Attacking a convoy in Sea State 0?

GoldenRivet · 01-29-08, 09:51 PM

the ability of the enemy to locate you by visual means depends on many things; among the most prominent factors are:

Speed of your boat
Weather condition
Sea State
Light levels

You may have a fair amount of luck approaching a convoy in calm sea, however the speed of your approach will be one of the greatest factors in determining how successful you are in the attack.

If you are approaching a single ship, or a convoy of ships in daylight conditions with a sea state of zero, your conning tower and your wake will be somewhat easily spotted by high power binoculars. Enemy AI is held to the same restrictions for spotting ships as the AI lookouts on your boat. therfore if you see the enemy, there stands a fair chance that he is equally capable of seeing you.

The best method for approaching a convoy in daylight conditions with a sea state at or near zero is to estimate the course of the convoy, maneuver your ship beyond visual range and proceed at maximum speed for a point along the convoy's course where you expect them to eventually pass. It is vital that you dive occasionally to monitor the progress of the convoy via hydrohphones, as convoys will change course temporarily for the purpose of evading u-boat threats, even if there is no confirmation of a u-boat in the area.

Once you have established your boat in the convoy's path, rig for silent running and dive to a depth of not less than 80 - 100 meters and wait for the lead escorts to pass. Once the lead escorts have passed, proceed to periscope depth and carry out a submerged attack.

Once the submerged attack is complete, dive to a depth of approximately 140 meters and attempt to egress through the rear area of the convoy. This will eventually put a fair distance between you and the moving convoy and eventually give the escorts encintive to return to their stations as opposed to carrying out a prolonged search and destroy mission against you.

If you wish to attempt a surface attack it is best to do so on a dark, near moonless night with a moderate or heavy sea. again, during the surface approach, high speeds will betray you. it is best to approach the convoy from their port or starboard forward quarters in the unprotected gap between the lead escort and the flanking escort(s).

Over time you will notice that the flanking escorts will break away from the convoy and initiate a zig zag type search pattern. it is during this time that you can initiate your most agressive maneuvering, however speed is still the limiting factor.

One surface attack strategy that has frequently worked for me is to close to within 1800 meters of the intended targets and turn to parallel their track. Once they are within the perameters for a bow shot (an arc between the bearings 270 - 0 - 090 degrees) i will fire a spread, order maximum speed and make a turn to egress the convoy through the same port or starboard forward quarter through which i entered the convoy. At this time i will put the convoy behind me and proceed at flank speed.

Once the torpedoes have impacted search lights will begin to scan the area and starshells will probably be fired in various quadrants where the escorts suspect the attack originated. *Usually* i am outside the range of spotlights and starshells by this time. Due to surface sound clutter, enemy hydrophones will be unable to detect the departing U-boat as long as it is on the surface. The only remaining means of locating the U-boat is visually or by radar.

* this attack method becomes obsolete as allied radar becomes more commonplace throughout the North Atlantic Theater of Operations later in the war and the surface approach should be abandoned in favor of the submerged approach!

MarkShot · 01-29-08, 10:06 PM

I was reading some German notes (formerly classified) on sub ops. It noted interestingly that even in heavy seas where the sub would be difficult to spot, the sub could always get picked up by a swell such that briefly the sub would be easy to spot as it would cease to be hull down.

Also, interesting that the Germans considered a raised scope while on the surface a servere liability as it would make the U-boat easier to spot. Whereas the Americans often patroled with the "high periscope" while surfaced to extend the field of vision. Perhaps this was because the lack of periscope sheers on the U-boat would induce too much vibration into the raised periscope.

GoldenRivet · 01-29-08, 10:12 PM

Quote:

Originally Posted by MarkShot

I was reading some German notes (formerly classified) on sub ops. It noted interestingly that even in heavy seas where the sub would be difficult to spot, the sub could always get picked up by a swell such that briefly the sub would be easy to spot as it would cease to be hull down.

Also, interesting that the Germans considered a raised scope while on the surface a servere liability as it would make the U-boat easier to spot. Whereas the Americans often patroled with the "high periscope" while surfaced to extend the field of vision. Perhaps this was because the lack of periscope sheers on the U-boat would induce too much vibration into the raised periscope.

this is correct, any surfaced ww2 submarine would be substantially easier to spot if it were carried to the top of a swell.

I once heard a military quote "There are no straight lines in nature."

This quote holds true from a trip wire in "the bush" all the way to the hard right angles which make up the structure of a conning tower protruding from the open sea. If a watchman is keen enough and knowlegable enough on "what to look for" all of the stealth and cunning you can muster just might not be enough.

good luck out there!

"Patience is the best of all instructors."

Schwuppes · 01-30-08, 02:52 AM

Quote:

Originally Posted by GoldenRivet

One surface attack strategy that has frequently worked for me is to close to within 1800 meters of the intended targets and turn to parallel their track....

Don't you mean perpendicular?
Otherwise I don't understand... if you're going a parallel course how can the target ever get into a suitable firing angle (i.e 345 - 15 degrees)?

Sebbe02 · 01-30-08, 04:26 AM

have another question too:

if you start going back up from, let's say, 100m to periscope depth after the first escort has passed you, do you still have enought time to make a proper solution? And do you use the engines or simply go up vertically?

GoldenRivet · 01-30-08, 07:38 AM

@Schwupps: initially yes it is perpindicular, but then i turn nearly parallel to their course to reduce the amount of time it takes to make the outbound turn and escape after the shots are fired. it is faster to turn about 45 - 90 degrees than it is to have to make a 180 degree turn after shooting. the idea is to get out of town before the shots impact and this technique simply reduces time spent turning away from the convoy.

@Sebbe02: Usually i blow ballast to about 40 meters and then order periscope depth. this greatly reduces the time required to reach PD. all of this should be done at ahead slow.

01-29-08, 09:51 PM	#1
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	the ability of the enemy to locate you by visual means depends on many things; among the most prominent factors are: Speed of your boat Weather condition Sea State Light levels You may have a fair amount of luck approaching a convoy in calm sea, however the speed of your approach will be one of the greatest factors in determining how successful you are in the attack. If you are approaching a single ship, or a convoy of ships in daylight conditions with a sea state of zero, your conning tower and your wake will be somewhat easily spotted by high power binoculars. Enemy AI is held to the same restrictions for spotting ships as the AI lookouts on your boat. therfore if you see the enemy, there stands a fair chance that he is equally capable of seeing you. The best method for approaching a convoy in daylight conditions with a sea state at or near zero is to estimate the course of the convoy, maneuver your ship beyond visual range and proceed at maximum speed for a point along the convoy's course where you expect them to eventually pass. It is vital that you dive occasionally to monitor the progress of the convoy via hydrohphones, as convoys will change course temporarily for the purpose of evading u-boat threats, even if there is no confirmation of a u-boat in the area. Once you have established your boat in the convoy's path, rig for silent running and dive to a depth of not less than 80 - 100 meters and wait for the lead escorts to pass. Once the lead escorts have passed, proceed to periscope depth and carry out a submerged attack. Once the submerged attack is complete, dive to a depth of approximately 140 meters and attempt to egress through the rear area of the convoy. This will eventually put a fair distance between you and the moving convoy and eventually give the escorts encintive to return to their stations as opposed to carrying out a prolonged search and destroy mission against you. If you wish to attempt a surface attack it is best to do so on a dark, near moonless night with a moderate or heavy sea. again, during the surface approach, high speeds will betray you. it is best to approach the convoy from their port or starboard forward quarters in the unprotected gap between the lead escort and the flanking escort(s). Over time you will notice that the flanking escorts will break away from the convoy and initiate a zig zag type search pattern. it is during this time that you can initiate your most agressive maneuvering, however speed is still the limiting factor. One surface attack strategy that has frequently worked for me is to close to within 1800 meters of the intended targets and turn to parallel their track. Once they are within the perameters for a bow shot (an arc between the bearings 270 - 0 - 090 degrees) i will fire a spread, order maximum speed and make a turn to egress the convoy through the same port or starboard forward quarter through which i entered the convoy. At this time i will put the convoy behind me and proceed at flank speed. Once the torpedoes have impacted search lights will begin to scan the area and starshells will probably be fired in various quadrants where the escorts suspect the attack originated. Usually i am outside the range of spotlights and starshells by this time. Due to surface sound clutter, enemy hydrophones will be unable to detect the departing U-boat as long as it is on the surface. The only remaining means of locating the U-boat is visually or by radar. * this attack method becomes obsolete as allied radar becomes more commonplace throughout the North Atlantic Theater of Operations later in the war and the surface approach should be abandoned in favor of the submerged approach! __________________

01-29-08, 10:06 PM	#2
MarkShot Ace of the Deep Join Date: Jul 2002 Posts: 1,134 Downloads: 93 Uploads: 0	I was reading some German notes (formerly classified) on sub ops. It noted interestingly that even in heavy seas where the sub would be difficult to spot, the sub could always get picked up by a swell such that briefly the sub would be easy to spot as it would cease to be hull down. Also, interesting that the Germans considered a raised scope while on the surface a servere liability as it would make the U-boat easier to spot. Whereas the Americans often patroled with the "high periscope" while surfaced to extend the field of vision. Perhaps this was because the lack of periscope sheers on the U-boat would induce too much vibration into the raised periscope. __________________ War games, not wars! --- Only a small few profit from war (that should not stand)!

01-30-08, 07:38 AM	#6
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	@Schwupps: initially yes it is perpindicular, but then i turn nearly parallel to their course to reduce the amount of time it takes to make the outbound turn and escape after the shots are fired. it is faster to turn about 45 - 90 degrees than it is to have to make a 180 degree turn after shooting. the idea is to get out of town before the shots impact and this technique simply reduces time spent turning away from the convoy. @Sebbe02: Usually i blow ballast to about 40 meters and then order periscope depth. this greatly reduces the time required to reach PD. all of this should be done at ahead slow. __________________

01-30-08, 04:26 AM	#5
Sebbe02 Sailor man Join Date: Jun 2007 Posts: 44 Downloads: 0 Uploads: 0	have another question too: if you start going back up from, let's say, 100m to periscope depth after the first escort has passed you, do you still have enought time to make a proper solution? And do you use the engines or simply go up vertically?