The Canal Zone

I could not find the records and photos of the SIAN YUNG salvage effort. So I will try to answer your questions from my failing memory.

The ship was a standard Victory Ship design with bunker tanks located accordingly and day tanks located in the engine room compartment. Because of the standard design it was fairly easy to find the bunker tank vents and to plug them using wooden plugs fixed by divers. Oil (heavy fuel oil or bunker C) still managed to leak out almost continuously until the ship was raised, but in decreasing amounts as time went by. Most of the oil was released during or right after the striking. My memory fails me on the estimate of the oil that was aboard at the time of the sinking. The ship was boomed using floating oil containment boom that was located not far from the sinking. Later a deep skirted oil boom was constructed and placed around the vessel during the extended salvage operations.

The main deck was approximately six to ten feet under water depending on the elevation of Gatun Lake at any particular time. The bridge deck was above the water and served as an observation and command and control center for much of the operations. The hatch covers were submerged. The bow bell was visible.

The oil was sucked out of the vents of the day tanks and double bottoms but, as stated above, oil continued to surface inside the boomed areas and oil recovery operations using sorbets, skimmers and vacuum trucks and barge mounted vacuum tanks for the first six months or so. After that, crews in motor and row boats patrolled the boomed area and recovered oil from the water surface.

The ship's hull has first repaired using large wooden soft-patches over the two major holes in the starboard side of the hull that extended into the engine-room.

A first priority was given to removing the cargo of rice and cotton. The rice began to ferment very rapidly raising the bacterial count in the water column. The primary fresh water intakes for the water treatment plant for the metropolitan area on the Pacific terminus of the canal was a scant 200 meters from the location of the sunk vessel.

First divers were employed to remove cargo. This proved very laborious and slow. The Panama Canal Dredging Division operated a large fleet of vessels for the maintenance of the canal. These included a 24-inch cutter head suction dredge (MINDI), an 8 1/2 cubic yard clamshell floating crane, and numerous launches, motorboats, tug boats and supporting equipment. The oil pollution operations were also the responsibility of the Dredging Division, so the operation found a ready made command and control structure in place.

The cutter head dredge was modified to remove the rotating cutter, and placed a multiple gimbaled articulating suction head. The opening of the suction pipe and steel plates welded along the outside perimeter to serve as cutters to rip the bags of rice open and to tear apart the bales of cotton. This worked quite well for the better part of the cargo. Divers ended up having to manhandle cargo that was lodged outside the reach of the suction head to a point where the dredge later sucked it up. The cargo was pumped into a diked containment area about a mile from the site of the ship. The cargo was rotting so badly that the odor became objectionable and the material had to be covered with earth to encapsulate the rotting cargo.

Once the cargo was removed, the first salvage attempts involved building coffer dams only on the cargo hold hatches. The floating crane HERCULES was brought alongside and its main hoisting cables were split with each of the two parts affixed to the slings port and starboard of the aft cargo hold. The idea was to pump the holds thereby creating buoyancy and using the HERCULES to provide stability to the floating hull. Pumping operations were started a number of times before a serious attempt was made to float the vessel. At this point the vessel began to oscillate due to the free surface effect of the water in the hull. The oscillations increased to a point and at a speed that was greater than the ability of the HERCULES to relieve the load. The load on a single part of the split main hoist approached 330 tons which well exceeded the 250 ton rated load of the HERCULES. The port line finally parted and the operation was terminated.

A number of other variations of attempts followed with no success. Finally, the entire main deck was cofferdam using a massive wooden and steel cofferdam. Much of the ships structures above the main deck were removed, including the masts, deck house, and stack. This lowered the center of gravity. In the mean time the sister ship to the HERCULES, the AJAX (which had been earlier sold by the Panama Canal) was hired and returned and refitted to aid in the final lifting of the vessel. With the AJAX on the port of the vessel between the vessel and the bank of the canal and the HERCULES outboard, both cranes were used to provide stability during the floating operation. Ultimately this combination of methods worked and the vessel was floated to a point where she had sufficient freeboard to allow her to safely (?) complete the transit to the Pacific terminus under tow.

At the port of Balboa, the pumps and all other gear was removed from the vessel, the patches inspected and augmented as necessary, and dynamite charges planted in the holds to allow for the final disposition of the vessel at sea. The bunker tanks had remaining oil removed and the ship was towed to sea where it was sunk in about 100 fathoms.

Some general observations that you may find surprising. The canal traffic was interrupted for only a relatively minor period of time at the beginning. Once the sunken vessel was shown to be stable (with cables later fastened to shore dead men anchors to insure the stability) traffic was resumed on a one way basis. A Canal pilot was stationed aboard the sunken vessel to coordinate the passing canal vessels. This worked very well with only a few close calls but no accidents as a result of the impediment. The ships starboard hull was about on the Southbound sailing line, so about 3/4 of the 500 yard channel was available for traffic. Further, additional tug support was provided on the larger wide beamed vessels to aid in passing the sunken vessel.

The salvage operations were under the supervision of Murphy Pacific, which at the time was under contract to the U. S. Navy Supervisor of Salvage. The matter of payment was disputed and the last I knew was the subject of extended legal action.

That is the best my old memory can do for now. If you have additional questions, perhaps they will spark a new thought and I will try to fill in more details. I do know that the entire operation was documented by the Panama Canal Company in written, photographic form and a detailed after-action report was prepared. This report along with copious exhibits of various attempts to salvage the vessel should be available from the Panama Canal Commission. The took still photos, cinema and videos throughout the salvage operations. I had some still photos but have not been able to find them yet. If I do, I shall be pleased to try to Email them to you.