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In 1942, a U.S. aircraft carrier in the South Pacific was launching scout bombers in search of Japanese submarines. One of those planes, piloted by Harold Dixon with Tony Pastula acting as bombadier and Gene Aldrich as radioman and gunner took off on what should have been a routine mission. After the patrol was over, they got turned around and couldn’t find their ship. Running out of gas, Dixon decided to ditch the plane. Of the experience, he wrote: “The plane struck the surface of the sea with a sound like the slap of a giant hand on the water. A great splash of water instantly covered the glass in front of me, momentarily shutting out my vision €¦ It is no great trick to set a land plane down on water, but these heavily armored war jobs are not intended to float.” All three men got out of the plane safely before it sank. They had not managed to recover much from the plane. They had a raft, which they had to blow up, and what was in their pockets: A pistol with three clips of ammunition, a can of rubber patching cement and patches, a pocket knife, a pair of pliers, a small steel mirror and a police whistle. They had nothing for navigational equipment except a small aerial navigator’s scale of mileage. Without exact locations of where the plane went down or to where the airmen planned to make landfall, we surmise they were northeast of the Marshall chain at approximately 10° N by 170° W. Dixon had no intention of drifting around. He was determined to shape a course for their 4-by-8-foot rubber raft and get to land. Using thread and a metal sinker, he figured out the drift of the boat, and using bits of rags thrown overboard and counting the seconds (they had no watches), he was able to calculate speed. Since they were north of the equator, Dixon used Polaris to check his headings every night. Then he discovered a pencil to make a chart. He wrote: “I knew the approximate position where we went into the water €¦ I would have to use dead reckoning €¦ I traced the lines of latitude and longitude on the front of a life jacket, and marked with tiny ovals the approximate spot where we had landed, and my estimate of our positions in the past days’ drifting.” After 34 days at sea, the men reached an island not occupied by the Japanese. Miraculously, the island also had a radio with which the men were able to call for rescue. Dixon was awarded the Navy Cross and his two crew were commended. Let us join the three men in their rubber raft and do a set and drift problem the same way Dixon did. We will make it a little easier on ourselves by including compass directions (True), so this can be plotted on a maneuvering board or on a universal plotting sheet. Let’s assume for the sake of the problem that the raft is headed in a direction of 230° T. By observation of his thread and sinker over the side, Dixon guesses the drift of the current is 140° T, setting at 1.5 knots. His speed through the water is 3 knots. A. Calculate the course the raft is making over the ground. B. Calculate what course Dixon has to steer to make good a COG of 230°. |
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