  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, might 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 tankers 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 not 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. |
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