E-boat


E-boat was the Western Allies' designation for the fast attack craft of the Kriegsmarine of Nazi Germany during World War II; E-boat could refer to a patrol craft from an armed motorboat to a large Torpedoboot. The name of E-boats was a British designation using the letter E for Enemy.
The main wartime production boats, from S26 onwards, were very seaworthy, heavily armed and capable of sustaining, briefly accelerating to. These were armed with torpedoes and Flak guns; commonly one 37 mm at the stern, one 20 mm at the bow with a twin mount amidships, plus machine guns. Armament varied and some S26 class boats substituted a 40mm Bofors or, less commonly, a 20mm flakvierling for the aft 37mm cannon.
The S26 class boats - which provided the bulk of the wartime deliveries - were long and in beam. Their diesel engines provided a range of, substantially greater than the gasoline-fueled American PT boats and British motor torpedo boats.
As a result of early war experience of combat against the fast and powerful S-boats, the Royal Navy created its motor gunboat force and later developed better-matched MTBs, using the Fairmile 'D' hull design.

History

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 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.
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. 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". 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.
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.

Layout

The internal layout of the E-boat remained the same for all types. Its length was generally divided by eight transverse bulkheads into nine watertight compartments. From bow to stern, these were:
  1. Containing a trimming tank, the anchor chain storage locker, forward "head" and crew washroom;
  2. the accommodation for senior ratings ;
  3. comprising the captain's cabin on the starboard side, and the radio room on the port side;
  4. the two forward fuel tanks, one on either side of a centreline walkway, located directly below the bridge;
  5. the forward engineroom, housing the two wing engines, still with a central walkway between them;
  6. the second engineroom held the engine driving the central shaft, with a walkway on each side, flanked next to the hull by auxiliary machinery;
  7. the two largest of the fuel tanks, again on either side of a central walkway, with a third tank of 1,490 litres below the deck;
  8. the junior ratings' accommodation, with bunks for fourteen men, plus the galley and the stern "head"; the boat's magazine was also in this compartment;
  9. the two aft fuel tanks and rudder gear.
The earliest boats lacked the first transverse bulkhead, and thus the senior ratings' accommodation was included in the first watertight compartment.

Personnel

The earliest six boats had a crew of 12 men, but by the time of the S7 and S14 types this had increased to 18. The S26 class required a complement of between 21 and 24 men, and this remained generally constant for all subsequent boats. This comprised a commanding officer, a Chief Boatswain, a Helmsman, about six seamen including those operating semaphore and engine telegraph posts, a Chief Engineer, three engineer NCOs, six engine-room ratings, two radio operators for radio communications including decoding, and a torpedo mechanic who doubled as the boat's cook.
Crew members could earn the Schnellbootkriegsabzeichen — denoted by a badge depicting an E-boat passing through a wreath. The criteria were good conduct, distinction in action, and participating in at least twelve actions. It was also awarded for particularly successful missions, displays of leadership or being killed in action. It could be awarded under special circumstances, such as when another decoration was not suitable.

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, motor torpedo boats, 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.
E-boats were organisationally under the command of the Seekriegsleitung or SKL, 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 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. 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, 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.
The E-boats of the 9th flotilla were the first naval units to respond to the invasion fleet of Operation Overlord. They left Cherbourg harbour at 5 a.m. on 6 June 1944. On finding themselves confronted by the entire invasion fleet, they fired their torpedoes at maximum range and returned to Cherbourg.
During World War II, E-boats claimed 101 merchant ships totalling 214,728 tons. 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.
E-boat crews were awarded 23 Knight's Cross of the Iron Crosses and 112 German Crosses in Gold.

Operations in the Black Sea

To boost Axis naval strength in the Black Sea, the OKW ordered to the region the transfer of six E-boats of the 1st S-flotilla, the last to be released from action in the Baltic Sea before refit. The Romanian port of Constanța, in the Black Sea, was chosen as the S-flotilla's headquarters. Transporting the six boats overland from Germany to Romania was an impressive logistical feat. The superstructure and all weapons were removed, leaving only the hull. After a long road journey of 60 hours, the boats arrived at Ingolstadt, Germany, where they were transferred back to water and towed towards Linz, Austria. There the superstructure was rebuilt, then the journey continued down the Danube to Galați, where the main engines were installed. The E-boats then continued on their own power towards Constanța, where refitting was completed.
The first two boats, S26 and S28, arrived in Constanța on 24 May 1942, the second pair, S72 and S102 on 3 June, and the final pair, S27 and S40 10 days later. After the sinking of S27 by a malfunctioning torpedo, four more reserve boats, S47, S49, S51 and S-52 were dispatched to the Black Sea, in order to replace boats undergoing maintenance. S28, S72 and S102 were soon relegated to the Constanța Shipyard for engine replacement, leaving only S26 and the newly commissioned S49 operational. On 1 January 1944, the 1st S-flotilla numbered six operational boats: S26, S42, S47, S49, S52 and S79, while S28, S40, S45 and S51 were all out of commission, undergoing repair in Constanța. Three more boats were shipped down the Danube and were being reconstructed at Constanța. On 1 June 1944, 8 boats were operational in Constanța: S28, S40, S47, S49, S72, S131, S148 and S149. The boats were however penned in harbor, due to fuel shortage. During July, S26, S28, S40 and S42 were transferred to Sulina at the mouth of the Danube, where S42 was fitted with a new propeller. They were joined by S72 in early August, the rest of the boats remaining in Constanța. On 19 August, S26, S40 and S72 were destroyed in port by a Soviet air attack. On 22 August S148 hit a mine and sank near Sulina, and on the following day, S42, S52 and S131 were destroyed in Constanța by a Soviet air attack. What remained of the S-flotilla was disbanded after Romania switched sides on the same day.