Return of Expedition to King’s Bay, June 19, 1925, 1:30 a.m. Left to right—Riiser-Larsen, Undal, Dietrichsen, Amundsen, Ellsworth, Feucht
It had always been Capt. Roald Amundsen’s wish to fly to the North Pole, and there if possible, abandon one plane in order to refuel the other from her, and with the remaining plane go on to Point Barrow, Alaska. Because the interest of us both lay, not in the attainment of the Pole—Peary having already been there—but the exploration of that great million square miles of unknown Polar Basin beyond, we took this into consideration in planning our 1925 flight from Spitzbergen with two aëroplanes.
The story of our flight over the Polar Sea to within 120 nautical miles of the Pole has already been told. Although we didn’t reach the Pole, the flight had shown that the meteorological conditions prevailing over the Polar Basin offered no hindrance to its successful exploration by means of the proper kind of aircraft.
After our experience with airplanes we decided to buy an airship, and we went to Italy because Mussolini had one that appeared to fit both our needs and the size of our purse.
The N. 1, built to the designs of Col. Umberto Nobile in the Italian State Airship Factory, and christened by us the "Norge," was of semi-rigid construction, 349 feet long and of 20 tons displacement. Her fuel capacity of 7 tons, to run her three 250 horse-power Myback motors, gave her a range of 3500 miles, or about 70 hours, at a speed of 50 miles per hour. Her gas capacity of 660,000 cubic feet was about 1/3 that of R.33.
The “Norge” was equipped with a Marconi wireless direction finder, the tuning-circuit for which was designed to cover a wide band of wave lengths; those used ranged from 900 to 1400 meters. The energy for the specially constructed valve transmitter was delivered from a windmill-driven generator supplying 3000 volts.
There was a delay of several days after the long flight from Italy to Spitzbergen, before the “Norge” was able to proceed on her journey across the Polar Sea. Favorable weather conditions were essential. We needed a clear sky with good visibility, and a favorable wind; also a high barometric pressure and a low temperature. These last two elements influenced greatly the lifting capacity of the dirigible. For each degree Fahrenheit that the temperature went down, the airship gained 80 pounds in lifting capacity, which was increased by 140 pounds for each tenth of an inch added to the barometric pressure.
Our only implements,—3 wooden shovels, sheath knives tied to skii sticks, and a two-pound belt ax.
Provisions consisted of pemmican, chocolate, oat biscuits, and dry milk, sufficient to last 16 men two months, with a daily ration of 500 grams for each man.