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Merry Christmas to all and to all a good night
Quote:
Originally Posted by FUBAR295
I use decks awash when the sea is smooth or calm and only during daylight hours and only early war up to early 1942. After that not so much.
Interestingly, I found no mention of decks wash in the Uboat Commanders Handbook, so not sure how often it was used in real life.
Good hunting,
FUBAR295
Neither did I and I've spent Christmas eve looking! THe 1943 edition when Germany knew it's Atlantic war effort was not keeping up: https://maritime.org/doc/uboat/index.htm
1.) In war, only submarine commanders who possess distinctive tactical knowledge and ability will be successful in the long run. In order, however, to understand and master the tactics (i.e., of submarine warfare), it is necessary to be thoroughly familiar with the weapon, and its characteristics and peculiarities; for it is on these that the tactics depend.
In addition, complete success as a result of a thorough exploitation of the possibilities of the weapon can only be achieved if all the officers in charge of it are trained to think along the same tactical lines.
The theoretical knowledge of the weapon, and of the appropriate tactics, must be supplemented, in the last resort, by the decisive requirement of a war-like spirit and an audacious outlook. The essence of submarine warfare is the offensive! For the commander of a submarine, therefore, the maxim: "He who wants to be victorious on the sea must always attack!" has special meaning.
2.) The following instructions, in which the experiences gained in the present war have been used, are concerned with the characteristics and uses of the submarines at present at our disposal, namely of submarines for torpedo attack.
The formulation of tactical rules for other types of submarines (artillery-carrying submarines, mine-laying submarines) will only be possible when some experience has been gained of these types of vessel.
Section
General
A. Essential Characteristics and Uses of the Submarine.
3.) The chief characteristic and strength of the submarine is its invisibility due to its ability to submerge. As a consequence, the submarine is distinguished, at the same time, by another special feature, the advantage of surprise.
4.) The characteristic of invisibility serves both as a means of attack and a means of protection, and thus forms the basis for the naval use and suitability of the submarine:
a) The underwater torpedo attack without warning, in daylight and on light nights during a full moon,
b) The underwater night torpedo attack
c) The gunnery action and bombardment at night (only directed against unescorted single vessels in remote sea areas),
d) the laying of mines (undetected),
e) in short, the carrying out of independent operations in parts of the sea dominated by the enemy, where our own surface ships cannot operate.
5.) The most important naval task of our existing type of submarine is the undetected torpedo attack. This task imposes the upper limits of the size of the submarine on the one hand because of the need for good general maneuverability, and on the other - having regard to the requirements of underwater warfare because of the need for easy steering below the surface. In contrast to other types of naval vessels, it is therefore not necessary to increase the size of submarines, to give them superiority over enemy vessels of the same category, since the attacks of submarines are directed against surface ships, usually much more powerful, whose offensive power is applied in a different way.
6.) If the size of the submarine is increased above these limits, in order, for example, to substitute for its proper use a greater suitability for minor (additional) operations, such as gunnery operations, its underwater fighting power is proportionately reduced. In that case, the ability of the submarine to go below the surface serves only as a protective measure, to enable it to evade the counteraction of the enemy.
7.) Compared with surface vessels of equal size, the submarine can stay a very long time at sea. In addition, its seaworthiness is unlimited, and it is in this respect in a stronger position than surface vessels of equal size. Both these considerations are of special importance in regard to its use in naval operations.
8.) As a result of the element of surprise by which it is characterized, the submarine - apart from direct naval successes which it is sought to obtain by its use - exercises a great influence on the military and strategical position, because the enemy must everywhere reckon with its appearance, and is influenced in a correspondingly high degree in his strategical decisions and military operations (detours, defensive measures, safety patrols, zigzag course).
9.) It must be required of the submarine that it shall be able to travel both on the surface and under water. For this purpose it requires two different systems of propulsion, the diesel motor for surface propulsion, and the "E" engine: electric motor for underwater propulsion. The need for this dual propulsion system doubles the weight of the engines which the submarine is forced to carry, and entails a corresponding reduction of the performance of the individual propulsion unit. This is the cause of the relatively slow surface and underwater speeds of the submarine as compared with surface warships. This is the chief weakness of the submarine, which is of fundamental importance for its tactical use.
10.) Other weaknesses of the submarine are its restricted underwater radius of action, its low position in the water, and its great vulnerability.
11.) The weaknesses of the submarine must be offset by clever tactics, unscrupulous use, and obstinate persistence even when the chances of success appear slender.
12.) Fundamentally, the part of the submarine in naval tactics is to operate alone, in accordance with its character and its principal task of carrying out, unseen, its annihilating attack on an adversary of considerably superior fighting strength.
13.) Consequently, there is no such thing as a concentration of submarines for the purpose of cooperating, and supporting one another, in a collective naval action.
A concentration of submarines can only have the object of a common tactical employment, but always without any distinct, close formal-tactical connection.
From the time the concentration goes into action, however, each submarine carries on the fight, as before, separately and individually, although, in such circumstances, reciprocal indirect support, as, for example, by simultaneous attack, is possible.
14.) The principal task of the submarine, which is strong in attack and weak in defence, is the undetected, and therefore surprising, underwater or surface torpedo attack.
In no circumstances must the commander of the submarine allow his attention to be diverted, by lesser tasks, from this chief purpose, unless priority is expressly ordered to be given to other than offensive operations.
15.) During every attack, situations may develop in which a continuation the attack appears to the submarine commander to be hopeless, or impossible. Only if the submarine commander, imbued with the determination to win, and unrelenting toward himself, conquers these feelings, will it be possible for him - in view of the few opportunities of attack which the war at sea will provide - to achieve any success at all.
16.) In all operations against the enemy, the commander of the submarine is entirely independent, and free to make his own decisions, unless special cooperation is called for.
Do not see danger everywhere and in everything, do not overestimate the enemy, do not always seek to place yourself in his position, do not assume that everything that is going on in the theater of war applies to yourself-these internal reservations and scruples are a sign of uncertainty, and of a negative attitude, which impairs your ability to reach a decision, and endangers the success of the operations.
Audacity and a readiness to take responsibility, coupled with cool, clear thinking, are the pre-conditions and the basis of success.
17.) Free [Paragraphs marked "free" are those left open for future additions under the particular subject heading where they are found.]
18.) Free
B. How to Prevent the Submarine from Attracting Attention.
19.) The chief value of the submarine is its characteristic ability, which it possesses in an exceptional degree, to attack without being seen, and thus to achieve the element of surprise. The precondition of success is surprise. If the submarine is seen by the enemy, it is deprived of almost every chance of success. The commander of the submarine must therefore make every effort to preserve the paramount advantage of surprise, as far as it is at all possible.
20.) In order to remain undetected, before and during the attack, the submarine must be neither sighted, nor sound-located, nor detected by ASDIC.
I. Action to be Taken by the Submarine, in Order not to be Spotted.
21.) In every situation, both on passage (or approach) and in launching the attack, the submarine must be guided by the motto: "He who sees first, has won!" Untiring vigilance of the look-out involves success and safety of the submarine, and is, therefore, at one and the same time, a means attack and defence.
Consequently, when operating on the surface, a sharp lookout should always be kept, systematically organized in sectors (examination of the horizon for ships, of the surrounding surface of the sea for periscopes, and of the sky for aircraft). The most dangerous enemy of the submarine is the aircraft, by reason of its great speed. Consequently, during daylight and on moonlit nights, the sky should be watched with special care.
22.) To keep a conscientious lookout tiring; consequently, the look-out should be punctually and frequently relieved. Sunglasses should be held in readiness for all members of the watch.
Particular attention should be paid to the sun sector, in order to be safe sudden air attack.
23.) The periscope should not be used in daylight, on the surface, except special circumstances (for example, in remote sea areas; also as under No. 24). It is the raised periscope on the surface that makes the typical submarine silhouette. Similarly, on submerging in daylight, the periscope should not be raised until the submarine is well below the surface. In the same way, the submarine should not surface during the day, before the periscope has been lowered.
24.) If, for urgent reasons, such as overhauling, it should become imperatively necessary to raise the periscope by day when the submarine is on the surface, the additional height of the raised periscope can be used in suitable weather to send up a look-out with binoculars, provided that surprise attacks by hostile airplanes are not to be anticipated. If the weather clear and the sea calm, advantage can be taken of the raising of the periscope, for an all-round view. On account of the relatively week magnification of the periscope, however, and of the almost inevitable vibrations and movement of the vessel, this seldom serves a useful purpose. The danger of betraying oneself by the raised periscope is greater.
25.) In clear weather, do not allow yourself to be seen on the dip of the horizon. Submerge, at the latest, when the top of the funnel of the sighted ship is visible in the dip of the horizon. Some warships, besides having lookout posts with binoculars on the mast, have range finders of great optical efficiency in the foretop. In clear weather, therefore, one should never be able to see more of the enemy than the tops of his masts. Anyone who can see more - i.e., who approaches nearer - automatically runs the danger of being sighted, himself, by the enemy.
It is better to submerge too soon than too late, and thus lose one's chance altogether. The limits of what is possible in various kinds of weather can only be learned by experience.
The look-out on merchant ships, and the danger of being sighted at night, are easily overestimated.
26.) If there is a danger of surprise attacks in sea areas efficiently patrolled hostile planes and warships, and especially if the submarine is engaged operations there that require it to be stationary, it must remain underwater from dawn to dusk.
27.) It may also be advisable to remain submerged in misty or foggy weather. In poor visibility, the approach of ships can be more easily detected underwater [from the sound of the ships' engines] by means of the hydrophone, than on the surface by the look-out.
28.) This possibility of using the hydrophone to help in detecting surf ships should, however, be restricted to those cases in which the submarine is unavoidably compelled to stay below the surface. The hydrophone must not lead to inactivity [passivity] underwater, which would be wrong; it is an auxiliary instrument and no more, and can never be a substitute for ocular perception and surface viewing. As soon as visibility allows, the, place of the submarine is on the surface. Otherwise valuable opportunities of attack are lost.
29.) The danger of a surprise attack exists, in particular, when the submarine comes to the surface, especially after traveling long distances at considerable depth. When coming up from a considerable depth, an all-round sound location should therefore be carried out at a safe depth, where the submarine cannot be rammed; i.e., at a depth of approximately 20 m, at "sound-location speed." Next, the submarine should go rapidly through the danger zone at periscope depth, with the periscope raised; careful all-round look-out with and without magnification - submersion up to 9 m, depending on the weather, then lower the periscope altogether (see No. 23) and surface at high speed. The manhole of the conning tower is opened as quickly as possible, and the commander - with, at the most, one man who is especially good as a look-out - goes up. It is not until the surface of the sea has again been examined with binoculars, in every direction, that the compressed air cells can be completely emptied of water.
30.) By careful supervision, the submarine should be prevented from leaving traces of oil (leaking oil tanks, etc.). Patches of oil may also be left behind when submerging, as a result of a residue of air in the compressed air cells. Consequently, the submarine should not remain near the place where it has submerged.
31.) After the submarine has submerged, the periscope can be shown in a low position, and left there, up to a distance of approximately 4 to 5,000 m from the enemy, according to the state of the weather.
At lesser distances, the "sparing" use of the periscope begins, that is to say, the periscope is frequently and intermittently shown, each time for a little while, in a very low position where it is almost always awash, while the submarine travels at low speed.
For rules for the use of the periscope when attacking, see Section II, C, No. 125.
32.) For the color of the periscope, a dull, dirty grey such as is used for the body of the submarine itself should be chosen, as this color is the least easy to detect in all conditions of light. Green paint, or stripes or checkered patterns, are very conspicuous in a poor light.
33.) Every aircraft sighted should be regarded as hostile until the contrary is proved.
34.) Submarines on the surface are not easily detected from an aircraft when the sea is rough, unless seen in their characteristic outline against the dip of the horizon. If the sea is calm, the track (wake) of the submarine is usually seen first from the plane, especially if the submarine is moving at speed.
35.) The submarine must endeavor to keep a sufficiently sharp look-out to be able to see the aircraft before it is spotted by the latter. It is then master of the situation, and will soon learn to decide whether it must submerge, or can remain on the surface; if it is not certain that the latter can be done, it is better to reduce the chances of success by a premature temporary submersion, or a retreat to greater depths to avoid being spotted by the aircraft, than to spoil the chance altogether by being spotted.
36.) In good visibility, it is possible to sight the plane in time. It is consequently right to remain on the surface in areas threatened from the air, and to keep the area under observation. More can be seen above water an below. In addition, by remaining below, valuable opportunities of attack may be lost.
37.) Conditions are different, in particular, in areas threatened from the air, when the submarine is engaged in operations that cause it to remain stationary in misty weather, with poor visibility and low clouds. In such circumstances it is right to remain submerged during the day, because, if it has surfaced, the submarine may easily be surprised by aircraft suddenly appearing in near sight, without being able to submerge in time, and reach safety.
38.) The submerged submarine is most difficult to spot from the plane when all its horizontal surfaces are painted very dark. All other bright objects on the upper deck, as, for example, the insulators of the net wire, must have a coating of dark paint. In case of need, paint which has crumbled, or been washed off during the operations, must be replaced; for is purpose, a quantity of dark paint should always be available during operations.
39.) A submarine painted in this way can only be spotted by an airplane, if the submarine is submerged,
a) when the sun is shining, and the sunlight penetrates the water below the surface; without the sun, the water is a dark mass, which hides all objects from view;
b) when the surface of the sea is not so rough - approximately from motion [sea] 2 to 3 upwards - that the continuous refraction makes it impossible to see below the surface, even when the sun is shining;
c) when the airplane is almost vertically above the submarine. Because of the high speed of the airplane, it is very difficult to spot a submarine moving under water.
The conditions described above - sun, rough sea, position of the aircraft in relation to the submerged submarine - are relatively more favorable or unfavorable for the airplanes in sea areas with exceptionally clear, or exceptionally turbid, water, for example, in the Mediterranean, and in the Baltic at the mouths of rivers. In sea areas where the water is clear, so that it is correspondingly easier to look into it from airplanes directly above, the submarine must therefore submerge, in good time, to a greater depth, in order not to be spotted.
40.) Even when the submarine is not traveling at speed, if the sea is smooth, the tracks [wake] of the screw [propeller] of the vessel, and of the periscope, may betray the submarine to the airplane. When there is a danger of air attack in such conditions, the submarine should therefore submerge in good time, diving to a considerable depth, except when the sky is kept under observation through the periscope.
41.) What to do in case of air attack: see Nos. 266 to 270....C. What to do in Case of Enemy Air Activity.
266.) For general rules of action in case of enemy air activity see Nos. 33 to 41.
In areas specially threatened by enemy air activity; the lookout should always be taken by the best members of the crew, the A.A. weapons should be ready for action, and manned, and the serviceability of the weapons should be ensured by frequent replacement and trials (firing tests).
267.) On passage, the safety of the boat is the chief consideration during operations, the attack. On passage, the submarine should therefore dive as soon as it is known that the enemy planes are trying to locate it (by radar or visual search; when attacking, it should not allow itself to be diverted from its purpose to every reconnaissance operation of enemy planes.
268.) Enemy planes which have located the submarine by radar or visual search, attack, wherever possible, out of the sun, or on the course of the submarine or the direction of diving, and turn on their headlights at night shortly before attacking.
269.) Fundamental rules: When an aircraft not flying in the direction of the submarine is sighted in the distance, do not in general submerge, but turn away, show the narrow outline, and reduce speed, so that the line of foam in the wake of the submarine disappears.
If an aircraft sighted in the distance is flying toward the submarine, submerge at once.
If a plane is sighted at night only when its lights go on in flying over, or passing near the submarine, so that it must make another run in order to attack, the submarine should submerge immediately.
If an aircraft flying toward the submarine is sighted so late that the submarine cannot get down in time, do not submerge, but fight off the plane with A.A. weapons. After the first attack, submerge at once, before the plane can make another run.
270.) After submerging during an attack, always go down at Once to depth A, and double.
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Quote:
Originally Posted by Huno41
So would it be better to go decks awash instead of snorkeling until anti-radar coatings are available?
Quote:
Originally Posted by FUBAR295
Better to snorkel if available in my opinion.
And even then your in trouble:
Quote:
The counter-countermeasure eventually arrived in the form of ASV Mk. III, a 10-centimeter radar system which used a nose-mounted parabolic antenna rather than the dipole array used on earlier 1.5-meter sets. Centimetric radar was made possible by the invention of the cavity magnetron by J.T. Randall and H.A.H. Boot. Unfortunately the development of ASV Mk. III was seriously delayed by the parallel development of H2S, a radar bomb-aiming system for Bomber Command. H2S also required centimetric resolution and cavity magnetrons. These were in short supply. Thanks to aggressive politicking by “Bomber” Harris H2S received first priority, thus pushing deployment of ASV Mk. III, undetectable by Metox, into early 1943. By May Allied shipping losses plummeted from 400,000 to 100,000 tons per month. U-boat sinkings also increased. Donitz ordered his captains to fight it out with attacking aircraft, no doubt contributing to the sinkings.
The next step in anti-submarine radar was naturally an even shorter wavelength set with better resolution and longer range. However, competition with Bomber Command for R&D personnel and scarce electronic components caused the Mark IV and Mark V projects to be canceled.
The Kriegsmarine eventually adopted a countermeasure to ASV Mk. III called Naxos. However, by that time a new ASV version, Mark VI, was in development. This system was similar to the previous Mark III, but with a wicked twist designed to tempt Naxos-equipped u-boats to remain surfaced even though a 10-centimeter radar transmission had been detected. ASV Mk IV had a signal attenuator which decreased the transmitted power output as the range to the target decreased. From the point of view of the Naxos operator, this looked exactly like a Mark III-equipped Coastal Command plane flying away from the u-boat rather than toward it.
In 1944 a new 3-centimeter H2S system was developed. Once more Bomber Command tried to hog the new radar technology for itself alone, but directives from Churchill allowed Coastal Command to share the bounty. The result was ASV Mk. VII. Originally intended to defeat improved radar detectors with directional capability the new system came online in time to confront the latest addition to Donitz’s stable — the Type XXI Elektroboot. This wonder-weapon was designed to run submerged for extended periods, days, even weeks at a time. The Type XXI used a schnorkel to provide air to its diesel engines, allowing the boat to charge its batteries while running at periscope depth. The radar cross-section of a schnorkel was too small for 10-centimeter radar to see it in any kind of typical sea condition expected in the North Atlantic. However, the Mark VII radar could just make out a schnorkel under ideal conditions. Thankfully, the Elektroboot appeared just when manpower and fuel shortages conspired to strangle the new u-boat force “in the cradle”. There were just too few trained crews available to make the Type XXI anything other than a deadly nuisance rather than a weapon able to reserve the tide of war. Essentially an air intake and chimsey that allowed the sub to keep using its diesel engines, while submerged. Only the periscope and snorkel would be above the water. For a while, this improved their situation. But then the allies developed a radar that could detect the small snorkel, and now the situation was even worse than before, as sub could be attacked by aircraft that they couldn't see coming as they were submerged. Essentially an air intake and chimney that allowed the sub to keep using its diesel engines, while submerged. Navy sub hunters also introduced some new weaponry to the Bay Patrol. Their Liberators now carried sonobuoys, air-delivered sonar transmitters able to detect U-boats moving under water. Once the sub’s location was marked, PB4Y-1 crews could then drop a Zombie, also known as the Mk 24 acoustic homing torpedo, on their unsuspecting prey. Furthermore, the “MADCATS” of VP-63 operated their Magnetic Anomaly Detector-equipped PBY Catalinas over the Biscayan gulf for a time. Airmen used this apparatus to identify the gravitational disturbance caused by a submerged metal object like a U-boat and then dropped depth charges on the contact. [COLOR="Lime"]
So would it be better to go decks awash instead of snorkeling until anti-radar coatings are available?
Snorkeling if desired to play historically correct. Make sure you have a rwr with it.
Also iirc the sub coatings don't work in the game. Someone correct me if wrong please.
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Since I play the 'total immersion' game, a schnorkel gives me a terrible headache. My ears pop everytime the wave hits the head of the schnorkel and the trapped diesel fumes are awful! It even gets into the breakfast Bratlingspulver!
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"Only two things are infinite; The Universe and human squirrelyness; and I'm not too sure about the Universe"
And even then your in trouble: Doenitz didn't just lose the Battle of the Atlantic; as Churchill put it : He lost the "wizard war"too. https://codenames.info/operation/musketry/
But it is the better choice of two evils.
__________________
Good judgment comes from experience. Unfortunately, the experience usually comes from bad judgment.
Decks awash was more commonly used historically than is practical in any of the Silent Hunter games, I've read several war accounts from U-Boat captains and crew and everyone mentions travelling at "decks awash" though they don't necessarily state it U-Boats are frequently referred to as only having the conning tower above water, especially for night attacks in the early war and for boats without Schnorkel's before late 1944.
12-25-20, 02:06 AM
Merry Christmas to all and to all a good night
a schnorkel gives me a terrible headache. My ears pop everytime the wave hits the head of the schnorkel and the trapped diesel fumes are awful!
It even gets into the breakfast Bratlingspulver!
if yer 'friggin' around!
https://www.subsim.com/radioroom/sho...69&postcount=1 
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