I. E. Rittenburg, H. & G. Engineer, U.S.C. & G. Survey

(From the U.S. Coast and Geodetic Survey

FIELD ENGINEERS BULLETIN

no. 10, December 1936, pp. 98-103.)

On the morning of October 6, 1935, the Douglas Airliner of the Standard Oil Company of California, en route from Oakland, California, to Salt Lake City, and carrying a crew of three men, failed to arrive at the Salt Lake Airport. About ten minutes before the scheduled arrival of the airliner at the Salt Lake Airport, the pilot had radioed in requesting ground wind velocities and data preparatory to landing there. From the time elapsed between the take-off at Oakland, his various reporting in stations and the time of his last request, his air speed was estimated at about 209 miles per hour. These data tended to locate the plane between Delle, Utah, and the Great Salt Lake.

On October 9, 1935, the body of George Anderson, mechanic of the lost plane, was found on the eastern shore of Stansbury Island. The next day, the body of R. S. Allen, the pilot, was found in the same vicinity about one to two miles northeast of the first body. Neither body was bruised or injured and death in both cases was due to strangulation. Two pillows, identified as pillows from the lost plane, were then found about 5 miles northeast of the northeast point of Stansbury Island.

These facts led to the theory that the plane had made a forced landing in the Great Salt Lake, that the landing had been a good one, the plane had remained afloat long enough for the men to divest themselves of clothing, that they had intended to swim to Stansbury Island, possibly using the pillows for rafts, and that they had dived into the water and had been strangled immediately as the waters of the Great Salt Lake are 28% salt solutions.

The Standard Oil Company was desirous of locating this plane and the third body which had not been found. A reward of one thousand dollars was offered for this information, i.e., the location of either the body or the plane, and numerous small boats with outboard motors attached began searching. Several ideas and methods, very fantastic to say the least, were proposed for a dragging of the lake to attempt to locate the plane. Finally after about a week, the Standard Oil Company requested the Coast and Geodetic Survey for the loan of an officer and the necessary equipment to make a systematic wire drag survey of the lake to locate the lost plane.

Therefore, on October 16 a telegram was received from the Director assigning me to this task. Contact was made with the officials of the Standard Oil Company and work was begun. This work was carried on every day including Sundays from October 17, 1935 to February 27, 1936, when the search finally ended in success.

Before any actual wire dragging could be attempted, numerous obstacles had to be overcome. Chief among these were a lack of available launches in the immediate vicinity; no landing for the launches could then be acquired, where supplies could be kept; no chart of the Great Salt Lake, only rudimentary topographic survey showing a few control stations; practically no hydrographic information of any sort; no actual knowledge of the area into which the plane had fallen; and the approach of winter with its adverse weather conditions.

It was found that at Colin, Utah, (the upper end of the Great Salt Lake, at the Southern Pacific Trestle, Lucin Cut-off) two launches, suitable for the work and the only two launches that could be called suitable on the entire lake, could be had. One of these proved to be practically a wreck and its engine of no value. The good launch was outfitted; the wrecked launch was rebuilt and the engine replaced by a new one. All this was accomplished in less than a week. Meanwhile a landing was built at Sunset Beach for the loading and storing of supplies, and as a base of operations.

As a reef extends about 1 ½ miles offshore from this landing, it was necessary to anchor the larger launches outside and ferry gasoline and other supplies from the landing to the launches by smaller outboard motorboats. The floor of the lake was found to be crystallized salt, about 18 inches thick and smooth and hard as glass. It afforded such poor holding ground for the launches that it was necessary to embed the anchors in the salt. This was done by a diver who chopped a hole in the salt and placed the anchors in the soft sand beneath.

The only practicable method of finding this plane was to wire drag the lake systematically. No hydrographic data of any kind were available. Accordingly it was necessary to run as many sounding lines as possible to secure information about the depths of water to be encountered, so that the drag could be set to the proper depth. This was done during the week while the launches were being repaired. The topographic maps were then taken into the field, checked, and found to be satisfactory in so far as the triangulation stations shown on the sheet were concerned. The hydrographic survey showed that the maximum depths to be encountered were about 25 feet.

On October 27, 1935, everything was in readiness and wire drag work was begun. Considerable difficulty was experienced on that day in trying to keep the launches on line. This was due to the inexperience of men hired, as naturally Salt Lake City being an inland city no sailors could be found. Consequently, it was requested that the office detail another officer to this project to be in charge of the end launch and to assist in the training of the men. Therefore, Lieutenant (j.g.) W. J. Chovan was immediately sent to Salt Lake City to take up this work. Too much credit cannot be given Lieutenant Chovan for his able assistance, as without his services the progress of the work would have been considerably retarded.

The next difficulty to overcome was procuring tenders suitable for this work. There were no inboard launches available on the lake that could throttle down low enough or that could continue to run all day. It was necessary then, to attempt to use outboard motor boats. They proved very unsatisfactory because of their unseaworthiness in general and the continual stopping and starting required of them with the incident delays to starting. The result was that considerable time was being lost by the wire going aground needlessly because of gradual shoaling of the water. This was inevitable as the ground wire was kept not over two feet from the bottom, and the launches could not make their rounds fast enough. Therefore, the Standard Oil Company purchased a launch in San Francisco and shipped it to Salt Lake City. This was a 28 foot fishing boat and proved to be suitable for the work although it did have too much freeboard and too large a turning radius. Better results were immediately apparent in the reduced number of times the ground wire hung up needlessly. However, it was felt that the wire should be tested for lift and depth more often than it was possible with only the one tender. Consequently another launch, previously used by the Coast and Geodetic Survey on the California coast wire drag, was purchased and shipped up. With the two tenders needless groundings were practically eliminated. Two way radio communication was established between all launches and the base at Sunset Beach. The drag launches would take frequent soundings and radio the depths obtained to the tenders. In that way the tenders knew at all times the depths of water being dragged.

Heretofore all the obstacles met with had been technical or physical things that could be overcome with the expenditure of effort and funds. Our greatest obstacle was still waiting for us in the person of Mother Nature. Winds will blow, cold and snow will come in the winter to Salt Lake, and daylight hours will be reduced. It was found that winds of 15 miles per hour would make it too rough for good dragging and winds of 25 miles or more would kick up a sea comparable to a heavy storm on the ocean. This was due to the shallowness of the lake with its maximum depth of 25 feet and the weight of the water. As this water is 28% salt, its specific gravity is about 1.2 or about 75 pounds per cubic foot, considerably heavier than sea water. This salt was very dangerous to the comfort of the men as the spray in the eyes, nose or mouth would burn and smart. It is said that a single mouthful of this water inhaled into the back of the throat could very easily strangle a man. This happened evidently to the three aviators lost with the plane. In passing, I might add that these seas were very short and steep which naturally tossed the launches around considerably. With the approach of winter the weather of course became colder and colder. However, work was carried on in temperatures ranging as low as 4 degrees below zero Fahrenheit as the lake water never freezes because of its heavy salt content. Aside from the personal discomfort of the men in working in this extreme weather, our greatest difficulty on the entire project was the slowing down of the launches and the clogging up of the water systems of the launches because of this cold weather and the precipitation of Sodium Sulphate occasioned by the cold.

At the beginning of the search the lake water was fairly warm and salt, Sodium Chloride, was precipitated as the lake is a super saturated solution of salts of various kinds. This salt would form on the hulls of the launches and around the drag lines and buoys. It did not, however, clog up the water systems of the launches. The speed of the launches at this time was about 7 miles per hour. This continued until about the first week in December. At this time the temperature of the water of the lake approached the freezing point of fresh water with the result that the lake stopped its precipitation of Sodium Chloride and began to precipitate Sodium Sulphate. This proved to be much worse than the chloride salt as it formed faster on the hulls and drag and even clogged up the circulating water systems of the launches 3 or more times a day. This sulphate salt slowed the launches down to barely 5 and even less miles per hour. All the time the work was getting farther and farther away from the base at Sunset Beach; the days were getting shorter and shorter with the result that the output of the party was being gradually cut down to the vanishing point. Ice scrapers were bought and an attempt to scrape this sodium sulphate from the sides of the launches was made. While all the salt on the sides and a few feet below the water could be scraped off, there would still remain vast quantities of this salt on the propeller blades, rudder and along the keel. Fresh water seemed to be the solution, so we went in search of a fresh water anchorage for these launches. During the Christmas holidays time was available for sounding and a fresher water anchorage was found. This new anchorage would add about 1 mile per hour more speed to the launches for a few hours in the morning, but during the day the sulphate salt would gradually accumulate again and the speed would be reduced again. From a dragging speed of 2 miles per hour, we were reduced to a speed of a little better than 1 mile per hour. Rather than cut down the width of the drag, 5000 feet, it was decided to add a third towing launch to act as a booster. Various positions were tried out for this third launch and finally it was found that maximum efficiency was had by having this third launch tow from the second buoy. This would allow the near towing launch full freedom in handling and would still be in the overlap areas to counteract any undue lift at this second buoy. By means of this booster launch our speed in dragging was increased to about 1.8 miles per hour. Finally about the middle of February 1936, the lake water began to warm up and the speed of the launches increased about ½ mile per hour daily until they were finally making their full speed of 8 ½ miles per hour. Needless to say this was quite a help. Our drag speed also increased to slightly better than 2 miles per hour without the booster launch. As this was fast enough because of lift, the third towing launch was dispensed with and she returned to her "tending." It seems as if there is a period from the middle of February to the first of June or July when the temperature of the water is too warm for the precipitation of Sodium Sulphate and too cold for sodium chloride. It is at this time when vessels can make their maximum speeds. Because of this slow speed, the increasing distance from the base to the working grounds and the desire to complete the job as soon as possible, it was decided to work long hours, from daylight to dark. Otherwise not much dragging could have been done as most of the time would have spent in running to and from work.

As has been said, dragging began on October 27, 1935, and was continued every day until discovery of the plane. It was decided to use a 5,000 foot drag with 400 foot sections as this seemed to give maximum efficiency considering the towing capabilities of the launches. As there was neither traffic nor tides on the lake it was decided to anchor the drag at the close of the day's work rather than take it up. This method worked well. The scale of the survey was 1:60,000 because of the large extent of this body of water. Because of this small scale it was impracticable to locate the end buoys so the launch positions were plotted. To obviate any chance of splits in these overlap areas, it was decided to use an overlap of 1,000 feet between adjacent drag lines which more than compensated for the error introduced in using the launch positions rather than the end buoy positions. The airplane was finally found on February 27, 1936 in 25 feet of water with a 23 foot drag. This culminated the longest and most expensive airplane search on record. A diver was sent down and the plane was positively identified and an examination of the plane was made. It was found that the wire of the drag had caught under the propeller hubs and wrapped itself around the wings. The plane was found upright which bore out the theory of a good landing, practically intact and partially salt covered. There was about 1 ½ to 2 feet of salt inside the cabin of the plane. The location of the plane was about 7 ½ miles from the bodies and in almost the exact middle of the lake northeast of the northeast end of Stansbury Island.

At the outset of the search, the prevailing opinion was that the plane would be found in the south end of the lake near Sunset Beach. This opinion was arrived at from rumors furnished by people claiming to have seen the plane, the airline course the pilot was supposed to be following lying near the south end, wind drift calculations and logic which would lead one to believe that if in trouble any pilot would logically attempt to land on the salt flats at the south end of the lake. Therefore, the search was started in this south portion of the lake with the result that this opinion was proved to be wrong. However, wind drift calculations did show that regardless of the direction of the wind the plane must lie in an area described by an arc of 8 miles radius from the bodies. Consequently this arc was swung on the sheet and a systematic dragging of this area was begun. Unfortunately the dragging was started from the Stansbury Island shore eastward. The plane when found was in this area but in the extreme NE end of this circumscribed area.

Upon the finding of the plane, the phase of the work to which I had been attached was over. Consequently, the instruments were transferred to the Standard Oil Company and I returned to my station in Florida.

The following information was obtained by correspondence:

After locating the plane there still remained the raising and dismantling of the plane. It was decided to tow the plane underwater to Colin on the Southern Pacific Trestle across the Great Salt Lake, for the following reasons rather than to bring it to Saltair. There would be less interference with the operations from the curious. A locomotive crane was available there and the Southern Pacific Railroad could furnish as many men as would be required for the actual lifting. The plane was freed from the bottom, raised about 7 feet off the bottom by means of hydraulic jacks and towed. Swings were put under the 2 larger drag launches, and attached to the nacelles of each engine. These 2 launches bore the greatest weight. They were lashed the proper distance apart by timbers across the bows and sterns. The larger of the two tenders, with a line rigged from the bow, carried the weight of the tail. With this 3 point suspension the tow left the scene of the discovery at about 9:30 A.M. and arrived at Colin about 7:30 that night.

Lifting the plane was far more difficult than anticipated due to the water absorption of the upholstery, carpets and sound proofing. For example, a chair cushion normally weighs eight or ten pounds, and when saturated with Lake water it weighed sixty-two pounds. Similarly, all of the structure which had small openings contained about 18 inches of salt. This includes the wings, fuselage and stabilizers. The net result was that instead of weighing between eighteen and twenty thousand pounds, the plane weighed between forty and fifty thousand pounds. the plane was finally lifted and set in the cradles provided for it.

Examination so far of the plane both inside and out has revealed no apparent reason for the accident. A detailed analysis based on facts obtainable from taking the plane apart piece by piece will be necessary before the cause of the disaster can be determined. Fifty gallons of gasoline were pumped from the tanks. Except for those parts of the plane made from a magnesium alloy, the gyrocompass, parts of the wheels, etc., the plane was apparently in perfect condition. These parts were eaten away completely due, no doubt, to the lake water. The plane is to be dismantled, every piece, bolt, nut, etc. will be washed off with fresh water and packed in oil for shipping to San Francisco where the final detailed inspection and analysis to determine the cause of the accident will be made.

(This article is accompanied by six photographs and a sketch. The photographs are captioned as follows:
Launch towed is "Marsh" rebuilt and used as one of the drag launches. Note foam on water.
"Marsh" after rebuilding showing heavy salt accumulation on sides.
Salt deposits around landing at Colin, Utah.
Salt (Sodium Sulphate) accumulated around aluminum toggle buoy.
Salt chipped away to show amount of deposit.
Model of plane showing the position of the drag when found.
The sketch is of the Great Salt Lake and is captioned, "Sketch Showing Position of Plane Found by Wire Drag.")