of fun and excitement.

Will try ASAS!

sharkbit · 07-23-12, 10:10 PM

AWESOME!!!!!

Ever since I read Michael Gannon's "Black May"(he goes a little bit into the development and use of them), I always thought that it was too bad Fidos weren't modeled in the game.

Thanks for the mod and the work that you put into the game.

Stiebler · 07-24-12, 01:34 AM

@Myxale:

Many users of GWX reported that my Stiebler4a(and 3a)_Addon_for_V16B1 patch, which contains the Air Torpedo fix, caused CTDs (crashes) when used casually with GWX.

However, two recent users discovered that the problem lay with inconsistent UnitTypes for the CAM-SHIP (M36B) in GWX (UnitType=102) and the patch (UnitType=8).

The latest release Stiebler4b_Addon_for_V16B1 addresses this issue in the instructions, so the CTD can now be avoided (simple) or fixed (harder).

See here:
http://www.subsim.com/radioroom/showthread.php?t=196674

Stiebler.

Anvart · 07-24-12, 06:38 AM

The repetition of the past... IIUC.

Myxale · 07-24-12, 07:06 AM

I have yet to try the mod. Free time is on the rare side!

But thanx for the head's up!

reaper7 · 07-24-12, 02:08 PM

Likewise I have yet to try the Mod, but it sounds like a spectacular addition to the Sim. Thanks for your continued excavation into the SH3 exe - you really are coming up with some great treasures.

Hitman · 07-24-12, 02:12 PM

Sounds good, but my concern is that by being computational you can't do evasive maneuvers, just wait out to see what your luck is when the dice rolls

Stiebler · 07-24-12, 02:33 PM

@Hitman:

Quote:

Sounds good, but my concern is that by being computational you can't do evasive maneuvers, just wait out to see what your luck is when the dice rolls

This is true, but nevertheless the fate of your U-boat remains (mostly) in your own hands.

You must be alert at all times to try to avoid aircraft attacks. If attacked by surprise, it is necessary to consider whether to crash-dive as an aircraft attacks; whether to dive slowly (or to slow down quickly after a crash-dive); and you must keep an alert eye and ear on console messages and what your soundman tells you.

Stiebler.

vanjast · 07-24-12, 03:18 PM

Computational makes it easy..
You hammer the throttle during crash dive then cut power and hard turn stbd or port. you should have enough momentum to avoid Fido.

Computational means that there has to be an assumption on the the noise level of the props, and as hinted , 1 knot seems to be the cloaking speed. Thus Fido locks onto the last known bearing before you cut the throttle.

Having momentum ensures that you get out of the way.... sort of

Ligne Maginot · 08-03-13, 02:32 AM

Precise as a Swiss watch.

Sepp von Ch. · 08-04-13, 11:49 AM

Hello Stiebler, thank you very much for your work. Can I continue to use with this mod Rubini´s great FIDO mod?

http://www.subsim.com/radioroom/showthread.php?t=197762

And what specifically (which files related to Fido) is new in your latest version of Stiebler4B_Addon_for_V16B1 in comparison with the older version, that I use?

Stiebler · 08-05-13, 03:30 AM

@Sepp von Ch:

This is the current list of mods included with the Stiebler4B_Addon_for_V16B1.

There should not be an older version of the Addon, or I should have given the new release a new Stiebler4C (or Stiebler5) suffix.

Silent-Running mod
Surrender mod
“Smoke on Horizon” mod
CAM-ship mod
Asdic mod
Reduce Ship Warnings mod
Change Patrol Grid mod
Minimum TC mod
Improved BdU Congratulations Fix
Null Grid Mod
Weather Meter
AirTorpedo (Fido) mod
ALSO:
NYGM weather improvement mod (self-contained - can be used by players of all super-mods that have the H.sie V1.6B1 patch installed.)
Ship Speed Fix (self-contained - can be used by players of all super-mods that have the H.sie V1.6B1 patch installed.)

Full details are provided with the documentation.
I would advise strongly against trying to alter individual files - if necessary, reinstall the whole patch over H.sie's V1.6B1 patch.

Stiebler.

07-23-12, 10:35 AM	#1
Stiebler Fuel Supplier Join Date: Oct 2005 Location: London, UK Posts: 1,237 Downloads: 29 Uploads: 4	Air Torpedo (Fido) Mod. The American acoustic homing torpedo (known as ‘Fido’ because it ‘sniffed out’ the enemy) was deployed from aircraft against U-boats from June 1943. This innovation was present in the old U-boat simulation ‘Aces of the Deep’, but was omitted by the devs from their creation of Silent Hunter III owing to a false belief that inevitably it sank the U-boat, which would make the simulation unplayable. In fact Fido was no more infallible than the German acoustic torpedo, fitted to U-boats and intended to sink ships. In both cases the acoustic torpedo was intended to steer towards the nearest loud sound in the water. For a German acoustic torpedo, intended as a defence against convoy escorts, the ‘loud sound’ was expected to be that of a closing warship making about 10-12 knots, and the sound receiver was attuned to the sound of the propellers at that speed. Fido was even cruder, because it steered directly towards the loudest sound. When a ship moves through water, the rotation of the propellers causes ‘cavitation’, the name given to the popping of bubbles. Cavitation is much more audible when the propellers turn quickly (high speed) than when they turn slowly. A U-boat caught on the surface by an aircraft would crash-dive at full speed in an attempt to get away - thus the propellors would be causing very loud cavitation. Under these circumstances, Fido was an effective weapon, and it has been credited with a hit-rate of some 25%. By contrast, the German acoustic torpedo T-V had a hit-rate of only 10% according to post-war analysis. However, the T-V was aimed only at a difficult target, which would probably be deploying decoys (such as the noise-making device ‘Foxer’, or even by dropping random depthcharges) whereas Fido faced no such distractions. If a U-boat dived very slowly, then Fido would be almost ineffective. Therefore orders were given to Allied air crews that Fido was never to be dropped under conditions where the enemy could see the presence of an acoustic torpedo. In practice, this meant that it was always dropped onto a U-boat that was already submerged (or in the act of submerging). The idea that a hit by Fido always destroyed the submerged U-boat is wrong. U 256, U 456 and U 333 all survived to return to the surface, where they reported that they had been hit by ‘bombs’ in the region of the propellers. There may have been other examples. ‘Aces of the Deep’ modelled this very well, with a warning to the U-boat commander that the soundman could hear a torpedo approaching. The trick to avoid being hit was then to reduce to slowest speed, when Fido would miss. I have added the same effect to SH3. The rules of the code are these: 1. If the aircraft would have dropped depthcharges, it is assumed also to have dropped an acoustic torpedo. 2. The U-boat receives a warning from the console of ‘torpedo incoming’, and a spoken warning ‘Torpedo in the water’ from the soundman. Time compression also drops to 1. 3. For the next 10 minutes of game time, the torpedo tries to locate the U-boat. If it has not succeeded after 10 minutes, then the torpedo is lost. 4. If the U-boat is located, a simple test of the U-boat speed is made. A probability factor is also applied. The slower the U-boat is moving at that time, the less likely it is to be hit. 5. If the U-boat is hit, then hit-points are deducted equivalent to 75% of the original maximum U-boat hit-points. (If the result is less than 0, as a result of earlier damage, the U-boat is sunk at once). You will also receive a console message from the Chief Engineer telling of the hit. 6. Fido is not used in this mod before 1 July 1943. This mod should cause the player to lose enthusiasm to wait around when seen by aircraft. Although it will occur only rarely, you may be hit by a torpedo even when moving at slowest speed (2 kts) underwater. In fact, I would advise manually moving the speed on the speed-dial to 1 kt while the torpedo is in the area. In real life, attacks by a pair of carrier-borne Avenger aircraft on a U-boat were quite common. One of the Avengers would carry a Fido. In order to mimick this, you need to add depthcharges to an Avenger, to replace part of the standard bombs loadout. Special files for this purpose are supplied as part of the mod. Finally... Several experienced and talented modders have tried previously to model the effect of an aircraft dropping a torpedo onto the U-boat. None of these attempts has been sufficiently successful to create a mod which could be released. I lack the skills of these modders, therefore: No graphic effects will be seen with this mod, it is entirely computational. You will not see the aircraft dropping a torpedo, you will not see the torpedo in the water, and there will be no visible explosion if it hits its target. My objective has been to improve game-play. Besides, since (by definition) the U-boat is submerged when FIDO is dropped, how can they see external events? Download the mod, with details, from here: http://www.subsim.com/radioroom/showthread.php?t=196674 Stiebler. __________________ NYGM Tonnage War Mod - More than a mod: it's an experience!

07-23-12, 11:37 AM	#2
Myxale Admiral Join Date: Feb 2006 Location: PQ AN 25 Posts: 2,178 Downloads: 70 Uploads: 0	Another great feature out of your hat! Kudos mate. I personally don't care much for graphical representation of certain game-play elements, as long as they are incorporated well and add to the game. This little mod sounds like it will add lots of fun and excitement. Will try ASAS! __________________ SH3+GWX SH5+WoS Still Sailing....still Deep

07-23-12, 10:10 PM	#3
sharkbit The Old Man Join Date: Apr 2008 Location: Denver, CO Posts: 1,529 Downloads: 334 Uploads: 0	AWESOME!!!!! Ever since I read Michael Gannon's "Black May"(he goes a little bit into the development and use of them), I always thought that it was too bad Fidos weren't modeled in the game. Thanks for the mod and the work that you put into the game. __________________ “Prejudice is blind. There will always be someone who says you aren’t welcome at the table. Stop apologizing for who you are and using all your energy trying to change their minds. Yes, you will lose friends, maybe even family. But you will gain your self-respect. You will know your worth. Once you have that, nothing can stop you.”

07-24-12, 01:34 AM	#4
Stiebler Fuel Supplier Join Date: Oct 2005 Location: London, UK Posts: 1,237 Downloads: 29 Uploads: 4	@Myxale: Many users of GWX reported that my Stiebler4a(and 3a)_Addon_for_V16B1 patch, which contains the Air Torpedo fix, caused CTDs (crashes) when used casually with GWX. However, two recent users discovered that the problem lay with inconsistent UnitTypes for the CAM-SHIP (M36B) in GWX (UnitType=102) and the patch (UnitType=8). The latest release Stiebler4b_Addon_for_V16B1 addresses this issue in the instructions, so the CTD can now be avoided (simple) or fixed (harder). See here: http://www.subsim.com/radioroom/showthread.php?t=196674 Stiebler. __________________ NYGM Tonnage War Mod - More than a mod: it's an experience!

07-24-12, 06:38 AM	#5
Anvart Admiral Join Date: Jan 2006 Location: Russia ® Posts: 2,492 Downloads: 122 Uploads: 1	The repetition of the past... IIUC. __________________ Alex ® Moses said: "Don't create yourself an idol"...

07-24-12, 07:06 AM	#6
Myxale Admiral Join Date: Feb 2006 Location: PQ AN 25 Posts: 2,178 Downloads: 70 Uploads: 0	I have yet to try the mod. Free time is on the rare side! But thanx for the head's up! __________________ SH3+GWX SH5+WoS Still Sailing....still Deep

07-24-12, 02:08 PM	#7
reaper7 sim2reality Join Date: Jun 2007 Location: AM 82 Posts: 2,280 Downloads: 258 Uploads: 30	Likewise I have yet to try the Mod, but it sounds like a spectacular addition to the Sim. Thanks for your continued excavation into the SH3 exe - you really are coming up with some great treasures.

07-24-12, 02:12 PM	#8
Hitman Pacific Aces Dev Team Join Date: Sep 2002 Location: Spain Posts: 6,109 Downloads: 109 Uploads: 2	Sounds good, but my concern is that by being computational you can't do evasive maneuvers, just wait out to see what your luck is when the dice rolls __________________ One day I will return to sea ...

07-24-12, 03:18 PM	#10
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,733 Downloads: 825 Uploads: 4	Computational makes it easy.. You hammer the throttle during crash dive then cut power and hard turn stbd or port. you should have enough momentum to avoid Fido. Computational means that there has to be an assumption on the the noise level of the props, and as hinted , 1 knot seems to be the cloaking speed. Thus Fido locks onto the last known bearing before you cut the throttle. Having momentum ensures that you get out of the way.... sort of

08-03-13, 02:32 AM	#11
Ligne Maginot Gunner Join Date: Dec 2012 Posts: 94 Downloads: 141 Uploads: 0	Precise as a Swiss watch.

08-04-13, 11:49 AM	#12
Sepp von Ch. Sea Lord Join Date: Dec 2009 Location: In my U-552 and Tiger Posts: 1,732 Downloads: 788 Uploads: 0	Hello Stiebler, thank you very much for your work. Can I continue to use with this mod Rubini´s great FIDO mod? http://www.subsim.com/radioroom/showthread.php?t=197762 And what specifically (which files related to Fido) is new in your latest version of Stiebler4B_Addon_for_V16B1 in comparison with the older version, that I use? __________________ *U-552* *Tiger* *IDF* Last edited by Sepp von Ch.; 08-04-13 at 12:42 PM.

08-05-13, 03:30 AM	#13
Stiebler Fuel Supplier Join Date: Oct 2005 Location: London, UK Posts: 1,237 Downloads: 29 Uploads: 4	@Sepp von Ch: This is the current list of mods included with the Stiebler4B_Addon_for_V16B1. There should not be an older version of the Addon, or I should have given the new release a new Stiebler4C (or Stiebler5) suffix. Silent-Running mod Surrender mod “Smoke on Horizon” mod CAM-ship mod Asdic mod Reduce Ship Warnings mod Change Patrol Grid mod Minimum TC mod Improved BdU Congratulations Fix Null Grid Mod Weather Meter AirTorpedo (Fido) mod ALSO: NYGM weather improvement mod (self-contained - can be used by players of all super-mods that have the H.sie V1.6B1 patch installed.) Ship Speed Fix (self-contained - can be used by players of all super-mods that have the H.sie V1.6B1 patch installed.) Full details are provided with the documentation. I would advise strongly against trying to alter individual files - if necessary, reinstall the whole patch over H.sie's V1.6B1 patch. Stiebler. __________________ NYGM Tonnage War Mod - More than a mod: it's an experience!