User:Xyl 54/sandbox 15

Sandbox 15

Page History

Title	Written	Posted	Deleted
TMWNW	Aug 2020	Oct 2020	Oct 2020
Completed	Oct 2020	-	-
Electroboat	Oct 2020	-	-
Amerikabomber	Oct 2020	-	-
Walter boat	Jan 2021	-	-
Test section	Jan 20121	-	Jan 2021

Completed

• TMWNW (draft Aug 20) to William Martin (Royal Marine officer), sept 20

Electroboat

Introduction

Original

Re-write

An elektroboot ("electric boat" in German) was a submarine designed to operate entirely submerged, rather than as submersibles that could submerge as a temporary means to escape detection or launch an attack. . OP

... (The term "Electroboat" (Blair II, p. :Milner p. :The Electroboats uboat.net page) ... while retaining surface manouverability. The effectiveness of Allied Anti-Submarine Warfare techniques, particularly the use of aircraft as A/S weapons, led the German Navy to look for a U-boat design that emphasized underwater performance. After experiments with exotically-fuelled Walter boats showed little progress, German designers turned to tired and tested solutions/technologies, such as streamlining and increased battery capacity for high underwater speed, and the use of airmasts (or schnorkel) for re-charging batteries while submerged. The production process for the electroboat was also revolutionized, relying on pre-fabrication to hasten the building process. However problems implementing this, and the rush to start production before the prototype boats had been built and tested, led to the first batch of electroboats being unfit for operational use; more than a hundred of these boats were relegated to training. Meanwhile Allied intelligence had learned of the plans for the electroboats and began to develop counter-measures; the submarine Seraph was re-conditioned as a high speed target for A/S exercises in the summer of 1944 and was operational by Sept 44. Exercises over the next few months (showed that while a high underwater sped was possible, the noise produced by cavitation made it possible for /two ships working together/ to track the target; above 9 knots/suggested some counter-measures, including an... Trials also pointed to an increased role for passive sonar measures (Milner p251-4 In the end only two Type XXI and six Type XXIII submarines made operational patrols during 1945. From January some nine patrols were made, resulting in/in which some five allied ships were sunk Milner points out that the official historian opined that the Allies never mastered the electroboat menace/threat (though he also states that Allied ASW commanders might have wanted the conflict to last a little longer, to enable them to do so). He concludes that while the electroboats might have created much drama, and significant losses, they were never going to change the outcome of the war. . RJ

Background

Original

Re-write

*History Even before the second world war the rocket designer Hellmuth Walter had been advocating the use of hydrogen peroxide (known as perhydrol) as a fuel. His engines were to become famous for their use in rocket-powered aircraft—notably the Me 163 Komet—but most of his early efforts were spent on systems for submarine propulsion. In these cases the hydrogen peroxide was reduced chemically and the resulting gases used to spin a turbine at about 20,000 rpm, which was then geared to a propeller. This allowed the submarine to run underwater at all times, as there was no need for air to run the engines. The system also used up tremendous amounts of fuel, and any boat based on the design would either have to be huge or have limited range. Thus the system saw only limited development even though a prototype was running in 1940. But when problems with the existing U-boat designs became evident in 1942, the work was stepped up. Eventually two engineers identified a solution to the problem. Instead of running the submarine entirely on the perhydrol, they used it just for bursts of speed. Most of the operations would then be carried out as with a normal boat, using a diesel engine to charge batteries. However while a conventional design would use the diesel as the primary engine and the batteries for short periods of underwater power, in this case the boat would run almost all the time on batteries in a low-speed cruise, turning on the perhydrol during attacks. The diesel was now dedicated entirely to charging the batteries, which it needed only three hours to do. The perhydrol design suffered from several design flaws which were not fixed before the end of the war. As an intermediate solution, the perhydrol propulsion system was dropped in favour of a conventional diesel/electric solution, but retaining the streamlined hull-shape. The battery capacity was increased significantly along with fuel stores, and the boat was designed to operate underwater for long periods. . OP

History== ... > change heading to Walter boats== Background== Submarine design, more so than with other warship types, is a product of the design choices and compromises made. Having to operate into different media, designs can emphasize surface or underwater performance; but will focus on one only at the cost of the other. During the First World War German U-boat design focused on the double-hulled submersible, with good surface performance, which suited their main role/employment as commerce raiders. By contrast, the US Navy, whose Holland-type submarines emphasized underwater performance, had been surprised and alarmed by the appearance of German U-boats operating of the coast of the United States(Halpern p336); their own submarines being incapable of crossing of crossing the Atlantic unescorted.(Conway p141) Similarly the Royal Navy, whose command of the sea and blockade had swept German commerce from the seas, had little need for commerce raiding submarines: However its submarines, which also focussed on underwater performance, were well suited for an anti-submarine role. This culminated in the R-class, the first submarine designed for a hunter-killer role, with high underwater speed, and superior hydrophone equipment. Prior to the Second World War German U-boat design followed on from the U-boats of the first; its Type I and II designs were improvements of the 1918 Type UBIII boat. By 1939 the German Navy again had a fleet of submersibles suited for a war on commerce, able to range far and wide as commerce raiders. However by mid 1942 Allied ASW technology and tactics had turned the tide was against submersible: Allie ASW vessels, which had lacked surface radar, could now find surfaced U-boats, and Allied aircraft, which had lacked both range and effective weaponry, could now find and destroy U-boats found on the surface. This led to the demand for a U-boat with improved underwater performance, to negate the ASW advantages the Allies now held. . RJ

Design

Original

Re-write

Electric U-boats== The result was the "Elektroboot" series, the Type XXI U-boat and a short range Type XXIII U-boat, finalized in January 1943 but with production only commencing in 1944–1945. When under water, the Type XXI managed to run at 17 knots (31 km/h; 20 mph), which was faster than a Type VII running full out on the surface and almost as fast as the ships attacking her. After the war, tests carried out by the United States Navy on two captured Type XXIs showed they could outrun some ASW ships by going in the direction of heavy seas. (The US Navy's first nuclear-powered submarine, USS Nautilus (SSN-571), used a modified Type XXI hull shape.) For most of the trip it ran silently underwater on batteries, surfacing only at night, and then only to snorkel depth. Weapons were likewise upgraded, with automated systems allowing the torpedo tubes to be reloaded in less than one-fourth of the time, firing homing torpedoes that would attack on their own. Even the interior was improved: it was much larger and fitted with showers and a meat refrigerator for long patrols. . OP

Design== In the late 1930’s German designer Hellmuth Walter had developed a high-speed submarine using Perhydrol (a type of rocket fuel); while trials were impressive the practical difficulties were too great to overcome in war-time, so German designers opted for tried and tested technologies to improve underwater performance. High underwater speed could be achieved by streamlining the submarine’s hull, and increasing electric power by increasing battery capacity. This had been demonstrated by the RN with its R-class hunter-killer submarines at the end of WWI, and was employed by the IJN in its experimental No.71 high speed submarine and its Ko-hyoteki midget submarines, both of which could top 19 knots underwater. Table=== Also, a means to reduce the need to surface was to employ an air-mast, or schnorkel, to enable the submarine to draw in air while at periscope depth. A common feature of pioneering submarines, the airmast was developed in the 1920’s into the schnorkel by the Dutch Navy. By combining these two technologies in one vessel the German navy was able to produce a design that rendered much of the Allied ASW effort useless. / obsolete. There was a cost, in design terms, of these two innovations. The increased battery capacity required for the increase in electrical power meant a larger vessel for the same offensive strength; The ocean-going Type XXI was almost a third larger than the comparable Type IX (1600t to 1100t surface displacement) for the same/a similar range ( and armament (6 torpedo tubes and 23 torpedoes; the type IX carried 24); while the coastal Type XXIII electroboat, with a similar size to the Type II (234t to 251t for the Type IIA) carried only two torpedoes compared to the Type II’s 6.(Conway Streamlining reduced the submarines sea-worthiness on the surface, leading to a surface speed no better than/ 2-3 kn slower than  that of the equivalent standard U-boat designs. Table=== Type VII = 17.7 kn surface (7.6 sub Type IX = Type II = 12-13kn surfaced (7kn sub . While ... the schnorkel (or "snort" (Blair)) allowed the electroboat to renew its air supply and recharge its batteries while submerged it was still dependent on contact with the surface, and on surface conditions, to do so. In addition schnorkelling was both tricky and unpleasant: it required considerable skill to maintain trim and keep the schnorkel/snort head above the surface without raising it so high that it became detectable, while ducking the head underwater as the diesel engine was running led to the engine drawing air from inside the submarine/U-boat, with drastic results on the crew within. Herbert Werner in his book Iron Coffins gives a graphic description of both the difficulties operating the snort and of the effects on the crew. Quote A further drawback of running the diesel engine underwater while using the snort was that it significantly increased the U-boat’s noise signature, while at the same time deafening the U-boat’s own hydrophone array, making it vulnerable to any ASW vessels nearby. . RJ

Construction

Original

Re-write

(Construction) The design was to be produced in two versions, primarily the Type XXI, and lesser numbers of the smaller Type XXIII. Both were much larger and more difficult to build than the existing designs, the Type XXI taking some 18 months. Mass production of the new type did not really get started until 1944 and subsequently only one combat patrol was carried out by a Type XXI before the war ended. This patrol is considered controversial. According to some sources, the U-2511 did not make any contact with the enemy. Another version suggests that the U-boat did make a contact with HMS Norfolk of the Royal Navy, but did not fire as the captain had already received orders of surrender. A number of boats were commissioned into Allied navies after the war for research purposes, and one into the Bundesmarine of post-war Germany. . OP

Construction== Two other decisions regarding innovations in the electroboat construction promised much but eventually had unfortunate consequences. The first was the decision to go into full production without producing prototype vessels first. This promised to get a head start on building up a sizeable electroboat fleet to return to the Atlantic campaign. The first boats were ordered in ? Jan 44, with a delivery date in November that year. However when the first boats underwent trials it became apparent they had severe shortcomings, such as structural defects and design flaws. Blair notes . . As a result the first 100 or so electroboats were unfit for operational use, and were relegated to training flotillas. Of 68 Type XXIII boats completed only 5 made operational patrols in the first 5 months of 1945, while of the 118 Type XXI’s only two sailed on patrol in the last week of the war. The second innovation was to adopt a modular approach to construction, pre-fabricating the boats in sections before bringing them together for assembly. This method had been used to great effect by the American shipbuilders to mass-produce merchant ships and escorts in their hundreds for the Atlantic campaign. The German (pre-fab) experience was less successful for several reasons First, with what Conway refers to as Nazi Germany’s characteristic mix of efficiency and muddle, her skilled shipwrights in German shipyards continued to produce obsolete Type VII U-boats, while the new electroboats were being built by inland workers with no experience in shipbuilding. Second, Roessler reports that in the pre-fabrication process, where components had to be merged together on a strict timetable, companies were given orders with ill-defined delivery dates.(Roessler) (Once delivered, structural flaws were apparent, such as ill-fitting modules and inadequate welds, leaving the early electroboats with a lesser dive capability than existing U-boats, Third/Second, while the US was immune to aerial bombing, German infrastructure and transport network was subject to daily bombardment, leading to delays and bottlenecks as component manufacturers lost production or fell behind. When the canal system was put out of action in September 1944, in some cases completed electroboat modules due for delivery by barge had to be re-cut into smaller components for transport by rail, negating much of the advantage pre-fabrication conferred. Once delivered …. Blair (vol I px, xi) lists poor structural integrity ...Electroboats/ the Type XXI components were fabricated by 32 different companies, most with little or no experience in submarine building. The 8 main components were found to be crudely made and did not fit properly. The pressure hull was weak and could not stand sea pressure at the expected depths, or against the pressure of underwater explosions. The Germans reported that hulls could fail at simulated depths of 900 feet.?the RN reported failure at 800 feet, less than the dive depth of conventional U-boats (the planned dive depth was 1200 feet, twice the usual depth for allied submarines and below the maximum for allied depth charges underpowered diesel engines .. new diesels designed with suoercharger for the required power; we  built the system so poorly designed and manufactured the supercharger could not be used. Result in slower surface speed and longer time foe recharging impractical hydraulic system ..much of the hydraulic gear was too complex and delicate, and located outside the pressure hull, vulnerable to salt water corrosion, and could not be repaired from inside the pressure hull imperfect and hazardous snorkels ...Snorkelling as a nightmarish experience; even in moderate seas the snort head dunked often, leading to an influx of salt water, despite the valves closing, and/ while the diesel would not only draw in the air from the boat, but would also release exhaust, causing gases such as carbon monoxide to build up. . RJ

Operational use

Original

Re-write

only one combat patrol was carried out by a Type XXI before the war ended. This patrol is considered controversial. According to some sources, the U-2511 did not make any contact with the enemy. Another version suggests that the U-boat did make a contact with HMS Norfolk of the Royal Navy, but did not fire as the captain had already received orders of surrender. A number of boats were commissioned into Allied navies after the war for research purposes, and one into the Bundesmarine of post-war Germany. . OP

Operation and counter-measures The electroboat was designed to allow the boat to remain submerged throughout its patrol if necessary. By 1944 Germany / the KM already had more conventional U-boats (mainly Type VII sea-going vessels) fitted with snorkels that could  submerged throughout their patrols if necessary; these would mainly move on electric power, using their snorkels about 3-4 hours a day to run their diesel engines to recharge the batteries and refresh the air; however these were limited by their design to an underwater cruising speed of about 5 knots, which limited their operational range. BdU had been forced to bring the U-boat Arms operations back the from the Atlantic and closer to base, to avoid paralysingly long transit times. The medium range Type VIIs, which had ravaged the North Atlantic, were by mid-1944 operating mainly in an the inshore campaign in the waters around the UK/ … The long-range Type IXs which previously operated down to West and South Africa were now restricted to the coast of US and Canada, while Type VIIs limited also by n habitability problems, able to operate only  in the waters around the UK. (Milner p.231 The design of the new electroboat allowed a cruising speed double that, with a corresponding increase in range, while the high underwater speed would allow the electroboat to sprint away from ASW vessels if detected. . Could cover 300 miles a day at 5 knots, ie. 3 times farther and twice as fast as older type boats (Milner p.252 Increased efficiency and improved habitability was expected to enable the Type XXI to patrol to Cape Town and back (Milner p.252 . Use of more modern pattern-running torpedoes could be launched from deep-running  fire-and-forget . Improved sensors and  more modern pattern-running torpedoes meant XXI could lie submerged under a convoy and / engage a convoy without venturing near the surface (Milner 251-2 . disadvantage was the danger of friendly fire damage meant U-boats forced to act alone/ no / precluded wolf pack operations  (Blair Allied intelligence had become aware of the electrobaot and Walter boat designs in 1943. In the summer of 1944 the British submarine Seraph was converted, by increasing battery capacity and streamlining, into a high-speed ASW target. Trials and exercises with Seraph offered some hope. They showed that operating at high speed underwater increased cavitation noise; found they could track a Uboat by hydrophone (passive sonar) . Counter-measures== (From Milner Battle of the Atlantic) Operational research estimated electroboats would be five times harder to find than older types and once found difficult to attack because of high underwater speed. Most ASW vessels built for endurance rather than speed and to merchant standard/ at merchant yards; only the new Captain class frigates were able to outrun Type XXI electroboat also, running at high speed deafened the ASDIC echo obscured by sounds of water across the dome  at speeds above 12-15 knots (Milner 253 . But Problem  studied in runup to D-Day, in expectation of landing fleet/ Neptune fleet being attacked by Walter boats. Never happened, but in summer of 1944 Seraph converted… and in October exercises carried out. At slow speeds (4kn or below Seraph presented normal ASDIC target; up to nine knots active contact could be maintained. At high speed, cavitation from propellers enabled target to be tracked by hydrophone at ranges up to 4-5000 yards, so contact could be maintained by two ships working together (one listening and tracking,, the other sprinting ahead/ and taking station ahead, before swapping roles/exchanging roles) though single ship easily shaken off/evaded. Based on this ORS recommended developing hydrophone sensing (passive sonar) use of sonobouys. As electroboats still tied to the surface by the need to snorkel, it was believed Swamp tactics/hunts to exhaustion  could s till be effective, though over a much larger / larger and more complex, needing larger forces. However while Seraph showed noise in the 9-12 knot range, USN post-war tests with captured XXIs showed lower noise signature; ‘at 12 kn noise similar to US fleet sub at 6;  up to 10kn extremely quiet, some cavitation above 10kn’(Milner p.254)  and required at least 7 ships for an effective search.<Milner p.254 . Allies never got to grips with these latest in U-boat technology; conclusion by Official historian we never achieved full mastery over U-boat However Milner suggests a number of ASW officers  would have liked the war to continue a few months longer to enabled them to get a grip of the problem. (Milner p.255) Record of eboats patchy; production problems meant most of XXIs built were unfit for operational use. Only 2 made operational patrols, in May 45. In 5 months of 1945 some 6 XXIIIs made patrols, none were found. U-2511 and Norfolk: see The Feint Attack at DUM: U-2511 and the myths around the feint attack on HMS Norfolk. Conclusion== Impossible to know how eboats would have affected the Atlantic war, but by 1945 campaign was not Germany’s to win. May have caused much drama and losses but change to influence the outcome of the war was long past.(Milner p.255 . . RJ

Opinion

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(www.historynet.com  Phantom of the Deep: Germany’s Underwater Wonder Weapon claims .The target production goal was to have some 1,500 examples in service - a number which no doubt would have devastated Allied navy and marine efforts in the region - and a target production goal of three submarines per week was envisioned, again aided by the boat's modular design.) . OP

Claim (from <www.historynet.com  Phantom of the Deep: "The target production goal was to have some 1,500 examples in service" Reply (notes from electroboat a ) response: (usual wehraboo wank!)/ production of 3 per week is 12 per month; 1500 would take 10 and a half years to build, Ignoring the fact that the Soviets were at the Brandenburg Gate/about to roll into Berlin and the western Allies were poised to cross the Rhine. Addendum Also, 12 per month is less than the 20 per month achieved earlier in the war (? ref) but also less than the loss rate; in the first 4 moths of 1945 the KM lost 86 boats (Neistle App 2, p.202) a loss rate of over 20 boats (and their experienced crews) per month. To avoid running out of crews the UbW would have had to withdraw completely, and feed in new boats at a rate of 12 a month, giving plenty of time for the Allies to develop counter-measures (or end the war by dropping an A-bomb on Berlin/Munich, or somewhere) . RJ

Electric boats (re-write)

Original

Re-write

Electric U-boats== The result was the "Elektroboot" series, the Type XXI U-boat and a short range Type XXIII U-boat, finalized in January 1943 but with production only commencing in 1944–1945. When under water, the Type XXI managed to run at 17 knots (31 km/h; 20 mph), which was faster than a Type VII running full out on the surface and almost as fast as the ships attacking her. After the war, tests carried out by the United States Navy on two captured Type XXIs showed they could outrun some ASW ships by going in the direction of heavy seas. (The US Navy's first nuclear-powered submarine, USS Nautilus (SSN-571), used a modified Type XXI hull shape.) For most of the trip it ran silently underwater on batteries, surfacing only at night, and then only to snorkel depth. Weapons were likewise upgraded, with automated systems allowing the torpedo tubes to be reloaded in less than one-fourth of the time, firing homing torpedoes that would attack on their own. Even the interior was improved: it was much larger and fitted with showers and a meat refrigerator for long patrols. The design was to be produced in two versions, primarily the Type XXI, and lesser numbers of the smaller Type XXIII. Both were much larger and more difficult to build than the existing designs, the Type XXI taking some 18 months. Mass production of the new type did not really get started until 1944 ...and subsequently only one combat patrol was carried out by a Type XXI before the war ended. This patrol is considered controversial. According to some sources, the U-2511 did not make any contact with the enemy. Another version suggests that the U-boat did make a contact with HMS Norfolk of the Royal Navy, but did not fire as the captain had already received orders of surrender. A number of boats were commissioned into Allied navies after the war for research purposes, and one into the Bundesmarine of post-war Germany. . OP

Electric boats== XXI XXIII Performance== (unreferenced; see comparison table Nautilus claim; not backed by nautilus article (attr. To GUPPY) Electric boats== Operational history== (add patrols table Fate== (add fates table) . RJ

Refs, Links, Categories

Original

Re-write

References External links {{ {{DEFAULTSORT: [[Category: . OP

References: Clay Blair : Hitler's U-Boat War Vol II: The Hunted 1942-1945 (1998) ISBN 0-304-35261-6 R Chesnau, ed. Conway's All the World's Fighting Ships 1922–1946 (1980) Conway Maritime Press, Greenwich, UK ISBN 0-85177-146-7 Marc Milner : Battle of the Atlantic (2003/20011) The History Press ISBN 978 0 7524 6187 8 Axel Niestle  : German U-Boat Losses during World War II (1998). ISBN 1-85367-352-8 Peter Padfield : War Beneath the Sea (1995) John Murray (Publishers) ISBN 0-7195-5168 4 Anthony Preston : The World's Worst Warships (2002) Conway Maritime Press ISBN 0 85177 754 6 Eberhard Roessler : The U-Boat: The Evolution and Technical History of German Submarines (1981/2001) Cassel & Co. ISBN 0-304-36120-8 Stephen Roskill : The War at Sea 1939-1945 Vol III, pt I (1960).ISBN (none) VE Tarrant : The U-boat Offensive 1914-1945 (1989) Arms & Armour ISBN 0-85368-928-8 External links: (no change needed for this part) Categories {{DEFAULTSORT: ' Image [[ . RJ

Tables

Comparative underwater speeds (different navies)

Name	Navy	Built	Speed (submerged)	Speed (surfaced)
[[British R-class submarine	RN	1918 (12 units)	14kn	9.5kn
[[Submarine No.71	IJN	1938 (1 unit)	21.25kn	13.25kn
[[German submarine V-80	KM	1940 (1 unit)	28kn	?
[[Submarines of the Imperial Japanese Navy#Ko-Hyoteki Type|KHT = [[Type A Kō-hyōteki-class submarine	IJN	1940 (50 units)	19kn (prototype = 25 kn)	?
[[Submarines of the Imperial Japanese Navy#Sentaka Type|ST = [[I-201-class submarine	IJN	1945 (3 completed)	19kn	15.75kn
[[Type XXI submarine	KM	1944-5 (118 completed)	17.2kn	15.6kn
[[Type XXIII submarine	KM	1944-5 (62 completed)	12.5kn	9.7kn

Comparison: conventional U-boat/electroboat

Type	Displacement	Speed	Range	Armament
Type II	251t	12-13kn surfaced /7kn sub	.	2TT, 6 torpedoes
Type XXIII	234t	.	.	2 TT, 2 torpedoes
Type VII	600t	17.7 kn surface (7.6 sub	.	6TT,
Type	(no equivalent)
Type IX	1100t	.	.	6TT, 24 torpedoes
Type XXI	1600t	.	.	6TT, 23 torpedoes

Production numbers

Type	Ordered	Completed	under construction	cancelled
Type XXI	828	118	33	416 (ref. Niestle p159)
Type XXIII	378	62	6	258 (ref. Niestle p173)

• Type XXI: Numbers = U-2501-2762 , 3001-3288, 3501-3684
• 'Type XXIII Numbers U-2321-2460, 4701-4891

+ Type XXI: construction
Yard	Order	Completed	Building	Not started	Contract changed	Cancelled
Deschimag	176	41	.	.	.	.(Niestle p. 159)
B&V	262	47	.	.	.	.
Schichau	184	30	.	.	.	.
Vulkan	206	0	.	.	.	.

+ Type XXIII production
Yard	Order	Completed	Building	Not started	Contract changed	Cancelled
Deutsche Werft, Germaniawerft , Ansaldo CRDA DW Toulon DW Nikolayev Linzer	.	.	.	.	.	.(orders p.26-7, notes p.221-2)
Total	378	62	6	5	47	258 (Niestle p. 173)

Type XXIII patrols

U-bt number	patrol/out	return	successes
U-2324	29 Jan	24 Feb	none (ref Blair p760-1  (App 2)
U-2322	6 Feb	3 Mar	1= 1317t (damaged)
U-2321	12 Mar	13 Apr	1= 1406
U-2324	3 Apr	25 Apr	1= 1150
U-2322	5 Apr	5 May	none
U-2329	12 Apr	26 Apr	none
U-2326	19 Apr	28 Apr	none
U-2336	1 May	14 May	2= 4669
U-2326	4 May	? → UK	none

Type XXI patrols

U-bt number	patrol/out	return	successes
(none listed)	(other sources say 2511, 3008)	...	(ref Blair p760-1  (App 2)

Electroboats Scuttled

Type XXI : 2501-52 = 31: 3001-44 =33: 3501-30 =22: total 96 (ref Blair p815 (App 18)

Type XXIII : 2327-71 =22: 4701-3= 3: total =25

(Type XVII : 792-5 =4: XVIIB : 1405-6 =2 total 6)

.Electroboats surrendered

Type XXI : 2502-, 3008- =12 (ref Blair p818 (App 19)

Type XXIII :2321-43 =21

Walter boats

Background

Original	Re-write
Electroboat#History == Even before the second world war the rocket designer Hellmuth Walter had been advocating the use of hydrogen peroxide (known as perhydrol) as a fuel. His engines were to become famous for their use in rocket-powered aircraft—notably the Me 163 Komet—but most of his early efforts were spent on systems for submarine propulsion. . OP	To be added RJ

Table

Walter boats

Type	Yard	Number	Order	Completed	Building	Not started	Cancelled after kl	Cancelled bf kl
V-80	Germania	V-80	1	1	-	-	-	(Niestle p.150)
V-300	Germania	U-791	1	-	1	-	-	- (N p.151)
Wa201	B&V	792, 793	2	2	-	-	-	- (N p.152)
Wk202	Germania	793-4	2	2	-	-	-	- (N p.152)
XVIIB	B&V	1405-16	12	3	2	-	1	6 (N p.153)
XVIIG	Ger	1081-92	12	-	-	-	-	12 (N p.155)
XVII K	Ger	798	1	-	1	-	-	- (N p.156)
XVIII	Ger	796-7	2	-	-	-	2	- (N p.157)
XXII	Howaldt	1153-4	2	-	-	-	-	2 (N p.172)
XXVI W	B&V	4501-4600	100	-	2	2	-	96 (N p.180)

Unfinished projects

Walter boats (none beyond planning stage)

Type	type	disp	notes	ref
XXIV	ocean-going	1800	-	(Roessler p.341)
XXVI	sea-going	950/1050/ 842	A, B, W	(R p.341)
XXVIII	coastal	200	indirect walter process	(R p.341)
XXXV	ocean-going	1000	oxygen-fuelled	(R p.342)
XXXVI	ocean-going	1000	oxygen-fuelled	(R p.342)
Schwertal	midget	11	-	(R p.343)

Amerikabomber

The Amerikabombers: some comparisons

Aircraft (date of introduction, numbers)	Details (range ml/km)
Heinkel 277 (no prototype)	range (main)= 3,728 mi, up to 11,100 km/6,900 mi in Amerikabomber role
Junkers 390 (2, Oct 43)	range= 8000km/ 4970mi combat range= 9704km/ 6030mi (reconnaissance mission) cr.= 9254 km/ 5750mi with 1930kg/ 4255lb bomb load (bomber mission)
Me 264 (3, dec 42)	range= 15000km / 9300mi
FW Ta400 (no prototype)	range= 9000km / 5600mi.
...	...
B-17 (12,731, july 35)	range 3219km/ 2000mi;
B-29 (3970, Sept 42)	range 5239km / 3290mi (ferry range =9000km/5600mi
B-36 (384, Aug 46)	range 6413km/3985mi (ferry range 16.000km/10,000mi

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Test section

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Fishcutter incident

Source: Original report at wlb.stuttgart.de

Original	Translation
Geheime Kommandosache Chefsache Abschrift Gefechtsbericht über die versenkung von vier danischen fischkuttern . Original	secret commando operation matter for the boss/top priority copy Combat report on the sinking of four Danish fishing trawlers . Translation

Original

Translation

in der nacht zum 23-24 Februar 1940 wurde eine stichfahrt mit ORG auf Weg 1 durchgefuhrt. wind SSW 2-3 seegang 1 starker nebel, zeitweise spruhregen, sicht knapp 200m. Funkschaltung: Kustenlangwelle. Kurs nach 21 Uhr wurde vom F.T. Personal Morsezeichen in nahe des wellenbereiches der kustenlangwelle aufgefangen. nach kenntnisnahme dieser tatsache wurde die planmassige uberwachung des F.T. verkehrs der naheren umgebung vergenommen. N.H.G. wurde gleichfalls besetzt. Sonderbericht uber F.T. ist als anlage I beigefugt. . Original

On the night of February 23-24, 1940, an ORG run was made on route 1. Wind SSW 2-3 swell 1 heavy fog, occasional drizzle, visibility almost 200m. Radio control/circuit: coastal long wave. Course after 9 p.m. was given Morse code was intercepted by the F.T. personnel near the wave range of the coastal long wave. After this fact became known, the scheduled monitoring of the F.T. traffic in the surrounding area was recorded. N.H.G. was also occupied. Special report on F.T. is attached as Appendix I. . Translation

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0014 uhr: zwo weisse lichter voraus (ein zu anker liegender grosserer fischkutter) 0015 uhr fahrzeug wurde mit handscheinwerfer beleuchtet, da die sicht nicht mehr als 150m betrug. Es handelte sich um den danischen fischkutter Ejjam aus Ebsbjerg E92. Standort M1. Qu.6826 rechte kante. 0017 uhr. Stichfahrt wurde fortgesetzt. nachdem kutter eben ausser sicht gekommen war, wurden etwa vier bis funf U-T morsezeichen gehort. Buchstaben konnten nicht ausgemacht wersen, da sie sehr schnell und verwischt abgegeben wurden. 0040 uhr. Ein fischkutter vor anker 100m querab gesichtet. Zur gleichen zeit mit N.H.G. einen langeren ton und drei kurz aufgefangen. Die abgelaufene strecke zwischen den kuttern betrug 4 sm. 0045 uhr. Gerat wurde aufgenommen, de ich den eindruck hatte, dass die durchlaufzeit von M.1 von ersten bis zwoten kutter abgestoppt worden war. Mein entschluss war daraufhin, die beiden kutter zu versenken. Es musste lautlos erfolgen, um abgabe einer F.T.-nachricht bezw. ein entkommen eines kutters im dichten nebel unbedingt zu verhindern. Dieses war nur durch rammstoss moglich. Deim aufnehmen des gerates wurde ein weiteres licht gesichtet. Nach genauer feststellung des ankerkurses der fischer wurde mit 17 sm zur versenkung angelaufen und der kutter E (?) un 0135 uhr mitschiffs auseinder geschnitten. Die untergangzeit betrug 1 min. 10 sek. . . Original

0014: two white lights ahead (a larger fishing cutter at anchor) 0015 o'clock the vehicle was illuminated with a hand lamp, as the view was no more than 150m. It was the danish fishing cutter Ejjam from Ebsbjerg E92. Location M1. Qu. 6826 right edge. 0017 o'clock. Stub drive was continued. after kutter had just gone out of sight, about four to five U-T morse signs were heard. Letters could not be made out because they were handed in very quickly and blurred. 0040 o'clock. A fishing cutter spotted at anchor 100m abeam. At the same time with N.H.G. one long tone and three short intercepted. The distance between the cutters was 4 nm. 0045 o'clock. The device was recorded and I had the impression that the throughput time of M.1 had been stopped by the first to the second cutter. I then decided to sink the two cutters. It had to be done silently in order to be able to deliver an F.T. absolutely to prevent a cutter from escaping in thick fog. This was only possible by ramming. When the device was recorded, another light was seen. After precise determination of the anchor course the fisherman started to sink at 17 am and the cutter E (?) Un 0135 clock amidships cut apart. The sinking time was 1 minute 10 seconds. . Translation

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0146 uhr Zwoten kutter E 348 versenkt. Untergangszeit 40 sek 0150 uhr Mit zickzackkursen gebiet auf weitere kutter abgesucht, jedoch ohne erfolg. 0215 uhr Marsch nach Qu. 6826 rechte kante. In der zwischenzeit wurde mir der anlage beigefugte funkspruch vorgelegt. 0230 uhr Zwo weisse lichter in sicht. 0234 uhr Dritten kutter E 456 gerammt, dreimal mit 17 sm angelaufen vorschiff sank nicht. 0248 uhr Bug gesunken. 0255 uhr Vierter kutter E.92 nach zwomaligen anlauf versenkt. kutter hatte eine lange von uber 50m 0300 uhr Ruckmarsch mit gerat nach funkt K . Original

0146 o'clock Zwoten cutter E 348 sunk. Set time 40 sec 0150 o'clock With zigzag courses area searched for further cutters, but without success. 0215 o'clock march to Qu. 6826 right edge. In the meantime, a radio message attached to the system was presented to me. 0230 o'clock Two white lights in sight. 0234 o'clock Third cutter E 456 rammed, started three times at 17 nm, forecastle did not sink. 0248 o'clock bow sunk. 0255 o'clock Fourth cutter E.92 sunk after two attempts. cutter had a length of over 50m 0300 o'clock march back with device after radio K . Translation

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Die durchschnittliche besatzungsstärke betrung 4-5 man. sämtliche boote waren in Ebsbjerg beheimatet. aus folgenden gründen wurde die versenkung durchgeführt : 1. Am 9. 2. waren mir die danischen fischer bereite verdachtig vorgekommen. Die gründe wurden in dem sonderbericht zum kriegstagebuch von 1. - 15. Februar niedergelegt. 2. Mitten auf dem weg 1 und 8 sm östlich von endpunkt weg 1 haben danische fischer nichts zu suchen. 3. Geschlussenelte funkspruche brauchen harmlose danische fischer nicht abzugeben. 4. die durchlaufzeit vom ersten bis zwoten boot mit U-T abzustoppen, liess darauf schliessen, dass die fischer nachdem sie von deutschen fahrzeugen sonit kurs und fahrt festgestellt hatten, diese angaben an englische U-boote veitergeben wurden damit diese rechtzeitig auf eine gunstige abschussposition gelangen konnten. Die vermutung, dass es sich um eine dem feind dienende tatigkeit handelte, wurde durch die tatsache bestatigt, das: a. nach den rammstossen bei keinen der kutter aus dem durchgeschnittenen laderaum auch nur ein einziger fisch an die oberflache kam. b. geschlüsselte funksprüche abgegeben wurden c. Bei zwo kuttern die Danen bereits beim ersten anlaufen schon an oberdeck standen und weder zeichen mit lampe noch irgendwelche warnsignale abgaben, was durchaus noch zeitlich noglich gewesen ware. Sie alle ahnten, was man mit ihnen vorhatte und fügten sich wortlos. Aus militärischen gründen wurde niemand aufgenommen. Bartels, KL u Komm M.1 . . Original

The average manning is 4-5 people. all of the boats were based in Ebsbjerg. The sinking was carried out for the following reasons: 1. On February 9, the danish fishermen seemed suspicious to me. The reasons were set out in the special report on the war diary from February 1st to 15th. 2. In the middle of route 1 and 8 nm east of the end point of route 1, danish fishermen have no business. 3. Closed radio messages do not need to be made by harmless danish fishermen. 4. Stopping the transit time from the first to the second boat with UT indicated that the fishermen, after they had determined the course and speed of German vehicles, passed this information on to English submarines so that they could get to a favourable launch position in good time . The presumption that it was an activity serving the enemy was confirmed by the fact that: a. after the ramming, none of the cutters from the cut-through hold only a single fish came to the surface. b. encrypted radio messages were given. c. with two cutters, the Danes were already on the upper deck when they first called in and gave neither signs with lamps nor any warning signals, which would have been absolutely impossible in terms of time. They all suspected what they were going to do with them and without a word they obeyed. (… what one intended to do...) Nobody was accepted (rescued) for military reasons. (… admitted/recorded...) Bartels, KptLt, CO. M.1 . Translation

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. Original	. Translation

Q-ships

Dittmar & Colledge (1972) British Warships 1914-1919 Ian Allan SBN 7110 0380 7

Q-ships p.126

earliest effective anti-submarine measure/ earliest effective attempt to meet the U-boat threat

most difficult problem in ASW at the time was detection;

decoy vessel circumvented that by inviting the U-boat to come to it/Q-ships afforded means to bypass difficulty when few effective means available

aside from decoys, ten trawler/submarine combinations employed

Q-ships most effective for period in 1915; thereafter value declined while usage increased

215 ships employed in role altogether

Breakdown

a) merchant conversion ?125

b) war construction 1 ([[HMS Hyderabad (1917)

c) warships (?76)

d) trawler/submarine combination 10

Warships: sloops 6 + 23 escort ship 1 armed boarding vessel 1 messenger boat 2 store carrier 8 yacht 3 tug 1 salvage vessel 1 lighter 1 trawler 18 drifter (sail) 6 motor drifter 5

• Q-ships at navalhistory.net

Special Service Vessels

Dittmar & Colledge p.316

Miscellaneous group of small vessels inc. tenders, yachts, ferrys etc

a) Tenders 17 (+ 4 individual vessels) listed

b) Yachts 5 (inc. Royal Yachts Alexandra Enchantress, Victoria & Albert)

c) Ferry service 4

d) misc.: gunboats 9

. …. "  : icebreakers 3

Links: HMY Alexandra (1907), HMY Victoria and Albert (1899), [[HMS Enchantress (1903)

• Special Service Vessels at navalhistory.net

Type XVII U-boat

Wa 201 {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Wa 201 |Ship displacement= 277, 294 |Ship length= 39 |Ship beam= 3.3 |Ship draught= 4.3 |Ship draft= |Ship propulsion= 2X210 Deutz, 2x2,500 Walter (792; 1x 2,500 793), 1x77 (fuel= 18 + 43 H2O2 |Ship speed= 9.0, 25.0 |Ship range= 117/20 submerged |Ship endurance= |Ship test depth= |Ship complement= 12 |Ship sensors= |Ship EW= |Ship armament= 2x533mm TT, 4 torpedoes |Ship notes= }} |}

Wk 202 {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Wk 202 |Ship displacement= 236, 259 |Ship length= 34.6 |Ship beam= 3.4 |Ship draught= 4.6 |Ship draft= |Ship propulsion= 2X210 Deutz, 2x2,500 Walter (794; 1x 2,500 795), 1x77 (fuel = 14 + 40 H2O2 |Ship speed= 9.0, 24.0 |Ship range= 1,840/9 surface |Ship endurance= |Ship test depth= |Ship complement= 12 |Ship sensors= |Ship EW= |Ship armament= 2x533mm TT, 4 torp |Ship notes= }} |}

Type XVIIB {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Type XVIIB |Ship displacement= 312, 337 |Ship length= 41.5 |Ship beam= 3.3 |Ship draught= 4.3 |Ship draft= |Ship propulsion= 2x210 Deutz, 1x2,500 Walter, 1x77 (fuel= 20 + 55 H2O2 |Ship speed= 8.5, 21.5 |Ship range= 3,000/8, 150/20 |Ship endurance= |Ship test depth= |Ship complement= 19 |Ship sensors= |Ship EW= |Ship armament= 2x533mm TT, 4 torp |Ship notes= }} |}

Type XVIIG {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Type XVII G |Ship displacement= 314, 345 |Ship length= 39.5 |Ship beam= 3.4 |Ship draught= 4.7 |Ship draft= |Ship propulsion= 2x210 Deutz, 1x2,500 Walter, 1x77 (fuel= 19 + 45 H2O2 |Ship speed= 8.5, 21.5 |Ship range= 3,000/8, 114/20 |Ship endurance= |Ship test depth= |Ship complement= 19 |Ship sensors= |Ship EW= |Ship armament= 2x533mm TT, 4 torp |Ship notes= }} |}

Type XVIIE {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Type XVIIE |Ship displacement= 340 |Ship length= 43.9 |Ship beam= 3.3 |Ship draught= 4.3 |Ship draft= |Ship propulsion= 1x900, 1x1,160 (fuel = 40 |Ship speed= 11.5, 14.5 |Ship range= 6,000/8, 224/4 |Ship endurance= |Ship test depth= |Ship complement= ? |Ship sensors= |Ship EW= |Ship armament= 2x533mm TT, 4 torp |Ship notes= transitional design for Type XXIII electroboat }} |}

Type XVIIK {{Infobox ship characteristics |Hide header= |Header caption= |Ship type= Type XVIIK |Ship displacement= 301, 340 |Ship length= 40.7 |Ship beam= 3.4 |Ship draught= 4.9 |Ship draft= |Ship propulsion= 1x1,500cc, 1x68 23 + 9.2 O2 |Ship speed= 14.0, 16.2 |Ship range= 2,400/12, 120/16 |Ship endurance= |Ship test depth= |Ship complement= 18 |Ship sensors= |Ship EW= |Ship armament= (none) |Ship notes= closed cycle test boat (Kreislauf) }} |}

V-300

German submarine V-300/ the V-300 was a was a 300-ton experimental submarine design created to to test the Walter hydrogen peroxide-based turbine propulsion system.

As originally /envisaged by its creator, Hellmut Walter, the V-300 was to have a similar shape to the V-80, / typical Walter boat shape with two turbines producing a total of 4000hp, giving a submerged speed of 25 knots

the detailed design work was done at Krupp’s Germania works in Kiel. The head oof U-boat Dec velopment, Adm. Fuchs, stipulated that there should be no departure from standard and well-tested design principles; as a result, the V-300 design became considerably larger, at 600 tons, with the addition of diesel engines for surface travel and electric motors for silent underwater motion. The design also acquired a conning tower (something Walter had not included) but lacked forward hydroplanes, as Walter believed control surfaces at the stern (as in an aircraft) would be adequate. The resulting design, produced in September 1941, displaced 610 tons on the surface, but was/would be capable of only 19 knots submerged (still over twice as fast as any conventional U-boat, but lower than Walter had envisaged for his high-speed U-boat. As a result, Walter returned to the drawing board and produced a new design, which became the Wa 201 and Wk 202 submarines.< Roessler p.172 Meanwhile Krupp Germania were given a contract to build V-300, designated U-791, but in January 1942 Walter approached Doenitz with his own design, winning approval for their construction, and in June 1942 the contract for V-300 was cancelled.<Roessler p.174

Sources

• R Chesnau, ed. Conway's All the World's Fighting Ships 1922–1946 (1980) Conway Maritime Press, Greenwich, UK ISBN 0-85177-146-7
• Axel Niestle  : German U-Boat Losses during World War II (1998). ISBN 1-85367-352-8
• Eberhard Roessler : The U-Boat: The Evolution and Technical History of German Submarines (1981/2001) Cassel & Co. ISBN 0-304-36120-8