This html article is produced from an uncorrected text file through optical character recognition. Prior to 1940 articles all text has been corrected, but from 1940 to the present most still remain uncorrected. Artifacts of the scans are misspellings, out-of-context footnotes and sidebars, and other inconsistencies. Adjacent to each text file is a PDF of the article, which accurately and fully conveys the content as it appeared in the issue. The uncorrected text files have been included to enhance the searchability of our content, on our site and in search engines, for our membership, the research community and media organizations. We are working now to provide clean text files for the entire collection.
F
A ifty years ago—the date was 4 September 1923 —the first rigid airship constructed in the United States made her maiden flight from Lakehurst, New Jersey. The flight was the culmination of an effort that began during World War I.
In 1916, Congress had authorized the building of such an airship. Since both of the Services had their own ideas about how to proceed, an Army-Navy group was formed. This group agreed upon a dirigible of the Zeppelin-type and established a Joint Airship Board.
From this interservice board came the following recommendations:
► that rigid airships be purchased in England to meet U. S. needs in the war zone;
► that such ships as were needed at home be built so that America might develop a capability in the art;
► that the responsibility for building rigids be assigned to the Navy because the ships appeared to possess primarily a naval value;
► that the production of helium, the non-flammable substitute for hydrogen as a lifting gas, be accelerated.
In October 1918, the Navy submitted to Congress a request for funds to construct four rigid airships and two hangars. Two of the ships would be built in Great Britain and two in the United States. The following month brought the Armistice and an immediate curtailment of naval spending. The requested airship program survived but was cut in half. One rigid, the ZR-i, would be built at home. A second, the ZR-2, would be bought from England. Shed space would be provided to accommodate both.
With no prior experience in rigid airship design and construction, the Navy decided that the surest way to build a successful one would be to copy a proven Zeppelin model. The German naval Zeppelin, L-49, had fallen on 20 October 1917 at Bourbonne-les-Bains in France and had been captured before its crew could set it afire. As a result of a most thorough examination, exact plans and detailed technical information were assembled. The Navy Department proposed to take advantage of this windfall and use the L-49 as a prototype of the ZR-i.
The American-built ship, however, would not be an identical copy. An additional 10-meter long section was inserted in the hull, lengthening her by about 30 feet. Certain of the longitudinal girders were stiffened. Improvements were made to the fins and rudders, also to the engine cars. A walkway along the top was provided. And, because this U. S. Navy airship was to moor to masts, the bow-was reinforced and mooring gear incorporated.
Many severe technological problems still remained to be solved, however.
Duralumin was not available in quantity. The subject of considerable research work in Germany, it had been given little attention in America. An intensive effort by the Aluminum Company of America was necessary before adequate production quantities of this lightweight alloy of largely aluminum and copper could be guaranteed.
American technicians and engineers also needed to know how to fabricate the necessary U-shaped channels and X-shaped lattices which, riveted together, would make up the triangular girders comprising the framework of the ship.
And then there were the gas cells, consisting of hundreds of thousands of goldbeater’s skins—the prepared outside membrane of the large intestine of cattle- cemented to a high strength, low weight, slightly rubberized cotton cloth. The skins had to be washed, scraped, and otherwise thoroughly cleansed of any fat or dirt before they could be applied to the cotton cloth. While awaiting application, they had to be kept in a solution of water and glycerine, requiring that they be wrung out by hand before being cemented. A technique for applying the skins to the fabric had to be developed. After considerable experimentation, rubber cement was selected as the adhesive. Following cementing, the skins were given a light coat of varnish. Goldbeater’s skins, so called because of their use in beating and separating gold leaf, were at the time one of the most gas-impervious materials known.
For a power plant, the Packard Motor Car Company came up with a "straight eight” 300-h.p. gasoline- fueled engine.
Construction of the ZR-i depended not only upon technical problems being solved but also upon a hangar being constructed. Camp Kendrick, an Army Chemical Warfare Proving Ground, located in the pine belt of
The ZR-1, which would become the Shenandoah, began to take shape as a symmetrical skeleton at the Naval Aircraft Factory, Philadelphia, where some of her 2,700 hull girders were arranged into a polygon frame ring, facing page. After checking for size and shape, a ring was disassembled and shipped to Lakehurst where the erection of the 680-foot-long ship was completed. A gas cell, upper photograph, was prepared for installation. Folded into accordion pleats, it would be brought into the ship, placed atop the keel, and inflated. Some of the ship’s 20 gas cells, which were filled only to about 85 % capacity to allow for helium expansion during flight, are visible in the lower photograph.
central New Jersey about 15 miles inland from the Atlantic, was selected as the hangar site. The facility was acquired by the Navy and renamed the Naval Airship Construction and Experimental Station, Lake- hurst. Upon it was built a steel-framed, asbestos-covered shed having a clear internal space of about 804 feet by 264 feet with a center height of 193 feet.
Inside this cavernous building, then the world’s largest single room, erection of the 680-foot-long ZR-i was started.
Her girders were fabricated at the Naval Aircraft Factory, Philadelphia, and shipped by truck and rail to Lakehurst for assembly. There, polygon-shaped rings about 79 feet across, began taking form. These transverse frames were then joined one to another by longitudinal girders. The structure was reinforced by steel wiring.
Along the bottom centerline ran a keel, triangular in cross-section, which was 9 feet high and 12 feet wide amidships. Where the dirigible tapered to become bow and stern, the keel narrowed. Fuel tanks, water ballast containers, living and messing spaces for the crew, and
stores of equipment and supplies were carried on or close to it. Men walked this keel fore and aft via a narrow 9-inch catwalk.
Within the tube-like hull hung 20 goldbeater’s skin gas cells, containing over 2,100,000 cubic feet of helium and held in place by a netting of ramie cord. They were equipped with spring-loaded relief valves which opened automatically when internal pressure exceeded a certain limit and with maneuvering valves manually operated from the control car. The automatic valves were located near the bottom of the cells, the maneuvering ones at the top. Helium, thus released, was exhausted through rearward-facing ventilator hoods along the top of the ship.
For the outer cover, high quality cotton cloth was stretched taut over the structure. It was then sewn, laced, or taped securely to it, and painted with aluminum dope.
From 1921 to 1923, these and other features—installation of the engines in the power cars, for example— were gradually completed and the 40-ton, $2-million craft readied for the air.
Following her flight of 4 September and others, she was christened USS Shenandoah—the Indian name for "Daughter of the Stars”—by Mrs. Edwin Denby, wife of the Secretary of the Navy.
Under Commander F. R. McCrary, U. S. Navy, the ZR-i began a series of flights along the Atlantic Coast to give her officers and men experience in operating a rigid airship. There was no other American rigid on which to gain such experience, the British-built ZR-2 having collapsed in flight over England in August 1921 with the loss of 44, including some of the U. S. Navy’s most experienced lighter-than-air personnel. The Shenandoah’s crew members were assisted in their training by Anton Heinen, a former German Zeppelin Company test pilot, who had come to the States under contract to instruct Navy men in airship flying.
.
On 16 November, the Shenandoah made her first mooring to the 160-foot high Lakehurst mast. As a result of this and subsequent couplings with the tower-like structure, a highly successful mooring technique was worked out. Three wire cables were dropped from the ship’s bow and quick-coupled to extension lines provided by the ground crew. Two were nose- steadying lines: the yaw guylines. The third, led out directly through the nose, coupled to a line which passed through the cup at the top of the mast and then to a winch. With this main line, assisted by the yaw guys, the ship was hauled up to the mast until her nose cone was drawn into the cup and locked in place.
The 16th of January 1924 found the ZR-i on the mast and riding out a severe winter storm. The ship had been satisfactorily riding out winds in excess of 60 m.p.h. At 6:44 p.m., following a deceptive slackening, a 74-m.p.h. gust suddenly slammed the craft, rolled her, and tore her away. Her bow ripped open and her two forward cells deflated, she drifted stern-first into the darkness of the night, leaving her mooring assembly and some of her framework still attached to the mast. Blown northward, Heinen and the naval personnel on board were able to ballast the ship to keep her in the air and to start the engines. Crew members tried to close off the gaping hole in the bow to prevent further
structural collapse and deflation of more gas cells. V- spite the extensive damage done to the nose and tb loss also of some of the covering of the upper fin, thc dirigible made her way back to Lakehurst, landiof safely about nine hours after having been ripped loos£ Repairs to the bow and fin kept the Shenando& hangar-bound four months. And it was about this tif^ that her control car was modified by removing Engi111' # 6 in the car’s after end. (The U. S. Navy follow^ the German practice of numbering engines starting with the sternmost and working forward in pairs.) Packard was taken out and an enlarged radio roon' substituted.
When the airship returned to operation on 22 May 1924, she did so with a new captain, Lieutenant Commander Zachary Lansdowne, U. S. Navy. Under his command, the ZR-i went on to achieve a number of airship "firsts.” These included mooring to the tender USS Patoka in Narragansett Bay on 8 August and making a 9,000-mile transcontinental flight in October. The latter took the ship to Fort Worth, San Diego, and Camp Lewis, Washington, then back again. At these stopover points, she tied up to expeditionary versions of the Lakehurst mast.
Back home following her 20-day cross-country trip, the Shenandoah found a newly-arrived stranger occupying and sharing her hangar. This was the ZR-3, a new Zeppelin built by Germany and just delivered to Lake- T hurst as a war reparations payment. Named the USS Los Angeles, she would become the most successful of America’s five rigid airships.
The presence of the Los Angeles meant the grounding °f the Shenandoah. Helium was still rare and cost $55 or more per-thousand-cubic-feet. The Navy didn’t have enough on hand to inflate both airships simultaneously. So, in order for the newer craft to operate, the Shenandoah was deflated.
The scarcity and high price of this fireproof gas was a continuing problem. As fuel was consumed in flight, th‘ the ships would become increasingly light. Commanded ers of hydrogen-filled dirigibles compensated for this |i» excessive buoyancy by valving. Hydrogen was cheap 0&, ar>d readily available. Not so helium. Some method
ll/r other than valving was needed to make up for the
jfd weight of the gasoline burned.
iP. Early in her career, the Shenandoah carried calcium oxide to extract water vapor from the air. During [ifflights on humid days, the weight of this substance 'fd increased about 50% from the amount of moisture it )</' absorbed. The idea was abandoned, however, because
too much had to be carried to be effective and because water absorption was not great enough on dry days.
In its place, a water recovery apparatus was developed which cooled the engine exhaust gases and retrieved their water content by condensation. The concept worked successfully. Forty-five parallel rows of aluminum tubes, one inch in diameter, arranged in ten banks and cooled by the airflow, were fitted to at least three of the ZR-i’s engines. Water was recovered equal in weight to about 105% of the weight of the fuel consumed. On the debit side, the gear added substantially to the airship’s drag and exacted a weight penalty of about one-pound-per-horsepower.
In June 1925, it was the ZR-3’s turn to be deflated. The Navy’s "one set of helium” was transferred back into the Shenandoah. During July, she moored again to the Patoka, completing the maneuver in 20 minutes. Other and varied flights were made but, much to the crew’s disappointment, not the proposed trip to the North Pole. Even so, it proved to be a busy summer and it would be climaxed by a tour of the Midwest.
On 2 September 1925, the Shenandoah set out for St. Louis, Minneapolis, and Detroit. Early the following morning, she was caught in a line squall over Ohio. Seized by powerful vertical currents, the airship broke apart in mid-air, killing Lansdowne and 13 others of the 43 men on board.
Thus, on her 57th flight, perished the "Daughter of the Stars.”
_
As a Naval Reserve officer, Lieutenant Vaeth served with lighter-than-air commands of the Atlantic Fleet during World War II. Later, as a Navy civilian, he headed the New Weapons and Systems Division of the Naval Training Device Center (ONR). Currently, he is Director of System Engineering for the National Environmental Satellite Service of the National Oceanic and Atmospheric Administration. His other writings on airships include the book Graf Zeppelin plus articles proposing their revival and use in terms of the technology of the 1970s and 1980s.