Type IX U-boat

Type IX U-boat was the long-range ocean-going submarine of the German Kriegsmarine in the Second World War, the boat that carried the U-boat war far beyond the reach of the smaller Type VII. Built in about 194 boats between 1937 and 1944, in the variants IXA, IXB, IXC, IXC/40, and IXD, the Type IX was larger, slower to dive, and more heavily armed than the Type VII, with a range that let it operate off the coast of America, in the Caribbean, off West Africa, and in the Indian Ocean. Its most famous successes came in early 1942, during Operation Drumbeat, when Type IX boats sank Allied shipping off the American east coast faster than the Allies could replace it. As the war went on, the Type IX became more vulnerable: it was large, slow to dive, and easy to detect, and Allied aircraft, radar, and escort groups sank most of the boats. The Type IX remained in service to the end of the war, and a handful survived to be studied by the Allies, but by 1944 it had been overtaken by the new Type XXI.

1. Key Facts

Class/Type	Type IX ocean-going U-boat (variants IXA, IXB, IXC, IXC/40, IXD)
Launched	First boat, U-37, launched 1938
Commissioned	1938-1944
Displacement	About 1,032 tons surfaced and 1,153 tons submerged (IXA); about 1,120 tons surfaced and 1,232 tons submerged (IXC)
Length	76.6 metres (IXC)
Speed	About 18.2 knots surfaced; about 7.7 knots submerged
Complement	48-56 officers and men
Armament	6 torpedo tubes (4 bow, 2 stern); 22 torpedoes; 1 x 105 mm deck gun; 1 x 37 mm and 2 x 20 mm anti-aircraft guns
Aircraft	None
Fate	About 194 built; most lost in action; a few survived the war

2. Development

The Need for a Long-Range Boat

The Type IX was designed in the mid-1930s, when the German navy was rebuilding under the Anglo-German Naval Agreement and needed a submarine that could operate in the Atlantic, far from German bases. The Type VII, which was designed for operations in the North Sea and the western Atlantic, had a range of about 6,500 nautical miles, which was not enough for sustained operations off America or in the South Atlantic. The Type IX, with a range of about 13,450 nautical miles at 10 knots on the surface, could cross the Atlantic, patrol for weeks, and return without refuelling. The design was based on the earlier Type IA, a large ocean-going boat of which only two were built, and it was scaled up to carry more torpedoes, more fuel, and a deck gun. The first boat, U-37, was laid down in 1937 and commissioned in 1938, and production continued through the war.

Variants and Production

The Type IX was built in several variants. The IXA, of which eight were built, was the original design, with a displacement of about 1,032 tons surfaced. The IXB, 14 boats, had a larger fuel capacity and a longer range. The IXC, 54 boats, was the main wartime variant, with a slightly larger hull and more fuel. The IXC/40, 87 boats, had a still larger fuel capacity and a range of about 13,850 nautical miles. The IXD, 30 boats, was a still larger design, with a displacement of about 1,610 tons surfaced and a range of more than 20,000 nautical miles, intended for operations in the Indian Ocean and the Far East. The IXD was built in two sub-variants, the IXD1, a transport boat, and the IXD2, a long-range attack boat. In total, about 194 Type IX boats were built, compared with about 703 Type VII boats, and the Type IX was always the minority type, reserved for the longest patrols.

3. Design

Hull and Layout

The Type IX was a double-hulled boat, with a pressure hull inside an outer hull that carried fuel, ballast, and torpedo tubes. The pressure hull was divided into six compartments: the bow torpedo room, the forward crew quarters, the control room, the officers’ quarters, the engine room, and the stern torpedo room. The boat was larger and roomier than the Type VII, with more space for the crew and for stores, and it was more comfortable on long patrols, although comfort was relative: the crew still lived in cramped, damp conditions, with no showers and little fresh water. The conning tower, with its bridge and anti-aircraft guns, was larger than that of the Type VII, and the boat carried a 105 mm deck gun forward of the tower, which was used to sink ships that were not worth a torpedo. The boat’s size made it slower to dive than the Type VII, taking about 35 seconds to submerge, compared with about 25 seconds for the Type VII.

Machinery and Range

The Type IX was powered on the surface by two diesel engines, producing about 4,400 horsepower, and submerged by two electric motors, producing about 1,000 horsepower. Her surface speed was about 18.2 knots, and her submerged speed was about 7.7 knots, slower than the Type VII but adequate for a boat that spent most of its time on the surface. Her range was her great advantage: about 13,450 nautical miles at 10 knots on the surface for the IXC, and more than 20,000 nautical miles for the IXD2. The boat could stay at sea for up to 70 days, and some patrols lasted longer. The price was vulnerability: on the surface, the Type IX was a large target, and its slow dive made it an easy victim for aircraft. The boat’s sonar and hydrophones were similar to those of the Type VII, and its periscopes and radio equipment were standard for the period.

4. Technical Specifications

Dimensions and Performance

The Type IXC, the most common variant, measured 76.6 metres in length, 6.8 metres in beam, and 4.7 metres in draught. Her surfaced displacement was about 1,120 tons, and her submerged displacement was about 1,232 tons. Her test depth was about 230 metres, although boats were sometimes driven deeper in emergencies. Her surface speed was about 18.2 knots, and her submerged speed was about 7.7 knots. Her range was about 13,450 nautical miles at 10 knots on the surface, and about 63 nautical miles at 4 knots submerged. Her complement was 48 to 56 officers and men, including the commander, officers, petty officers, and ratings. The boat carried 22 torpedoes, or 44 mines in place of torpedoes, and its fuel capacity was about 208 tons. The figures vary between variants, and sources differ by small amounts because the boats were modified during production.

Sensors and Equipment

The Type IX carried the standard German submarine sensors of the period: a Gruppenhorchgerat, a group listening device, for passive sonar, and an active sonar set for ranging. Its periscopes were the attack periscope, for torpedo aiming, and the observation periscope, for general observation. Its radio equipment included a transmitter and receiver for long-range communication with headquarters, and a radar detector, the Metox, which warned of Allied radar. Later in the war, boats were fitted with a snorkel, a breathing tube that let the diesels run while submerged at periscope depth, although the snorkel was less common on the Type IX than on the Type VII. The boat’s torpedo fire control was manual, with the commander calculating the firing solution from the periscope, and the torpedoes were the standard G7a steam and G7e electric types, with a range of about 5,000 metres at high speed.

5. Armament

Torpedoes and Deck Gun

The Type IX carried six torpedo tubes, four in the bow and two in the stern, and 22 torpedoes. The torpedoes were the main weapon, and the boat could fire a spread of four from the bow, reload, and fire again. The stern tubes were used for a parting shot at a pursuing escort, or for attacking a ship behind the boat. The boat also carried a 105 mm deck gun, mounted forward of the conning tower, which was used to sink small ships and to finish off damaged ships, saving torpedoes for larger targets. The deck gun was effective in the early war, when Allied ships were unarmed, but by 1942 most merchant ships carried guns of their own, and the deck gun became too dangerous to use. The boat also carried mines, which could be laid from the torpedo tubes, and it was used for minelaying off American and African ports.

Anti-Aircraft Guns

For air defence, the Type IX carried a 37 mm anti-aircraft gun and two 20 mm anti-aircraft guns, mounted on the conning tower platform. The guns were a last resort, because a submarine that fought an aircraft on the surface was likely to be sunk, and the standard tactic was to dive. Later in the war, some boats were fitted with a heavier anti-aircraft armament, including a quadruple 20 mm mount, in an attempt to fight off aircraft, but the tactic failed: Allied aircraft were too numerous and too well armed, and boats that stayed on the surface to fight were sunk. The anti-aircraft guns were more useful against single aircraft in the early war, and they were sometimes used to shoot down patrol aircraft that had found the boat. By 1944, most Type IX boats had their deck guns removed to save weight and to reduce drag, and they relied on diving to escape.

6. Service History

Operation Drumbeat

The Type IX’s most famous operation was Operation Drumbeat, the U-boat offensive off the American east coast in early 1942. In January 1942, five Type IX boats, under the command of Reinhard Hardegen in U-123, sailed to America and found the coast undefended: ships sailed with lights on, without escort, and without blackout, and the American navy had almost no anti-submarine forces. In the first months of 1942, the Type IX boats sank hundreds of thousands of tons of shipping, often within sight of the American coast. Hardegen’s U-123 alone sank eight ships in two weeks, and the operation was a shock to the American public, which could see burning tankers from the beaches of Florida and New Jersey. The success of Drumbeat was due to the Type IX’s range, which let it operate off America for weeks, and to the unreadiness of the American defences.

The Atlantic and Beyond

After Drumbeat, Type IX boats operated across the Atlantic, in the Caribbean, off West Africa, and in the Indian Ocean. They sank ships in the Caribbean oil trade, mined American harbours, and carried out long patrols to the Indian Ocean, where they operated from Japanese bases at Penang and Singapore. The boats also carried out special missions: they landed agents in America, supplied other U-boats at sea, and carried cargo to Japan. As the war went on, the patrols became more dangerous: Allied aircraft, with radar and Leigh Lights, could find and sink U-boats on the surface at night, and escort carrier groups hunted them across the Atlantic. The Type IX, large and slow to dive, was particularly vulnerable, and losses mounted. By 1943, the U-boat war was lost, and the Type IX boats that sailed were often sunk before they reached their patrol areas.

7. Notable Actions

U-123 and Reinhard Hardegen

U-123, a Type IXB under Reinhard Hardegen, was the most successful Type IX of the war. On her first Drumbeat patrol, in January and February 1942, she sank eight ships totalling about 53,000 tons off the American east coast, including tankers and freighters. Hardegen’s tactics were bold: he attacked at night, on the surface, in shallow water, where the American defences could not reach him. He later commanded a second Drumbeat patrol, in which he sank more ships, and he became one of the most decorated U-boat commanders of the war. U-123 survived the war and was scuttled in May 1945, but Hardegen’s patrols remain the best-known example of the Type IX in action. The boat’s success showed what a long-range submarine could do when the enemy was unprepared, and it also showed how quickly the advantage could be lost.

U-505 and the Capture

U-505, a Type IXC, is the most famous Type IX because she was captured intact by the American navy on 4 June 1944. The boat had been damaged by depth charges from the escort carrier USS Guadalcanal’s hunter-killer group, and her crew abandoned her, leaving the codebooks and the Enigma machine aboard. An American boarding party from the destroyer escort USS Pillsbury boarded the boat, secured the Enigma machine and codebooks, and towed her to Bermuda. The capture was kept secret, so that the Germans would not know their codes had been compromised, and it gave the Allies valuable intelligence. U-505 survived the war and is now preserved at the Museum of Science and Industry in Chicago, the only Type IX on display, and one of only a handful of U-boats preserved anywhere in the world.

8. Fate

Losses in the Atlantic

Most Type IX boats were lost in action. Of the about 194 boats built, about 141 were sunk, and many of the survivors were scuttled at the end of the war or handed over to the Allies. The losses were heaviest in 1943 and 1944, when Allied air power and escort groups made the Atlantic impassable for U-boats. The Type IX’s size and slow dive made it an easier target than the Type VII, and its long patrols exposed it to danger for longer. Some boats were lost to accidents, mines, and friendly fire, but most were sunk by aircraft, destroyers, and escort carriers. The last Type IX patrols, in 1945, were to the American coast and the Indian Ocean, and the boats that sailed often did not return. The war ended with the Type IX obsolete, overtaken by the Type XXI, which could stay submerged and outrun escorts.

Survivors and Preservation

A handful of Type IX boats survived the war. U-505, captured in 1944, is preserved in Chicago. U-534, a Type IXC/40, was sunk in May 1945 and raised in 1993, and is now on display in Birkenhead, England. U-864, a Type IXD2, was sunk by the British submarine HMS Venturer in February 1945, the only known case of a submarine sinking another submarine while both were submerged, and her wreck lies off Norway. The other survivors were divided among the Allies after the war and scrapped or used for trials. The Type IX’s legacy is preserved in U-505, which is visited by hundreds of thousands of people each year, and in the records of the U-boat war, which show the Type IX as the boat that carried the war to the farthest corners of the Atlantic.

9. Legacy

The Long-Range Submarine

The Type IX proved that a submarine could operate across an ocean, far from its base, for months at a time, and it set the pattern for post-war long-range submarines. The American, British, and Soviet navies studied the Type IX after the war, and its range, habitability, and armament influenced the design of post-war boats. The Type IX also showed the limits of the long-range submarine: it was too large and too slow to dive to survive in waters dominated by aircraft, and its success depended on the enemy being unprepared. The lesson was learned by the German navy itself, which replaced the Type IX with the Type XXI, a boat designed to stay submerged and to outrun escorts. The Type IX’s greatest legacy, however, is in the history of the Battle of the Atlantic, where it carried the U-boat war to America, the Caribbean, and the Indian Ocean, and showed that no coast was safe from submarines.

Memory and the U-boat War

The Type IX is remembered for Operation Drumbeat, the offensive that brought the war to the American coast, and for U-505, the boat that was captured and preserved. The Drumbeat patrols are remembered in America as a time when burning tankers could be seen from the beaches, and in Germany as the high point of the U-boat war. The Type IX’s crews, who sailed on the longest and most dangerous patrols of the war, suffered the highest losses of any U-boat type in proportion to their numbers, and their story is told in the memorials to the U-boat war in Germany. For historians, the Type IX stands as an example of a weapon that was superbly suited to the war it was designed for, and that became obsolete when the enemy learned to counter it.

10. Frequently Asked Questions

What was the Type IX U-boat?

The Type IX was a German long-range ocean-going submarine of the Second World War, built in about 194 boats between 1937 and 1944. It was larger, slower to dive and more heavily armed than the smaller Type VII, with a range that let it operate far from German bases. Type IX boats operated off the coast of America, in the Caribbean, off West Africa and in the Indian Ocean, far beyond the Type VII’s reach. Its most famous successes came during Operation Drumbeat in early 1942, but later Allied aircraft, radar and escort groups sank most of the boats.

How many Type IX U-boats were built?

About 194 Type IX boats were built between 1937 and 1944, in the variants IXA, IXB, IXC, IXC/40 and IXD. The IXA, of which eight were built, was the original design, and the IXB, with 14 boats, had a larger fuel capacity and a longer range. The IXC, with 54 boats, was the main wartime variant, while the IXC/40, with 87 boats, was the most numerous, with a larger fuel capacity. The IXD, with 30 boats, was a larger design intended for operations in the Indian Ocean and the Far East, and the Type IX was the minority type, compared with about 703 Type VII boats.

What was Operation Drumbeat?

Operation Drumbeat was the U-boat offensive off the American east coast in early 1942, and the Type IX’s most famous operation. In January 1942, five Type IX boats, under Reinhard Hardegen in U-123, sailed to America and found the coast undefended. Ships sailed with lights on, without escort and without blackout, and the American navy had almost no anti-submarine forces ready. In the first months of 1942 the Type IX boats sank hundreds of thousands of tons of shipping, often within sight of the American coast, and burning tankers could be seen from the beaches.

How far could a Type IX travel?

A Type IXC could travel about 13,450 nautical miles at 10 knots on the surface, enough to cross the Atlantic and patrol off America for weeks. The larger IXD2 could travel more than 20,000 nautical miles, and the boat could stay at sea for up to 70 days. That range was the Type IX’s great advantage, because the Type VII, with a range of about 6,500 nautical miles, could not sustain operations off America. The price was vulnerability, because on the surface the Type IX was a large target, and its slow dive made it an easy victim for aircraft.

What happened to U-505?

U-505, a Type IXC, was captured intact by the American navy on 4 June 1944, and she is the most famous Type IX because of that capture. The boat had been damaged by depth charges from the escort carrier USS Guadalcanal’s hunter-killer group, and her crew abandoned her. An American boarding party from the destroyer escort USS Pillsbury boarded the boat, secured the Enigma machine and codebooks, and towed her to Bermuda. The capture was kept secret, so the Germans would not know their codes had been compromised, and U-505 is now preserved at the Museum of Science and Industry in Chicago.

How did the Type IX differ from the Type VII?

The Type IX was larger, longer-ranged and more heavily armed than the Type VII, but it was slower to dive and easier to detect. The Type VII was the standard Atlantic boat, built in about 703 boats, while the Type IX, with about 194 boats, was reserved for the longest patrols. The Type IX took about 35 seconds to submerge, compared with about 25 seconds for the Type VII, and its size made it a larger target on the surface. It was also roomier than the Type VII, with more space for crew and stores, which mattered on patrols that could last up to 70 days.

11. Sources

1. Wikipedia, “German Type IX submarine” — variants, production, specifications, and service.
2. Clay Blair, “Hitler’s U-Boat War: The Hunters, 1939-1942” and “The Hunted, 1942-1945” (Random House, 1996-1998) — the U-boat war and Operation Drumbeat.
3. Erich Groner, “German Warships 1815-1945, Vol. 2: U-boats and Mine Warfare Vessels” (Conway, 1991) — specifications and production data.
4. Uboat.net, “Type IX” — boat lists, patrols, and losses.
5. Michael Gannon, “Operation Drumbeat” (Harper and Row, 1990) — the U-boat offensive off America.
6. Museum of Science and Industry, Chicago, “U-505” — the capture and preservation of U-505.