Development

This design was chosen because the theatre of operations of such boats was expected to be the North Sea, English Channel and the Western Approaches. The requirement for good performance in rough seas dictated the use of a round-bottomed displacement hull rather than the flat-bottomed planing hull that was more usual for small, high-speed boats. The shipbuilding company Lürssen at Vegesack, Bremen, overcame many of the disadvantages of such a hull and, with the private motor yacht Oheka II in 1926, produced a craft that was fast, strong and seaworthy. It was also extremely seaworthy and very light, being constructed of wooden planking over alloy frames. This attracted the interest of the Reichsmarine, which in November 1929 ordered a similar boat but fitted with two torpedo tubes. This became the S1, and was the basis for all subsequent E-boats.^{[citation needed]}

After experimenting with the S1, the Germans made several improvements to the design. Small rudders added on either side of the main rudder could be angled outboard to 30 degrees, creating at high speed what is known as the Lürssen Effect.^[7] This drew in an "air pocket slightly behind the three propellers, increasing their efficiency, reducing the stern wave and keeping the boat at a nearly horizontal attitude".^[8] This was an important innovation as the horizontal attitude lifted the stern, allowing even greater speed, and the reduced stern wave made E-boats harder to see, especially at night.^{[citation needed]}

The rounded wood planking hull helped reduce weight, and flattened at the stern area, the aft section area was reduced at high speeds, it allowed more hydrodynamic lift.^[9]

Operations with the Kriegsmarine

E-boats were primarily used to patrol the Baltic Sea and the English Channel in order to intercept shipping heading for the English ports in the south and east. As such, they were up against Royal Navy and Commonwealth, e.g., Royal Canadian Navy contingents leading up to D-Day, motor gunboats (MGBs), motor torpedo boats (MTBs), motor launches, frigates and destroyers. They were also transferred in small numbers to the Mediterranean, and the Black Sea by river and land transport. Some small E-boats were built as boats for carrying by auxiliary cruisers.^{[citation needed]}

E-boats were organisationally under the command of the Seekriegsleitung or SKL (the naval warfare command, responsible for the planning,execution and direction of naval warfare), and were administratively organised into flotillas, each originally comprising 8 boats. Consequently most orders for new construction were placed in batches of eight boats, or of multiple of eight. The first half-flotilla (1st Schnellbootshalbflotille) was formed in July 1932, but was reorganised as 1st Schnellbootsflotille in June 1935. A second flotilla was established in August 1938, and a third in 1940. Eventually there were fourteen operational flotillas, numbered 1st to 11th plus 21st, 22nd and 24th, together with three training flotillas (Schnellbootsschulflotille). Each flotilla required the backup of a depot ship; initially this was provided by the converted steamer Nordsea, but from 1934 a series of purpose-built tenders were commissioned - the Tsingtau in 1934, followed by the Tanga (in 1939), Carl Peters and Adolf Lüderitz in 1940, and finally the Herman von Wissmamm and Gustav Nachtigal.

E-boats of the 6th & 9th flotillas from Cherbourg attacked Exercise Tiger on 28 April 1944, causing about 749 American Army and Navy casualties.^{[citation needed]}

The E-boats of the 9th flotilla were the first naval units to respond to the invasion fleet of Operation Overlord.^[11] They left Cherbourg harbour at 5 a.m. on 6 June 1944.^[11] On finding themselves confronted by the entire invasion fleet, they fired their torpedoes at maximum range and returned to Cherbourg.^[11]

During World War II, E-boats claimed 101 merchant ships totalling 214,728 tons.^[12] Additional claims include 12 destroyers, 11 minesweepers, eight landing ships, six MTBs, one torpedo boat, one minelayer, one submarine, and a number of smaller craft such as fishing boats. They also damaged two cruisers, five destroyers, three landing ships, one repair ship, one naval tug, and numerous other merchant vessels. Sea mines laid by the E-boats sank 37 merchant ships totalling 148,535 tons, a destroyer, two minesweepers, and four landing ships.^[12]

E-boat crews were awarded 23 Knight's Cross of the Iron Crosses and 112 German Crosses in Gold.^[12]

Yugoslav Navy

Eight E-boats were built by Lürssen, Vegesack for the Yugoslav Navy from 1936 to 1939. These were named Orjen, Durmitor, Suvobor, Kajmakcalan, Velebit, Dinaira, Rudnik and Triglav. Each measured 28.00 (overall)/27.70 (waterline) x 4.46 x 1.51 m (91 ft 10in/90 ft 10in x 14 ft 4in x 4 ft 11in) and 51 tonnes standard (61.7 tonnes full load). Three Daimler-Benz BF2 petrol engines of 1,100 hp each = 3,300 hp = 33 kts, while they carried 5.8 tonnes of petrrol to give them a radius of 265 nmiles @ 33 knots. Each carried two 550mm torpedo tubes, a 40mm gun and 16 men. Kajmakcalan and Durmitor escaped to Alexandria in April 1941 to join the Allies; the other six fell into Italian hands and became Ms41 to Ms46, four of them eventually captured by the Germans and refitted with standard 533 mm torpedoes (see below under "S2 class").

Italian MS boat

The poor seaworthiness of the Italian-designed MAS boats of World War I and early World War II led its navy to build its own version of E-boats, the CRDA 60 t type, classed MS (Motosilurante). The prototype was designed on the pattern of the six German-built E-boats captured from the Yugoslav Navy in 1941. Two of them sank the British light cruiser HMS Manchester in August 1942, the largest warship to be sunk by fast torpedo craft in the Second World War.^[20] After the war these boats served with the Italian Navy, some well into the 1970s.^[21]

Service in the Spanish Navy

The Kriegsmarine supplied the Spanish Francoist Navy with six E-boats (S1 to S6) in December 1936 during the Spanish Civil War, and sold six more (S73, S78, S124, S125, S126 and S134) to them in 1943 during the Second World War. Another six were built in Spain with some assistance from Lürssen. A motor boat of the early series, either the Falange or the Requeté, laid two mines off Almería that crippled the British destroyer HMS Hunter on 13 May 1937. The German-built boats were discarded in the 1960s, while some of the Spanish-built ones served until the early 1970s.^[22]

Service in China

This section does not cite any sources. (February 2021)

The Chinese Nationalist Navy had three S7-class boats during the Second Sino-Japanese War.

• Yue-22 (岳-22)
• Yue-253 (岳-253)
• Yue-371 (岳-371)

Yue-22 was destroyed by Japanese planes, Yue-371 was sunk by its sailors to avoid being captured by the Japanese soldiers and Yue-253 was captured by the People's Liberation Army during the Chinese Civil War. Yue-253 was renamed "Hoiking" (海鯨), meaning "Seawhale" in Chinese. The People's Liberation Army Navy used it as a patrol boat until 1963.

The Chinese Nationalist government also ordered eight E-boats and a tender, Qi Jiguang (戚繼光). These were all taken over while under construction by the Kriegsmarine in 1939. The E-boats had MB502 diesels and were shorterr (by 2.18m) than the standard S26 design of boats. They were re-numbered as S30 to S37, while the Qi Jiguang was renamed Tanga.

Service in the Romanian Navy

Germany sold four E-boats to Romania on 14 August 1944.^[23] These vessels displaced 65 tons, had a top speed of 30 knots generated by three Mercedes-Benz engines totalling 2,130 kW (2,850 hp) and were armed with two 500 mm (19.685 in) torpedo tubes. Each of the four boats had a crew of 25. They were numbered 10 to 13 (formerly S151, S152, S153 and S154) and served in the Romanian Navy until at least 1954.^[24]

Post-war service

Operators

S1

The first post-WW1 torpedo boat was ordered in November 1929 to be built by Lürssen at Vegesack, near Bremen, in 1930 as their Yard No. 12120, using mahogany and light metal composite. Originally numbered as UZ(S)16, it was commissioned into the Reichmarine on 7 August 1930. It was renamed W1 on 31 March 1931, and then as S1 on 16 March 1932. It measured 26.8 x 4.2 x 1.06 metres (87 ft x 13 ft 9in x 3 ft 6in) and had a displacement of 39 tons standard (50 tons full load). Powered by three Daimler-Benz BF2 12-cylinder 900 hp petrol engines on three shafts, with a rating of 2,700 bhp, it had a sustained speed of 34.2 knots (maximum 39.8 knots). It carried two 500mm (19.685 inch) torpedo tubes and one 20mm flak gun. It had a complement of 12 (later 18) men. Along with the next five boats (S2 to S6), it was stricken on 10 December 1936 and sold to Spain as Badajoz (renamed LT15 in 1939).

The number S1 was re-used in 1939. Five boats had been ordered by Bulgaria from Lürssen, Vegesack, of which the first four were delivered as F1 to F4. The fifth boat was retained in Germany and given the number S1. These were petrol-engined boats, similar to the S2 class built for the Kriegsmarine. Although commissioned in 1939, its petrol engines gave frequent problems, and on 10 September 1940 its stern was rammed (by S13) in Vlissingen, and was later removed from active service.

S2 class

The first production of the E-boat in 1931, a lengthened version of the prototype S1. The first two were ordered from Lürssen on 28 April 1931 and the other two on 16 July 1931. Each measured 27.95 x 4.2 x 1.06 metres (91 ft 8in x 13 ft 9in x 3 ft 6in) and had a displacement of 46.5 tons standard (58 tons full load). Powered by Daimler-Benz petrol engines on three shafts, with a rating of 3,300 bhp, they had a speed of 33.8 knots. Armament and men as in S1. They formed a "Half Flotilla" and were used for training crews for later E-boats; all were stricken on 10 December 1936 (along with S1) for transfer to Spain.

The numbers S2 to S5 were re-used in 1943. Eight petrol-engined boats similar to the original S2 class had been ordered from Lürssen, Vegesack, and completed in 1937-39 for that navy as Orjen, Durmitor, Suvobor, Kajmakcalan, Velebit, Dinaira, Rudnik and Triglav. When Italy occupied Yugoslavia in April 1941, two of them (Durmitor and Kajmakcalan) escaped to Alexandria and served with the Allied forces, while the other six were commissioned into the Italian Navy as Ms41 to Ms46.^[34] In September 1943 Ms41 (ex Orjen) at Monfalcone and Ms45 (ex Suvobor) at Cattolica were scuttled, while the other four were captured by the Germans on 9 September and renamed S2 (ex Velebit), S3 (ex Dinara), S4 (ex Triglav) and S5 (ex Rudnik); all four were scuttled by the Germans at Salonika in October 1944.

S6

The first diesel-powered boat was also ordered from Lürssen, Vegesack on 28 August 1932. Its dimensions and other details were the same as for S7 to S9. It was stricken and sold to Spain on 10 December 1936 (together with the preceding petrol-engined boats) and renamed Toledo (renamed LT14 in 1939 and stricken in 1942).

S7 class

Built from 1933 onwards. Similar to S6, but with an improved hull form, these were the first operational diesel boats. The first three, ordered (together with S6) on 26 August 1932, were fitted with MAN L7 19/30 diesels on three shafts giving a speed of 36.5 knots and measured 75.8 tonnes standard (95 tonnes full load), while the last four - ordered on 20 July 1932 - were equipped with the more reliable Daimler-Benz MB502 diesels of 3,960 hp to produce 35 knots, and were 78 tonnes standard (92 tonens full load). They had a fuel capacity of 10.5 tonnes, giving them a radfius of 600 nmiles @ 30 knots. All measured 32.36 x 5.06 x 1.36 m (106 ft 2in x 16 ft 6in x 4 ft 6in) except that S10 to S13 had a draught of 1.42m (4 ft 8in). These carried the larger 533mm (21-inch) torpedoes rather than the 500mm of the petrol-driven boats; two torpedo tubes were mounted on the forecastle, and the boats also carried a single 20mm MgC/30 gun, with a crew of 18 (later 21) men.

S14 class

Improved S7 type, ordered on 16 July 1934 (first two) and 5 November 1935 (last two) with new MAN L11 (11-cylinder) engines producing 6,150 hp, which proved unsatisfactory. Enlarged hull, measuring 34.62 x 5.26 x 1.67 m (113 ft 7in x 17 ft 3in x 5 ft 6in) and displacing 92.5 tonnes standard (105.4 tonnes full load). After S17 was broken up, the surviving three boatrs were transferred to the Fast A/S Group in 1940.

S18 class

Built from 1937 onwards. Two new boats were ordered on 21 December 1936 (S18 and S19) and six more boats (S20 to S25) on 29 December 1937. Almost identical to the S14 class, but with 3 Mercedes Benz MB501 engines (of total 6,000 hp) instead of MAN engines. The bridge, which had been in front of the wheelhouse on earlier designs, was raised to the wheelhouse roof to increase all-round visibility.^[35]

1938 Orders

In May 1938 it was planned to order six additional boats every year until 1943 (thus providing a projected S26 to S61). However, a speeding-up of production was decided on. Twelve additional boats were ordered - all from Lürssen - in August 1938. These were of two different models, due to accommodating different Daimler-Benz diesels.

1939 Orders

24 more boats were ordered - all from Lürssen (S44 and S45 were first scheduled to be built by Stettiner Oderwerk, but in the event all of this batch were contracted to Lürssen - on 24 September 1939. The pre-war Mobilisation New Construction Programme had called for 48 new boats per year, but this target was raised to 60 boats in September 1939 by the Naval War Staff. They called for a fleet level of 40 to 50 operational boats, with 16 being built annually as replacements. Sixteen were virtually identical with the S26 type (measuring 34.94 m in length and with 20-cylinder MB501 diesels), other than simplified ventilators and other minor changes.^[40] This design was to provide almost all of the Schnellboote built in Germany for the rest of the war.

While until this date all boats had been procured from Lürssen, but the German Navy had been seeking a second yard to add to its construction capacity, and on 25 September a contract for eight boats (numbered from S101 to S108) to the standard S26 design was awarded to Schlichting-Werfk at Travemünde. This second builder was assigned a new series of numbers in the "101 range to distinguish them from the Lürssen boats.

Following the outbreak of war, another eight boats were ordered from Lürssen on 14 November 1939 to the same Schnellboot 1939 design as the S30 group (measuring 32.76 m in length and with 16-cylinder MB502 diesels),

1940 orders

On 4 June 1940 a further batch of boats to the S26 design was ordered. This comprised 8 boats from Lürssen (S62 to S69) and 9 boats from Schlichting (S109 to S117). S67 introduced an improved design with a partially armour-plated cupola (the Kalotte or skull cap) over the bridge, providing protection from weather as well as small arms fire, with a lower profile. From 1943 orders onwards, this armoured bridge became standard, and was also retro-fitted to many of the earlier boats. Various armaments were carried including 40 mm Bofors or 20 mm Flak aft, MG34 Zwillingsockel midships.
(Note the designation '38b' sometimes seen is not Kriegsmarine nomenclature and originated in a postwar American hobby publication).

Following the German occupation of France in June 1940, the Naval War Staff decided that 160 E-boats were now needed (comprising 26 flotillas), with 8 flotillas based in France and 6 each in Norway, the Baltic and the North Sea.^[40] On 26 August an additional four boats (S70 to S73) were ordered from Lürssen, and in December Schlichting were given another order, this time for eight boats (S118 to S125),

1941 orders

Another 40 boats were ordered in 1941, 16 from Lürssen on 3 January (numbered S74 to S89), another 16 from the same yard on 18 September (numbered S90 to S100 and from S134 to S138) and 8 from Schlichting at Travemünde (S126 to S133), also on 18 September.

1942 orders

Orders for a further 16 boats were given to Lürssen on 24 February 1942. The first 12 of these were numbered S139 to S150; the next sixteen numbers were allocated to construction at Schiedam in Holland, so the final four of the Lürssen batch were numbered S167 to S170.

S151 class

Eight smaller torpedo boats were building for the Dutch Navy at Gusto Werf, Schiedam (near Rotterdam) as TM54 to TM61 inclusive. When Holland was occupied by the Germans, these were seized and completed (with some design modifications) by German and Dutch shipyard workers and renumbered as S151 to S158. They measured 28.3 x 4.46 metres (92 ft 10in x 14 ft 7in), displacing 57 tons. Originally the Germans planned to sell these to Bulgaria, and they were formed as the new 7th S-flotilla in October 1941, but the Kriegsmarine's need for them in the Mediterranean had caused them to be sent south via the French inland waterways. They were authorised to transfer to the Mediterranean on 15 July 1942, and arrived there on 8 October, finally reaching Augusta, Sicily on 15 December, when they became operational.^[42]

Eight further vessels had been intended by the Dutch Navy as TM62 to TM70, and material had been collected for their construction at Schiedam. They were cancelled with the German occupation in May 1940; they were re-ordered (as S159 to S166) from Gusto Werf on 11 July 1941, but construction of these stopped in April 1942.

Continuation of S139 batch

All these were part of the order placed on 24 February 1942, and the first three were identical to S139 batch. However the final boat, S170, was the prototype (along with S228 at Travemünde) for the final series of boats ordered in December 1943 (few of which were completed) with the first MB518 engines of 3,000 hp for evaluation; her details were the same as for that final series of orders.

1943 orders

Needing to increase production, orders for two batches of vessels were placed during the first half of 1943, totalling sixty boats. An order for sixteen boats was placed with Lürssen's yard on 15 January 1943 (S171 to S186), and another order for eight boats with Schlichting at Travemünde on the same day (S187 to S194). On 7 May another batch was ordered from the same builders - twenty-four from Lürssen (S195 to S218) and twelve from Schlichting (S219 to S230), although the final two from the Schlichting order were seemingly deferred, to be re-included in the much larger order placed in December.

Like the S139 batch, almost all of these were a metre longer than the original S26 class in order to have room to fit the new supercharged MB511 engines. The sole exception was S228 - the final boat from this batch to be completed at Travemünde, which was that yard's prototype for the final mass series which were ordered in December 1943, built to carry the new MB518 diesels, and was thus the equivalent test-bed at that yard to S170 from Lürssen. All the other 57 boats completed from this batch had MB 511 diesels fitted.

The final batch ordered on 4 December 1943 comprised a massive total of 282 units - S229 to S260 (32 boats) from Schlichting; S301 to S425 (125 boats) from Lürssen; and S701 to S825 (125 boats) from Danziger Waggon at Danzig. The first four of the Schlichting boats (S229 to S230) were completed by April 1945 but not placed into service; these were presumably broken up in the shipyard following the cessation of hostilities. Of the projected numbers from the other two builders only the first five from Lürssen and 9 from Danzig were completed. Another seven were launched but not completed; these were scuttled in the North Sea, while fourteen more were scrapped in the Lürssen shipyard (S308 to S328) and others at Travemünde and Danzig. The remainder were all cancelled.

S501 class

These small ex-Italian Navy boats of the Baglietto fast type (or MAS526 type) were taken over by the Germans in the Black Sea on 20 May 1943.^[34] The first seven of these measured 18.7 x 4.7 x 1.5 m (61 ft 4in x 15 ft 5in x 4 ft 11in) and displaced 25.2 tons (29.4 tons full load). These 2-shaft boats were driven by 2 Isotta-Fraschini petrol engines of 2,000 hp to reach 42 knots. They carried two 450mm torpedoes plus one MG or 20mm gun, and 6 depth charges, with a crew of 10. All 7 were transferred to the Romania in August 1943, but seized by the USSR on 5 September 1943.

S601 class

Further small ex-Italian Navy boats of the Baglietto fast type (of various classes)^[34] were taken over by the Germans.

S700 class

Late war design proposal with stern torpedo tubes and 30 mm gun turret forward. These were intended to be slightly larger, of prefabricated construction, and to be propelled by the supercharged MB518 engines. They were to have carried two stern-firing torpedo tubes in addition to the usual two bow tubes, with a special 30mm gun in a bow turret. These were ordered from Danziger Waggonfabrik at Danzig on 4 December 1943 as S701 to S825 (125 boats), but only the first nine boats were built, and these were completed to S100 design specification with MB511 diesel engines after the production of the MB518 engine was cancelled due to Allied bombing. The other boats were cancelled or scrapped unfinished in the shipyard.

In the 1944 Programme it was intended to increase production of E-boats to deliver 150 boats per annum, but this level was never achieved. In November 1944 there were 292 boats on order, of which 138 were under construction, usually awaiting delivery of the new MB518 engines, while the other 154 boats were unstarted. Eventually, as the ability to provide engines increased, only 19 of the 138 boats were actually completed.

KS-boats (Kleinst Schnellboote), originally KM-series (Küstenminenleger)

A class of small fast attack craft designed as offensive mine-layers (rated Küstenminenleger),able to carry up to 4 mines, and to operate close to enemy shores. They measured 15.95 x 3.50 x 1.10 m (52 ft 4in x 11 ft 6in x 3 ft 7in); 15/16 tonnes standard (18/19 tonnes full load). Powered by 2 BMW MB507 12-cylinder aero engines producing 1,650 hp (32 knots), although four boats (nos. 1, 2, 5 and 6) had two Junkers 4-cylinder diesels of 1,500 hp to produce speeds of 30/40.9 knots; radius 225 miles at 25 knots. A total of 36 were ordered (most on 29 and 31 July 1940, but KM1 to KM4 were ordered on 26 August, and KM25 and KM26 on 11 October 1940), but as their engines proved unreliable, they were not used in their intended role and instead most were employed in lakes and rivers, being attached to the Peipusee Flotilla (KM3 to the Ladogasee Flotilla). As minelayers they carried four TMB mines and a single Mg39 gun, plus a crew of 6. 21 boats were equipped with 2 x 450mm fixed stern torpedo tubes replkacing the mines, and were reclassed as KS-boats (Kleinst Schnellboote), retaining their original numberss but replacing the "KM" prefix by "KS".

Of the unreclassified boats, KM27 to KM30 were all sunk by Soviet aircraft in the Gulf of Bothnia during 1943.

LS-boats (Leichte Schnellboote)

Another class of even smaller fast attack boat, not intended to operate independently, but to be based on auxiliary cruisers or other vessels operating in overseas areas. They measured 12.50 x 3.46 x 1.02 m (41 ft x 11 ft 4in x 3 ft 4in). These 2-shaft boats weighed 11.5 - 13 tons. The first six were powered by two Junkers 6-cyl JuMo205 aircraft engines, they reached 38 knots. Later boats had two Daimler-Benz MB507 12-cyl diesels of 2,000 hp reaching 40.9 knots, and with an endurance of 300 miles at 30 knots. They carried two 450mm torpedo tubes (instead of up to 4 mines), but had depth charges and a single 20mm MG (in an enclosed turret), plus 7 men. A total of 34 of these boats were ordered, the prototype from Naglo Werft, Berlin, and all the others from Dornier Werft, Friedrichshafen, but the prototype was not completed and only the next eleven were completed; another six (LS13 to LS18) were taken over by France incomplete following the war's end, and completed for them; the final 16 (LS19 to LS34) were cancelled in 1944.

Source: https://www.german-navy.de/kriegsmarine/ships/index.doc