CHAPTER IXVulnerability of Airships

Lessons in streamlining gained from building and flying blimps became useful when barrage balloons came into the picture as a new defense weapon.

The mooring mast made the blimps expeditionary craft, eliminated the need for large ground crews, permitted more flying days per month, increased safety.

Floating Navy blimps and barrage balloons, with their curious star-fish tails, give the service dock something of the appearance of a giant aquarium.

Principal use for the rigid airship in wartime is as an airplane carrier, with half a dozen planes to extend its reconnaissance range and determine the enemy’s position.

It was this co-ordination between men in green eye shades, working over the drafting board and wind-tanned pilots, studying gray skies and phosphorescent control boards, which enabled the organization to meet the war emergency of large scale production of non-rigid airships.

There was another by-product result arising from the fact that the company, even in the doldrum days, when there were few orders for ships, had kept its engineers at work on research and its ships flying on experimental missions. It all happened suddenly, a colorful circumstance not often found in the sober humdrum of the business world.

A great plane manufacturer, having more defense work than its crowded shops could handle, looked around for some company with experience in the fabrication of light metal, to whom it could farm out some of the details.

Goodyear Aircraft Corporation, the aeronautic subsidiary, was asked to build tail surfaces for Martin bombers. A curious thing happened. Men whose work had been primarily with airships, rather than airplanes (omitting the quite different field of airplane tires, wheels, and brakes) found themselves on familiar ground when they swung over to heavier-than-air construction.

Here was the same problem of getting maximum strength with minimum weight, of selection and treatment of light alloys, of intricate stress calculations, and a hundred ingenious devices to measure those stresses, enabling designers to turn out a scientifically designed structure. The background was there—not to mention their experience and studies in streamlined design—to reduce resistance, get maximum performance from power plants.

The difference was that in the case of the airship savings in weight mount fast, because of size. The importance of light weight and high strength had come home to airship designers years before.

Their experience was directly applicable to the new field. Other orders came in, from Curtiss, Consolidated, Grumman, and soonthe huge plant was humming with the production of parts for fighters and bombers.

Then a four-company arrangement was set up by the government to expand airplane production still further, and after that an order for complete planes. The original plant was now jam-packed with lathes and drills, jigs and presses, and three huge new plants were built alongside and across the road, and Goodyear Aircraft Corporation found itself with thousands of men, building not only airships, but airplanes and airplane parts as well.

Every large company took on new tasks in defense, but in this case Goodyear was able to move quickly, and give unexpected support to the airplane program by reason of its long research in a different field. This result, it is true, grew chiefly out of research in rigid airships, rather than non-rigids, but both played a part in another instance—barrage balloons.

England was using them, might ask this country to supply some. The American government too might have use for them. So, long before there was even any hint of orders, Mr. Litchfield threw a new problem to the engineers at Goodyear Aircraft and the operating men at Wingfoot Lake—the job of designing an efficient barrage balloon. They were not to make Chinese copies of foreign balloons, but draw on their experience in lighter-than-air and see if principles and technique established there could not be applied to design balloons which would ride with maximum stability in gusty and unstable air. Men went to work, designing, building, flying, observing, rejecting, altering, improving, week after week, month after month, until several satisfactory types were evolved. One of these was capable of flying at 15,000 feet, twice the usual height. Orders began to come in, and the little group of men and girls in the balloon room quickly grew into a large organization. The department outgrew its quarters, took over room after room, expanded to subsidiary plants outside Akron.

One instrument developed illustrates how the airship men were able to utilize past experience in a new project.

Mounted alongside the winch on the ground, it gave exact information, as often as was wanted, as to what the barrage balloon was doing, a mile or three miles up.

This assembly included a moving picture camera, which continuously, or at fixed intervals, or at any instant desired, by means of radio control, would photograph recording dials and show these things: wind velocity at the balloon, tension on cable, gas pressure inside the balloon, temperature of confined gas, temperature and humidity of the air surrounding the balloon, angle of attack at which the balloon faced the wind, both fore and aft and from side to side, also a clock, which showed the time the readings were recorded.

These pictures, when developed gave the engineers the data from which they could modify designs and arrive at a type of balloon which would ride most easily aloft, avoid undue tugging and surging on the cable—incidentally permitting smaller gauge and weight cable to be used for a given height with ample safety margin.

Perhaps the largest single result, however, growing out of the fleet operations was that it had created manufacturing facilities, ships and personnel on which the Navy could draw, as fully as it wanted, in emergency, and with little more delay than the time it took for a man to change his uniform.

Boettner, Sewell, Blair, Hobensack and Hill followed the others into the service. Hobensack’s ground crew in California signed up with him in a body, and men from other ground crews, expert in rigging, in motors, radio, in mooring out and maintenance joined up. In the end only Fickes and Crum were left at Akron to build the new ships, and Sheppard, Crosier and Massic to test-fly them, then ferry them to their destinations.

The student pilots at Wingfoot Lake had finished their training just in time. About half of them went immediately into the Navy, were commissioned and sent to the various bases, the others remained at Akron as replacements to the other pilots, in testing and delivery flights, or on key posts in airship construction.

The experience accumulated by the blimp pilots under varying weather conditions over the country proved useful to the Navy, particularly in the expeditionary operations which coastal patrol would demand. It was useful as well in helping train navy aviation cadets for the growing airship fleet. Five of the pilots, Sewell, Boettner, Rieker, Stacy and Smith had reached the rank oflieutenant commander by the end of 1942, and Lange, full commander, had become commanding officer of a new Navy station on the west coast. Two of the public relations men, Lieutenants Petrie and Schetter, old airship troupers, followed the fliers into uniform.

The airship service suffered its first casualty in 1942 when Lt. Trotter, gallant and resourceful pilot of balloons and ships, was killed in a collision, in which Lt. Comdr. Rounds also lost his life.

The Goodyear fleet passed out of existence with the war. The ships being the same size as the Navy training ships, it was a simple matter to change them over, paint the new name on their broad sides.

Facilities for ship construction became useful also in the new war. An airship hangar is unlike any other structure in the world. It must be broad and high and free of supporting girders. There were two large airship docks at Akron, half a dozen smaller ones over the country. At hand, too, was equipment for helium purification and storage, along with radio and weather gear, mobile mooring masts and other specialized equipment which only lighter-than-air uses. There was the balloon room, too, with a wealth of experience dating back to the first World War, and which with new jobs like building barrage balloons, rubber rafts and assault boats grew to large dimension.

Wingfoot Lake was more than doubled in size, and the large airship dock, occupied at first by heavier-than-air production, had to be changed back later for airship assembly, to meet the Navy’s mounting demands for ships. The bases at Washington and Los Angeles were converted to other aeronautic uses; the two-ship dock at Chicago and the one at New York were torn down and moved to Akron to provide additional space for ship assembly.

And so the fact that the company had maintained an airship fleet for a number of years had the result that in emergency when the Navy needed ships and men to fly them, Goodyear was ready. All of which was not foreseen when Mrs. Litchfield pulled a cord to release a flock of pigeons and christen the pioneer ship Pilgrim, at a pasture-airport outside Akron in 1925.

Airship and escort warship

Mention airships and most people will immediately raise the question of vulnerability.

Large, slow moving, a tempting target, airships could be shot out of the sky by ship or shore guns, or by hostile airplane fire, it is argued, almost as easily as a dinner guest touching his cigaret to a toy balloon.

And this is probably true, with reservations, if enemy ships or anti-aircraft batteries or planes were around. But the airship, non-rigid, has no more business in such areas than a British airplane carrier would have to drop anchor in Hamburg harbor.

It was because of the imminence of attack from sea or shore or air that neither England nor Germany used airships in the present war, particularly since they would have to use the inflammable hydrogen gas. It was because such attack on American airships from any of these three sources was much less likely—and that we have helium gas, which does not burn—that this country is using them.

Their chief field of operations is not off the enemy’s coasts but our own, along that broad ribbon of waters used by our coastwise shipping, an area roughly marked in the Atlantic by the 100 fathom curve, the favorite fishing grounds of enemy submarines. Thousands of miles of blue water, not the narrow lanes of the North Sea or British Channel are between them and the shore guns of an enemy.

An enemy fleet, though likelihood of this seems remote, mightpenetrate those coast waters in attempted invasion, attack the blimps with anti-aircraft fire. But such an enemy, arriving in force, would have either to knock out our Atlantic fleet, or slip past it in surprise attempt. In the remote later contingency, the information relayed back by airship radio that the enemy was moving in would be worth losing airships or any other craft, to get.

The third hypothesis, attack by airplane, is also conceivable. But if long-ranging enemy planes were able to get that close to our shores they’d have more important business in hand than wasting time and powder on a helium bubble bobbing in the air, 10,000 feet below—which in any event would already have radioed the news ashore.

In the fairly remote contingency that the airplane did choose to attack the blimp, it would find the position of that moving target, flying at an indeterminate distance below, much more difficult to calculate than a fixed target ashore, no easy thing to drop bombs on.

If it swung down close, it might riddle the bag with machine gun bullets but without necessarily sinking it—as witness the case of Trotter’s ship in Oklahoma leaking gas for 72 hours from 14 gaping holes and still able to fly 400 miles for repairs. The plane would have almost to cut the blimp in two with a spray of bullets to destroy it—if it chose to use its precious far-borne ammunition in such fashion—and would find it better to attack from below, on the chance of a lucky hit into the airship structure or controls, or one which disabled its crew. But in that event the airship, also armed, shooting it out from its more stable gun platform above would have as good a chance as the plane.

The airship is vulnerable—as are all other military craft—but used as the Navy proposes to use airships, it may be said to have an acceptable degree of vulnerability, in view of its potential usefulness in its special field—defense against submarine attack on convoys or coastwise shipping.

The airship’s advantages have been pointed out, but may be repeated. These grow out of its speed range, from zero to a maximum of 65 knots or so. Its slow speed, as compared to the airplane has the compensation that it does not have to circle around to maintain altitude, can keep any suspect object under continuous observation. Its high speed enables it to reach a given point much sooner than the fastest surface scout.

Barrage balloons—spiders who spin out webs of steel as they ascend—but these spiders are out to catch fliers, not flies, enemy fliers who threaten our democracy.

Modern armies towing a few of these pocket sized barrage balloons along, might not be too much concerned over attacks by strafing airplanes.

This Strata Sentinel will fly at 15,000 feet, twice the height of other barrage balloons. By that time the lobes will be completely filled out by expanding pressure of the lifting gas.

This airship, silhouetted against the afternoon sun might be pacing a peaceful cruiser race through the surf off Long Beach, on the Southern California coast. Or it might be leading units of the mosquito fleet to sea off Cape Cod, to hold an enemy U-boat in check till ships of heavier armament could arrive.

Helium-inflated, fast, long ranged, the modern K-type Navy patrol ship is a far cry from the primitive airships of World War I. They are armed with bombs and machine guns.

In brilliant sunshine, or overcast, in fog or rain or snow, the blimps take off from their bases day after day, on guard against any enemy who may invade the coastal waters. A faint smoke screen, miles distant over the endless waters, may turn out to be a peaceful merchantman—or a vessel with grimmer purpose, seeking the advantage of surprise attack.

Airship over cargo ship

The detection of a submarine even on the surface is largely a matter of looking in the right direction at the right time. The open windows on all sides of the airship, without obstruction by wings give it special value in this field.

A submarine submerged is still harder to find as its tell-tale feather is not easy to spot from a speeding plane or from the crow’s nest of a surface craft.

A non-rigid airship throttling down to the speed of its prey, and having the altitude of the airplane, has a much better chance of sighting the submarine, before it can launch its torpedoes.

Taking off in fog, flying in low visibility, compelled to fly close to the water, these factors do not worry the airship or handicap its usefulness overmuch, and might under given conditions prove extremely useful.

The airship appears to have some advantage too in the length of time it may remain on station, ranging from 30 hours at high speed to undetermined days at low. Indeed its endurance is not so much a matter of fuel capacity as of the ability of crews to stand long watches without relief.

There might be emergencies where airship scouts were wanted on continuous duty over a considerable period. Commander Roands’ experiments point out interesting possibilities in this respect, through the transfer of fuel and supplies from a surface ship, and the taking on of fresh crews.

This generally was the case men saw for the airship up to 1941, as having potential usefulness, in the event of war, against attack by sea.

Then came Pearl Harbor, and America’s entrance into a new war. German U-boats, larger, faster, more deadly, moved swiftly in to attack, as if waiting for the signal. The Japs made reconnaissance raids along the West Coast.

“Wolf packs” of submarines in new under-water tactics stalked convoys, picked off stragglers. More than 600 coast-wise ships, merchantmen from the Caribbean and South America, and tankersfrom the Gulf, were sunk in the first year of war. The loss of tankers brought serious complications ashore, the rationing of gas along the eastern seaboard to conserve supply for military purposes. Despite a quickly expanding program of ship construction merchantmen were being sunk faster than they could be built.

The Navy’s sea-frontier defense moved to meet the attack. Non-rigid airships were assigned a place in that program, wherever they could be utilized and with what ships were on hand, and new airship construction was rushed.

Under authorization from Congress, a program of airship and base construction, together with helium procurement, was accelerated, and by the end of the year, stations were in commission or being built at key points along both coasts and the Gulf of Mexico.

Akron expanded its facilities many fold for the building of new airships, which were flown to the various bases with increasing frequency during the year. Large classes of officers, aviation cadets and enlisted men went into intensified training at Lakehurst and Moffett Field, preparing themselves to man the ships as fast as they were delivered.

The blimps which have been available to the sea-frontier forces have rendered valuable service in patrol and escort missions. Their exact record of performance, including number of submarine sinkings, obviously cannot now be published.

On sighting a submarine, or finding indication of its presence, the tactical doctrine might call either for attack, or to stand by, summoning airplanes and surface craft in for the kill, keeping the enemy under unsuspected surveillance the while, and saving the blimp’s own depth bombs for another action.

The airship is capable of carrying on patrol and escort missions day after day under a wide range of weather conditions, going for months at some stations, even in the winter, without missing a day.

Though no detailed summary of airship activities is possible now, it is no secret that, just as in the last war, the submarines avoided attack upon convoys where airships were on guard. The German high command tacitly admitted that this was one type that the U-boats did not want to meet, an enemy immune to its torpedoes, whose presence the sub’s under-water detectors did notreveal, and which might appear overhead without warning. Admiral Doenitz, commanding the German submarine force, testified in a press interview to their respect for our blimps.

The battle against the submarines will be long and difficult, and ships will still go down and men will be lost, but the chase will be relentless as long as the menace exists. Airships, non-rigid, have taken their place in that phase of America’s war effort.

Little is available in the way of bibliography on lighter-than-aircraft, their history and characteristics. Among the best works dealing with this subject are Captain C. E. Rosendahl’s, “What About the Airship?” (Scribner’s), and “Up Ship” (Dodd Mead); Captain Ernst Lehmann’s “Zeppelin” (Longman’s) and Captain J. A. Sinclair’s “Airships in Peace and War” (Rich & Cowan, London).

Copies of “The Story of the Airship (Non-Rigid),” may be procured through The Goodyear Tire & Rubber Co. at Akron, Ohio; or at Los Angeles, or branch offices.

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