National Geographic : 1926 Jul
STANDING ICEBERG GUARD IN THE NORTH ATLANTIC The 1925 ice patrol season saw the first serious experiments to destroy icebergs by high explosives. Our first subject was a berg showing io feet above water, with a length of 50 feet, an "old" berg, honey combed by weathering. A commissioned officer and a boat's crew of eight planted 210 pounds of TNT under a ledge of the berg; then pulled away to a safe distance, reeling off the electric control calle as they went. The officer closed a switch and a tre mendous explosion shook the air and the water. One end of the berg fell off and the sea all about was afloat with small ice. We estimated that we cut two days off the life of this berg. It was a different story when we tried TNT on a bigger block of sound ice. This next specter was 300 feet long and about 150 feet high. From one side pro jected one of the long, dangerous ice tongues, covered with about 10 feet of water. We laid the mines on the shelf and set them off. The berg shivered, a shower of loose ice tumbled off the upper ledges, a geyser of water and black powder smoke went up loo feet and came down, and the calm of Nature settled back upon the sea and ice. No damage. Next we shot a line across the project ing end of the berg. On one end we at tached the mine, lowering it to 75 feet below the surface and balancing the weight with a bag of iron on the other end of the rope. The explosion shook the berg more, but there was no percep tible damage. That charge would prob ably have given a mortal blow to the strongest ship afloat. STANDING DEATHWATCH ON A BIG BERG Our attempts to mine and destroy a third iceberg are of especial interest, be cause this was the largest that came into the steamer lanes last year, and because we trailed its steps to its grave from the time it was a strapping giant of a million and a half tons until it disappeared. We first sighted the berg on May 26, well north on the edge of the Banks. It was christened No. 14. All bergs that are potentially dangerous are numbered. No. 14 hugged the Banks and sailed southward at the modest rate of 21 miles per day. After determining that there was only one more berg to the north, we steamed south and picked her up near the tail of the Banks on June 2. We knew we were approaching No. 14 the second time before we could see her, because of a white line reflected against the clouds of the horizon. Soon the look out shouted, "Ice ahead !" Although we were still more than 20 miles away, the topmost pinnacles could be seen, since No. 14 was 267 feet above the water. As the ship approached in the calm sea and clear sky, the berg stood out shapely, fantastic, beautiful, and enormous in size. Closer view showed that it was drydock in shape, with two walls of uneven height. Both sides were 512 feet long-that is, the length of an average city block. One of the boys on board was all for towing it down to Boston or New York and selling it to some ice concern. In deed, its million and a half tons would supply New York's summer demand for two and a half months. LEAVES FROM THE DIARY OF A BIG BERG "June 3.-No. 14 heading right for the tail of the Banks. We hope she will ground because that will end our troubles. "June 7.-A heavy fog shut down, con cealing our ward. "June 5 and 6, the same. We estimate her drift, take a position 5 miles south, and shout to the world by radio that ice is north of us; take warning! "June 7.-At 5:20 a. m. the fog lifts; sight No. 14 about 7 miles away. The berg looks the same until we approach, and then, without warning, the highest wall topples in with a crash that would awake the dead. It leaves a natural bridge across the 'drydock.' No. 14 has moved 6o miles south and west. To-day we are witnessing the beginning of the end. "June 8.-No. 14 is now in 42 degrees water, whose warmth is undermining the berg's constitution. Learn this by watch ing the tilt of the water lines. "June 9.-We decide to take a hand in the destruction of No. 14. First we ex plode mines on a tongue and then under water, as we did with the second berg, but with even less effect. Then we decide to try to dig a hole with four charges placed on a smooth water-polished shelf 40 feet wide terminating in a cliff 200 feet high.