Unfortunately for the immediate future, the West Coast flight had expended 640,000 cubic feet of helium—about 17 percent of the Navy’s fiscal year’s allotment from Fort Worth. The plant’s output could not possibly satisfy the operational demands of ZR-1 and ZR-3 concurrently. And so, in her moment of triumph, Shenandoah was deflated for an extended overhaul and repair while her helium was donated to ZR-3. It was expected that sufficient helium would be accumulated by March 1925 to operate both ZRs, but demand was nearly equal to the available supply. The Navy therefore had no choice but to extend the grounding of ZR-1 nearly eight months. Operations by ZR-3, christened Los Angeles on 25 November 1924, would dominate air station operations to June 1925.
Zeppelin in sight! The “reparations airship” flies over the Lakehurst station, 15 October 1924. Touchdown concluded an 82.5-hour transatlantic leap, the fourth aircraft to cross. At that moment, Shenandoah was riding to an expeditionary mast at North Island. The air station’s helium plant and power house are at the upper right. NARA
ZR-1, Shenandoah (left) and ZR-3, Los Angeles, early 1925. Deflated, ZR-1 is supported about equally between cable suspensions to the overhead and cradles under all the cars together with shores. Short of funds, the LTA program could not obtain helium sufficient to operate both ZRs concurrently. Operations were therefore alternated, one ZR undergoing extended overhaul and repair while the other flew for several months. Shenandoah’s helium was lost with her, grounding Los Angeles for seven months. Neither represented a fleet-type ZR. Their volume was too small to permit extended at-sea operations. Clements courtesy D. H. Robinson
During this enforced layover, Lansdowne considered a number of improvements to his command to save weight and to increase the range and speed of Shenandoah. The most significant (and controversial) was a radical alteration of the ship’s valving system. Shenandoah was equipped with eighteen automatic valves at the base of her gas cells, plus sixteen maneuvering valves at their tops—the latter operated by wires from the bridge. No valve was gastight: air through the automatics decreased purity; the maneuvering valves allowed helium (hence lift) to escape to the atmosphere. Helium conservation had become something of an obsession with Lansdowne. He had already removed eight of the maneuvering valves and had instituted the use of gastight “jam pot” covers over the automatics. At first, these were used only in the hangar; soon, however, the ship was flying with them. To avoid dangerous overpressure in the cells, these were removed by the riggers if the airship approached near to pressure height. Now Lansdowne insisted on removing ten of the automatics and the gas trunks serving them as well. An estimated four hundred pounds was saved plus a slight increase in gas volume gained by elimination of the trunks. BuAer approved this change with great reluctance. With only eight automatic valves, twelve of the gas cells could relieve overpressure only through the fabric inflation manifold that interconnected all the cells. So outfitted, the airship could rise over pressure height only at an estimated four hundred feet per minute with reasonable safety. Lansdowne was warned of this repeatedly while the change was being executed. When Shenandoah experienced an unprecedented and uncontrollable rise on her final, fatal flight in 1925, heated debate ensued: Had this alternation in fact caused the ship’s structure to fail?
Requests for publicity cruises had not diminished. Politicos from the Midwest, among others, were demanding an appearance by the Navy’s airships over their cities and towns. Los Angeles obliged locally, flying to Annapolis on 2 June 1925, where she moored to Patoka, swinging to anchor in the Chesapeake. But “L.A.” suffered engine failure on a flight to Minneapolis and aborted on 7 June. Lansdowne therefore was ordered to reinflate his command; Los Angeles would undergo overhaul, with special attention to her engines and cells. The lieutenant commander protested (as was his right), citing hot weather and its pernicious effects on cruising radius and, as well, the prevalence of Midwestern thunderstorms during the spring and summer. The Navy Department was far from sympathetic; still, the Midwest operation was postponed to September.
Shenandoah was reinflated (with Los Angeles’s helium) by late June. Operations during July and August included experiments with new equipment as well as purely naval missions with units of the fleet. A number of tactical search problems were conducted with the battleship Texas of the Scouting Force, with uneven results. These were, literally, the fleet’s first such exercises with a U.S. rigid airship. Antiaircraft gunnery practice with Shenandoah towing a target sleeve was logged, refueling at sea assessed, towing exercises made with Patoka, and tests of a sea anchor conducted. The concept of airplane hook-on operations was advanced at this time. While Shenandoah never carried an airplane, hook-on tests were begun using Los Angeles as a “carrier.” These experiments were to reach a high state of refinement with Akron and Macon as lighter-than-air “carriers.”
There remained the Midwest flight, now scheduled for the first week in September. Shenandoah’s route and times were advertised in advance (to Lansdowne’s annoyance). At 1452, 2 September 1925, Shenandoah cast off the high mast. On board were forty-one crewmen and two passengers. The first leg would take her to the Army’s airship base at Scott Field, near St. Louis, thence indirectly to Minneapolis and to the new Henry Ford mooring mast erected at Detroit. The Alleghenies were logged shortly after midnight.
From Wheeling the course was set for Zanesville. Over Ohio the ship made very little ground speed, and a severe electrical display was evident to the north and east. Different headings, altitudes, and engine speeds were tried with little success. Lt. Cdr. Charles Rosendahl, navigator, relieved Lt. Cdr. Lewis Hancock Jr., the ship’s executive officer, at 0400. About twenty minutes later “during my drift observations out the window, there appeared on the starboard bow a thin dark streaky cloud just apparent in the dull moonlight. . . . Almost immediately the Captain came over to view this formation that was either coming towards us or building up rapidly. About this same instant, Chief Rigger [E. P.] Allen at the elevators reported the ship rising. He was told to check her. This he could not do.”24
Utterly without warning, Shenandoah had entered an area of extreme atmospheric instability, with unprecedented vertical currents of air. The elevators were ordered hard down and the engines set to full power. Nonetheless, the ship was carried upward, nose down, to thirty-one hundred feet. Two engines overheated and failed. The air became turbulent, causing the ship to pitch and roll. A second, more severe rise began, and the helpless ship was carried rapidly upward—later calculations showed an upward current of twenty-one hundred feet per minute—through pressure height to six thousand feet despite use of the maneuvering valves.
Up in the keel passageway, the off-watch section of the crew asleep in their bunks needed no general alarm to arouse them. Trained instinct plainly told them the unusual motion of the ship meant we were in difficulty. . . . They slipped into their clothes and began to help their shipmates on watch. The clanging of engine telegraphs told the engineers more speed was wanted. “Anti-knock dope” had to be injected into the fuel for maximum engine speeds at that altitude. . . . The deck force, patrolling throughout the keel, watched that the control wires did not jam; they rushed to each gas cell valve to see that it was operating. Jackknife in one hand, they felt the bulging cells with the other, ready to slash the fabric . . . should it exceed what their trained touch told them was safe. Keel officers wended their way from stem to stern directing and inspecting.25
It was clear that the ship was in grave peril. A blast of cold air through the hatches indicated that Shenandoah had reached a cold air mass that was overrunning the warmer air below. Shenandoah