Evening Star Newspaper, November 10, 1929, Page 108

s Fighting Planes Within a Hangar- Like Shell, Mount Bio Guns in Tur- rers and Cruise 10,000 Miles Wiih- out Landing. BY WILL P. KENNEDY. ISTORY entered a new epoch at Akron the other day, with many high officials of the Government as witnesses. A mobile fortre-s for the sky, a gigantic flying hangar capabl: of housing five Jarge fighting planes, with heavy machine guns and light artillery, is being built, larger than the Capitol Building or any United States battlesh p. This is to be the largest airship in all the werld, much larger than the Los Angeles and Gral Zeppelin together—the first of twin ships being built for the Navy. Rear Admiral William A. Moffett, chief of the Bureau of Naval Aeronautics, drove the golden rivet in the master ring, which is to be in the highest point in the hull of the ship. This ceremony was equivalent to the time-h:nored cercmony of laying the keel of a great sea- going vessel. . THIS ZRS-4, as the ship will be known until b an official name is selected, will be longer than three Washington city blocks. With the nose at Fourteenth and P streets, the ship would extend along F street, past Thirteenth and ‘Twelfth streets, with the tail beyond the Cc- lumbia Theater near Eleventh street. So huge is the bulk that it could not be crowded between the building lines. With the bottom of the control car resting on the pavement of F street, the top of the hull would be level with the top of the National Press Club Building. The dirigible will be driven by eight powerful engines, housed, for the first time in dirigible history, in the hull of the ship. It is expected to fly at a maximum speed of about 85 miles per hour and to cruise 6,000 miles with full military load without refueling. At a speed of 58 miles per hour the dirigible could travel 10,000 miles without landing. The first visible evidence cf the size of this aerial monster was given the visitors from the National Capital when they first glimpsed the airship dock in which the construction will take place. This dock, now mearing completion, is the largest building without interior supports in the world. More than 40,000 perscns can stand beneath the great arching roof, or 10 foot ball gam~s could be played simultaneously inside the ‘Cwscd doors. It 15 a building that literally stretches itself ‘'out over the ground when the sun beats down !Each of the giant “orange-peel” doors of this Akron, Ohio, airship factory and dock weighs 600 tons. Through them the THE SUNDAY STAR, WASHINGTON, D. C, Just by way of com parison. NOVEMBER 10, 1929, America’s Superdreadnaught of ¢ Larger Than the Los Angeles and Graf Zeppelin Put Together, the New Flying Fortress of the United States Navy, Under Construction at Akron, Ohio, Will Carry Five An_artist shows the size of the Navy's new ZRS-4, now being constructed at Akron, Ohio, over the Capitol. The great craft will carry five fighting planes in its hull, and it is armed with artillery. upon it and shrinks again at night; a building that rests upon giant moving rollers instead of being firmly anchored to its foundations. Four huge doors close the structure—doors so large that the task of cpening any one of them is equal to swinging the side of an 18-story sky- scraper on hinges. So vast and hollow is the building that a windstorm can attain cyclonic proportions within its walls. | The doors of this hangar could be closed on the Capitol Building. The building would house the airplane carriers Saratoga and Lexington, the largest naval vessels ever built for the United States, together with the Washington Monument and the Statue of Liberty. Six miles of standard railroad tracks could be laid on the floor area, which covers eight and one-half acres. Walk the length of the building four times and you will have covered nearly a mile. The sheeting covering the building, laid out flat, would cover 18 acres. ‘There is room inside for 49 airships the size of the Defender, largest of the present Goodyear fleet. The building itself is 1,200 feet lcng, 325 feet wide and 211 feet high, from the floor to the observation platform on top. Ti!lbm)dtng!ueuhmermtofmchrevo- changes in engineering design that it points the way to larger and still larger dirigibles, which, in the past, have been limited to the size of the buildings which could be constructed to house them. In this building the same principles of stream-line construction have been carried out which marked the de- velopment of automobile bodies, speed boats and airplane fuselages. The result’ is a building unlike any other in the wcrld. It has much the appearance of a mountainous egg cut in two the long way and laid flat against the earth. The ends are rounded off like the end of an egg to reduce resistance to the wind and every element of roof and wall has been designed to lessen the wind pressure. This is totally different frcm the old hangars. They almost always had blunt ends, which pro- tests, extending over many months, to determine the best shape for the great building which now rises above Akron like a mountain. The mere matter of creating doors for this airship dock presented more tremendous and difficult prcblems than might be found in the erection of a skyscraper. Dirigible hangars of the past had had doors based on principles al- most as old as civilization itself. They either swung open and shut cr they slid open. As the size of the doors grew greater these types be- entire Capitol Building, with the exception of the dome statue, could be entered. . being ripped bodily from their supports. It was obvious that neither of these types of door would serve for the great new super-airship factory at Akron. The situation demanded something entirely new and it has duced. The new type is known as peel” door and each section & quarter section of an orange peel. tions are hung on enormous pivots at and the bottoms run upon trucks sufficient carry a whole fleet of street cars. The doors are opened with electric power and when open fit tightly against the sides of the building, never encountering any greater wind pressure than when closed. This one development alone has added enormously to the practicabili'y of dirigibles, making it possible to get them into or out of their hangars quickly, regardless eof weather conditions. ' DESPITE all the wind pressure that must be withs'ood by the airship dock and all the colossal weight of its 7,200 tons of steel, the building must be mounted upon rollers so that practically the entire four-city-block-long build- ing can move itself back and forth and up and down. It is well known that almost any ma- terial expands with heat and contracts with cold. In ordinary buildings this expansion and contraction is so small that it takes care of itself. But in a single-unit building 1,200 feet long, one city block wide and equal to 22 stories becomes so great that the structure probably would burst itself asunder if it were firmly fixed to its foundations. So huge are some of the structural members that they could not be shipped to the sita if fabricated and assembled at the steel mills. tion for erection. Preparation of the dock site required the re- moval of 1,000,000 cublc yards of earth. ‘The substructure work consists of concrets footings carried on vertical, inclined and hori- zontal concrete piles. Concrete ties across the building, heavily reinforced and connected with the footings, were necessary to take the thrust from the arches. The piles carry a load of 30 tons each and 1,300 were required. The docking rails for moving the airships in and out are spaced 300 feet apart and extend 1,600 feet beyond each of the building. Down the center is a standard railroad track, which will carry a guide trolley to keep the hull of the airship centered in the building. ‘The interior floor area of the dirigible dock Is 364,000 square feet and the cubical content of the building is 45,000,000 cubic feet. The area of the roof, owing to the arching shape, I8 687,000 square feet and the skylights total