Military, WW2

When a Blimp Attacked & Sunk U-Boat U-134

Blimp Bandits: Before the start of World War Two the airship was no stranger to military and naval service. German Zeppelins had been used to bomb mainland Britain during the Great War and both the British and German Navies had also used them for patrolling between 1914 and 1918.

In the 1920s and 1930s the airships would see a golden age, with behemoths like the Graf Zeppelin making intercontinental travel a reality for the great and good in the interwar years. However, when the Hindenburg caught fire while attempting to dock in New Jersey in May 1937 it seemed the airship had had its day in the sun.

The US Navy had given the operational use of blimps serious thought just before the outbreak of war in Europe in September 1939. As the war flowed into its second year in 1940, Congress put into action the ’10,000 Planes Act.’

Graf Zepplelin
Graf Zeppelin over Rio de Janeiro in 1930

K Class Blimp

‘The President of the United States is hereby authorised to acquire or construct naval airplanes and nonrigid lighter-than-air craft, and spare parts and equipment…including eight hundred and fifty airplanes for the Naval Reserve, and a number of useful nonrigid lighter-than-air craft at a total of not more than forty-eight.’

With this act the airship program was put into effect with the craft being put to the task of antisubmarine warfare, as they had done in the Great War. When the US entered World War Two after the Japanese attack on Pearl Harbor on December 7th 1941 the US Navy had only ten airships in their fleet.

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But this number would steadily grow as the war went on. One of the types of airships used by the Navy for this purpose was the ‘K’ Class blimp built by the Goodyear Aerospace company. The first ships flew in 1938 and in October 1940 the Navy issued a contract to Goodyear for 6 of the K class blimps. A total of 134 were eventually manufactured over 2 decades by the company for the Navy and for civilian use.  The K class blimps usage by the navy was outlined by The Chief of Naval Operations:

The patrol type nonrigid airship (ZPN) now being constructed for this program is the “K” class of 416,000 cubic feet volume, 250 feet length and 77 feet overall height. Carrying a crew of 3 officers and 5 enlisted men, these blimps with a military load of 2 to 4 depth bombs plus machine guns will have a cruising range of some 1500 to 2000 nautical miles at a cruising speed of 45 to 60 knots… The obvious logical uses for these ships are in the detection of – and attack on – mines and submarines, and in the escort, when desirable, of convoys through the coastal shipping lanes.’

Airships were fitted with depth charges.
US Navy sailors attach depth charges to the underside of a K-class blimp at NAS Weeksville, North Carolina in 1944

Blimp K-74

The blimps would also use an onboard radar system to help with the detection of enemy submarines. They were designed to observe, lay mines and work in tandem with convoys in the hunt for U-boats within their patrol radius. They were not to actively fight the enemy in open combat. However, there would be one known instance of an attack made by a blimp on a U-boat.

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On the night of the 18th July 1943 Blimp K-74 was taking part in a night patrol of off the southeast coast of Florida. Her crew was aided in their search for enemy vessels by an almost full moon. Her crew of 8 was led by Lt Nelson Grills. A declassified Fleet Airship Atlantic bulletin from August 1943 details the moment the crew first became aware of enemy activity that night:

The K-74 was flying at 500 feet altitude, on a track of 189 degrees true, and at a ground speed of 47 knots. At that moment, a radar blip

was detected.’

The blimp reported would turn out to be a U-134 which was on its 9th patrol. The type VIIC submarine had started the war patrolling the coasts of Norway in December 1941. She had sunk the merchant ship SS Scapa Flow in November 1941 as well as 2 other vessels before her encounter with K-74 in 1943. The U-boat was above the water when the crew of the American blimp spotted her:

‘One-half mile to the port of the airship a submarine was seen perfectly silhouetted in the bright moonlight.’

German Submarine U-134
The German submarine, U-134, under attack during WW2. It lived something of a charmed life until its eventual sinking in 1943


Lt Grills went against procedure and did not report the sighting of the U-134 and began an attack run on the submarine instead. As the blimp bore down on its target U-134 swung left at a 90 degree angle but the blimp pressed on and drew in even closer. Then at a range estimated to be approximately 250 yards the U-boat opened up on the blimp with its deck guns.

The US crew replied in kind with Aviation Machinist’s Mate Third Class Garnet Eckert firing back with the blimps with an M2 Browning. However, the German fire proved to be deadly accurate and a round from the 20mm deck gun tore a hole in the blimp’s gas bag. A final attempt was made to destroy the U-134 with depth charges; two were dropped close to the U-boat but they failed to sink her.

After this attack K-74 had caught fire but the crew were initially able to keep the flames at bay. Inevitably the damaged sustained from the U-boat was too great and K-74 crashed into the sea at around midnight. The American crew successfully managed to escape the blimp as it started to sink but all was not over yet.

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Lt Grills remained at the sinking wreckage to destroy valuable equipment and papers to stop them falling into enemy hands, he was then separated from the rest of the crew who had floated out of site. Eventually the rest of K-74’s crew returned to the wreckage to keep themselves afloat with the exception of Aviation Machinist’s Mate Second Class Isadore Stessel who had drifted away from the crash site being a weak swimmer. The downed crew were spotted at 7.45am on the 19th of July by a J4f search plane which had come across them in the water.

USS Dahlgreen

The plane then went on to make contact with the nearby destroyer USS Dahlgren which started to make its way to the stricken crew. During this time Stessel, who had taken in a large amount of sea water, was attacked by a shark.

The rest of the crewmen linked up to defend themselves in case of a further attack. Ensign Everlsy reported seeing Stessel struggling and heard him screaming as he was dragged under the water by the shark. He was the only American airship crewman to be killed during World War Two. The USS Dahlgreen finally located the surviving K74 crew and had them safely aboard at 10 am. Lt Grills was picked up some nine hours later.

A welcome escort.
A K-series blimp escorts a merchant ship during World War II.

Amazingly, after the airship had crashed, Kaptain-Lieutenant Hans Gunther Brosin of the U-134 had managed to get alongside the sinking blimp, boarding it to take pictures and even removing a piece of the wreckage and bringing it back with him to his U-boat.

How he did this without the crew of K-74 knowing is a mystery. The photos Brosin took were transferred to another U-boat before the U-134 was sunk on the 27th of August 1943 by depth charges dropped from a Wellington bomber and an attack by HMS Rother. There were no survivors.

Thus marked the end of the K-74 incident. The Fleet Airship Atlantic Bulletin that documented the encounter was only declassified in 1958, the same year the Americans discovered the photos taken by Kaptain Brosin. Lt Grills was considered for both a court-martial and a DFC for his actions. Neither came to fruition. Stessel’s family posthumously received a Purple Heart 54 years after the incident.  K-74 was the only K-Class blimp lost to enemy action during World War Two. The last K-ship was retired from naval service in March 1959.