----------------------------------------------------------------------- Page 49----------------------------------------------------------------------- Page 50 This decision was the proper one under the conditions, but carrying it out was dangerous. All flood and vent valves on the four pontoons at the bow were closed. The motion of the pontoons was violent and erratic; seas swept over them steadily. The order to open the valves and sink the pontoons was given to Boatswain Hawes and the surfboat crew (see figs. 17 and 18); three men, Badders, Wickwire, and Weaver, volunteered to carry it out. One at a time they boarded the pontoons and fought the sea; pounded into a state of collapse they were successively hauled back to the surfboat each with the valves on his pontoon open; with his men all gone Boatswain Hawes himself leaped aboard the last pontoon and swung open its valves. The pontoons flooded quickly and settled evenly; No. 1 port pontoon showed slightly for about 10 seconds after the others had completely disappeared and then vanished; the "S-51" sank the rest of the way with no disturbance visible at the surface. The "Falcon" buoyed off all hoses, let go the moorings at about 2 p.m., and with all other vessels of the salvage fleet ran for shelter at Point Judith. The two pontoons which had gone adrift were soon brought in behind the breakwater by the "Sagamore" and the "Wandank". In the late afternoon the broken chains were removed by the "Falcon", and the "Vestal" repair party immediately started to recondition the pontoons. A 100-ton floating derrick, the "United States", had a week before been towed from the New York Navy Yard to Point Judith to be handy for contingencies even though she could not safely be taken out to sea; a crew for the derrick was mustered from the personnel of ships present, and with the repair ship "Vestal" and this derrick a miniature navy yard was at once put in commission, which shortly did remarkable work. While the events were still fresh, a study was made to determine the causes of what had happened. It was concluded that the bow pair of pontoons must have been more buoyant than estimated; this was evidently the case with the No. 3 pair also. In the case of the bow pontoons the leakage after the valves were closed must have been much less than what the bubbles at the surface indicated. No means, unfortunately, existed of knowing the buoyancy inside a pontoon, unless it happened to be completely empty or completely full; other than in these two conditions its buoyancy could only be estimated with the flow of air in through a long hose and the leakage of air out through the battered shell as two highly uncertain factors governing it. It appeared that sufficient buoyancy had accumulated forward when work ceased late on June 21 to give a slight positive lifting moment at the bow. Motion, however, was prevented by the suction effect. The air put in during the morning was either aft or amidships and could have had but a negligible effect on the forward lifting moment; actually the air put in the stern pontoons would tend to reduce the forward moment by shifting the center of buoyancy aft and would help to hold the bow down. It is probable that the motion of the sea was sufficient to rock the "S-51" in her bed on the bottom. Such motion at that depth had been observed previously by divers in the swaying back and forth of the pontoons afloat over the hull. On this occasion the lightened ship was rocked sufficiently to break loose the suction on the bow, which rose with accelerating force as the expanding air forced water out of the bow pontoons on the way up and increased the buoyancy. By the afternoon of the following day, the sea had subsided enough for diving and the "Falcon" returned for an examination of conditions. The "S-51" was found with a strong starboard list, about 20 degrees, and with the bow clear of the bottom back to frame 40; the stern was on the bottom. There was no evidence either forward or aft of damage to the "S-51" due to the events of the previous day, except some dents in the bow buoyancy tanks where the pontoons had rubbed. The midship pair of pontoons ----------------------------------------------------------------------- Page 51 
Figure 16: Bow pontoons driven out of alignment by the sea,
June 22, 1926.----------------------------------------------------------------------- Page 52 (No. 3 pair) was afloat in proper position abreast the conning tower, but both the No. 1 and the No. 2 pairs of pontoons were in a huddled group at the bow. Three of these pontoons were standing vertically on end alongside the submarine; the fourth one was floating horizontally about 5 feet above the submarine's deck. All four of these pontoons were battered and out of position; it was clear they would have to be cast loose and brought up for repairs. The bow of the submarine was found about 15 feet to starboard of its former location, the boat evidently having swung somewhat with the storm. Except for the work required to remove and replace the four bow pontoons and to replace the two pontoons carried away at the stern, the condition of the job did not look worse than two days before. The condition of the divers, however, was critical. They were much worn from their previous exertions, especially during the last two weeks, and they were in no condition to undertake another strenuous diving operation. To some of them the job looked hopeless and their spirits were at low ebb. It was with some difficulty that the surface and diving crews were made to see that an immediate continuance of work was imperative; when convinced that success was possible the divers turned to again with an enthusiasm and a vigor that far surpassed their efforts of the preceding month. The first operation attempted was to run through a pair of reeving lines for replacing the No. 2 pair of pontoons. The keel here was barely touching the bottom and it was essential to get the lines under before it settled. One line was passed through at frame 30 and the divers sawed it back to frame 42, its designated location. For the second reeving line, this could not be done, and Eadie had to wash through a new tunnel at frame 50, which he was able to complete in about one hour, this speed being due to the new nozzle. The first line through the tunnel was cut in half by the bilge keel and another had to be run. On the reeving lines, wire lines and then a pair of 2.5-inch chains were run through; the wires and the chains were laid out on the bottom until wanted. The next step was to clear away the pontoons at the bow. The pontoon still afloat was secured across the submarine by the lashing wires and these had to be cast loose. One of the wires lay across the deck where it was easily reached by Chief Torpedoman Kelley and cut with the torch; the other wire ran about 6 feet clear of the side and was out of reach from the deck; furthermore it was under a strain from the floating pontoon. To cut this wire, Kelley lashed the torch to the end of a squilgee handle, reached out toward the wire with the torch already lighted and the cutting trigger pulled, and speedily burned the wire in half. Freed of this strain, the pontoon swung across the deck toward the divers, who started to run; it caught one of them and knocked him off the boat; the pontoon then rose about 10 feet until it took up on both chains. Kelley managed to haul his partner back aboard, fortunately not injured, and both divers came up safely but badly shaken. Before proceeding further, it was necessary to sink this pontoon, the flood valves of which had not been touched while it was on the surface, as they were inaccessible then. The next divers down on the job found this pontoon still afloat but almost vertical, and reaching the valves was difficult; the next day this was accomplished and the pontoon sank, still standing on end. This completed a trying situation, all four of the bow pontoons being vertical which was their worst position for work. An attempt was made to capsize the port No. 2 pontoon by attaching a 6-inch manila line to the high end and hauling on it with the "Falcon"; after some heaving the line broke but the pontoon stayed as it was. In view of this failure, it was determined to attempt the release of the toggle bars holding the chains to the pontoons; even though the diver would have to work on a vertical surface, Grube, one of the newly trained divers, went down on this job and hanging by his life line (which was tended from the top of the pontoon by another diver) managed to remove the locking pins ----------------------------------------------------------------------- Page 53 
Figure 17: Wickwire boarding bow pontoons, June 22, 1926.----------------------------------------------------------------------- Page 54 and haul the 130-pound toggle bars out of the chain links, thus freeing the chains. When the divers were clear, the air was turned on and this pontoon soon floated up; the mate pontoon of this pair was then blown clear of water and came up, bringing the pontoon chains with it. Both pontoons were dispatched to Point Judith in tow of tugs for repairs. The bow pair of pontoons took two days to cast loose and bring up, due to the tangled condition of the chains and the hoses. When finally raised, the port bow pontoon was found to have several large holes punched in its side; both bow pontoons were well battered and were sent to Point Judith for overhaul. The bow towing bridle previously installed was found useless, as it had torn free of the port bow plane guard through which it passed; Kelley burned the bridle in half and sent it up. A new towing pennant of chain and wire was sent down and shackled into the bullnose; this pennant was the one actually used later for towing. As a preventer, another towline was secured around the gun mount with a length of 1.5-inch chain and held in position near the bow by a 1.5-inch chain bridle passing completely around the ship; from this point a towing wire led forward. Both the above towlines were laid out on the bottom ahead of the "S-51" and buoyed off. On the evening of June 30 the divers had completed all work on the towlines and in clearing away damage; the "S-51" was again ready to attach pontoons. Meanwhile at Point Judith the damaged pontoons had been hauled out of water by the derrick "United States" and landed on her deck. The derrick was secured alongside the "Vestal" (fig 19) and the repair forces of the "Vestal" worked night and day to repair and calk the battered steel cylinders and replace the missing wood sheathing. New valves and sheathing were hurriedly shipped from New York. By the end of June the first pair of pontoons was ready the other two pairs were well advanced. The presence of the "Vestal" avoided a delay of two weeks which would have been required to send the pontoons to the nearest industrial plant for repairs. On July 1 the "Falcon" was ready to lower pontoons, and the first pair was towed out from Point Judith. The weather was rather bad for lowering pontoons, but the lowering operation was successfully carried through without mishap, the pontoons being lowered and secured to the chains which had some days before been run through and laid out for the No. 2 pair of pontoons. An attempt was made to combine the leveling-off operation with the lowering of the second pontoon of this pair by holding the pontoon over the submarine with the 12-inch lowering lines while the first pontoon was floated off the bottom into position. On account of the violent motion of the suspended pontoon, the divers were unable to stay on the ends of the second pontoon long enough to open the flood valves, and came up seasick from the motion. As the pontoon could not be made buoyant without first opening the food valves, nothing could be done except to sink the first pontoon again and lower the second one to the bottom, where the 12-inch lowering lines were cast off. The manila lowering lines were so stretched and reduced in diameter by the strains on this day that they had to be discarded and a new pair provided for the remaining pontoons. Fortunately a spare set of 12-inch lines was available on the "Vestal". On July 2 a pair of reeving lines was run under the stern of the submarine, the wires hauled round, and a pair of 2.625-inch chains rove through and equalized. A pair of pontoons was lowered and secured, but as the weather was as bad as on the previous day, no effort was made to level them off. On July 3 the last pair of reeving lines was run under the bow. To keep them from slipping up the rising forefoot and getting clear, the divers first secured a piece of 2-inch pipe from the mushroom anchor hawse pipe in the keel down to the bottom, into which the pipe was driven about 1 foot. The reeving lines were run through abaft the pipe and followed up with the wires and the 2.625-inch chains; the after chain was passed through the starboard and port bow plane guards; the forward chain came in way of the anchor well in the keel. ----------------------------------------------------------------------- Page 55 
Figure 18: Wickwire clearing air hose, June 22, 1926.----------------------------------------------------------------------- Page 56 The port pontoon of this pair was successfully lowered and secured. In submerging the starboard pontoon of the pair, preparatory to lowering, the forward lowering line, which was wet, slipped on the bitts while the flood valves were being closed and the pontoon went down at this end enough to carry the extension wrench about 4 feet under water, the flood valve being still open. Badders, who was trying to close the valve, jumped into the water, and by several dives got the valve nearly closed, when the extension wrench hit the side of the "Falcon" on a surge and carried away. As the pontoon could not safely be lowered with a partly open flood valve, some air was blown into that end of the pontoon to lighten it somewhat; by that time Eadie was ready in a diving rig and was put overboard in it to close the valve, which he did about 8 feet under water. The pontoon was then lowered to its position over the submarine, where it was held while the diver inserted the toggle bars. The mate pontoon was blown off the bottom and floated up into position over the submarine. When this was done, the divers opened the flood valves on the suspended pontoon and it was blown until it became buoyant, as indicated by loss of strain on the lowering lines. When this was attained, the lowering lines and wires to chains were cast off and the bow pair of pontoons was leveled off in final position. The flood valves were immediately closed to minimize leakage. This pair of pontoons was the only pair that the salvage party was able to lower, secure, and level off afloat in one continuous operation. Its success was due to the moderate weather which prevailed that day, better weather being needed for leveling than for lowering. Three pairs of pontoons having been lowered and secured in three successive days, the morale of the salvage force was considerably bolstered up, and the men were driving hard again to clean up the job and get away. On July 4 the "Falcon" rigged for leveling pontoons, with only a moderate swell. The standard method was used. Commencing with the No. 2 pair of pontoons, a 1-inch wire was secured to each end of the starboard pontoon. This was gradually lightened by blowing until the "Falcon" winches were able to lift it when it was hoisted into position above the submarine. The port pontoon was then blown until it floated up level alongside the starboard pontoon (as usual, the port pontoon rose one end first). The starboard pontoon was then blown until it was buoyant, after which it was cast loose, and the flood valves closed on both pontoons. The "Falcon" then shifted position and quickly leveled off the stern pair of pontoons in the same manner. One of the divers next went down with a blowing hose and blew out the port side ballast tanks Nos. 3, 4, and 5 through the open Kingstons. To get at the starboard tanks, it was necessary to wash the Kingstons clear, as the submarine had a bad starboard list. This was done and the starboard ballast tanks Nos. 3, 4, and 5 were blown dry. The pontoons now being in position, lashing was started. The old lashings on the No. 3 pair of pontoons were found intact, with no work required. A pair of wires were measured off and sent down for installation as lashings on the new No. 2 pair of pontoons. The divers installed the wire lashing on the after chain, but were unable to install the wire on the forward chain as they found that the forward end of the port No. 2 pontoon had sunk until it rested on the bottom; the forward end of the starboard pontoon had correspondingly gone up. As no appreciable external leakage was visible, it was believed that the internal bulkhead must have leaked, allowing considerable water to flow to the forward end of the port pontoon and thus causing that end to sink. On account of the lateness of the hour, nothing could be done that night. July 5 dawned with passable weather, a choppy sea, and a moderate swell. As the weather prospects for the next day were poor, it was decided to blow the submarine that day and get out before the next storm; consequently, diving commenced unusually early. ----------------------------------------------------------------------- Page 57 The first step was to level off the No. 2 pair of pontoons again. To do this, a pair of 1-inch wires was secured to the starboard pontoon, the forward end of which was floating high, and a vent hose to the surface was also connected to the vent valve at the high end. The diver also opened all flood valves on both port and starboard pontoons of the pair. The forward end of the starboard pontoon was then vented and the forward end of the port pontoon was blown. The wire line to the forward end of the starboard pontoon soon developed a strain; it was lowered away gently until the pontoon was level; meanwhile the forward end of the port pontoon floated up until that pontoon also was level. Both pontoons were then given additional air all around to insure buoyancy and the leveling wires were cast off. The remaining lashing wire was then secured across the deck of the submarine to the forward chain, and all essential lashings were complete. Eiben went down forward to secure the open end of a diver's air line to the stem, to act as a telltale to indicate the rise of the bow. Eiben also opened the flood valves on the bow pair of pontoons. Wickwire went down aft to secure a similar telltale to the stern and opened the flood valves on the stern pair of pontoons. Knowing that he was making the last dive on the job, on behalf of all the divers Wickwire kissed the "S-51" good-by and (demonstrating the firm faith of the divers in their work) promised to meet her next in the dry-dock at New York. Wickwire came up shortly before noon. Certain forward tanks, which on June 21 were dry, were on this occasion left flooded. The No. 2 bow buoyancy tank was considered lost, as it was evident that the deck forming its tank top was dented enough to make it nonwater-tight and the capacity of the tank did not warrant repairs. The forward trimming tank and the water round torpedoes tank had vented themselves down practically to atmospheric pressure while the bow was at the surface. On sinking again, these tanks reflooded nearly full under the bottom pressure. Had time permitted they would have been blown down again, but the weather forecasts were such for the following day that it was considered unsafe to risk further work which would run the job over until July 6, when a promised storm would put the expedition in the same position as two weeks before. Work on the forward tanks was abandoned, but with regret. Another consideration causing some anxiety was the fact that about 150 tons of buoyancy in the six forward pontoons was going to be unavailable for lifting the bow while the stern was up. (Pl. 5.) This resulted from the fact that when the stern rose to the surface, the six pontoons forward would assume the angle of the boat, about 25 degrees. Under such an angle, the after half of each pontoon could be blown down only until the air reached the flood valve, when it would escape, leaving a considerable wedge of water, amounting to 25 tons per pontoon, which could not be blown out until the bow reached the surface and the pontoons leveled off. The reoccurrence of such a condition can be prevented in future operations by fitting a sluice valve in the center bulkhead with an outside control rod. By leaving the flood valve to the end of the pontoon which will rise first closed and the sluice valve open (this to be done after the pontoon has been leveled and lashed) all the water in the high end can be blown out through the low end flood valve, thus obtaining the complete buoyancy of the pontoon, for lifting while on the bottom. It had been the intention originally to make sure of this buoyancy by blowing the after halves of all six forward pontoons dry before lifting the stern; the forward halves could be blown completely dry in any position. Plate 5 illustrates this. However, with the experience of June 22, in the background, this intention had to be abandoned; no chances could now be taken of letting the bow rise first, and it was considered imperative that the stern be up before any additional buoyancy (beyond what was necessary to float them) be given the six forward pontoons. Confirming the soundness of this position, the last two divers up reported that the "S-51", which up to the evening before had had a list to starboard of at least 20 degrees was that morning ----------------------------------------------------------------------- Page 58 nearly upright, with a list of not over 5 degrees to starboard. It was clear that the submarine was again moving, with slight or no suction holding her. The condition on the morning of July 5 of the compartments and tanks which were available on June 22, with the buoyancies which were expected in them when the ship rose, was as follows: ------------------------------------------------------------------------------- | | Buoyancy | Compartment | Condition at | at noon, | Expected | noon, July 5 | July 5 | Buoyancy --------------------------------------+-------------------+----------+--------- No. 2 bow buoyancy tank ..............| Flooded ..........| 0 | 0 Forward trim tank ....................| .. do ............| 2 | 2 Water round torpedo tank .............| .. do ............| 1 | 1 Port ballast tanks 3, 4, 5 ...........| Dry ..............| 50 | 50 Starboard ballast tanks 3, 4, 5 ......| .. do ............| 50 | 50 C.O.C. ...............................| Flooded ..........| 0 | 60 Engine room ..........................| .. do ............| 0 | 96 Motor room ...........................| Three-fourths dry | 100 | 137 Tiller room ..........................| .. do ............| 12 | 12 After group oil tanks ................| .. do ............| 25 | 33 | | -------- | -------- Total compartments ................| ..................| 240 | 441 =============================================================================== | | Buoyancy | Pontoons | Condition at | at noon, | Expected | noon, July 5 | July 5 | Buoyancy --------------------------------------+-------------------+----------+--------- No. 1 pair (bow) .....................| Just buoyant .....| 20 | 110 No. 2 pair ...........................| .. do ............| 20 | 110 No. 3 pair ...........................| Partly buoyant ...| 80 | 110 No. 4 pair (stern) ...................| Just buoyant .....| 20 | 160 | | -------- | -------- Total pontoons ....................| ..................| 140 | 490 Grand total for lifting ..............| ..................| 380 | 931 | | ======== | ======== Reserve buoyancy in Nos. 1, 2, 3 pairs| | | of pontoons (regained at surface) .| ..................| .........| 150 Forward group oil tanks | | | (to be blown at surface) ..........| ..................| .........| 43 | | | -------- Additional attainable buoyancy | | | at surface .....................| ..................| .........| 193 Total buoyancy at surface for | | | towing operations ..............| ..................| .........| 1,124 ------------------------------------------------------------------------------- It will be noted that the margin for lifting the bow from the bottom was not great, but it seemed adequate. Furthermore, in a pinch there was always available the forward group of oil tanks with a buoyancy of about 43 tons, which could be blown while on the bottom, although at the risk of bulging or bursting the tank top when on the surface. However, even if these tanks ruptured under such use for lifting, it could only happen at the surface and by then the lost buoyancy in the forward pontoons would again be available to counteract the loss of the forward fuel-oil tanks. On the above calculations it was deemed best to proceed with the raising and risk no delay merely to obtain added buoyancy forward. When the last diver had left the bottom the "Falcon" hauled clear, with the submarine about 150 feet away on the port beam and parallel to the "Falcon". The mooring buoys ahead and astern were dragged clear to afford an approach for the "Sagamore", which steamed in ahead and picked up both the buoyed-off bow towing lines to the submarine; and for the "Iuka", which came in astern and similarly picked up the stern towline to the "S-51". On the "Falcon's" starboard side the mooring buoy there was dragged clear and the "S-50" moved in close aboard, where she anchored and a 2.5-inch fire hose was run to her to carry compressed air to the "Falcon's" manifold. On the "Falcon's" forward manifold, with 12 valves, were secured the blowing hoses to the compartments (4 hoses) and to the No. 1 and No. 4 pairs of pontoons (8 hoses). To the manifold on the port side, with 10 valves, were secured the hoses from the No. 2 and No. 3 pairs of pontoons (8 hoses) and the 2 telltale hoses leading to the bow and stern of the submarine. Below the manifold valve to each hose was secured a pressure gauge, so that the ----------------------------------------------------------------------- Page 59 pressure in any compartment or pontoon could be determined by shutting the line off momentarily from the manifold and permitting the pressure to balance in the hose with that in the compartment. At 12.17 p.m. Wickwire was hauled out of the water and the compressed air was turned on both motor and engine rooms. With both low-pressure compressors and the high-pressure compressor on the "Falcon" going full speed, and all the air that the "S-50" was able to supply through the fire hose, it was possible to maintain a pressure in the manifolds of 90 pounds. At 1.17 p.m. after blowing an hour, a stream of air started discharging at the surface over the engine-room hatch; blowing was kept up a few minutes longer to make sure both motor and engine rooms were dry. At 1.25 p.m. air was turned on the C.O.C. Within a minute air started to discharge at the surface over the vicinity of the conning tower. This was a severe shock, as it could only indicate that the C.O.C. had previously been nearly dry, or that the air was escaping from the C.O.C. as fast as it entered, or that the blowing hose to the C.O.C. had carried away somewhere near the submarine. It being well known that the C.O.C. was practically flooded up to that time, it was deduced that no buoyancy was being gained or was going to be gained in the C.O.C., for all the air was escaping either through a broken hose or through possible damage over the conning tower. No examination could be made, as the "Falcon" was not in diving position over the boat; to get her there would take several valuable hours from the afternoon; besides it was dangerous to bring the "Falcon" over the already buoyant stern of the "S-51", not to mention the danger the diver ran of being caught on a rising boat. Delay was undesirable in view of weather conditions. A check of the situation showed a loss due to the C.O.C. of 60 tons; this loss was about equally divided between bow and stern due to the central position of the C.O.C. The stern could easily stand the loss; the bow could hardly afford it, but as even the bow still figured a small margin, it was decided to proceed. The use of the forward group of fuel-oil tanks with its 43 tons of buoyancy now began to appear necessary in spite of the possible danger of damaging the tank tops. The C.O.C. was thus seen to be lost, but as it was isolated from the engine room abaft it, the latter compartment was in no way affected and there was then justified all the extra labor which had been expended by the divers in making each compartment a separate water-tight unit. At 1.55 p.m. air was turned on both ends of the stern pair of pontoons and on the after ends only of the forward (No. 1) pair of pontoons. At the same time, the pressure in both engine and motor rooms, which was equal to the bottom pressure, about 57 pounds, was reduced by opening their blowing hose vent valves on deck and allowing them to vent to the atmosphere until the pressure had dropped in them to about 35 pounds. The water could not reenter due to the nonreturn valve in the spill pipe in the engine-room salvage hatch. The reason for this reduction in internal pressure before raising the stern was that no salvage hatch had been fitted to the motor room. The regular hatch to that compartment was left in place and held down from the outside by an additional bolted strong back, but it was not desired to expose this hatch and strong back to any more internal pressure during the rise than was necessary, consequently the venting down before the rise. At 2.06 p.m., after blowing the stern pontoons for only 11 minutes, a large mass of bubbles appeared at the stern; shortly after the stern pontoons broke through the surface, riding easily with over half their volume exposed. They were probably not over half buoyant when the stern started to rise. (See figs. 20 and 21.) 45129-27--5 
Figure 19: Damaged pontoons aboard derrick
"United States" at Point Judith.
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