ZRN: The Rigid’s Last Best Hope

R. K. Smith wrote, “The Navy’s General Board had in 1937 passed on the Durand Committee’s recommendations for a large rigid ZRCV-type rigid at that time, instead opting to recommend procurement of the long-discussed training airship. The Board specified a 3 mil cu ft capacity with the provision to carry at least two airplanes. Section Six of the Naval Expansion Bill, passed May 17, 1938, specified: “There is hereby authorized to be appropriated the sum of $3,000,000 to be expended at the discretion of the President of the United States for the construction of a rigid airship of American design and American construction of a capacity not to exceed three million cubic feet either fabric covered or metal covered to be used for training, experimental, and development purposes.” So, it seemed, at last there would be a US Navy rigid airship again, and it would be designated “ZRN.”

zrnBuAer responded with a three mil cu ft girder-and-fabric design that was 650 feet long and carried three contemporary airplanes. The BT-2/SBD-1, replacement for the BT-1 used with the ZRCV design of two years earlier, would have been the most likely airplane to be equipped with skyhooks.  With the aid of the Naval Airship Association’s Technical Committee, Herman Van Dyk has here re-created the BuAer ZRN design as it would have been configured and flying by 1939. However, not all in concerned agreed to the girder-and-fabric plan.

Congressman John O’Connell wrote to CNO Admiral Leahy in June 2nd, suggesting an impartial panel of non-airship, non-Government structural experts be employed to choose the best frame structure for the new airship. “…I have for several years advocated the construction of American airships upon American design, particularly that their construction be upon a dirigible frame of the ‘self anchored suspension bridge’ principle, in preference to the Zeppelin frame that is an adaptation of the ‘arch frame bridge’… I desire that we build only that which is the best design, as may be approved by unbiased leading American structural engineers.” He sent copies of the letter to BuAer chief RADM A. B. Cook, fellow Congressmen Carl Vinson, and Senator David Walsh. Sadly, his was a voice in the wilderness.

cnoCNO Admiral Leahy (right) responded to Congressman John O’Connell letter telling him in no uncertain terms there would be no unbiased board of experts to determine anything about airships. The Administration had chosen to set aside the Durand Committee’s recommendations, so there seemed little point in hiring a new bunch of experts to make to call re: conventional wire-and-fabric, or metalclad, for the new airship.

In SNAFU, Rosendahl deals with the ZRN by writing, “We came within a hair of getting a medium-sized training rigid airship, but through manipulations no less than sordid, the Navy saw to it that this prospect got scuttled.  For example, upon the conclusion of a hearing on the subject by a Congressional Committee, a high ranking naval officer got a committee member aside and said, in effect – “Forget what was said here today.  The Navy doesn’t want another rigid airship.”  Not long before this, I had called on this ranking officer to discuss a revived airship program, and he had promised me he would give the matter ‘a fair breeze.’   Little did I think that by ‘fair breeze’ he meant a blast that would wreck it.”

20160725_120237-copyGoodyear-Zeppelin during the “years of confusion” had been conducting extensive testing and development for the anticipated order of a new rigid airship even as they’d creating another in a series of seemingly minor, likely one-of a kind blimps, this one designated K-2 (photo, related test). Not a strain on their resources, the G-Z rigid team was ready with new girder design, extensive data on stress and aerodynamic loading, and of course, fin design.  In March, 1939, G-Z submitted a design to meet the ZRN requirements. Its “Type 3” was 650 ft in length and had a 99.35 ft. maximum  diameter, containing 3,416,000 cubic feet of helium.

There is no evidence it was given serious consideration.

fdrThe main problem lay at the highest level of Government.  “The discretion of the President” was the fatal flaw in Section Six of the Naval Expansion Bill’s wording. Roosevelt’s long standing grudge with what he disrespectfully called “that rubber company” suddenly took a most bizarre twist with profound implications for the Navy – and rigid airships in particular. With seemingly no more consideration than the day he decided to set the value of the dollar based on a “lucky number,” Roosevelt arbitrarily picked a dimension  – 325 feet – and dictated that no rigid airship could exceed that length!

A scandal involving Hughes Aircraft and Franklin Roosevelt’s son was eventually made public. However, no one thought it worthy of an investigation (let alone prosecution) when it was rumored some Roosevelt contributors owned stock in Detroit (Metalclad) Aircraft. No one challenged Roosevelt’s unique intervention – which was not a veto – that was clearly designed to favor Detroit Aircraft’s squat metalclad design in the ZRN competition.  It is otherwise inexplicable.  3 mil cu ft of capacity was impractical with a 325 foot length, the resultant airship less aerodynamic than a football.  As R. K. Smith wrote, “In short, Franklin Roosevelt’s dwarf airship was a militarily useless joke.”

John T. Flynn wrote of the Roosevelt’s new ‘New Deal’: “Public spending and rising public debt kept the freighted and harried business machine going at a halting gait. But it never went back to full production and by 1938, despite all the spending, faltered and sank back into full depression. Roosevelt had launched a dozen theatrical projects like the NRA, the AAA, the CCC, the PWA, the WPA and other gaudy and giddy adventures in boondoggling without ever touching the real trouble and in the end, by 1938, he was back from where he started, plus a Federal debt that had doubled.”  Too bad for the country the Commander-in-Chief also had so little understanding of the laws of aerostatics.

21d82f2917e4c5855678fe426c846673It could also be argued that, had a Congressional caucus created and legislated funding for such a plan, President Franklin Roosevelt might have still vetoed it based on the fact the newly-created wealth would have been distributed among a very small number of favored industries. It’s likely few of those were counted among Roosevelt’s supporters. (In fact voting on one airship proposal was moved off the agenda when a key Congressman died.) Too bad for the rigid airship that the administration’s Detroit Aircraft connection was not stronger.

Obviously no visits from the DELAG’s for LZ-130 could provide free training before the spring of 1939. The Navy’s requirement for qualification, which specified fixed hours in a rigid airship left the Navy in a quandary that, with Roosevelt’s unique intervention,  demanded action. On 20 DEC 38 Bu Aer Chief A.B. Cook sent a memo to the Navy Judge Advocate General  RADM Woodson trying to deal with legalities: “The question of whether the ZMC-2 metal-clad airship is a “rigid airship” within the scope of the generally accepted definition… In several places the ZMC-2 airship was represented to the Committee as a rigid airship, although admittedly small in size and experimental in nature.” So ZMC-2 was a legal rigid.  Little did anyone realize this somewhat forced definition would complicate, rather than simplify, the rigid airship question, owing to the political situation.

zmc-25While rewarding his friends and punishing his enemies like any other master politician, Roosevelt should have been advised of the incompatibility of 3 mil cu ft and 325 feet… but evidently no one dared. Clearly it was not practical for even the metalclad design to cram 3 million cubic feet into such a short length. Ignorant of or indifferent to the laws of aerostatics, Roosevelt had inadvertently created a back-door method by which the nation could have received smaller but quite capable airships. Someone realized it would not violate the spirit of the law to use the money for three ships of one million cu ft each.

metal-w-hookThe monocoupe airship simply did not fit into the bureaucracy’s mold for funding: since the first days of airships, there were only rigid, semi- and non-rigid.  (Photo, ZMC-2; note hook-on plane in corner) An enclosure of lifting gas being just a bag, or a bag within a structure, should have been no different on an accountant’s ledger – but, inexplicably, it was.   An blimp-looking airship that could fly with zero internal pressure defied classification, and is still argued today. The odd situation was further complicated by Congress having awarded rigids to the Navy alone. Once defined as a rigid, metalclads had to go to the service that clearly did not want them!

The literature pays little attention to the moncoupe airship concept in general – or Metalclad in particular. The unique and promising concepts put forth by Slate Aircraft in their “City of Glendale” prototype – which worked in model form, at least – is all but ignored. ZMC-2 had been forced upon the Navy by political action alone.  The Navy certainly would not embrace the technology, so experiments to encourage improvement and find air-yatch-mastapplications were all but non-existent. For comparison, the reader must understand the state of the art of airships in the US during the “years of confusion:” they were limited to non-rigids, mainly of Goodyear, the Army and Navy and the occasional private effort, including Anton Heinen’s “Air Yacht,” shown in this photo, which pioneered the idea of a landing wheel before the Navy airships had them. Some cite Commander Charles Rosendahl as the primary opponent of the metalclad, but his disagreements with Anton Heinen were no secret. (People who knew him told the producer Heinen kept a goat in his back yard; he’d  named it “Rosie.”)  Though BuAer guru C.P. Burgess called the metalclad “the ultimate airship,” Heinen’s remarks about the ZMC-2 have not been recorded. Heinen and his “Air Yacht” team got a contract to advertise for Noxema and hit the road with their mobile mast truck in support. (Heinen’s feud with Rosendahl did not end well.)

During the 1920s and early 30s the US Army had spent its LTA allotment purchasing many different non-rigid airships of various designs from multiple contractors. Many types of cars, multiple engine variations and even a rather large semi-rigid envisioned as an airplane tender were created. (Their extensive developments are detailed by author James Shock in US Army Airships 1908-1942.) It was assumed that, as war approached, the best design, having been proven in real-world testing, could quickly be put into mass production – by multiple tc-13-liftoffcontractors. Their first non-rigid of helium-realistic dimensions, the TC-13, even had an internally mounted spy basket. (Photo; images of its spy basket are only on motion pictures, included in our DVD Airship History Series.) Though it had long considered a metalclad, the Army had contracted Mercury Aircraft, not Goodyear or Detroit, for its next experiment, the TC-14.

Supporting an expensive rigid, the Navy could ill afford much R & D in the non-rigid arena. Indeed, just weeks after Macon sank, a BuAer memo of March 1935 called for the next non-rigid. This single airship was to contain many improvements to the cobbled-together non-rigid K-1 (photo), whose imag0235awkward spy basket had already been removed as impractical. The so-called K-2 would be of helium-realistic capacity, and the memo specified that its internal gaseous fuel bladder should not starve the engines when approaching empty – as the “Rube Goldberg” K-1 had done.  While soliciting bids the Navy managed to purchase Goodyear-Zeppelin President Paul Litchfield’s personal blimp, the Defender, whose incompatibility with the rest of the Goodyear blimps had become an unaffordable luxury as the Great Depression deepened. (Designated G-1, it was still flying, wood-trimmed luxury interior and all, as the US entered WWII.) The Army’s second helium-realistic non-rigid, TC-14, had been flying for years before the Navy put together enough money to contract the proposed K-2. Not surprisingly, most of the items on the 1935 wish list had to be sacrificed for economy, and the new design had nothing to do with the old K-1 or even the lessons learned in the Army’s last two designs.

Finally, in the closing weeks of 1938, Goodyear-Zeppelin delivered its newly designed non-rigid airship, designated K-2. Few in G-Z expected the K-2 to be anything more than another one-off design study, similar to the Army’s TC-13 they had constructed a few years earlier. The “wish list” had been ignored; the modest prototype K-2 used ordinary airplane engines mounted somewhat awkwardly, could not afford the advantageous gaseous fuel, and lacked armament, or even sensors. It did not even have some of the advanced featuresk-2-wreck of the latest Army blimps, but it utilized the standard Army bomb arm-and-drop mechanism for its internal bomb bay. According to Rosendahl, K-2 did feature a “borrowed radio” and could carry more submarine-detecting “Mark 1 eyeballs” under less efficient helium than previous blimps.  As Navy pilots got the feel of the new larger non-rigid, one senior officer managed to get the trim so out of balance that K-2 was impaled on trees edging the landing pad. Even as it repaired the K-2, Goodyear-Zep submitted a new design to meet the original ZRN requirements.

Since non-rigids were requisitioned under a different category, hardly different than furniture or airplanes, they had avoided the high-level political wrangling that had delivered the ultimatum for the ZRN by 1939: metalclad, or nothing. Thus armed with essentially a Presidential edict, all Ralph Upson and company zmc-2-drawneeded was a hangar to build them.  (Their original building in Michigan was too small and had actually been partially disassembled to remove the prototype back in 1929.) In a series of communications, Detroit Aircraft approached Goodyear-Zeppelin about a merger, of sorts. In a passionate five-page letter of January 18, 1939, W. B. Mayo spelled out how the two companies could share resources and make money giving the government what it wanted. Metalclad had the technology, and the all-powerful President’s ambivalence; Goodyear-Zeppelin had the hangar in which to build it. Obviously Ralph Upson would have to make nice with his former employer.

In a move that has repercussions to this day, Paul W. Litchfield (in grey coat, with the first blimp to be helium-tested, Pilgrim) replied tersely, “The only type of ship which has proven satisfactory litchin commercial service is the rigid fabric covered airship.”  When competitive bidding was opened for the ZRN on March 2nd, one can only wonder what would have been possible if Litchfield had softened his rhetoric and accepted Metalclad Aircraft’s offer of a partnership. Roosevelt would have been pacified. The metalclad could have been hydrogen inflated with no fear of fabric fire; airship performance could have returned to the capabilities predicted in the early 1920s. Aligned with Rosendahl and others in the Navy who wanted no monocouple design,  nonetheless Goodyear-Zeppelin was certainly aware of their former employee’s progress with all-metal airships.  At least one patent for a metalclad design was granted to a G-Z engineer in 1940.

airdockUnwilling to co-operate with the metalclad men and give the President what he tolerated, Goodyear-Zeppelin attempted to work with the aerostatic-awkward dimensions. They submitted 4 proposals to BuAer. Type 1 & 2 of 1,200,000 cuft met the required 325 ft. max length with 82 and 82.8 max diameters.  Rosendahl, in his postwar rigids’ history,  wrote the narration that stated “ships of this size [and shape] are useless.”  (When questioned by a friend later in life, that perhaps it was a mistake to stand up to the President, Rosendahl still insisted no rigid at all was preferable to even three 1-mil cu ft metalclad rigids.)

edisonThe Honorable Charles Edison, Secretary of the Navy (right) wrote,  “I feel, however, that a majority of fair minded people who take the time and trouble to study airship history inevitably come in some degree to the conclusion that airships are of value to us as a nation… They are a half-finished project or experiment… a challenge. I want to see large airships proven out… Let us pave the steps of future airship progress with courage and purpose.” Edison, believed the in the airship carrier and made one more passionate plea for the good of the nation in a letter to Roosevelt on 20 APR 39.

Roosevelt ridiculed Edison in a 3 MAY 39 answer, also refusing, “I do not approve the construction of another large rigid airship for the Navy on the type of the ill-fated ‘Los Angeles,’ ‘Akron,’ etc.” (!)

Roosevelt’s cluelessness concerning the Navy’s most successful airship – indeed, the second most successful rigid airship in aeronautic history – is shown in what might be a Freudian slip, still showing his resentment over his firm’s loss of face with the LZ-126 lawsuit debacle.  Roosevelt also thwarted a last-minute end-run to set aside money to begin the authorized small rigid. HR 3519 of 1939, authorizing construction of a 300 Ton Naval Airship, never reached Roosevelt’s desk to suffer the indignity of a most certain veto.

Regardless whether of frame-and-fabric or “metal balloon,” this nation could have (some say should have) had a proven design built and flying when America entered WWII. Even the small rigid of R-34 size, saddled with helium, would have been capable of convoy escort New York-Azores or Bermuda, and in rotation, Azores/Bermuda -Liverpool. K-type non-rigids of half that capacity transited the Atlantic those ways in 1944, though with military payload they would not have had the endurance to stay with a slow convoy or fought headwinds for such a duration. It would be the 1950s before non-rigids advanced to size similar to the proposed three-for-one metalclad ZRN(s). A ZPG-2 airship of about one million cu ft capacity criss-crossed the Atlantic, and then some, in 1958, staying aloft nearly 12 days without refueling. With three 1 million cu ft monocoupe airships with which to start a fleet, the anti-submarine capability of the US Navy would have been arguably better than with the few blimps it did have when Pearl Harbor was attacked.

The Germans had hung up and propped up their Grafs to make money as tourist attractions. The rigid airship now had but one hope: the ZRCV, and its powerful admirer, Earnest J. King.

Read on to  ZRCV: The Giant That Almost Was


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