The Navy's first deep-sea submarine salvage was of the USS SKATE (F-4), which was lost in approximately 51 fathoms (306 feet) while making a short submerged run off the island of Oahu, Hawaii, in March 1915. This was the Navy's first loss of submarine and crew.
The F-4 had a length of 142 feet, with a submerged displacement of 400 tons and a designed depth of 200 feet. After the accident, an oil slick and air bubbles about 2 miles from the harbor entrance lead to dragging operations that positively located the boat; there were no apparent signs of life. The submarine lay far deeper than any divers had ever descended with existing equipment and methods. In and effort to reach the boat on the day of the loss; two Navy Divers dove to a depth of 190 and 215 feet, but neither reached or sighted the vessel. The only chance of saving any possible survivors was to drag the boat into shallow water because no lifting gear could be made and rigged in the time available. Dragging would work only if the boat was not completely flooded. Sweeps were made by the NAVAJO and INTREPID to pass a wire rope around the hull and drag it into shallow water. An attempt at this was made the following day, but the boat could not be moved. Rescuing the crew appeared hopeless but one more attempt was warranted. A dredge was brought to the scene; if a portion of the submarine remained unflooded and buoyant, there was a possibility of moving the boat into shallow water by heaving with the dredge and towing with tugs. No progress could be made (one of the wires parted at its maximum load). This answered the question whether the F-4 was filled with water -- it was, and rescue effort was regretfully concluded.
Because the F-4 was the Navy's first submarine loss, there was an intense desire within the Navy to determine the cause of the casualty. There was also a huge public outcry for the recovery of the bodies of the crew. Naval Constructor LCDR Julius Furer, who was in Hawaii for the construction of the new Naval Station at Pearl Harbor, was placed in charge of the technical side of salvage. After evaluation the situation and consultation with Navy Salvors, it was determined that multiple short lifts and tows were the only feasible way of raising the boat. Faced with a lack of specialized equipment for the job and a base under construction in Hawaii; Salvors were forced to do what they do best - improvise with what was on hand to get the job done. Two sturdily constructed 104x36 foot barges belonging to a local construction company had the strength to support the downed submarine. A lifting system was built using I-beams planned for a coal storage facility, sugar mill shafts were used as windlasses along with miscellaneous machinery that was either available or made for the job.
Knowing that the positions of the lift slings would be crucial to the success of the salvage and that their positions could only be verified visually, five of the Navy's top Divers were ordered in from the Navy Yard. At the time the Navy Yard was responsible for the test and review of all diving equipment and techniques. These divers were Gunner Stillson, Frank Crilley, Stephen Drellishak, Frederick Nilson and William Loughman. Chief Crilley made the first dive just two days after arrival. He reached the F-4, more than 300 feet down, and reported that the boat was upright but the slings would have to be moved. The difficulty of working at this depth cannot be overstated. Keep in mind that all of these dives were conducted with air -- breathing HE02 had not been discovered yet. The futility of attempting to work at these depths was demonstrated when a diver remained on the bottom for thirty minutes trying to pass a small reeving line. He was unaware of fatigue on the bottom, but collapsed from exhaustion on the surface and did not regain strength for several days. In another instance Chief Loughman became entangled in a steel hawser at a depth of 250 feet down breaking his hip in process. Loughman fell unconscious and GMC Frank W. Crilley dove in after him, disregarding personal safety. He found Loughman and worked for an hour and a half to free him. For his heroism, Crilley became the first Navy Diver to be awarded the Medal of Honor on February 15, 1929. For more info on this heroic rescue see the "This Day in Diving History" email sent April 17.
After multiple lifts over the course of months the submarine had been moved to 48 feet of water by June. The problem was now how to move her in one lift through Honolulu Harbor with out breaking the sub up which would totally block the harbor. It also had to achieve a depth of 25 feet or less to fit into existing drydocks. In order to accomplish this, Salvors developed what would be known as the submarine pontoon salvage method. To do this, chains were moved under the boat and attached to huge pontoons that were built for this operation. These pontoons were 32 feet long with a lifting capacity of 420 tons and were built with wooden sheething all around to prevent impact, chaffing, or puncture to the hull due to frequent contact. On 29 August, the pontoons were blown dry, the submarine was towed into the harbor and placed in drydock. It was immediately discovered that the cause of the accident was leakage through rivet holes where the rivets had been eaten away by battery acid. This resulted in immediate design changes to all U.S. Navy Submarines.
The methods, lessons learned, and equipment employed in this operation would be used during the raising of the USS SQUALUS (SS-192) years later.
Note: For more reading about this historic salvage operation check out the following hyperlink to UnderSea Warfare Magazine
http://www.navy.mil/navydata/cno/n87/usw/issue_29/f4.html
H/Y
Thursday, September 10, 2009
This Day in Diving History -- 29 August 1915 -- USS SKATE raised (late entry)
Monday, August 31, 2009
This Week in Diving History -- August 28, 1965 -- SEALAB II
** This Week in Diving History -- August 28, 1965 -- SEALAB II leaves surface **
On August 28, 1965, the first of three teams of divers moved into what became known as the "Tilton Hilton" (because of the slope of the landing site) also known as SEALAB II. This first day of the operation happened to be one of the divers involved birthday; Bob Barth, who turns 79 today-Happy Birthday Bob!
SEALAB II rested at a depth of 205 ft 65 miles off the coast of LaJolla, CA. Whereas SEALAB I tested and proved the concept of saturation diving, SEALAB II provided evidence that useful work could be done. The Navy conducted physiological and psychological studies to determine man's effectiveness underwater for an extended period. Navy Divers not only evaluated the structural engineering of the habitat. They did things like working on a mock-up of a submarine hull, tested undersea tools, conducted salvage ops using syntactic foam; they set up a weather station, mined ore samples, experimented with plants, and studied ocean floor geology just to name a few things. They also experimented with a trained porpoise named Tuffy from the U.S. Navy Marine Mammal Program, to do courier work between the habitat and the surface. 
Each team spent 15 days in the habitat, but aquanaut/astronaut Scott Carpenter remained below for a record 30 days. During that time, he was able to speak with astronaut Gordon Cooper who was in the Gemini space capsule, orbiting the Earth. Also a congratulatory telephone call was arranged between President Lyndon B. Johnson and Scott Carpenter while he was still under pressure. The fact that Carpenter was breathing Helium-Oxygen made him sound unintelligible to operators. Much was learned about working in the ocean and contributions were made to a large number of undersea science and engineering disciplines. SEALAB II was no doubt a success and represented another large step forward in enabling human beings to live and work in a hostile environment. SEALAB II was designed, built, and outfitted at Hunter's Point Naval Shipyard in San Francisco at a cost of $850,000. It was designed to house ten men at a depth of 200 feet for 30 days. The habitat was 50' long and 12' in diameter, and included four separate areas: entry, laboratory, galley, and living spaces. Entry while on the ocean floor was from below the habitat, with divers emerging into the pressurized habitat through an open moon pool.
Construction of SEALAB II's cylinder end bell used technology ahead of its time. The large dish-shaped cap was formed from a sheet of one-inch thick flat steel placed over a die. In order to shape it, one hundred pounds of C-4 plastic explosive were distributed on the side of the blank opposite the die. The whole package-die, blank, and charge, weighing 60 tons total-was lowered 30 feet beneath the surface of San Francisco Bay where the explosive was detonated. In approximately .004 seconds the end bell was formed. Explosive metal shaping on this scale had never been attempted before. If you would like to see this end bell, visit the Naval Undersea Museum in Keyport, WA. 
Note: This photo entitled "Bob-Barth-Scott-Carpenter-Sealab.jpg"; is a picture taken at the dive station on the support barge of Sealab Two, Bob Barth is shaking Wilbur Eaton's hand as he and Scott Carpenter are making ready to swim down to the house (they were the first two to leave surface). 
H/Y
Friday, August 21, 2009
Diving History -- Diving on the Silver Screen
The idea of diving into an unknown potentially dangerous environment has long appealed to writers in Hollywood. The recent movie Men of Honor is very familiar to everyone in the diving community. The following are a few other notable movies that come to mind:
James Bond: Ian Fleming's fictional MI6 agent James Bond had several movies that involved diving. Two of the most diving intensive ones were:
-Thunder ball (1965). During an underwater battle with SPECTRE (the movies bad guys), Bond is rescued by a military unit who parachutes to the area for underwater battle against the SPECTRE divers. Bond joins the fray, killing them off with high tech submarine weapons, his knife and his hands.
-For Your Eyes Only (1981). 007 goes deep underwater in a mini sub
that he locks out of and has an underwater battle with a bad-guy wearing a JIM one atmosphere diving suit. Bond plants an explosive charge on the back of the suit and manages to escape just in time before it explodes.
John Wayne: The Duke didn't fare to as well as a Diver. He starred in two movies as a Deep Sea Diver and died in both of them.
-Reap the Wild Wind (1942). After a ship goes down at sea, John
Wayne suits up in a deep sea diving rig to confirm if a woman was trapped inside and died. While down in the wreck he discovers proof that she was on board and had drowned. As they are leaving not only does a massive storm
hit but a giant squid attacks his dive buddy (talk about a bad day). John
Wayne could have easily escaped but attacks the squid, saving his dive buddy but sacrifices himself in the process.
-Wake of the Red Witch (1948). While retrieving treasure/gold on a
sunken ship, the ship begins to shift causing debris from the ship to fall all around him. Eventually this debris piles on the Duke, trapping him and leading to his ultimate demise.
Gojira (Godzilla 1954)
-After reaping havoc, death and destruction on Tokyo; Godzilla
returns to Tokyo Bay for a little underwater R&R. After all else fails, the good people of Tokyo turn to the only ones that can save them from the monster -- two hard-hat divers. Both divers descend into Tokyo Bay with an "Oxygen Destroyer Bomb", the ultimate weapon that destroys what else -- oxygen. Once on the bottom, they spot Godzilla resting underwater.
Seemingly unaware of the divers, Godzilla slowly wanders around as the divers activate the Oxygen Destroyer. As one of the divers watches Godzilla dying from the weapon, he cuts his own umbilical and dies with Godzilla, sacrificing himself so that his knowledge of the horrible weapon will not be known to the world. A dying Godzilla surfaces, lets out a final scream, and sinks to the bottom, disintegrating into a skeleton, and then into nothingness.
The Deep (1977)
-Nick Nolte and Jacqueline Bisset play a young couple enjoying a
tropical vacation who discover a glass ampoule while diving off the coast of Bermuda. A treasure hunter identifies the ampoule as part of a valuable shipment of World War II morphine lost at sea, atop the even greater treasure of a sunken Spanish galleon. Thus begins a race for drugs and treasure pitting Nolte and Bisset against a ruthless drug lord (Louis Gossett Jr.) who'll do anything--even resort to Haitian voodoo--to get what he wants. The movie's best known for Bisset's wet T-shirt scuba-dive, but also has some exciting highlights including a moray eel that attacks on cue and... well, uh, Jacqueline Bisset in a wet T-shirt.
Leviathan / Deep Star Six (both 1989)
-Very similar movies released at close to the same time. Both are
basically "Alien" or "The Thing" set in a deep sea underwater habitat.
Basically, divers disturb or discover some sort of creature that wreaks all sorts of havoc on the habitat and its occupants. A daring escape at the end allows the hero and heroine to survive certain death. In one of the movies a diver tries to escape the habitat without decompressing and suffers an extreme case of "the bends" causing his head to bleed until his body eventually totally explodes.. Hoo-Yah.
The Abyss (1989):
Perhaps one of the most technical underwater movies made that used the largest underwater set of any diving movie to date. Most of us know the story, but here are some cool technical details about the making of the film.
1. All of the underwater scenes in the movie were shot in containment tanks at the abandoned Cherokee Nuclear Power Plant in Gaffney, South Carolina, including the largest underwater set in the world at 7 million gallons (60 feet deep, 200 foot diameter). The tank was filled to a depth of 40 feet, but there was still too much light from the surface, so a giant tarp and billions of tiny black plastic beads were floated on the surface to block the light. During a violent storm the tarp was destroyed, thus shifting production to night time.
2. The water for the tank was fed in from nearby lakes and needed large filters to cleanse it and was chlorinated heavily. This caused many of the actor's hair to become green and even white. The huge quantities of the chemical also caused all the large steel underwater movie props to rust, plugging up the filtering system. For financial reasons, the "Deepcore" set was never dismantled. It stands today in the abandoned (and drained) South Carolina nuclear power plant.
3. The masks were specially designed by Bob Kirby of Kirby Morgan to show a full view of the actors' faces, and had microphones fitted so that dialogue spoken at the time by the actors could be used in the film. The noises made by the regulators in the helmets were erased during sound post-production. Because the diving rigs were not fed by umbilicals, all breathing air had to be supplied via backpack assembly. This being the case, free flow helmets would have been far too wasteful so a demand breathing system was incorporated without oral nasal masks (CO2 build-up anyone?). The tank was equipped with an underwater high pressure manifold with whips so four divers at once could fill their backpacks on the bottom without surfacing.
4. Perhaps the most frequently asked question people ask about the film is in regards to the liquid breathing scene. The Navy has experimented with breathing an oxygen-rich liquid (perfluorocarbon), rather than breathing air. Problems with oxygenation, carbon dioxide removal and lung mechanics prevented this from becoming anything other than experimental.
For the movie, five different rats took five different takes for the liquid breathing scene in the movie. What is seen in the film isn't a special effect. The rat really was subjected to the anxiety of being submerged in this liquid, where it panics and struggles and is then pulled out by its tail as it expels the liquid from its lungs. The rat that actually appeared in the film died of "natural causes" a few weeks before the film opened.
H/Y
What movies get you excited about diving? Comments are welcome!
This Day in Diving History - Treatment Tables 5 and 6 introduced into the U.S. Navy
The use of oxygen in recompression therapy in the Navy does not go back as far as many believe. In fact, it was not until the 1924 edition of the US Diving Manual that a standard recompression therapy was recommended at all; but these were all air tables. Treatment pressure was based on either the depth of the dive (or a multiple thereof) or the depth of relief, oxygen simply wasn't used back then. It wasn't that no one hadn't thought of using O2 however. The roots of using oxygen as therapy for diving illness can be traced back to Paul Bert's experiments way back in 1870. He first observed that when 100% oxygen on the surface was administered to animals after decompression, some of the signs would resolve. Surprisingly, Bert did not try hyperbaric oxygen, which was first proposed several years later. Initial results were actually disappointing, probably because the therapy was too brief.
In 1939, two US Navy medical officers (Yarbrough and Behnke) first published results of DCS treatment using compressed oxygen, but despite their success, the technique was not initially adopted. Instead for the next 20 years, the US Navy continued to recommend a variety of air tables despite long treatment duration and high failure rates. While these deep air tables provided a higher amount of oxygen, they also caused divers to take up amounts of inert gas in doing so. In the early 1960s, the US Navy instituted another series of investigations into low-pressure oxygen tables. Originally tests used 33 feet as a treatment depth; but due to a high recurrence rate, they were altered to use an initial recompression to 60 feet. This treatment depth not only dramatically improved treatment success, but did so in keeping the risk of oxygen toxicity at an acceptable level - the Navy had found "the sweet spot".
On August 22, 1967, Treatment Tables 5 and 6 were introduced into the U.S. Navy. These treatment tables marked the first time that 100 percent oxygen was used at relatively shallow treatment depths in comparison to the deeper air treatment tables (TT's 1-4). Two additional tables were also introduced (TT-5A and TT-6A) that began with an initial deep short excursion on air followed by treatment profiles identical to tables 5 and 6 (TT-5A was quickly abandoned). Because of the success of low-pressure oxygen treatment of decompression sickness, tables 1-4 are now rarely used. Continued experience with the O2 treatment tables revealed frequent reoccurrences of decompression sickness with the shorter procedures in Tables 5, which now sees limited use for treating diving related illness. TT's 7 and 8 were developed in the 80s to address a longer need for oxygen breathing at 60 feet or deep blow-up respectively; followed by TT-9 in the 90s mostly for non-diving disorders with great success.
Reading: Check out "Diving Medicine" by Alfred A. Bove and Jefferson Davis. This book is commonly referred to as The Bove ('Bo-veigh') and I guarantee that either your friendly neighborhood Master Diver, Diving Medical Officer or Diving Medical Technician has a copy.
H/Y
Monday, August 17, 2009
Post NEDU SAT Dive
Six divers entered the Ocean Simulation Facility (OSF) on August 12th and were pressed to 165 feet of seawater where they conducted 12 hours of in-water diving.
Upon completion of required work the divers started their three days of decompression.
Saturation diving is a complex method of mixed gas (helium) diving that, in the US Navy, is currently only conducted at NEDU. Divers at NEDU are "locked in" to the OSF for a period of up to 30 days to conduct dives as deep as 1000 feet of seawater.
Monday, August 10, 2009
Diving History -- The Brooklyn Bridge
Opening day of Brooklyn Bridge showcased it as a symbol of American ingenuity. Its was the longest suspension bridge in the world and its two towers stood as the tallest structures in New York City and the entire western hemisphere for several years.
Construction began on January 3, 1870 with two granite block Gothic inspired towers to support its massive cables. One tower is located on the Manhattan side, the other on the Brooklyn side of the bridge.
They were towed into position and sunk on the river bottom. Compressed air was then pumped into the chambers to keep water from rushing in, and men inside dug away at the mud and bedrock at the bottom of the river. As the stone towers were built on top of the caissons, the men beneath, dubbed "sand hogs," kept digging ever deeper. Once they reached solid bedrock, the digging would stop, and the caissons were filled with concrete, thus becoming the foundation for the bridge. To expedite the descent of the caissons, dynamite was used for the first time in bridge construction. These workers were paid wages of $2.25 per day.Work inside the caisson was exceedingly difficult.
The atmosphere was always dirty and misty, and as the caisson work occurred before Edison perfected the electric light, meaning the only illumination was provided by gas lamps. The "sand hogs" had to pass through a series of air locks to enter the chamber where they worked. After working long hours, as workers would quickly depressurize themselves through the locks; a strange phenomenon would commonly occur. Upon surfacing, workers would experience painful symptoms in their joints and about their bodies. This would cause them to limp in a manner that appeared similar to the "Grecian bend" (a dance for fashionable ladies of the era). Those affected with this ailment would be chastised by their fellow workers for "doing the Grecian bend". 
This was later shortened to simply "the bends" and is still used as a description for decompression sickness. Workers affected with the bends would experience some relief of the symptoms when they returned to work under pressure in the caisson the next day - although no one understood why at the time. Dr. Andrew Smith first utilized the term "caisson disease" describing 110 cases of reported decompression sickness (most cases weren't reported) as the physician in charge during construction of the Brooklyn Bridge. The project employed 600 compressed air workers. Recompression treatment was not used as it didn't exist. All in all, the foundations took three years to construct and cost 27 workers their lives.There were so many occurrences of the disease in the caisson workers, that it caused the halt of construction of the Manhattan side of the tower. This was 30 feet short of bedrock when soil tests underneath the caisson found bedrock to be even deeper than expected. Today, the Manhattan tower rests only on sand in 78 feet of water; the Brooklyn tower sits in bedrock in 44 feet of water.
The Brooklyn Bridge's opening ceremony was attended by several thousand people and many ships were present in the East Bay for the occasion. One week after the opening, a rumor that the Bridge was going to collapse caused a stampede, which crushed and killed twelve people. On May 17, 1884, P. T. Barnum helped to squelch doubts about the bridge's stability-while publicizing his famous circus-when one of his most famous attractions, Jumbo, led a parade of 21 elephants over the Brooklyn Bridge.
Books: To read more about the construction of the Brooklyn Bridge, check out "The Great Bridge" by David McCullough.
Diving History -- The Brooklyn Bridge
Opening day of Brooklyn Bridge showcased it as a symbol of American ingenuity. Its was the longest suspension bridge in the world and its two towers stood as the tallest structures in New York City and the entire western hemisphere for several years.
Construction began on January 3, 1870 with two granite block Gothic inspired towers to support its massive cables. One tower is located on the Manhattan side, the other on the Brooklyn side of the bridge. In order to anchor the towers to the East River, they were built atop caissons, which 
were large wooden boxes with no bottoms. They were towed into position and sunk on the river bottom. Compressed air was then pumped into the chambers to keep water from rushing in, and men inside dug away at the mud and bedrock at the bottom of the river. As the stone towers were built on top of the caissons, the men beneath, dubbed "sand hogs," kept digging ever deeper. Once they reached solid bedrock, the digging would stop, and the caissons were filled with concrete, thus becoming the foundation for the bridge. To expedite the descent of the caissons, dynamite was used for the first time in bridge construction. These workers were paid wages of $2.25 per day.
Work inside the caisson was exceedingly difficult. The atmosphere was always dirty and misty, and as the caisson work occurred before Edison perfected the electric light, meaning the only illumination was provided by gas lamps. The "sand hogs" had to pass through a series of air locks to enter the chamber where they worked. After working long hours, as workers would quickly depressurize themselves through the locks; a strange phenomenon would commonly occur. Upon surfacing, workers would experience painful symptoms in their joints and about their bodies. This would cause them to limp in a manner that appeared similar to the "Grecian bend" (a dance for fashionable ladies of the era). Those affected with this ailment would be chastised by their fellow workers for "doing the Grecian bend". This was later shortened to simply "the bends" and is still used as a description for decompression sickness. Workers affected with the bends would experience some relief of the symptoms when they returned to work under pressure in the caisson the next day - although no one understood why at the time. Dr. Andrew Smith first utilized the term "caisson disease" describing 110 cases of reported decompression sickness (most cases weren't reported) as the physician in charge during construction of the Brooklyn Bridge. The project employed 600 compressed air workers. Recompression treatment was not used as it didn't exist. All in all, the foundations took three years to construct and cost 27 workers their lives.
There were so many occurrences of the disease in the caisson workers, that it caused the halt of construction of the Manhattan side of the tower. This was 30 feet short of bedrock when soil tests underneath the caisson found bedrock to be even deeper than expected. Today, the Manhattan tower rests only on sand in 78 feet of water; the Brooklyn tower sits in bedrock in 44 feet of water.
The Brooklyn Bridge's opening ceremony was attended by several thousand people and many ships were present in the East Bay for the occasion. One week after the opening, a rumor that the Bridge was going to collapse caused a stampede, which crushed and killed twelve people. On May 17, 1884, P. T. Barnum helped to squelch doubts about the bridge's stability-while publicizing his famous circus-when one of his most famous attractions, Jumbo, led a parade of 21 elephants over the Brooklyn Bridge.
Books: To read more about the construction of the Brooklyn Bridge, check out "The Great Bridge" by David McCullough. 
H/Y
