Official Salvage Report on the USS S-5 (SS 110)
FOURTH NAVAL DISTRICT
NAVY YARD, PHILADELPHIA, PA
Sept. 19, 1921
From: Commandant, Fourth Naval District.
To: Chief of Operations,
Navy Department, Washington, D. C.
Subject:- Salvage of S-5; report of conditions when work was abandoned on August 30, 1921.
C. P. NELSON, Acting.
Copy to Comdt. Navy Yard.
Chief of Opr. (1 extra).
U. S. S. FALCON
Navy Yard, Philadelphia, Pa.
September 7, 1921
From: Commander C. W. Fischer, G. C., U. S. N.
To: Commandant, Fourth Naval District.
Subject: Salvage of S-5; report of conditions when work was abandoned on August 30, 1921
(a) My letter to Commandant 4th Naval District, August 19, 1921
1. My letter, reference (a), dated August 19, 1921, reported the status of salvage work on the S-5 on that date. Since then, owing to bad weather, only three days diving has been done, on August 20, 24 and 30. The conditions discovered as the result of the diving on August 24th were such that a radio dispatch was sent to the Commandant, Fourth Naval District, on August 25th, in part as follows:-
"... taking into consideration the still unknown location of certain air leaks, the difficulty of stopping those already located, the bad weather, and fatigue of the personnel, I am extremely doubtful if she (S-5) can be raised before the beginning of the bad season. Instructions are requested as to continuing the work."
2. On August 30, 1921, in accordance with instructions from the Navy Department, Operations, the Commandant of the Fourth Naval District directed that work on the S-5 be abandoned and that FALCON return with all equipment to the Navy Yard, Philadelphia. Diving was stopped on August 30th and the FALCON proceeded to pick up the mooring buoys, anchors and chain.
3. The condition of the S-5 when she sank is given in paragraphs 2, 3 and 4 of my report, reference (a). The plan for salvage and the methods for carrying this plan into effect are also described in paragraphs 5 and 6 of reference (a).
Present Condition of S-5.
4. When diving was stopped on August 30th, 1921, the condition of the S-5 was as follows:
(a) Vessel lying on a hard, flat, sandy bottom, listed about 20 to port, and down by the head about 6 feet. Position about 40 miles E. S. E. of Cape May, Lat. 38 - 41' N, Long. 74 - 08'W. Depth of water 144 foot at low tide.
(b) the port bow diving rudder is broken short off. The starboard one is rigged out, and set at hard rise.
(c) Torpedo Hatch: the door or flap in the superstructure over the hatch has been opened and the wedge-like shape in front of the torpedo hatch has been filled in with concrete to prevent the hatch springing open when pressure is applied to the interior of the vessel. This hatch has been tested with air pressure and no leaks were reported.
(d) Torpedo Compartment: A hole has been pierced through the hull about 8"x6" in size, near the forward end of the compartment, between frames 18 and 20, on the starboard side. The bottom of this hole is just above the level of the deck in the torpedo compartment. A T-N-T bomb was used to cut this hole. The air inlet valve at the top of the compartment, leaking into the superstructure ventilation pipe from the main induction valve was left open, according to the Commanding Officer. It was through this valve that water entered the torpedo compartment and caused the S-5 to go down by the head as she sank. The Commanding Officer also reported that the valve to the compartment air salvage line was open. The after bulkhead of the torpedo compartment is probably ruptured at or near the top of the boat, as shown by the fact that when air is forced into the torpedo compartment through the hole in the bottom, large quantities of bubbles are immediately seen to issue from the battery compartment hatch.
(e) Battery Hatch: the original hatch was removed by using TNT. and the hatch coaming itself removed and is now on the FALCON, thus leaving the hatch trunk and the battery compartment open to the sea. The size of the battery compartment made it necessary to remove as much water as possible from it. It was by no means certain that the opening in the bulkhead between the battery compartment and the torpedo compartment was low enough to permit the battery compartment to be drained by way of the torpedo compartment. In fact it is more than probable that the opening is near the top, the door sprung or the deadlight in the door broken. Owing to the double hull and the presence of the battery it would have been difficult to pierce a hole through the hull from the outside. It was therefore decided to remove the hatch cover and fit in place of it a false cover with a device in the false cover for removing the water. After one type of false cover had proven unsatisfactory, we installed a one inch plate fitting on the top of the hatch coaming and held down against a 3/4 " rubber gasket by 16 hook bolts. The cover has a 4" pipe into it, connected to a length of 3" flexible suction hose which extends down to the battery deck and their terminates in a double strainer. The upper end of the 4" pipe extends through the hatch cover and about three feet above the superstructure deck where it is fitted with a non-return flap valve which will permit water to pass out of the compartment but will prevent its entry. The air for blowing is admitted through a two inch pipe screwed through the hatch cover and fitted at its upper end with valves and connections for four one inch air lines.
Then this device was tested, air was found to leak around the coaming itself as well as from under the false cover. The bolts securing the coaming were removed and the whole coaming, false cover and fittings brought on board the FALCON, where it was found that the coaming itself was cracked and that five of the hook bolts were not holding. The crack has been repaired (with smooth-on instead of brazing as previously reported), and the device is now ready to be replaced.
On August 24th, it was found possible to send a diver down in the torpedo hatch trunk, and examination of this trunk disclosed two vertical cracks, one on the port side and one aft, running nearly all the way from top to bottom of the trunk and averaging about 3/8" wide. The vertical seam in the trunk (on the starboard quarter) appeared to have the caulking started. These cracks permitted air to escape from the interior of the vessel into the upper ballast tank from which it escaped and made its appearance along the starboard side (the high side) of the superstructure, abreast the conning tower. The divers reported it will be possible to close part, if not all, of these cracks , by driving pine wedges into them.
(f) Battery compartment: This compartment, as previously described, is open to the sea because the hatch is off. It also is in communication with the torpedo compartment through probable rupture of the of the forward bulkhead. It is in communication with the upper ballast tanks through the cracks in the battery hatch trunk. There being no other available way to remove water from the central compartment, several TNT bombs were placed against the bottom of the door leading to the central operating compartment and exploded. It is believed that this door has been damaged sufficiently to permit water to drain from the central compartment into the battery compartment.
The divers reported a mass of material jammed up under the bottom of the battery hatch trunk blocking one half of its area. A piece of 16 gauge metal about two feet wide extends up inside the trunk to within a few inches of the top. From these facts, and the further fact that the forward bulkhead of the battery compartment permits free passage of large volumes of air through it, I am of the opinion that the battery explosion reported by the Commanding Officer must have been of considerable force. The failure of the forward bulkhead may have been due to the increased pressure on it when the S-5 was towed over the rumored "deep spot" of 200 or more feet. The cracks in the hatch trunk may have been caused by the TNT bombs used in removing the hatch cover and blowing the central compartment door, but from the description of them and of the maps of wreckage under the hatch, I incline to the opinion that the battery explosion lifted the whole battery deck and is the cause of most, if not all, of the other damage.
(g) Conning Tower and Central Operating Compartment: the conning tower hatch was cut off at the hinges with TNT and a 1" steel plate on a 3/4 " rubber gasket secured to the coaming with 16 hook bolts. During the operations the binnacle stand, close to the conning tower was sprung and was found to leak air around the base. It was, therefore, removed and a steel patch fitted over the opening, using the original bolt holes or studs, supplemented by hook bolts. Some minor leaks still exist in these patches. The eye-port glasses in the conning tower, some of which were found to be cracked or broken, have been replaced by steel and oak disks, held in place against rubber gaskets by the usual eye-port keeper rings. As stated in a previous paragraph, it is believed that the door between the central compartment and the battery room has been damaged sufficiently to permit the draining of the bulk of the water from the central compartment to the battery compartment.
(h) Engine Room: the engine room hatch has been fitted with a 3" channel iron strongback held down by two stout hook bolts. To provide a place to hook one of these bolts it was necessary to cut away a piece of the superstructure deck. To provide egress for the water, TNT was used to cut a hole in the outer hull, between frames 96 and 98, near the forward end of the engine room, and about four feet to the starboard of the duct keel. This hole, irregular in shape, is about 18" x 22", and communicates with the engine room itself, through a lubricating oil tank which had been used as an emergency provision locker. The manhole cover for this tank had been taken off to get at the provisions, and was left off by the crew. Thus through this hole in the bottom access is gained to both the engine room and the motor room, because the door to the motor room, had been left open by the crew. This is known because when air was forced into the engine room it escaped from both the engine room and motor room hatches. The engine room hatch is now practically air tight, but the engine room is full of water. Now that the engine room hatch is tight, air still escapes from the engine room, appearing in bubbles from the periscope sheers above the main induction valve, from the high side of the superstructure abreast the conning tower, and from the superstructure ventilation pipe between the engine room and the main induction valve. This latter fact was determined by removing bolts from a flange in the pipe (10" in diameter and apparently of galvanized steel) and wedging the flanges apart. A hand hold plate in the upper ballast tank was removed from the starboard side abreast the after end of the periscope sheers, but no air escaped; hence it is believed there is no communication between the engine room and the upper ballast tanks. The other air leaks seam to indicate that air escapes from around or under the cover placed over the main induction valve. If this is so, (and the leaks from the ventilation pipe support this view), the 10" air intake valve in the engine room is not tight, (this valve seats with pressure from the outside).
Leaks may exist through the forward engine room bulkhead and through the battery ventilation duct into the battery compartment, but this has not been definitely established.
(i) Motor Room: the motor room hatch has been re-enforced by a 3" channel iron-strongback as was used in the case of the engine room hatch. In order to secure the two hook bolts the screws were removed from the portable superstructure plate around the motor room hatch and the plate lifted off. The motor room hatch is practically airtight. The motor room is in communication with the engine room because the door between is open.
(j) Tiller Room: the forward door of the tiller room is closed but the compartment is open to the sea through the hole cut in the hull which enabled the crew to escape.
(k) Main Induction Valve: This valve, difficult of access, because of its position in the periscope sheers, was closed by concrete. A section of the plating of the shears was cut out by TNT, and concrete poured down on top of the valve. Indications are that this work dose not hold air, because of the air coming out of the top of the periscope sheers, and that from the starboard side of the superstructure. Since writing reference (a), two more plates have been pulled off of the side of the periscope sheers, which operation has reveled a large volume of escaping air that may well be ascribed to leaks through or around the main induction valve. I have, therefore, changed the opinion expressed in reference (a) that the induction valve was tight, and now believe that it leaks. This fact can be determined by breaking the ventilation piping forward and aft of the main induction valve and blank flanging it. Then, if air is turned on the torpedo compartment and the engine room , non escapes through the periscope sheers, there will be reasonable proof that the induction valve is not air tight. This is, however, a difficult and tedious job, and has been only fairly started when orders were received to stop work on the S-5.
(l) Superstructure: the superstructure deck has been turn up or removed in the following places: around the battery hatch; between the conning-tower fair-weather and engine room hatch on port side, to expose the 10" ventilation pipe; around the engine room hatch; around the battery hatch
(m) Bridge: the space around the conning tower hatch was so restricted and cornered with radio antennae, bridge instruments, ect., that the divers could not work. The port half of the bridge rail (chariot), complete with teak backing, weather plating, ect., was, therefore, pulled off and brought to the surface. several plates have been torn off the periscope sheers.
WORK REMAINING TO BE DONE.
5. Before any further determination of facts regarding the condition of the S-5 can be made, or the vessel raised by compressed air, the following work must be done:
(a) Stop leaks due to cracks in the battery hatch trunk.
This is difficult and painstaking work, but I believe it is can be accomplished by using pine wedges. Estimated time 12 diving days.
(b) Replace the battery hatch closing device with its piping for the admission of air and the egress of water. Estimated time - 3 diving days.
(c) Tear off, cut off, or otherwise clear away the superstructure decking forward and aft of the conning tower fair-weather, so that the ventilation pipe (about 6" dia. forward and 10" dia. aft) can be broken and blank flanged. None of the flanges located thus far have all their bolts accessible and it may be necessary to cut the pipe by hack-saw or chisel. This is the most difficult job to do. Estimated time - 15 diving days.
6. After this work has been done, it is believed that the hull will be found to hold air. If such is the case, the next step is to:
(d) Drill holes in each of the six main ballast tanks so that water can be blown out of them uniformly. No definite results have been as yet obtained by attempting to spring the main ballast kingpins, although it is believed that at least one of them has lifted.
7. The S-5 should then be ready for blowing and lifting, unless other leaks or breaks show up, -in which case they must be stopped or reduced until the total leakage is much less then the available air compressor capacity when operating at about 85 lbs. per square inch, (the static pressure on the bottom is 64 lbs. The excess of 21 lbs. is the allowance for losses in transmission through the hose, losses due to reduction in temperature, and an allowance of, say, 8 lbs. excess pressure to cause the water to flow out of the vessel).
8. Owing to the uncertainty as to the integrity of bulkheads, it is not certain that the S-5 can be balanced while she is lifting. If the engine room bulkhead is tight, as there is every reason to believe, there should be no difficulty in raising the stern first and then lifting the bow. If this bulkhead is not tight, however, it might be necessary to resort to a pilot pontoon or some similar service to bring her to an even keel fore and aft.
9. It has by no means been demonstrated yet to my satisfaction that it is impossible to raise the S-5 with the methods that have been followed during 1920 and 1921. In the last analysis success will depend on the ability to stop the existing air leaks. Several of these are known to involve difficult and tedious, but not impossible, work. In my opinion it will be possible to raise her unless it is found that the inner hull is leaking under the upper ballast tank, in which case I do not believe the leak can be stopped. On the other hand, the value of the vessel after being raised is doubtful due to her long submergence with consequent corrosion and deterioration. Under the existing conditions, I do not believe any further expenditures in the effort to raise her would be warranted. It is suggested, however, that next summer, if training in deep sea diving is needed, that such training might be given on the S-5, as the work to be done will involve almost every operation required of divers at such great depths.
CAUSES OF FAILURE.
10. In my opinion the reasons for the lack of success in raising the S-5 are as follows:
(a) Failure of the cement or concrete to seal the main induction valve.
(b) Damage to battery hatch trunk and possible damage to interior ventilation and other pipes, due to a battery explosion.
11. Four hundred and seventy-seven dives have been made on the S-5, without any serious casualty or sickness. In only about 10% of the dives were any evidences of caisson disease noted, and these promptly yielded to treatment in the recompression chamber. Only two cases of caisson disease were deemed of sufficient importance to be reported to the Bureau of Medicine and Surgery. This record is believed to be rather remarkable, especially when it is considered that practically none of the divers had worked in water as deep as 100-feet for two or more years before the S-5 work was begun.
12. It is a matter of keen regret to me that the S-5 has not been successfully salvaged. I wish, however, to state that failure has been due to no lack of effort or enthusiasm on the part of the personnel. Both officers and men have worked faithfully and well in the performance of this duty, which has been arduous for all, and hazardous for the divers. As a result of these efforts, the Navy now has a vessel equipped for deep sea diving, and a force of some fourteen divers capable of steady, efficient work in depths up to 150 feet.
Copy to -
Director of Submarines,
Bureau of Construction & Repair.
-- from the National Archives