Thomas Sanger, Author at Thomas C Sanger

This is the U-30 submarine commanded by Fritz-Julius Lemp that attacked the SS Athenia

H.M.S. Bulldog (right) prepares a party to board U-110 before the submarine sinks. Photo credit: wwii-pows.mooseroots.com

Meet the Character: Fritz-Julius Lemp, Part 7

August 14, 2016August 30, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

What happened to Fritz-Julius Lemp?

On April 15, 1941, Kapitänleutnant Fritz-Julius Lemp left the German submarine base in Lorient, France, in command of U-110. It was Lemp’s second patrol in his new boat (see blog post “Fritz-Julius Lemp, Part 6,” Aug. 1, 2016). His first patrol had ended two weeks earlier without sinking a single ship.

Twelve days into his patrol, Lemp sank a small British freighter and received word a few days later of an allied convoy bound for Canada. No doubt thinking his luck had changed for the better, he rendezvoused with a second submarine the morning of May 9, ahead of the oncoming ships.

A full moon made the usual U-boat tactic of a nighttime surface attack more risky, and delaying the attack for more favorable conditions risked losing contact with the convoy. The two commanders agreed to make a submerged attack as soon as possible. As senior officer, the aggressive Lemp chose to attack first.

He was surprised to see an unusually large number of escorts accompanying the convoy but decided to attack anyway. After the escorts passed and the convoy was directly above, he came up to periscope depth, picked out his targets and fired four torpedoes. Two shots hit and sank two British cargo ships. The third torpedo damaged but didn’t sink its target and the fourth misfired.

Lemp’s crew readjusted the misfire, which had never left its tube, and he coolly prepared to attack his fourth target again. But U-110 had stayed at periscope depth too long. Three of the escorts, including the group flagship, H.M.S. Bulldog, detected the submarine and attacked.

The escorts’ depth-charges knocked out U-110’s electric motors and rudder. The boat’s stern took on water and started to sink. Leaks in the forward battery compartment began to generate chlorine gas. Amazingly, the submarine somehow surfaced on its own, possibly because a high-pressure air line had been ruptured and filled U-110’s tanks with air.

From the bridge atop the boat’s conning tower Lemp saw Bulldog and two other ships bearing down on him, intending to ram his boat. He ordered everyone to abandon ship immediately. With no time to set demolition charges, Lemp called for all vents to be opened to scuttle the boat.

Once in the water with his crew, Lemp realized U-110 wasn’t sinking. Coming to the same realization, the escort group commander aboard Bulldog called off the attack in favor of capturing the abandoned U-boat. If the British boarded his boat, Lemp knew they would recover the secret Enigma communications device and its code books, left behind on the sub in the crew’s haste to escape.

With an armed boarding party from Bulldog on its way to U-110, Lemp was seen attempting to swim back to the boat, apparently intending to open the valves. But before he could reach the submarine, Lemp mysteriously disappeared. Some German crewmen claimed he was shot by the boarding party as he swam for the submarine, a claim the British denied. Other crew members said they saw Lemp throw up his arms and sink below the surface, an apparent suicide.

It was an uncertain end to a storied naval career bookended by two monumental mistakes: sinking the passenger ship Athenia and allowing the Royal Navy to capture the Enigma machine, a major intelligence coup for the British.

Meet the Character: Fritz-Julius Lemp, Part 6

August 1, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

Oberleutnant Fritz-Julius Lemp, the man who sank the British passenger liner Athenia, met with representatives of the German Naval High Command in Berlin during the final days of September, 1939. (See blog post “Fritz-Julius Lemp, Part 5,” July 15, 2016.) He had been ordered to explain his actions, which violated international law.

At 26 years old, Lemp was among the youngest commanders of the German submarine fleet, but he had a well-earned reputation for courage in battle. Some of that pluck must have accompanied his presentation to the High Command. The senior officers recommended against putting Lemp on trial, apparently accepting his explanation that he thought he was attacking a British armed merchant cruiser, a ship that would be a legitimate target.

A separate factor in Lemp’s favor may have been the German government’s month-long denial of any responsibility for sinking Athenia. Taking disciplinary action against the young U-boat captain might have risked revealing the truth and embarrassing the government. At the same time, it also could discourage bold action by other U-boat captains.

U-boat fleet commander Kommodore Karl Dӧnitz may have been pleased that his young captain had not suffered a humiliating punishment. After all, on his first war patrol Lemp had sunk two British cargo ships, rescued two British pilots, survived a punishing depth-charge attack and navigated his badly damaged ship more than 1,000 nautical miles back to its home port in Wilhelmshaven. Nevertheless, Dӧnitz ordered Lemp to be confined to quarters for several days because he had failed to properly identify Athenia as a passenger ship.

During this period, Dӧnitz apparently ordered that U-30’s daily log be altered to show the submarine was many miles away when Athenia was attacked Sept. 3, 1939. It would not be until the Nuremberg trials in 1947 that Dӧnitz would admit U-30’s responsibility for the attack. (See blog post “Nazi Denials,” July 1, 2014.)

Despite his initial setback, Lemp soon returned to active duty and began to carve out a distinguished naval career. He received a promotion to Kapitänleutnant Oct. 1, 1939, and sailed seven more war patrols in U-30, eventually sinking 17 ships and damaging two others.

The German Navy celebrated Lemp by publicizing his exploits as one of its “U-boat Aces,” rallying support for the war effort and glamorizing its “gallant” submarine commanders. At age 27 he was awarded the Knight’s Cross, Germany’s highest medal for valor, while on his final patrol in U-30.

In March 1941 Lemp, now 28, took command of U-110, a somewhat larger submarine than the Type VIIA U-boat he had commanded thus far in the war. U-110 was a faster boat and could sail twice as far as U-30 before having to refuel. As he contemplated his new command, Kapitänleutnant Lemp could not have known he had less than five weeks to live.

His story concludes in our next blog.

A Royal Navy warship conducts a depth charge attack similar to the one endured by U-30 after attacking the British freighter Fanad Head. Photo credit: www.sfgate.com

Meet the Character Fritz-Julius Lemp, Part 5

July 14, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

The last thing a submarine commander wants to see in his periscope is the sight of two enemy destroyers bearing down on his position, but that is exactly what Oberleutnant Fritz-Julius Lemp saw immediately after sinking the British freighter Fanad Head, Sept. 14, 1939. (See blog post “Fritz-Julius Lemp, Part 4,” July 1, 2016.)

Lemp ordered a crash dive to 80 meters, but the first salvo of depth charges rocked U-30, causing leaks and damaging many of the boat’s instruments. Seeking to escape the deadly explosions, he eventually took his boat down to 144 meters (470 feet), close to its operating limit. U-30’s hull creaked ominously under the pressure and was constantly buffeted by the falling depth charges, but the boat held together. During this extended ordeal Lemp’s quiet self-control calmed his crew and further burnished his reputation for coolness under pressure.

Following the nine-and-a-half hour pounding and with U-30’s batteries running low, Lemp slowly brought his boat to the surface at 11 p.m. The submarine was battered and leaking water, but he managed to slip away under cover of darkness.

He had hoped to set a course for his base in Wilhelmshaven, Germany, but soon discovered the boat’s guidance controls had been damaged. He also realized his badly wounded crewman needed serious medical attention, so Lemp navigated by radio beacon to Reykjavik, Iceland. The neutral port allowed him a limited stay, but it was enough time to stop most of the leaks and make running repairs to assure the boat could submerge in an emergency.

Lemp also arranged for Machinist Mate Adolf Schmidt to enter a local hospital. Before doing so, however, he had Schmidt sign a statement under oath that he would not reveal to anyone the events of Sept. 3, 1939, the day U-30 fatally torpedoed the British passenger ship Athenia.

The next day, Sept. 20, U-30 left Reykjavik to begin a week-long journey home, navigating by the stars. Along the way, the U-boat dived several times to avoid detection whenever a plane or ship was spotted on the horizon. A few days into the journey one of the boat’s two diesel engines quit working. On his final approach, Lemp refused the offer of a tow from a German minesweeper and his boat limped into Wilhelmshaven under its own power the morning of Sept. 27. Waiting for him at dockside was U-boat fleet commander Kommodore Karl Dӧnitz.

Lemp immediately told Dӧnitz he thought he sank Athenia. Accounts of the meeting ascribe various scathing remarks to the senior officer, but he likely suspected U-30’s involvement all along. Lemp explained the circumstances regarding the action and accepted that he had mistakenly identified the ship as an armed merchant cruiser. He also learned that for the past three weeks Germany had been denying responsibility for the attack because none of its ships reported any activity in the area where Athenia went down.

Dӧnitz ordered his young captain to go to Berlin and tell his story to the Naval High Command. As he boarded the plane the next day for the flight to Berlin, Lemp undoubtedly knew he faced a possible military trial for his actions. We will see the outcome in our next blog.

View from the bridge of U-30 after the submarine stopped the British freighter Fanad Head, and before being attacked by Royal Navy aircraft. The figure in the white hat (center, back to camera) in most likely Fritz-Julius Lemp. Photo credit: dinger.byethost.com/fanad.htm.

Meet the Character Fritz-Julius Lemp, Part 4

June 30, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

Oberleutnant Fritz-Julius Lemp caused an international uproar when he torpedoed and sank the British passenger ship Athenia, Sept. 3, 1939. (See blog post “Fritz-Julius Lemp, Part 3,” June 16, 2016.) Lemp’s action was forbidden by international treaty, and he did not report it to headquarters because he thought his radio transmission might give away his position to the enemy.

As a result, the German high command was caught by surprise the next day when word of the attack appeared the news. Absent any report of such action from its submarines in the North Atlantic, the German government immediately denied responsibility for the attack and blamed the sinking on the British, saying it was a ploy to rally world sentiment against Germany. The British, meanwhile, produced witnesses who had seen the submarine and accused Germany of ignoring the treaty and waging unrestricted submarine warfare.

The young German U-boat commander was unaware of this raging propaganda battle. There is no way to know what Lemp was thinking about his colossal mistake, but he dutifully observed the rules of submarine warfare for the remainder of U-30’s combat patrol.

A week after sinking Athenia, Lemp torpedoed and sank the British freighter Blairlogie while observing all the appropriate protocols, even staying with Blairlogie’s lifeboats until dawn, Sept. 11, when the crew was rescued by an American ship.

Three days later, he chased down another British freighter, Fanad Head, and sent a boarding party to the ship as her crew got off in lifeboats. While the party was aboard the freighter, Lemp was surprised by two Royal Navy planes from the aircraft carrier Ark Royal. Fanad Head had radioed its situation, giving the Royal Navy time to scramble the planes and send three destroyers racing to her location.

Temporarily abandoning his boarding party, Lemp quickly submerged to save his boat from the air attack. In their haste, the planes flew so close to the water when dropping their bombs debris from the explosions caused them to crash. The pilots survived and swam to the freighter, where the German boarding party pulled them from the water.

Concerned about further attacks from the sky but wanting to rescue his boarding party, Lemp surfaced U-30 next to Fanad Head and accidentally ran his bow into the freighter’s hull. In quick succession he learned that three Royal Navy destroyers were bearing down on them from the opposite side of the freighter, a member of his boarding party had been seriously wounded and his men had rescued two British pilots.

Lemp brought his crewmen and the British pilots aboard U-30 and submerged. Because of the damage to his bow, he launched a torpedo from his boat’s stern tube and sank Fanad Head with this single blow.

As the freighter disappeared, however, he saw the British destroyers closing in quickly and ordered U-30 down to a depth of 80 meters (260 feet). Waiting silently in the deep, Lemp and his crew had no idea what to expect from their first sustained depth charge attack.

Meet the Character Fritz-Julius Lemp, Part 3

June 16, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

Having torpedoed the first British ship of World War 2, Oberleutnant Fritz-Julius Lemp brought his submarine, U-30, to the surface after nightfall, Sunday, Sept. 3, 1939, to take a closer look at his victim. (See blog post “Fritz-Julius Lemp, Part 2,” June 1, 2016.) He saw the ship in distress, dead in the water, its stern riding low and listing six degrees to port. On deck, its crew busily lowered lifeboats into the water.

At some point during his observations, Lemp decided the ship was not sinking fast enough and ordered another torpedo to finish the job. At the same time, he received a note from U-30’s radio operator that a ship identified as Athenia had begun sending a distress signal that she had been torpedoed and was sinking fast.

The third torpedo proved to be a misfire and it is possible Lemp called out the gun crew to sink the ship with the U-boat’s 88mm. deck gun. (Details of Lemp’s attack were lost when his war log was altered.) Assuming Athenia was the name of his victim, he left the bridge to consult his copy of the Lloyds Register of Ships and determine her tonnage. At that moment, Lemp supposedly discovered he had torpedoed a passenger ship, an act forbidden by the international treaty Germany had signed in 1936.

Today, the question remains whether Lemp knew he was attacking a passenger ship when he fired that first torpedo. By all accounts, he was a capable commander, courageous and cool under pressure, but he also had a reputation for pushing the envelope. With such scant details of his personality, it’s possible to attribute his behavior to a variety of motivations.

Perhaps Lemp thought he was doing the unspoken bidding of his U-boat fleet commander, Kommodore Karl Dӧnitz, who considered the international treaty governing submarine warfare to be unworkable because it required submarines to warn merchant ships before they attacked.

Striking ships without warning maximized the U-boat’s effectiveness and could help neutralize the Royal Navy’s significant superiority over Germany on the high seas. Sinking a passenger ship would show just how implacable an enemy Nazi Germany intended to be.

On the other hand, Lemp, who was one of the younger U-boat captains, may have been eager to prove himself in the eyes of the fleet’s more experienced commanders and, thus, took the ill-advised shot. U-30 crew members who survived the war claimed that Lemp was shocked when he learned he had struck a passenger liner. He apparently ceased his attack with the deck gun and left the scene without reporting his actions to U-boat headquarters or revealing his presence by offering to aid survivors.

While the evidence is circumstantial it seems to point to Lemp’s having made a mistake when he attacked Athenia, most likely thinking he was firing on an armed merchant cruiser.

The war with England was only nine hours old and this young U-boat commander had committed a colossal blunder. But his war patrol would last another three weeks, time enough for Lemp to redeem himself, as we will see in our next blog.

Pre-war photo of U-30, commanded by Fritz-Julius Lemp. Photo credit: u-historia.com

Meet the Character Fritz-Julius Lemp, Part 2

May 31, 2016 by Thomas Sanger • Meet the Character, Thomas C. Sanger • Leave a Comment

On Sunday afternoon, Sept. 3, 1939, the German submarine U-30 sailed into its combat patrol area in the northernmost reaches of the sea lanes leading into and out of the British Isles. U-30 was commanded by Oberleutnant Fritz-Julius Lemp, a young but well-respected U-boat captain (see blog post “Fritz-Julius Lemp, Part 1,” May 14, 2016).

Two hours earlier Lemp had learned of the declaration of war between Germany and England. He understood from his commanders he was not to attack Royal Navy ships in order to avoid embarrassing the British at the outset of hostilities when there still might be a chance to reach a peace agreement. Lemp’s principal targets were to be cargo ships.

Attacks on merchant shipping were governed by complicated “prize rules” established by international treaties. If Lemp discovered a British merchantman sailing without naval escort, he had to surface to give warning before attacking. Once the ship stopped he was required to board the vessel to determine if she carried any war material. If contraband was found, the rules allowed him to sink the ship, but only after its crewmen were safely away in lifeboats. Passenger ships could not be attacked under any circumstance.

The rules were further complicated by the British practice of outfitting some merchant ships with naval guns. These “armed merchant cruisers” would assist Royal Navy warships in patrolling Britain’s shipping lanes. A few cargo ships were turned into so-called “Q-ships,” merchantmen with their guns hidden from view. Any unsuspecting U-boat that came to the surface to give warning with intent to board such a ship would quickly become the prey instead of the hunter.

Shortly after entering his combat zone that Sunday afternoon Lemp spotted a large freighter and gave chase. He broke off the chase, however, when he discovered the ship was from Norway, a neutral country, and thus immune from attack. After several hours of fruitless searching U-30’s lookouts spotted a large ship on the northeastern horizon, sailing alone and heading west. Lemp put his boat on a course to intersect the mystery ship and the two slowly converged over the next three hours.

To avoid detection, U-30 submerged shortly before sunset at 7 p.m. Although Lemp hadn’t been able to determine the ship’s nationality, he may have suspected she was a merchant cruiser. The ship was sailing well north of the merchant shipping lanes, proceeding in an evasive zigzag pattern and was blacked out to avoid detection at night.

With darkness falling and the big ship now only about 1,500 yards away, Lemp decided to attack and likely fired at least two torpedoes. His first shot was the only one to hit home, but it proved to be fatal. Though he didn’t know it at the time, Lemp had become a footnote of history – the man who commanded the first successful U-boat attack on a British ship in World War 2.

Unfortunately the ship he had struck was the passenger liner TSS Athenia, exactly the type of ship he was forbidden to attack under international law.

Lemp’s story continues in our next blog.

Fritz-Julius Lemp, commander of U-30. Photo credit: alchetron.com

Meet the Character Fritz-Julius Lemp, Part 1

May 14, 2016 by Thomas Sanger • Meet the Character, Without Warning Book • Leave a Comment

Of all the characters I researched for my forthcoming historical novel, Without Warning, Fritz-Julius Lemp was the most enigmatic. Lemp commanded the German submarine that sank the first ship in the Battle of the Atlantic during World War 2. His attack on the British passenger liner Athenia is the central event of the novel, which is told through the experiences of eight characters, including Lemp.

Who was he, and why did he loose the fatal torpedo when he had strict orders not to attack unescorted passenger ships?

Trying to answer these questions proved largely futile, although I gained tantalizing glimpses through the accounts of a few sailors who served with him and from histories of the German U-boat war.

Lemp was born Feb. 19, 1913, in Tsingtau, China. The port city was the administrative center of a 200-square-mile concession Germany leased from China in 1898. His father was a junior ranking Army officer, who returned to Germany with his wife and young son before Tsingtau fell to the Japanese at the start of World War 1 in 1914.

There is little record of Lemp during his formative years in Germany, although he would have grown up during a time of great social unrest and economic hyper-inflation. At age 18 he carried on what may have been a family military tradition by joining the German Navy as an officer trainee.

In 1935 he became a full-fledged naval officer (Leutnant zur See), and a year later volunteered for U-boat service. At the time, the Unterseeboot Fleet was made up entirely of volunteers, a condition established by the fleet commander, Kommodore Karl Dӧnitz, in an effort to create an elite force. Lemp attended submarine school and served a tour of duty as a watch officer aboard U-28, before undergoing further schooling to qualify for command of a U-boat.

At the relatively young age of 25, Lemp, now holding the rank of Oberleutnant, was given command of U-30 in November, 1938. Some months later, he experienced a defining moment in his young career when U-30 collided with another submarine during submerged maneuvers. His quick thinking and cool execution of emergency procedures were credited with saving his boat and the 42 men aboard. It is not clear exactly what happened or who, if anyone, might have been a fault. But from that day forward, Lemp enjoyed the complete confidence of the officers and men sailing with him.

When the German Army invaded Poland on Sept. 1, 1939, nearly all of Germany’s ocean-going U-boats were poised for attack in designated waiting zones beyond the shipping lanes into and out of Great Britain. Three times the previous year the U-boat fleet had been similarly deployed in anticipation of possible hostilities with England, but each time conflict was avoided and the fleet had been recalled.

In the early afternoon of Sept. 3, word was flashed to all German armed forces that England and Germany were at war once again, 21 years after the end of World War 1. It would prove to be the first day of the brief, but momentous combat career of Fritz-Julius Lemp.

His story continues in our next blog.

U-boat successes like the sinking of HMS Courageous on Sept. 17, 1939, masked basic problems with German torpedoes at the start of the war. Photo credit: theatlantic.com

War History The Trouble with Torpedoes, Part 3

April 28, 2016 by Thomas Sanger • Thomas C. Sanger, War History • Leave a Comment

German submarines sank 114 ships (more than 420,000 tons of cargo) in the first few months of World War 2, September through December, 1939. Despite these widely publicized successes – including sinking the Royal Navy aircraft carrier Courageous and battleship Royal Oak – German Rear Admiral Karl Dӧnitz was angered by a large number of torpedo misfires reported by his captains. (See blog post “The Trouble with Torpedoes, Part 2,” April 15, 2016.)

By the end of the year, complaints from the commander of the U-boat fleet led the navy to replace the head of the Torpedo Directorate, the department responsible for the design and development of torpedoes. The new chief soon reported the fleet’s torpedoes were defective in many ways, and he set about finding solutions. Yet every time the Directorate fixed one defect a new one cropped up.

Many of the problems centered on the torpedo’s detonator, or pistol, the device that exploded the warhead when the torpedo reached its target. The standard pistol for all torpedoes allowed U-boat captains to choose between a contact and magnetic detonation. A contact setting caused the torpedo to explode when it struck a ship’s hull, while a magnetic setting exploded the torpedo when it detected the magnetic field of a ship’s hull, ideally right beneath its keel.

The Directorate quickly resolved problems with the contact mode, but solutions for the magnetic mode proved more difficult because of its sensitivity. The magnetic field of a target varied with a ship’s size and was also affected by the Earth’s magnetic field. In addition, the depth setting for the torpedo was critical because if it passed too far beneath a ship it didn’t detect a magnetic field and failed to detonate.

Slowly, one by one, problems came to light involving the pistol’s magnetic detonation setting. As early as October 1939, Admiral Dӧnitz ordered his captains to use only the contact detonation setting. When the Directorate announced the design had been corrected, Dӧnitz approved using the magnetic setting again. Almost immediately misfires increased and he reinstated the magnetic detonator ban.

Even though this cycle continued with maddening regularity, German torpedoes proved effective enough in the Battle of the Atlantic to sink 1,900 ships and 10.2 million tons of cargo from 1940 through 1942. But for the flawed torpedoes, U-boats might have wreaked far more devastation during these early years, particularly because Allied anti-submarine weapons and tactics experienced their own developmental problems.

In early 1943, the Torpedo Directorate introduced a new, more dependable detonator, but the golden opportunity had been lost. While Germany was perfecting its torpedo design, the Allies had been making improvements in underwater detection technology, airborne radar, depth charge weaponry and surface tactics. U-boat captains found it increasingly difficult get into position to launch their improved torpedoes or to escape destruction once they were discovered by Allied navy hunter-killer groups.

In May, 1943, Allied navies sank 41 German U-boats, nearly three times the total of the previous month. It proved to be a turning point in the Battle of the Atlantic as the U-boats’ successes steadily declined for the remainder of the war.

A magnetic detonator was designed to explode a torpedo beneath a ship and break its keel with a single blow. Photo credit: uboat.net

War History The Trouble with Torpedoes, Part 2

April 14, 2016 by Thomas Sanger • Thomas C. Sanger, War History • Leave a Comment

In the opening months of World War 2, German submarine captains reported numerous torpedo failures. Time and again they watched their shots miss completely, fail to detonate once they reached their targets or detonate prematurely. U-boat fleet commander, Rear Admiral Karl Dӧnitz, estimated at least 30 percent of the torpedoes launched by his captains were duds. (See blog post “The Trouble with Torpedoes, Part 1,” April 1, 2016.)

One problem landed on Dӧnitz’s desk two weeks after the start of the war in early September, 1939. It involved the torpedo’s guidance systems that kept it on a pre-set course and depth once it left the submarine. These parameters were dialed into the torpedo before it was fired. After leaving its tube, the torpedo changed its course and depth as necessary in order to run true to its target.

The torpedoes delivered to the fleet at the start of the war were equipped with the course changing guidance system, but by mistake they had been fitted with stationary fins that did not allow them to be steered. When this egregious mistake was corrected, however, the success rate did not significantly improve.

Admiral Dӧnitz suspected most misfires were caused by the detonator, or pistol, the device that caused the torpedo’s warhead to explode once it reached its target. A sophisticated detonator, which could be set to explode the warhead either when it stuck a ship’s hull or detected the hull’s magnetic field, was adopted at the end of September 1939 as the standard for all torpedoes.

A contact detonation resulted when a torpedo struck its target several feet below the waterline and usually breached the ship’s hull. However, the explosion wasted much of its energy in the form of a large plume of water that erupted alongside the hull. As a result, one or two more torpedoes might be needed to sink a large ship.

By contrast, a magnetic detonation was designed to explode the warhead beneath a ship, where its energy would be more efficiently concentrated on the ship’s keel. The explosion usually broke the keel, breached the hull and sank the ship within minutes. Because such damage could be inflicted by a single torpedo, U-boat captains preferred the magnetic setting.

Magnetic detonation required the torpedo to pass close enough beneath the ship to detect its magnetic field. Maintaining the torpedo’s proper depth was critical to its success. In addition, the detonator had to be set at the proper calibration for the strength of the target’s magnetic field, which varied with the size of the ship. U-boat captains also needed to account for the Earth’s magnetic field, which changed depending on the U-boat’s distance from the magnetic north pole.

When the complaints began to pile up, the Torpedo Directorate, the German navy department charged with Torpedo design and development, questioned whether U-boat captains were accurately estimating the data used to calibrate the magnetic detonator.

Admiral Dӧnitz’s frequent complaints prompted the Naval High Command to establish a Torpedo Inspectorate to study the growing misfire reports. But if Dӧnitz thought his fleet’s torpedo problems were about to be resolved, he would be sorely disappointed, as we will see in out next blog.

Photo caption: Problems in the design and production of German torpedoes led to many misfires by U-boats early in World War 2. Photo credit: www.navweaps.com.

War History The Trouble with Torpedoes, Part 1

April 1, 2016 by Thomas Sanger • Thomas C. Sanger, War History • Leave a Comment

We may never know for certain the details of the German submarine U-30’s attack on the British passenger ship Athenia. The U-boat’s log book was altered to allow the German navy to deny responsibility for the attack by showing the sub was many miles away when Athenia was torpedoed, Sept. 3, 1939. (See blog post “Nazi Denials of the U-30 Attack on the SS Athenia;” July 1, 2014.)

We know, however, that the commander of the submarine, Oberleutnant Fritz-Julius Lemp, experienced a frustration common to many of his fellow captains at the start of the war – torpedo misfires. While Lemp’s first shot hit home and eventually sank the passenger ship, two subsequent torpedoes failed.

In his initial attack, Lemp fired at least two (some say four) torpedoes, according to accounts from U-30 crew members. The U-boat’s radio man, Georg Hӧgel, reported the second torpedo became stuck in the submarine’s torpedo tube and when finally launched, it exploded prematurely. In other accounts, the second shot ran out of control, forcing U-30 to dive to avoid being struck by its own torpedo. Even in versions that describe a salvo of four torpedoes being fired, only the first shot hit its target. (The attack on Athenia is the central event in my forthcoming historical novel, Without Warning.)

Lemp later surfaced in the dark of night to assess the damage he had done. He decided the ship was sinking too slowly and might even stay afloat long enough to be towed to port and salvaged. With a stationary target and favorable attack angle, U-30 fired another torpedo to finish off the crippled ship, but it failed to strike home. Shortly after this last shot, Lemp discovered he had mistakenly attacked a passenger ship – an action forbidden by submarine warfare protocols in affect at that time – and he left the scene without taking any further action.

Three weeks later, U-30 returned to its home base in Wilhelmshaven, Germany. Lemp apparently launched only two other torpedoes during the remainder of his combat patrol – both fired at stationary targets – and both detonated as designed. Once in port, he admitted sinking Athenia and was ordered to explain his actions to the German Naval High Command in Berlin. Faced with justifying his attack on a passenger ship and possibly having to save his naval career, Lemp is unlikely to have spent much time reporting his torpedo misfires.

Nevertheless, over the next several months the misfires became a high priority for the man in charge of Germany’s U-boat fleet, Rear Admiral Karl Dӧnitz. Despite the admiral’s complaints, U-boat successes during these early months apparently led Naval High Command to discount reports of torpedo failures.

But as we will see in our next blog, the misfires pointed to larger and more systemic problems, and the failure of top naval commanders to correct them in a timely manner undermined the U-boat fleet’s contribution to the Nazi war effort.