POLAR SUBMARINE

Dominion, Volume 24, Issue 149, 20 March 1931, Page 9

POLAR SUBMARINE

Wilkins Prepares For Unique Venture BROADCASTING PLANS By Telegraph—Press Association—Copyright. Washington, March 18. Sir Hubert Wilkins was granted authority on Wednesday by the Radio Commission to maintain radio communication with the United States on his Polar expedition In the submarine to be christened “Nautilus.” The license covers a series of hign frequencies for broadcasting, and communications will have 200-watt power with the call letters WSEA. INGENIOUS VESSEL Will Skid on Ice Ceiling When you first hear of a submarine voyage under 2000 miles of polar pack ice, there is an immediate reaction against men “committing suicide in so futile an. undertaking,” writes Fitzhugh Green in “The American Magazine.” But pure science demands that we find out the depth and shape of the bottom of the Bolar Sea, and pure science still wonders whether there is land in the unknown area of the Polar Sea; what life inhabits the waters under the polar pack; what currents move these waters; what, if any, bearing on weather these currents have; and so on. The commercial aspects of. Sir Hubert Wilkins’s forthcoming expedition are more SP From England to Japan via the Pole the distance is only about 6900 miles, or about half of the Panama distance.. From New York to Nome. Alaska, it is 9000 miles via the Canal, and only a little over 5000 miles by submarine under the northern ice. From New York to the Philippines by canal in 12,900 miles. Using the ice-choked North-west Passage, a submarine could travel between the same ports and cover only 9000 miles, or 3900 miles’ saving in time, fuel, mechanical wear and tear, and other overhead. There are also the possibilities of the great lands bordering on the Polar seas—Siberia and Alaska. Ice-breaking Prow.

“The reason the polar submarine ’will run when surface ships jammed is that the surface ship’s bow acts as a wedge, and the only way she can then make progress is to split the iee field apart,” says Simon Lake, designer of Sir Hubert's submarine Nautilus. An important feature of the Nautilus is its trapdoor for submerged diving. This leads from under her bow and permits a diver to descend while she is under the, surface. This is made possible through a sona,l diving compartment in the front end of the boat. The diver enters and an air pressure is raised to the level of the water pressure without. He can then open a trapdoor in the deck, from which leads a ladder to the sea. Air pressure keeps water from entering. This device is of peculiar importance to the under-ice submarine. It permits a diver to emerge from the boat and place a bomb under the ice overhead. Then the boat backs off and the bomb explodes, tearing a hole through to the air above. Must Reach Surface. The necessity for the polar submarine to force her way through the ice to the surface arises, not from the desire for those aboard her to inspect the pack, but because a submarine’s batteries must be charged by gas or oil engines every few hundred miles of her voyage. She runs submerged on her electric motors, for which the power is supplied by the batteries. When the fuel engine runs, air is required. Should the ice above her be too thick to break with a bomb, it will be pierced by a unique boring machine which Simon Lake has designed. As the diameter of the submarine is roughly fourteen feet, she can house a drill about fourteen feet long to penetrate that thickness of solid ice. This drill will project upwards through her conning tower, and will be sheathed in a tube about six inches in diameter. The tube will go up with the drill and finally emerge above the surface of the ice. It also contains a periscope with which the commander can look about him while his boat is still a prisoner under the pack. The submarine will not cruise at all times.under a well-nigh impenetrable floe of massive dimensions. There are practically no icebergs in the Polar Sea, aud the polar pack itself is continually being split and torn by tides and winds. Wide lanes of open water form at all times, winter and summer. Because of this it is estimated that the Nautilus will never be more than twenty-five miles from either thin ice or open water on her North Pole voyage. Inverted Toboggan. The cruising radius of the Nautilus with her engines will be auotit three thousand miles. She will probably have to cover about two thousand miles between Spitzbergen and the open water north of Alaska. Thus she will have a fifty per cent, factor of safety. Over her one-hundred-foot length is built an inverted toboggan, or bumperbar, to guide her under the ice. The upper surlace of this- device will be sharpened to help her break through. Since her gauges will tell those aboard her at all times what depth the submarine has reached, and since the bumper-bar’s exact distance above the hull is known, the navigator can always tell within a few inches just how thick the ice is over his head. When Nansen made his famous drift in the Fram he made many borings to determine the average thickness of the floes. He found that for the old fields, apart from narrow pressure ridges, a figure of twelve to fourteen feet was about the usual thing. One of the most extraordinary things about the Polar Sea is that its temperature remains almost constant at 28 deg. above zero Fahrenheit, while that of the air above the ice may be as low as 90 deg. below zero. Further, since sea water is brine, it does not freeze or stay frozen at 32 deg. above zero in the same way that fresh water does. In some concentrations of salt it does not solidify until the temperature is nearly zero. Hence, the sea water actually melts the sea ice with which it comes into contact. Throughout the trip, the Nautilus will make continuous sounding of the Polar Sea, something that has hitherto been impossible. Bv. means of her electric apparatus she will throw a sound wave to the bottom of the ocean. The time interval required for this sound to be echoed back is automatically resolved into depth.

Diagrams showing the surface and submarine cruising methods of the Nautilus are Included lu to-day’s illustrations section.