F-4 salvage

Search for the Lost Boat

Once it was realized that F-4 had not returned when it should, all manner of craft went out from Honolulu to search for the boat. It must be remembered that in 1915 Hawaii was an undeveloped paradise with little modern infrastructure. The F-boats were based in Honolulu because the base at Pearl Harbor was in its infancy and was not yet capable of supporting warships. In 1915 Hawaii was still a remote outpost.

Here two men are using a box with a glass plate in the bottom that allowed a clearer view of things underwater.

Photo in the private collection of Ric Hedman.

Early in the search the Navy was using every means to locate the lost submarine. All they had to go on was some air bubbles and oil. They began dragging grapples in hopes of snagging the lost vessel. These hopes were soared when a heavy object was hooked. It turned out to be the lost three and a half ton anchor from the battleship USS Oregon (BB-03). The Oregon lost her port anchor on May 30, 1901 due to a defective link that nearly killed Chief Bosun J.E. Murphy when the link parted. Murphy was a hero in the Battle of Santiago during the Spanish-American War.

According to the Board of Investigation Report, when the weight of the anchor was discovered Jack Agraz, Chief Gunners Mate, a Navy diver from the USS F-1, donned his gear and followed the line to the target. Three crews of four men each manned the hand turned air pump suppling air to him. He discovered the grapple chain was wrapped around "an old anchor" at 215 feet. The F-4 had not been found.

Photo in the private collection of Ric Hedman.

Another false alarm when part of the periscope was discovered. Newspaper article describing the early search that went on for the F-4 and the recovery of a portion of one of her periscopes.

Photo in the private collection of Ric Hedman.

Chief Gunners Mate (Torpedo) John "Jack" Agraz, USN was a diver and a crewmember on the F-4's sister boat F-1. Agraz would make dozens of dives during the search for F-4. He was a large and powerful man, with the constitution of an ox. His friends described him as fearless and determined, full of guts and stubbornness. He had been born in Guadalajara, Mexico in 1879 and had come to the United States in 1904 seeking adventure, which he found in the U.S. Navy. He made dives to over 200 feet with a Schrader Mk IV diving helmet and breastplate resting on his shoulders, without wearing a watertight diving suit or weights! He wore only long john underwear and a pair of deck shoes. He did not decompress on the way up (that was still a developing science) and never suffered from the bends. He was performing physical feats that astounded the men he worked with. His bravery was unquestioned.

Photo in the private collection of Ric Hedman.

As stated above, in March 1915 the U.S. Navy presence in Hawaii was still in a very early stage. Most of the routine diving tasks involved shallow water dives (less than 50 feet) in warm tropical waters. Because of this, most divers (including Jack Agraz) simply perched the diving helmet and breastplate on their shoulders and did not use a waterproof suit or weights. This is a Schrader Mk IV helmet and breastplate sitting on a diving launch during the F-4 operation. It may have been used by Agraz on one of his incredible deep dives. It is sitting on a hand-cranked air pump and facing to the left. The air pump was hand-cranked by two burly men and was used to send air down to the diver. The helmet and breastplate are rigged up with a heavy line that will allow the diving tenders to lower the helmet into the water so that the diver can rest it on his shoulders. With the air being sent down by the men operating the pump, the water level was usually just below the diver's chin when he was submerged. The diver could easily duck out from the helmet and swim to the surface if he ran into trouble. In this mode the helmet was being used like a shallow water helmet, fine for shallow dives but exceedingly dangerous for deep water dives like what was needed to reach the F-4. Agraz made a dive to 215 feet with one of these rigs perched on his shoulders. Author Jon Gates has stated that Agraz preferred to dive this way, as it gave him a degree of freedom that he wouldn't have had it he was wearing a suit. However, it is actually likely that there were no diving suits available in Hawaii at the time, thus giving him no choice.

Photo in the private collection of Ric Hedman.

A rather crowded diving launch hovering over the scene of F-4's sinking. Given the fact that none of the men appear to be operating the pump, it is likely that there is not a diver in the water from this launch. The men are intently trying to peer though the water, with one man using a glass bottomed bucket to try to see better. Most of the diving on the F-4 was conducted from these launches, as there were no specialized salvage ships in Hawaii at that time.

Photo in the private collection of Ric Hedman.

Here is an interesting action photo. It appears that a diver has come to the surface (possibly Agraz) and had his helmet and breast plate removed and then he has slid back into the water. You can see his form under water. One man has his arm into the water and looks to have a hold of him. A second man is reaching for him and everyone else is looking on in concern. Someone may have pulled the helmet off too early.

Photo in the private collection of Ric Hedman.

Salvage Work

The F-4 was soon found and it was determined that the crew was lost. The Navy was determined to salvage the vessel, but deep water salvage was still very much a developing science and therefore they lacked the technical ability to do so. Naval Constructor LCDR Julius Furer was assigned to lead the effort and he determined that lifting the boat with pontoons was going to be the best method. Six pontoons had to be built at the Mare Island Navy Yard. This is a starboard quarter view of the Pennsylvania-class armored cruiser USS Maryland (Armored Cruiser No. 8) with the six specially made pontoons loaded aboard. The Maryland was standing by at Mare Island and as soon as the pontoons were ready they were loaded and the Maryland steamed at full speed to Hawaii with the cargo, along with a host of specialized salvage gear, diving equipment, and experienced deep-sea divers. There are four pontoons loaded aft and two loaded forward.

Photo in the private collection of Ric Hedman.

The Maryland moored in Honolulu Harbor after having off loaded her cargo of six pontoons and associated diving equipment. Curious onlookers stop to examine the huge warship. Note that her flags are at Half-mast, likely in honor of the F-4's crew.

Photo in the private collection of Ric Hedman.

The dredge California was moved from Peal Harbor, where she was being used to deepen the harbor, to the F-4 location with thoughts she could raise the F-4. Ultimately, she was used to position the cables and chains under the F-4. She is seen here with the Young Brothers launch/tug Louise alongside and an unidentified tug in the background.

Photo in the private collection of Ric Hedman.

Looking closely at this photo you can see the men at work pumping air to a diver below. The men worked in crews of four for a short period of time before being relieved for a break.

Photo in the private collection of Ric Hedman.

F-2 (Submarine No. 21) standing by near the wreck, running her high-pressure air compressors to send air to the pontoons. In the background, just above the small skiff, can be seen the Quarantine Dock Building, located on Sand Island. Once raised the F-4 would be moored to that dock while waiting for the dry dock to be made available.

The rope that is being worked on by the men on deck can be seen floating in the water in front of the submarine. There is a similar one stretching from the after deck to what is assumed to be the salvage barge. The F-2 is probably in the process of mooring to that barge to supply the air needed for the pontoons.

Note the proximity to the shore. The F-4 sank just outside of the entrance to Honolulu Harbor, in Mamala Bay. With Oahu essentially being the top of an underwater mountain, the water depth drops off precipitously as soon as you leave the harbor.

Photo in the private collection of Ric Hedman.

The salvage barge with its air manifold for distributing air from the F-2 to the six pontoons that have been sunk on either side of the F-4, connected together with chains snaked under the hull. Officers and officials sit under the awning out of the tropical sun.

Photo in the private collection of Ric Hedman.

Raising the Boat with Pontoons

Pontoons can be tricky beasts to work with, and this series of photos show the efforts made by the salvage force lifting the F-4 from the bottom. Cables suspended below these pontoons were slung under the F-4, and once the water was forced out of the pontoons with compressed air, they physically lifted the F-4 off the bottom. In several of the photos a man can be seen standing on a pontoon wearing overalls and a bowler hat. That is Master Rigger Fred Busse, a member of Furer's team, supervising the rigging process. Note that many of the pontoons are not floating level, and balancing them was a constant headache. In several of the pictures the USS Navajo (Fleet Tug No. 52) is seen standing by to assist.

Photos in the private collection of Ric Hedman.

The lifting and movement of the F-4 was done in several stages. The first lift brought her to about 250 feet. The whole assembly (F-4 and pontoons) was then towed towards Honolulu until the F-4 gently grounded in about 84 feet of water. The chains were readjusted, and she was towed again until she grounded at 50 feet. This photo shows her very near the harbor, probably at one of those intermediate stages.

In the center background is the Navy floating cantilever pontoon crane YD-25. The crane had a lifting rating of 150 tons. Too little to have lifted the flooded F-4. She was destined to become a visual fixture at Pearl Harbor for the next dozen years.

In the left background the USS Maryland is moored. She is the vessel that brought the six lifting pontoons to Hawaii.

Newspaper photo.

In a photo taken just a few minutes after the one above, the riggers are shown readjusting the lifting chains to the shortest amount so that the F-4 could fully enter the harbor and be placed in drydock.

Photo in the private collection of Ric Hedman.

This is an artist's impression of what the F-4 looked like suspended below her lifting pontoons. The artist cleverly used the photo above as a start, then superimposed his own image below it. Yes, the F-4 was nearly upside down while it was being towed, as this was the position in which she hit the bottom after sinking. Unfortunately, the artist got the orientation wrong. She was actually laying on her port side, not the starboard side as shown here.

Photo from Beneath the Surface: WWI Submarines Built in Seattle and Vancouver by Bill LIghtfoot.

Two more views of the F-4 and her pontoons under tow, now very near the drydock inside Honolulu Harbor. The locally owned Young Brothers tugboat Makaala is seen on the far left.

Photos in the private collection of Ric Hedman.

In Drydock

Without a drydock of their own (the Pearl Harbor facilities were far from finished), the Navy was forced to contract with the Inter Island Company for use of their drydock. F-4 is shown here in the dock on August 31, 1915. A crowd of men has gathered to examine the remains of the boat. This view is looking at the nearly upside down F-4's bow, with pontoons on each side. Behind is the Hilo based tug Printer that had reserved dry dock time to repair her hull after a collision with one of her scows that was used to haul rock for the Hilo Harbor Breakwater.

Newspaper photo.

This photo was taken shortly after the one above, from a higher angle. The inspection and remains recovery process has just begun.

Photo in the private collection of Ric Hedman.

A broad angle view of the entire drydock. The Inter Island Drydock was a floating drydock, meaning that it partially submerged to allow vessels to float over it. Ballast tanks in either side of the dock would then be pumped out, raising the dock and its vessels.

Photo in the private collection of Ric Hedman.

Once the dock was fully out of the water, the full extent of the damage to the F-4 was visible for the first time. The implosion in the started in the overhead of the torpedo room, nearing the torpedo loading hatch. It was a natural weak point in the structure where two hull plates were riveted together. The hull collapsed inward, nearly 150 psi knocking a huge hole in the pressure hull. Further collapse was stopped by the nearly instantaneous flooding of the rest of the boat.

In this view the boat is upside down, with the port side facing up, looking at the bow. The strake like object at the top is the port side bilge keel, with the main keel just to the right of that. It is important to understand that the leaking battery acid did not cause the implosion. The battery acid weakened the bottom of the hull structure, causing a leak which made the boat heavy, quickly resulting in a loss of control. It was when the boat exceeded crush depth that the hull imploded.

Admiral Clifford J. Boush, Commandant of the 14th Naval District in Hawaii, is seen in the foreground, wearing the long white coat.

Photo in the private collection of Ric Hedman.

Once all the excitement died down the Navy let several Photographers in to record the damages. The man at the right looks to be operating a movie camera.

Photo in the private collection of Ric Hedman.

Photo in the private collection of Ric Hedman.
Photo courtesy of Mike Dilley, whose father, Homer 'Pat' Dilley, sailed aboard the USS F-2.

Two more views of the F-4 in drydock, from different angles. The men standing near the implosion hole give scale to the size of the hole.

A view from aft, showing damage to the rudder, stern planes, and propellers. The stern planes and rudders have been torn away during the salvage effort. The ram for the planes and rudders can be seen under the right-hand propeller. The skeg for holding the lower rudder is twisted almost 90 degrees to port.

These newly installed experimental propellers were of a special design that were intended for low RPM and high efficiency. It is thought that at high speeds they would have done little to drive the submarine to the surface. The official report stated that these propellers "were the secondary cause of the disaster" by providing insufficient water flow over the stern planes and thus negatively impacting the control of the vessel.

Photo in the private collection of Ric Hedman.

A sailor, who appears to be a second class petty officer, stands alongside the F-4. He has a pretty grim look on his face. Could be a sailor from one of the other F-class submarines.

The extensive damage to the after end of the submarine is very evident. Remembering that the submarine is almost upside down, the twisted piece of metal to the left and twisted towards the camera is actually part of the upper skeg running from the deck to the rudder. It has been bent over more than 90 degrees. The blades of the screws have been bent over and a huge chip has been made in the blade of the screw.

Photo in the private collection of Ric Hedman.

In a photo taken several days later, if you look closely you can see that the bent propellers have been removed from the stern. A large hull plate has been removed from the engine room area to facilitate the removal of the bodies of the crew. Most of the crew took refuge there as fumes and water filled the rest of the boat, but quickly died when the watertight door failed under pressure. There is also a smaller hole on the bottom (top) of the submarine, perhaps to pump fuel out of tanks.

Photo in the private collection of Ric Hedman.

What remains of the port engine exhaust system, exposed after the superstructure was ripped away by the salvage efforts.

Photo in the private collection of Ric Hedman.

A close up of the implosion damage to the F-4's hull. It looks like crumpled tin foil, such was the force of the implosion. Note the frayed mass of hemp mooring lines still in their below deck locker, stowed there on the morning March 25, 1915 when the boat got underway for its final voyage.

Photo in the private collection of Ric Hedman.

A very rare photo taken of the forlorn F-4 in drydock. The photo was likely taken by an unauthorized civilian, as there is a note on the back indicating that he nearly got his camera smashed by a guard and that he was quickly run off the premises.

This photo shows the F-4 with her bow cap rotated to line up with two of her four torpedo tubes. This was done so that the weapons in the tubes could be removed. To access the other two tubes the cap was rotated to the right. To completely close all four tubes the cap was rotated so that the openings were vertical and behind the stem.

Photo in the private collection of Ric Hedman.