Dockside Classic: USS Burrfish (SSR-312) – A Deep Dive Into The History Of The Radar Picket Submarine

A picket is defined as, “A detachment of one or more troops, ships, or aircraft held in readiness or advanced to warn of an enemy’s approach.” Equipping a submarine with radar might seem obvious for protecting a naval fleet since it can quickly submerge to hide after detecting the enemy, but bulky (and balky) electronics equipment and already severely-cramped conditions had to be overcome. In fact, it would take a half-century for a workable solution to be realized and only fifteen years later, the radar picket submarine mission would be obsolete.

While an early form of radar intended to help avoid ship collisions had been patented in 1904 by German inventor Christian Hülsmeyer, it never became commercially viable. Thirty years of research and technological advances were needed before British meteorologist Robert Watson Watt—investigating reports of a German ‘death ray’ based on radio—realized that radio signals could be used to locate aircraft at long distances. In early 1935, he submitted a secret report to the Air Ministry entitled “The Detection of Aircraft by Radio Methods,” which was soon followed by an experimental demonstration. This resulted in the creation of the “Chain Home” radar system along Britain’s East and South coasts that enabled early detection of German air raids and arguably was a deciding factor in The Battle of Britain.

As the war ground on, Allied Naval forces began advancing across the Pacific toward Japan. In late October, 1944, US troops invaded the Island of Leyte, touching off a naval battle—possibly the largest ever fought—that would ultimately see heavy Allied losses from the first major use of Kamikaze (“Divine Wind”) aircraft by Japanese forces.

In early April, 1945, Allied forces launched the largest amphibian assault of the war on the Ryukyu Islands of Okinawa, a battle that would rage for 82 days. A ring of 15 radar picket stations was established, with each station typically made up of one or two destroyers supported by a pair of landing ships for additional anti-aircraft (AA) power. Among these were a small number of purpose-built radar picket destroyers that had sacrificed their torpedo tubes in order to add more radar equipment and AA firepower.

A battle report dated 20 July, 1945 identified radar pickets as a fundamental need and that, “The accomplishment of the important task of the advanced radar picket requires a sufficiency of properly equipped ships which are adequately supported by other surface craft and covered by Combat Air Patrol (CAP) for as much of the time as possible. To be truly effective the picket must be capable of remaining on station” [emphasis mine]. The biggest challenge to using surface ships as radar pickets was that they were the first vessels encountered by approaching Kamikazes. Knowing the important function of these ships, they were hit first and hard, resulting in heavy losses to the pickets.

The report further stated that, “The use of submarines for radar pickets is being considered. After detecting and reporting the approach of enemy planes, the sub could dive. Limited range of present submarine radar—plus rearrangements inside hull—are problems to be solved before submarines can perform this duty.”

With the invasion of Japan being anticipated for November, 1945, the US Navy ordered 24 fleet-type submarines to be modified with periscope-mounted SV air-search radars for radar picket work at shallow submergence. Two had been completed with four more in progress when Japan surrendered that August. The end of the war reduced the immediate need for radar picket submarines, but development continued.

In late 1946, two Tench-class fleet submarines were modified for radar picket operations; the USS Spinax (SS-417) and USS Requin (SS-481). While not designated specifically as radar picket subs (SSR), they both saw the addition of SR-2 (air search) and SV-2 (low-angle surface search) radars mounted on the afterdeck with all the electronics and the combat information center (CIC) located in the after torpedo room just below.

Stern torpedo tubes were retained, but had to be loaded externally and electric generation and air conditioning had to be increased to support the additional electronics. This setup made for a more survivable picket than a surface ship, but salt-water spray tended to short out the above-deck components and extreme crowding below decks made for a less-than-effective solution.

US Navy Fleet Type Submarine Classes

Gato Class Balao Class Tench Class
77 built from 1940–1944 120 built from 1942–1946 29 built from 1944–1951
2,424 tons displacement submerged 2,416 tons displacement submerged
311′-8″ length, 27′-3″ beam 311′-6″ length, 27′-3″ beam 311′-8″ length, 27′-3″ beam
4 x diesel engines (1,600 HP each @ 720 or 750 RPM) driving electric generators; 2 x 126 cell batteries; high-speed electric motors with reduction gears or low-speed direct-drive motors; two propeller shafts
21 knots surfaced, 9 knots submerged 20 knots surfaced, 9 knots submerged
Range: 11,000 nautical miles (20,372km) at 10 knots, typically on patrol for 75 days
Diving Depth: 300′ (90m) Test, 450′ (137m) Emergency, hull thickness = 9/16″ (14.3mm) mild steel Diving Depth: 400′ (122m) Test, 600′ (183m) Emergency, hull thickness = 7/8″ (22.2mm) high-tensile steel
10 torpedo tubes (6 bow, 4 stern), 24 torpedoes carried
Crew: 10 officers, 70–71 enlisted men

This is a good point to take a more detailed look at the three classes of Fleet submarines manufactured during WWII. The general layout was similar for all three, with the most significant change being the high tensile steel ‘thick skin’ introduced on the Balao-class boats that enabled them to dive as deep as 600′ (183m) in an emergency. The crush depth was calculated at 900′ (274m), but no-one ever came back to confirm it. Balao-class boats looked so similar to the earlier Gato-class that the Japanese never realized and were setting their depth charges far too shallow—that is, until Congressman Andrew J. May blabbed this highly sensitive fact at a press conference in June 1943. Vice Admiral Charles Lockwood, commander of the US Pacific submarine fleet, estimated May’s leak cost the Navy as many as ten submarines and 800 crewmen killed in action and was quoted as saying, “I hear Congressman May said the Jap depth charges are not set deep enough. He would be pleased to know that the Japs set them deeper now.” Tench-class boats incorporated minor improvements over the Balao-class boats.

The Navy’s Bureau of Ships used the lessons learned from these first conversions to launch a formal radar picket submarine program, appropriately named Project MIGRAINE due to all the headaches caused by the added equipment. The seawater issues were mitigated by locating the search and height finder radars on separate high masts mounted aft of the conning tower, out of the reach of spray when surfaced. Below decks, the crew’s mess and galley became the CIC, and all four tubes were removed from the after torpedo room to make room for relocated crew berthing. Two tubes were removed from the forward torpedo room for storage and yet more equipment. Electronics included SV-1 (aircraft warning), SV-2 (low angle surface search) and AN/BPS-2 (air search) radars, as well as a YE-2 homing beacon transmitter. Two boats received the MIGRAINE I conversion: Tench-class USS Tigrone (SSR-419) and the only Balao-class boat to be converted, the USS Burrfish (SSR-312). We’ll take a closer look at Burrfish a bit later…

Due to the Requin and Spinax continuing to have issues with their original conversions, they were sent back for MIGRAINE II conversions–essentially the same modifications as the MIGRAINE I boats, but with the height finder radars left in their original locations on the afterdeck, where they continued to have issues with salt water spray during surfaced operations. As an interesting side bit of trivia, Spinax briefly appears in the opening scenes of the 1953 science fiction movie, Phantom from Space, where she is seen on radar picket duty.

The Cold War was in full swing by this point and air defense of US carrier battle groups deployed near Russian territories called for more radar picket subs. Cramped quarters continued to be an operational hinderance, so the MIGRAINE III conversion took the drastic measure of cutting the hull in two and inserting a 24’ (7.3m) ‘plug’ ahead of the main control room for an expanded CIC and more electronics. The aft torpedo tubes were removed for crew berthing as in the earlier conversions, but the full complement of six forward tubes were kept.

A larger, streamlined sail was fitted with BPS-2 search radar mounted aft of the periscopes, AN/BPS-3 height finding radar on a pedestal behind the sail, and an AN/URN-3 TACAN beacon on the afterdeck. Six Gato-class boats would receive this conversion between 1951–1953, giving the US Navy ten radar picket submarines for use just as the Korean conflict was drawing to its tenuous close.

Two additional purpose-built conventionally-powered radar picket boats (Sailfish-class) would be commissioned in 1956, the USS Sailfish (SSR-572) and USS Salmon (SSR-573). With streamlined sails and hulls, they boasted surfaced speeds of 20.5 knots and submerged speeds of 15 knots. This was a slight improvement over the MIGRAINE boats, but was still far too slow to keep up with surface battle groups, which limited their effectiveness. Nonetheless, seven SSRs were assigned to the Atlantic fleet and operated in the Caribbean and North Atlantic, as well as participated in NATO exercises and deployments in the Mediterranean as part of the US Sixth Fleet. The remaining five boats went to the Pacific fleet and operated off the North American Pacific shores and in WESTPAC deployments to the US Seventh Fleet.

The launch of the USS Nautilus (SSN-571) in 1954 indicated that the future for submarines would be nuclear. One final purpose-built radar picket boat would be constructed, the Triton-class USS Triton (SSRN-586), shown above, which, at nearly 6,000 tons surface displacement and 447’ length, was the longest US submarine until the USS Ohio (SSBN-726) was constructed in the early 1980s. The Triton boasted a (published) surfaced speed of over 30 knots, submerged speed of over 27 knots, and a 700′ (213m) test depth. She was the only US submarine to carry two nuclear reactors, and the last to have a conning tower located inside the sail. Three main deck levels assured plenty of room for dedicated air-control equipment. On Triton’s maiden voyage, Captain Edward L. Beach was ordered to attempt the first submerged circumnavigation of the world, which was successfully completed 41,500 nautical miles and nearly three months later.

Right about the time Triton was being launched, Grumman introduced the E-1 Tracer airborne early warning aircraft, which effectively obsoleted the radar picket submarine mission overnight. The Triton was reclassified as an SSN attack submarine, and all of the conventionally-powered SSR boats were withdrawn from radar picket operations in 1961, with two of the MIGRAINE III boats immediately being scrapped. The remainder were either temporarily decommissioned, converted back to conventional attack boats (SS) or converted to auxiliary general submarines (AGSS) for use in non-combat operations. The Sailfish survived on active duty the longest; she was decommissioned in 1978 and was sunk as a target vessel in May, 2007.

In a humorous aside, it was reported in April, 1962 that a kite had been found snagged on the former MIGRAINE III boat, USS Raton (SS-270). Charles Schultz took the opportunity a few weeks later to further cement in print one of Charlie Brown’s signature foibles.

One former SSR survives today as a museum boat, the USS Requin (AGSS-481), located at the Carnegie Science Center in Pittsburgh, Pennsylvania, USA.

So let’s now take a closer look at the Burrfish in order to get a more complete picture of the many lives these unique boats experienced.

On 9 July, 1942, seven months after the Japanese sneak attack on Pearl Harbor, the United States Congress authorized an additional 1,900,000 tons of combatant ships to be constructed. Originally named Arnillo, Hull Number SS-312 was renamed Burrfish (after an Atlantic coast swellfish) on 24 September, 1942. One of 265 orders for Balao-class boats (of which 119 would be completed to the original design), her hull was laid down on 24 February, 1943 at Portsmouth Navy Yard in Kittery, Maine. She was christened by Miss Jane Elizabeth Davis at the launch on 18 June, 1943 and was subsequently commissioned on 14 September, 1943.

Burrfish completed six war patrols, sinking one 5,894 ton Japanese tanker, and with USS Ronquil (SS-396) assisting, destroying a 200 ton patrol vessel. She also participated in several special missions, including rescuing ditched B-29 bomber airmen and conducting reconnaissance missions of the beaches of Palau and Yap. After returning from her sixth patrol in May, 1945, she was ordered to the Portsmouth Navy Yard in Maine for major overhaul. The war ended on September 2, 1945 with representatives of the Empire of Japan signing the instruments of surrender on the deck of the USS Missouri. Burrfish would spend the next year conducting various local operations off the US East Coast before being decommissioned in October 1946 and laid up in the “Mothball Fleet” on the Thames River.

Two years later, Burrfish would be recommissioned and assigned for conversion to the radar picket mission, with the designation SSR-312. The conversion took a year, and included replacement of her original high-speed motors and their whiny reduction gears to low-speed, direct-drive motors. Her batteries were replaced and she also received a snorkel system. Her sail was never converted to the more streamlined configuration, however. She would rejoin the fleet in early 1950 and operated along the Atlantic seaboard and conducted training exercises out of Guantanamo Bay, Cuba during this time.

Late 1950 saw her operating in the Mediterranean Sea, visiting Navaron Bay, Greece, Toulon, France, Souda Bay, Crete and Taranto and Naples, Italy. She would return to Charleston Naval Shipyard in South Carolina in late 1951 for overhaul.

Upon completion of her overhaul in early 1952, my father (back row, second from left) would join her crew as an E3 Machinists Mate in charge of the forward engine room where he kept two of four Fairbanks-Morse 38 8-1/8 diesel engines going.

This cutaway view gives a good idea of the arrangement of a Fleet boat ‘drivetrain.’ The engines turned generators that in turn charged the two 126-cell batteries or powered two Elliot main propulsion motors rated at 2,740 shaft horsepower. In addition to Fairbanks-Morse engines, some boats used General Motors 16-248 or 16-278A diesels that were a more conventional V16 configuration, each making 1,600 HP at 750 RPM.

As fitted in Burrfish, the opposed piston, 9-cylinder, two-stroke diesel Fairbanks-Morse engines each made 1,600 HP at 720 RPM. This photo is from the USS Requin, and shows that half the engine was situated in the hold below the platform deck. Later Fairbanks-Morse-powered boats used 10-cylinder engines.

This cross section clearly shows why these engines acquired the nickname “rock crushers.”

Following her overhaul, Burrfish made a refresher/training cruise to Puerto Rico, then sailed back to the Mediterranean Sea for a tour of duty with the US Sixth Fleet. The boat is docked at Marseilles, France in the photo, and due to the harbor being too small to turn the boat around, she was backed down the channel to the dock, which must have made for quite a sight.

Burrfish would return to the US East coast in August, 1952. My dad told a story of how, when transiting the Straits of Gibraltar, they experienced a rapid seawater temperature drop that cracked numerous cylinder liners in the main propulsion diesels. All four engines had to be torn down to salvage enough good liners to put one engine back online for a return to port for repairs. She would finish her tour in the United States Virgin Islands before heading back to the Philadelphia Naval Shipyard for another overhaul. Dad was done with his four year enlistment at this point and returned to civilian life and a career in teaching.

Burrfish would deploy several more times, operating along the US Eastern coast, and in the Caribbean and Mediterranean Sea. Her final deployment in September, 1955 was to the Arctic Ocean area where, along with the USS Redfin (SSR-272), she collected intelligence on ‘potential enemies of the United States.’ Upon return to her home port of Norfolk, Virginia, she would operate locally until June, 1956, when she was inactivated and placed in the Reserve Fleet on the Thames River at the end of the year.

Toward the end of the decade, the Canadian Government approached the US Navy with a request to lease a surplus US submarine for use as a training target for Canadian antisubmarine forces. The USS Burrfish was selected, and would become the first Canadian-flagged submarine in forty years.

After a $900,000 refit back to her WWII configuration, Burrfish was reclassified back to SS-312. She was again decommissioned and signed over (under lease) to the Canadian Navy, where she became Her Majesty’s Canadian Ship (HMCS) Grilse (SS-71), named after a famous Canadian yacht/warship.

HMCS Grilse would spend most of her operating time in the Pacific. After a six month refit and overhaul in 1963, she spent a week dockside conducting simulated cruises with full crew aboard. A crewmember related the story of how she settled to the bottom of the harbor (i.e. sank) during one of these training sessions and it was a group of sea cadets on the sailing sloop Oriole who lifted the emergency receiver on the periscope to hear: “Uh, could you notify someone we have a spot of bother here?”

In addition to her training duties, HMCS Grilse participated in a research program conducted by the Pacific Naval Laboratory (PNL) of the Defense Research Board of Canada to see how long a submarine’s wake turbulence could be detected after its passing. Probes were extended out of a forward torpedo tube for acquiring data. French polymath Benoit Mandelbrot was among the scientists that analyzed this data, and he later stated that it had a great impact on his thinking on fractals and financial market turbulence.

After eight years of service, The Canadian Navy prepared to return the boat to the US Navy. On 2 October, 1969, to the accompaniment of a band and speeches, the Canadian flag and commissioning pennant were lowered and HMCS Grilse (SS-71) was formally returned to the US Navy, which had already stricken her from the Navy List.

USS Moray (SS-300) being sacrificed as a torpedo test target in 1970 near San Clemente Island, CA.

On 19 November 1969, Burrfish met her end as a radio-controlled target ship in the test of a helicopter-deployed Mark 46 torpedo.

USS Moray (SS-300) at rest—the only Balao-class submarine situated at a diveable depth on the US West coast.

The torpedo hit her hull in the vicinity of the pump room, and Burrfish sank in 1,600′ of water off San Clemente Island, California, where she rests today.

Additional reading: Diesel-Electric Submarines: World’s Biggest Hybrids (by Lee Wilcox)


Author’s Note: Along with two buddies, my Dad joined the Navy right out of high school in 1949 and qualified on the USS Congor (SS-477), earning the right to wear submariner ‘dolphins.’ He turned down a Naval Academy appointment because the only degree they offered was in Marine Engineering. After his time in submarine service, he earned a Masters and Doctorate in Education from the University of Georgia, specializing in vocational education. In retirement, he authored an adult literacy textbook entitled Applied Technical Mathematics. We always enjoyed hearing his submarine stories, and accompanied him several times to the annual Submarine Memorial Service at the Navy base in Kings Bay, Georgia. Dad lost his battle with vascular dementia in late 2018, and—like the Burrfish—is now on eternal patrol… This article is presented in his—and all Cold War submariners—honor.