The lighter-than-air (LTA) component of the U.S. Navy, whose World War II role is generally unknown and often downplayed, is due for a major reassessment. While a great deal of investigative work remains to be done, research shows the “helium umbrella” over our merchant marine looked more like a brick wall to U-boat crews. Based on research by diver Edward Michaud and newly declassified information, new investigations could correct some misconceptions concerning the role of the airship squadrons of World War II.1
No K-type airship ever sank a submarine as simply as “sighted sub, sank same.”2 This is false. On 25 August 1944, the fC-25 sighted a German U-boat (code named “LT” by the Office of Naval Intelligence [ONI] ) surfaced off the coast of Chatham, Massachusetts. The K-25 struck the U-boat with one charge just aft of the conning tower, breaching the hull, sinking it as it tried to submerge.3
The blimp was a relatively ineffective offensive weapon.'' This is inaccurate, despite even the negative record being incomplete. In a well-documented action, the K-74 made a surface attack against the U-I34 off Florida in July 1943. Because it was not known that the attack had rendered the U-134 mortally vulnerable, the command pilot was almost court-martialed. Virtually unknown, a year later, the K-14 attacked a submarine off Bar Harbor, Maine, with heavier casualties on both sides. That time the command pilot was found negligent by the board of inquiry.5
“The airship is not known to have been credited by the Navy . . . with having single handedly destroyed any U-boats.”6 True, credit has been denied where it is due. Patrolling in the Caribbean on 26 April 1943, the K-45 received a moving signature, dropped its depth bombs, and scanned for results. Suddenly a U-boat surfaced behind the K-45; they had missed. Disarmed, the K-45 withdrew and radioed for help.7 The submarine escaped in the seven hours it took for surface units to arrive. Casual research has not revealed which U-boat was so damaged to make a desperate surfacing. What if one of the K-45’s charges had been lucky enough to strike the U-boat that April day, instead of causing just enough damage to compel it to surface? When the K-type weapons system was operated correctly, victory was too complete. The vanquished did not send up a white flag—he drowned in his cracked hull.
The U.S. Navy had no method to verify blimp crews’ combat reports, unlike gun camera film brought back by a fighter jock or postmission photo reconnaissance assessment of a bombing run. The formidable task of relocating a specific spot in an airship mission’s enormous patrol area would have taxed precious resources.
There has been no systematic effort to match both sides of the stories, as has sometimes been done with major combatants. In only a few cases8 have both attacker and airship defender in the same action been identified. This continues today; for example, there have been no attempts to connect the recent discovery of a U-boat lying off Barnegat Light, New Jersey, with nearby Lake- hurst—“airship city.”
By mid-1943, operational flights along the U.S. coastline were all but continuous. One squadron, ZP-21 out of Richmond, Florida, had at least one airship aloft 24 hours a day, 7 days a week, for 965 continuous days, until the last day of the war. One U-boat captain said, “Every time I raise my periscope, an airship is there!”9 Most estimates state the Germans had more than 850 operational U-boats, more than 725 of which never came home. Certainly not every blimp crew that claimed to have bombed a MAD signature motionless was wrong.
Several veterans have related actions where the system worked as designed—where K-ships located and attacked and/or tracked submerged submarines and were relieved or ordered away by surface units.10 Actions considered confidential at the time were not logged so that future historians might easily find them. For example, the widely known K-74 action against the U-134 is not included in the official Naval Air Station Richmond history.
“Most officers considered [blimps] worse than useless because they could be spotted more easily than the most smoke-careless freighter.”11 The record clearly shows just the opposite: no group of ships was ever successfully attacked while under blimp protection. In the log of the U-69 on 12 September 1942, the captain reported “airship continuously in sight” after several hours of waiting to attack a convoy. At 2001 hours he noted, “Airship now over fresh convoy . . . the amusement at first caused by the appearance of airships has given away to a certain amount of respect.” Early the next morning, he gave up his pursuit of the convoy.12
Further, few are aware of the humanitarian and utilitarian tasks blimps also performed. Flashing commands to a radioless convoy straggler—even dropping notes accurately on deck when signal lights were misunderstood— prevented harm without combat victory. This principle takes on a more personal intimacy when heavily loaded troopships were protected, or when providing safe passage from friendly fire for our own submarines.13 A merchant vessel saved with its cargo intact was of immeasurably greater value than a U-boat sunk.
By James Shock’s estimate, during World War II, more than 1,000 people owed their lives to blimp rescue.14 Despite his and other well- researched reports, the rescue record is also not complete13 and its value is not assessed. The value of saving ace Captain Frank Baldwin, U.S. Marine Corps, from drowning can be measured in the number of enemy planes he later shot down.16 But the effect of his rescue on overall morale—indeed, that only our side possessed this unique rescue system—was immeasurable. The photo of freezing survivors using tree branches on the snow to spell out “SEND BLIMP” was not widely published, but speaks volumes.17
Even less known was the blimp’s role in research and development. Were it not for the airships, the bulky prototype LORAN gear would have had to wait for a suitable oversized airplane testbed. Its successful blimp-borne tests in early 1942 were one of many immeasurable examples of lifting gas making up for deficiencies in the test articles, whose earlier adoption helped the war effort.
The L-8’s delivery of vital B-25 bomber parts to the crowded deck of the USS Hornet (CV-8) is publicized and its value measurable. Routine delivery of mail to a crowded troopship has been forgotten, but was uplifting to the confined troops.18 Yet these are but a few examples of services that could not be accomplished by any other craft of the day. There is an important lesson here for today’s conceptual artists: With modem technology, buoyant craft could be constructed that would accomplish tasks not possible for heavier- than-air craft at any cost. “We cannot start building airships now in the middle of a war, but it behooves us to look ahead and learn from experience.”19
“The airship was a reasonably effective defensive weapon.’’20 True, the blimps could be spotted—and that is why U-boats drained their batteries waiting for a better attack opportunity, or started worrying about their own survival. “We have been complimented by the Nazi radio itself on two occasions. While broadcasting excuses for U-boat failures, it has spoken of the airship patrol off our shores.”21
Part of the measure of any weapons system’s usefulness is its cost-effectiveness. Early in the war, commandeered Goodyear advertising blimps—armed only with radios and small arms—represented one of the most cost-effective ship- protection system in history.22 The K-ship’s low purchase price and operating cost, coupled with its high mission availability and reliability and good safety record, are often overlooked in comparing antisubmarine warfare systems.
LTA assessment suffers from the classic optimist- pessimist argument. A search that did not turn up a U- boat also verified that none were in the K-ship’s track. This argument demonstrably was more positive when no mines were spotted in ships’ paths by their buoyant troubleshooters. “Minesweepers, used to waiting for explosions to announce the presence of mines, liked having the blimps tell them mines lay ahead. They liked it even better when blimps told them there were no mines ahead.”23 One can graph what would have happened if the USS Gilbert Islands had hit a Japanese mine.24 The fact that the ZP-14 was requested to assist the Allied mine-clearing effort in the Mediterranean, and that they were in this service long after V-E Day, is ignored.
“Most of the convoy escorting took place in the later, less dangerous part of the war.’’25 Blimp squadrons did not reach effective strength until early 1943—and by that time, U-boats largely had abandoned the coastal Americas. Did blimps cause the withdrawal? Mid-1943, widely considered the turning point in the Battle of the Atlantic, saw better intelligence and more ASW measures, sinking a record number of U-boats. Submariners faced these ASW forces throughout their operating areas—why abandon the coastal Americas’ fertile hunting grounds in particular? Gordon Vaeth’s interview with Admiral Donitz reveals that the Germans considered airships “one of the Allies’ most effective defensive systems— posing a significant danger to his U-boats.”26
Just how seriously did U-boat crews take the airships? They knew of airborne radar, and eventually subs were equipped with an awkward radar detector. Did they know an airship might be able to detect them underwater? Author William Althoff cites rumors of secret weapons circulating among U-boat crews when increasing numbers of submarines failed to return.27 Because MAD gear was so secret that even mentioning the acronym was a court-martialable offense, it’s unlikely the Germans knew of its effectiveness.
However, thousands of sonobuoys were dropped by passing airships. A U-boat surfacing after waiting for an airship to pass would have bumped into a sonobuoy sooner or later. Returning it to Germany, it wouldn’t have taken the brightest technician to figure out it was a hydrophone connected to a radio transmitter and to conclude the airship could thereby hear the submerged submarine, rendering it vulnerable to airship attack.28
This leads us to conclude that, given improved ASW taking a toll on U-boats everywhere, the lack of a practical defense against the “Luftschiff” caused a decrease in sub deployments into coastal areas protected by airship. While this is hardly the only possible explanation, it is one that fits the facts.
Investigation of the ASW airship should continue, focusing on at least these relatively inexpensive areas of research:
1. Interview surviving U-boat veterans who sailed off the coastal Americas and record their specific recollections about “Luftschiffs” or “kleine Zeppelins.”
2. Pick up where J. Gordon Vaeth retired and locate U-boat logs he did not access.
3. Scan the newly declassified records of decoded U-boat radio transmissions. The Office of Naval Intelligence began recording, if not quickly decoding, before 1942. As they logged the ASW measures they encountered, we can bet U-boat crews complained about tougher defenses in their coded radio transmissions.29
4. Solicit specific claims of U-boat encounters from surviving K-ship crews for matching with the above.
5. Solicit K-ship crew claims of successfully attacking submerged targets, obtaining all available specifics, with hope of matching incidents to information provided on at least previously charted U-boat hulks.30
The recent move of U.S. Navy World War II records to the National Archives at College Park, Maryland, gives a kind of “one-stop shopping” for access to many required records. A work team for this assignment could come from the Naval Airship Association—many of its members could spare the time and divide the labor.
In the uncertain days before the U.S. entry into World War II, then-Captain Charles Rosendahl wrote an article praising the airship’s role in sinking submarines and protecting shipping during the previous war.31 This was pivotal in swaying the Roosevelt administration to include “no more than 48 useful, nonrigid airships” in the 10,000-plane program of 1940. Had this call not been heeded, and the K-ship assembly line not been in place, the conduct of the U-boat war would have been quite different.
Modern study could ease the U.S. Navy’s hesitation to return displacement vessels to the air above our fleet. It could open an entirely new technology to ease the sealift problem. It could help consummate the U.S. Coast Guard’s 50-year flirtation with employing the simple efficiency of buoyant flight. Those who ignore LTA’s past will not be able to benefit from its potential future.
1. Diver Edward R. Michaud made many details of his discoveries public in the 2 February 1997 Brockton (Massachusetts) Sunday Enterprise. Both ZP-li cases were discussed in Portland Monthly Magazine, vol. 12, no. 5 (July/August 1997).
2. A universally held belief, even among airship proponents. Contrast that with this, from Proceedings of October 1943: “ . . . the blimps have been successful in bagging many subs—just how many, the Navy will not yet say.”
3. The complete story of the “LT” is a political thriller, in which the K-25's successful attack was an unexpected final chapter. The case is summarized by Michaud in his Status Report to the First Federal District Court, Boston, Civil Action 95-11374RCL, 21 November 1996.
4. “The Airship in World War II: Assessing a Unique Element in Naval Air Power,” in Martin L. Levitt, Air Power History, fall 1992.
5. A. W. Moffat, A Navy Maverick Comes of Age (Bantam Books, 1977). “But it was obvious that the court wanted no record of any sub attack in those waters. At the hearing they admitted no evidence except that obtained from interrogating the survivors. It would not even accept in evidence the written statement of the technicians that they found many bullet holes in the fabric. . . . When the bag was spread out on the field they were able to determine that the bullets entered the bag aft of the car and exited at the top amidships.” At least the Board’s minority opinion bravely refused to rule out enemy action. The Portland, Maine, Press Herald and the Boston Globe reported on 5 January 1997 that Greg Brooks may have located the U-boat that limped a few miles away before succumbing to K-14’s attack.
6. J. Gordon Vaeth, U.S. Navy Airship Operations in World War II.
7. J. Gordon Vaeth, Blimps and U-Boats (Naval Institute Press, 1992).
8. The K-3 vs. the U-432 per mutual log entries; K-37 vs. the U-107, per professor Jurgen Rohwer.
9. Vaeth, Blimps and U-Boats.
10. A personal friend of Vice Admiral C. E. Rosendahl, Airship Rigger Hepburn Walker, Jr., said many in airships were aware of an incident off NAS Weeksville where ZP-14 blimps had located and attacked a U-boat, only to be ordered out of the area by the senior officer present afloat, a Coast Guard officer from the nearby Elizabeth City station. Captain Jones related a successful K-ship hunter/airplane killer action off Brazil to the author via phonecon.
11. S. E. Morison, History of the United States Naval Operations in World War II, vol. 1, “The Battle of the Atlantic” (Little, Brown & Co., 1947).
12. Vaeth, Blimps and U-Boats.
13. R. H. O’Kane, Clear the Bridge (Bantam Books, 1977). “Our escort, a blimp from Sunnyvale . . . took station ahead . . . primarily to help identify Tang as friendly so that we would not be driven down by our own planes.”
14. J. R. Shock, U.S. Navy Pressure Airships 1915-1962 (Atlantis Productions, 1993). Previous to this volume, rescue operations were reported separately, in the Atlantic through 1944, by reference 24; and the Pacific, intermingled with other operations, in a memorandum “Operations of Fleet Airships and Costs of Blimp Program” compiled by C. E. Rosendahl, 18 January 1945.
15. K-ship command pilot Joseph Lundy showed photos of a downed Army A-20 and the pilots he rescued from the Brazilian jungle; similar to others, it was not recorded. At the 1997 NAA reunion, two K-shipmen told of having dropped a raft to mid-air collision survivors, then using the airship’s mooring lines, towed them for many long, careful hours to safety. How many other rescues were too routine to record?
16. Captain R. F. Tyler, Report on Rescue Operations, 1946.
17. Buoyant Flight editor Eric Brothers located this photo in Goodyear company papers.
18. Serving as a U.S. Army infantryman, later General Motors executive and lighter-than-air author James Shock and his shipboard comrades received mail via Navy blimp.
19. In the 2 November 1939 issue, Flight (a British magazine) lamented that so many Royal Navy assets were tied up searching for two German surface raiders that could have been located by a couple of cheaper airplane-carrying rigid dirigibles. The failure of the commercial airship R-101 led to the abandonment of British military airships, despite history’s largest lighter-than-air fleet having a pivotal role in saving Britain from starvation in World War I. After a nearly 70-year hiatus, the British Ministry of Defence tested an airship for military applications.
20. Extrapolated from “The Airship in World War II: Assessing a Unique Element in Naval Air Power,” Martin L. Levitt, Air Power History, fall 1992.
21. An officer quoted in Mason Sutherland, “Aboard a Blimp Hunting U-Boats,” National Geographic (July 1943).
22. Interview with Captain M. H. Eppes, U.S. Navy (Retired). As the most cost-effective defensive system in the war, the only airship on the West Coast in 1941—the Goodyear advertising ship Resolute— patrolled Los Angeles harbor armed only with pilot Art Sewell’s hunting rifle. L-8’s return without its crew is reported as everything from love triangles to alien abductions. It is never noted that this weapons system came home alone after suffering engine failure and structure damage, then was repaired to fight again.
23. A. S. Lott, Most Dangerous Sea (Annapolis, MD: Naval Institute Press, 1959). There is a lesson here for mine countermeasures conceptual artists.
24. Fleet Airships Atlantic, Report on Airship Rescue Operations. Captain R. F. Tyler notes K-60 prevented a carrier from striking a mine. Information on the ZP-33 auxiliary base at Quilloyute, Washington, as to its success in countering Japanese FUGO balloon bombs has not been found.
25. Morison, ibid.
26. Vaeth, Blimps and U-Boats.
27. W. A. Althoff, Sky Ships: A History of the Airship in the U.S. Navy (Orion Press, 1991).
28. The Reagan administration somehow avoided a scandal when a captured and dissected Russian sonobuoy was found to have Texas Instruments microchips on its circuit board.
29. An interview with former cryptographer Preston Howley, stationed at the Chatham, Massachusetts, radio listening station in 1944, was a crucial disassociated witness verification of the K-25's combat action. But some Office of Naval Intelligence records may have been destroyed before being declassified, and surviving records would not reveal actions—like landing saboteurs—where radio silence was maintained.
30. At the 1993 NAA reunion, former K-ship radioman Howard Synder gave details of what he believed was a victory over a submerged submarine. The time available to collect reports from the few combat K-shipmen who are still living is limited.
31. C. E. Rosendahl, “The Case for the Airship Today,” presented at the National Aviation Forum, Washington, DC, 29 May 1940.
