McCann Rescue Chamber
Encyclopedia
History
During the first two decades of the United States NavyUnited States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
Submarine Force, there were several accidents in which Navy submarines sank with the loss of life. The impetus for the invention for the chamber was the loss of S-51
USS S-51 (SS-162)
USS S-51 was a fourth-group S-class submarine of the United States Navy.Her keel was laid down on 22 December 1919 by the Lake Torpedo Boat Company of Bridgeport, Connecticut. She was launched on 20 August 1921 sponsored by Mrs. R.J. Mills, and commissioned on 24 June 1922 with Lieutenant W. S...
on 25 September 1925, and the loss of S-4
USS S-4 (SS-109)
USS S-4 was an S-class submarine of the United States Navy. In 1927, she was sunk by being accidentally rammed by a Coast Guard destroyer with the loss of all hands but was raised and restored to service until stricken in 1936.-Building:...
on 17 December 1927. In the case of S-4, all of her officers and men were able to reach non-flooded compartments as the submarine bottomed in 110 ft (33.5 m) of water. However, the majority soon succumbed. In her forward torpedo room, six men remained alive. Heroic efforts were made to rescue these six, who had exchanged a series of signals with divers by tapping on the hull. In extremely cold water and tangled wreckage, Navy divers worked to rescue them, but a storm forced a stop to this effort on 24 December. Forty men lost their lives.
These experiences led submariner Charles B. "Swede" Momsen to think of technical alternatives for rescuing survivors from sunken submarines, which at that time was still a virtual impossibility. Momsen soon conceived a submarine rescue chamber that could be lowered from the surface to mate with a submarine's escape hatch and proposed the concept through official channels. While in command of the submarine S-1
USS S-1 (SS-105)
USS S-1 was the lead boat of the S-class of submarines of the United States Navy. The Navy had awarded contracts for the first three S-boats under the same general specifications but of different design types...
(SS-105), in 1926, Momsen wrote the Bureau of Construction and Repair
Bureau of Construction and Repair
The Bureau of Construction and Repair was the part of the United States Navy which from 1862 to 1940 was responsible for supervising the design, construction, conversion, procurement, maintenance, and repair of ships and other craft for the Navy...
(BuC&R) recommending the adoption of a diving bell
Diving bell
A diving bell is a rigid chamber used to transport divers to depth in the ocean. The most common types are the wet bell and the closed bell....
for the purposes of rescuing entrapped personnel from submarines. But this idea was pigeonholed by the bureaucracy, even during his own subsequent assignment at BuC&R. The loss of S-4 with all hands put the Navy was very much "on the spot" because of the loss of lives that might have been saved. The pressure of this incident forced favorable action and Momsen, using the aircraft hangar from S-1, designed and built a prototype submarine rescue chamber.
Boston Navy Yard
The Boston Navy Yard, originally called the Charlestown Navy Yard and later Boston Naval Shipyard, was one of the oldest shipbuilding facilities in the United States Navy. Established in 1801, it was officially closed as an active naval installation on July 1, 1974, and the property was...
, where she was drydocked and repaired. She returned to active duty in October 1928 and was employed thereafter as a submarine rescue and salvage test ship. Momsen went to sea in the reconditioned S-4 to carry out practical experiments and training with the rescue chambers.
Work with S-4 helped to develop equipment and techniques that bore fruit a decade later, when 33 men were brought up alive from the sunken submarine Squalus. The first diving bells for rescuing men from submarines were designed by the BuC&R in 1928. The diving bell went through a series of tests off the shores of Key West, Florida
Key West, Florida
Key West is a city in Monroe County, Florida, United States. The city encompasses the island of Key West, the part of Stock Island north of U.S. 1 , Sigsbee Park , Fleming Key , and Sunset Key...
. Based on these tests, Momsen had several changes in mind for the bell, and after nearly two years of experimentation full of highly interesting results, the final bell was evolved and christened a "rescue chamber." This success was catalyst for gaining approval for development of the submarine rescue chamber in 1930. Before he could make these changes, Momsen went to the Bureau of Construction and Repair to work on an underwater breathing apparatus for individual escapes. Momsen turned to devising the "Momsen Lung"
Momsen lung
The Momsen lung was a primitive underwater rebreather used before and during World War II by American submariners as emergency escape gear. The Momsen lung was invented by Charles B. Momsen . Submariners would train in a 100-foot deep escape training tower using this apparatus...
, demonstrating it successfully in a series of unauthorized experiments in the Anacostia
Anacostia River
The Anacostia River is a river in the Mid Atlantic region of the United States. It flows from Prince George's County in Maryland into Washington, D.C., where it joins with the Washington Channel to empty into the Potomac River at Buzzard Point. It is approximately long...
and Potomac
Potomac River
The Potomac River flows into the Chesapeake Bay, located along the mid-Atlantic coast of the United States. The river is approximately long, with a drainage area of about 14,700 square miles...
Rivers, and finally attracted enough favorable attention to see the lung adopted by the Navy in 1929.
Lieutenant Commander
Lieutenant Commander
Lieutenant Commander is a commissioned officer rank in many navies. The rank is superior to a lieutenant and subordinate to a commander...
Allan Rockwell McCann
Allan Rockwell McCann
Vice Admiral Allan Rockwell McCann, was a United States Navy officer who served in World War I and World War II.-Education to World War I:...
was put in charge of the revisions on the diving bell. From July 1929 to July 1931, McCann was assigned to the Maintenance Division, Bureau of Construction and Repair, where he developed the submarine rescue chamber. When the bell was completed in late 1930, it was produced as the McCann Submarine Rescue Chamber (SRC)(Navy designated the first 12 of these as [YRC] 1-12, YRC-4 was lost aboard the USS Pigeon, at Bataan, Philippines during the first days of WWII. YRC-5 was aboard the USS Widgeon (AM-22)
USS Widgeon (AM-22)
USS Widgeon was an acquired by the United States Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing. Later converted to a submarine rescue ship. Widgeon was named by the Navy after the widgeon, a fresh water duck.Widgeon USS Widgeon...
during the Pearl Harbor
Pearl Harbor
Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...
attack.). In 1931 a one-fifth scale model of a diving bell for submarine rescue work was built and tested. Design called for the bell to withstand the external pressure encountered at a depth of at least 300 ft (91.4 m) of water, and the test showed the model fulfilled this requirement with a factor of safety of about 3.5. The vessel was tested under external pressure, failure occurring in the shell at a pressure of 470 psi (3,240.5 kPa). Since the head of the vessel remained intact, it was decided to make a test of the head itself in order to determine its strength relative to that of the shell, and if possible to obtain some measure of the stresses occurring under load. The head collapsed at a pressure of 525 psi (3,619.7 kPa), indicating its strength under external pressure was about 10% in excess of that of the shell.
The revised Submarine Rescue Chamber had improvements including a soft seal gasket for sealing the submarine/bell interface skirting, and a floor installed to maintain air-space in the bell during raising and lowering. Momsen in his speech to the Harvard Engineering Society on 6 October 1939 credits Allan Rockwell McCann
Allan Rockwell McCann
Vice Admiral Allan Rockwell McCann, was a United States Navy officer who served in World War I and World War II.-Education to World War I:...
with the improvements which made the bell operational, safe and large enough to hold up to eight rescued crewmen and two operators.
The Squalus rescue
In 1939, the McCann Rescue Chamber made its debut when it was used to successfully rescue thirty-three survivors from Squalus, At the time of Squalus accident, Lieutenant Commander Momsen was serving as head of the Experimental Diving UnitUnited States Navy Experimental Diving Unit
The United States Navy Experimental Diving Unit is the primary source of diving and hyperbaric operational guidance for the US Navy...
at the Washington Navy Yard
Washington Navy Yard
The Washington Navy Yard is the former shipyard and ordnance plant of the United States Navy in Southeast Washington, D.C. It is the oldest shore establishment of the U.S. Navy...
. And the submarine rescue ship
Submarine rescue ship
A Submarine rescue ship serves as a surface support ship for submarine rescue and deep-sea salvage operations. Methods employed are the McCann Rescue Chamber, Deep Submergence Rescue Vehicles and deep sea diving operations....
USS Falcon
USS Falcon (AM-28)
The third USS Falcon, was in the United States Navy. She later became a submarine rescue ship.Falcon was launched 7 September 1918 by Gas Engine and Power Co., and C. L. Seabury Co., Morris Heights, New York; sponsored by Mrs. W. J. Parslow; and commissioned 12 November 1918, Lieutenant B. E....
(ASR-2), commanded by Lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...
Grant A. Sharp, was on site within twenty-four hours lowered the Rescue Chamber — a revised version of a diving bell invented by Momsen — and, in four dives over the next 13 hours, recovered all 33 survivors in the first deep submarine rescue ever. McCann was in charge of Chamber operations, Momsen commanding the divers. Although there was no reason to believe anyone was alive in the aft part of the ship, a fifth dive was made to the aft torpedo room hatch on May 25. This run confirmed the flooding of the entire aft portion of the ship.
Design
Limitations
The McCann bell suffers severe limitations in strong currents and when dealing with a pressurized submarine or one lying at extreme angles. It is also incapable of functioning below 850 ft (259.1 m). The USN Submarine Rescue Chamber (YRC) is air transportable to a Vessel Of Opportunity (VOO) Mother Ship (MOSHIP) which requires little modification to use the system. Transfer Under Pressure (TUP) to and from pressurized environments such as submarines or hyperbaric chambers is not possible with this system, even though TUP is essential where being subjected to ambient pressure may be life threatening. Since the creation of the Deep Submergence Rescue VehicleDeep Submergence Rescue Vehicle
A Deep Submergence Rescue Vehicle is a type of Deep Submergence Vehicle used for rescue of downed submarines and clandestine missions. While DSRV is the term most often used by the United States Navy other nations have different designations for their vehicles.- Chinese models :The People's...
s Mystic
DSRV-1 Mystic
DSRV-1 Mystic is a Deep Submergence Rescue Vehicle that is rated to dive up to 1500 metres. DSRV1 was built by Lockheed for the U.S. Navy and launched 24 January 1970....
and Avalon
DSRV-2 Avalon
DSRV-2 Avalon is a Mystic class Deep Submergence Rescue Vehicle that is rated to dive up to 5000 feet . The submarine was acquired in response to the loss of the so that the Navy would have a way to rescue submarine crews trapped far beneath the ocean surface.Avalon was launched in 1971...
, the McCann Rescue Chamber is rarely used, but is part of the Submarine Rescue Chamber Flyaway System (SRCFS) which is capable of worldwide submarine rescue missions. Once launched, the SRCFS is able to operate around the clock.