19 May 2017

Aboard a Zeppelin to Africa, 1917

From African Kaiser: General Paul von Lettow-Vorbeck and the Great War in Africa, 1914-1918, by Robert Gaudi (Caliber, 2017), Kindle Loc. 6233-6255, 6268-6280, 6300-6317, 6404-6408:
L59, pushed by a tailwind from the direction of the German Reich, rumbled south from Jamboli in the freezing dawn of November 21, 1917, at speeds in excess of fifty miles per hour. The great lumbering airship cast her shadow over Adrianople in Turkey at nine forty-five a.m., and over the Sea of Marmara’s chop a short time later. At Pandena, on the southern shore, she picked up the railroad tracks to Smyrna, a steel ribbon barely visible after sunset. At seven forty p.m., L59 pulled free of the Turkish coast at the Lipsas Straits. Now the Greek Dodecanese Islands—Kos, Patmos, Rhodes—passed below, nestled like dark jewels in the black Mediterranean waters, notoriously stormy this time of year. But tonight, the Zeppelin surged forward beneath a clear sky and brilliant stars. [Lieutenant Commander Ludwig] Bockholt, who had made his life in the navy, had long ago learned to steer by them when necessary.

L59’s crew of twenty—excluding Bockholt and [medical doctor Max] Zupitza—included twelve mechanics to service the five Maybach 240-horsepower engines (one in the forward control car, two opposed on the belly one-third of the way back, and two aft, each driving a single, massive twenty-foot propeller); two “elevator operators” (the elevators, movable flaps at the tail, controlled the upward or downward incline of the nose cone); a radio operator; and a sailmaker, whose job it was to sew up tears in the muslin envelopes affixed within the belly filled with the flammable hydrogen/oxygen mixture that kept the massive airship afloat.

As in the seaborne navy, watches divided the day into four-hour increments. As L59 approached the island of Crete at eight thirty p.m., a quarter of the crew just gone off watch opened their dinnertime cans of Kaloritkon, a bizarre sort of self-heating MRE. These undigestible, oversalted tubes of potted meat literally cooked themselves via a chemical reaction when exposed to air—heating food over open flame and smoking being strictly verboten aboard the flammable airship. The Kaloritkons, which everyone hated, took much water to wash down, and water was scarce, with barely 14 liters allotted per man for the duration of the voyage. At ten fifteen p.m., L59 passed above Cape Sidero at Crete’s eastern extremity at 3,000 feet. Then the stars by which Bockholt had been guiding the Zeppelin to Africa suddenly disappeared, blotted out by a solid mass of black, churning clouds, shot through with bright veins of lightning. The Zeppelin headed into this cloud bank and, buffeted by thunderclaps and driving rain, was also suddenly consumed by a strange, vivid flame, cool to the touch, that seemed to dance across every surface of the doped canvas envelope.

“The ship’s burning!” called the top lookout—alarming, but no cause for alarm: This was St. Elmo’s fire, named after Erasmus of Formia, the patron saint of sailors. Technically a luminous plasma generated by coronal discharge in an atmospheric electrical field, it burned a vivid violet-blue and, in nontechnical terms, was entirely beautiful....

At five fifteen a.m., the sun cracked the rim of earth and the huge airship passed over the African continent at Ras Bulair on the Libyan coast. Miles of desert lay ahead; no Zeppelin had flown across such a landscape before. Now the level wastes of sand and rock stretched monotonously below L59’s keel, from horizon to horizon. Soon, the sun, blazing down, began to dry her canvas skin, still drenched and heavy from the storm. The airship grew lighter as the watery sheen evaporated; lighter still as fuel consumption continued apace. Then the gas in her envelopes, expanding with the heat, blew out the automatic valves into the atmosphere and soon, L59 became dangerously light and increasingly difficult to handle. To compensate, Bockholt flew her “nose down” throughout the day, shifting 1,650 pounds of ballast aft as a counterbalance.

In the late morning, hot desert air rose in bubbles of buoyancy, alternating with heavy downdrafts of cooler air. This caused a roller-coaster effect that made most of the crew violently airsick. Even the hardened navy veterans among them, used to storms at sea, were not immune to the stomach-churning sensation of weightlessness as L59 plunged into the downdrafts and precipitously rose again. Despite all this, L59 plowed ahead and made the Farafra Oasis around noon. This incandescent patch of green slid by below, its date palms rustling in the hot wind....

Flying a Zeppelin is a difficult undertaking under the best conditions: Gas expands and contracts according to changing temperatures; lift and buoyancy fluctuate; all must be counterbalanced ceaselessly by the release of ballast water, the measured shifting of cargo, the canting of nose or tail via clumsy elevator flaps—and all this becomes doubly difficult over the desert. Bockholt had lightened his airship by 4,400 pounds of ballast in the last full heat of day and had even tossed some boxes of supplies overboard. He knew the rapidly cooling temperatures of the desert at night would contract the gas, causing the Zeppelin to sink. To counterbalance this sinking effect, he had planned to fly the ship at four degrees “nose up” on her four remaining engines.

But he had not counted on the humid, dense air of the Nile Valley. Even at 3,000 feet, ambient temperatures had reached sixty-eight degrees by ten p.m.; they rose steadily after midnight and still L59’s lift capacity gradually diminished. Finally, at three a.m., L59 began to lose altitude precipitously. The engines stalled. Forward thrust gone, the Zeppelin sank through the atmosphere from 3,100 feet to just under 1,300, not high enough to clear a looming desert escarpment; a minute later, her main radio antennae sheared off upon contact with an outcropping of red rock.

Now Bockholt ordered his crew to lighten the ship even further. With all engines stopped, 6,200 pounds of ballast and ammunition went overboard. The crew watched cases of ammunition, much needed by the Schutztruppe, shatter and explode on the ragged slopes below. But this sacrifice had its desired effect: Gradually, the sinking super Zeppelin stabilized; slowly, she rose into safer atmospheres:

“To fly steadily at 4 degrees heavy at night can easily be catastrophic, especially with sudden temperature changes in the Sudan, as at Jebel Ain,” Bockholt later confided to L59’s war diary, “particularly if the engines fail from overheating with warm outside temperatures. . . . Ship should have 3000 kg of 4 percent of her lift for each night to take care of cooling effect.”

Clearly, it was a complicated business.

L59, now less than 125 miles west of Khartoum, had two-thirds of the perilous journey behind her. But presently, to the dismay of all aboard, Bockholt turned the great airship around and pointed her nose cone due north ....

At last, at seven thirty a.m. on November 25, 1917, L59 made her docking station at Jamboli. Her mooring ropes dropped, the ground crew drew her down and walked her into the long shed. China Show had ended in failure. The twenty-two aeronauts, wobbly-legged, nearly deafened by the droning Maybachs at close quarters, stumbled down the ladders to the ground in the gray Balkan morning. They had been in the air for almost four days and had covered 4,200 air miles—the longest distance in the shortest time of any airship to date.

1 comment:

Anonymous said...

Fascinating story.