by Orr Kelly
The skipper of the USS Grayback met with planners of the operation in the Philippines and told them he could do the job.
The Grayback was an old diesel-powered submarine originally built in the 1950s to carry a Regulus missile. It had a large hangar for the missile on its deck. When the Regulus was phased out, the frogmen were quick to propose that they team up with the crew of the sub. The hangar area, they explained, was big enough to hold two SDVs or one SDV and a good deal of other equipment. And since the hangar area was dry, the frogmen could prepare for a mission in relative comfort.
The SDV is sometimes called a minisubmarine, but that is a misnomer. Unlike a submarine, which contains an airtight crew compartment, the SDV is not sealed against the sea. The men must wear underwater breathing apparatuses, and their only protection against the cold water is their wet suits.
Well before the creation of the SEALs, the UDT teams had for many years worked with submarine crews, learning how to use the escape tower to “lock out” of and “lock in” to the sub. But the Grayback, with its big, dry hangar, gave them an entirely new capability. Their only complaint was that the sub, designed to loiter for long periods until it was called on to launch a missile attack, was slow, only capable of creeping along at five knots.
In Operation Thunderhead, speed was not a problem, but stealth was all-important. The entire operation was so secret that the crews of the surface ships crowding the Gulf of Tonkin were not told about it. This meant the Grayback had to work its way past three aircraft carriers, plus cruisers and destroyers; maneuver in close to the Vietnamese coast; and then settle gently to the bottom without being detected.
A more modern nuclear-powered submarine might not have been able to slip through an entire American fleet undetected. But the Grayback was an older model. On the surface it was powered by diesel engines. But when submerged, running slowly on electricity from its batteries, it was almost inaudible, even to the most sensitive passive sonar.
The skipper promised not only that he would reach the designated point, but that he would remain there for the nearly three weeks that the operation might go on, surfacing only at night when necessary to recharge his batteries.
In the middle of the night of 3-4 June, Dry, who was a member of SEAL Team One, and three other men climbed from the submarine up into the hangar and prepared for their “takeoff.” Two of the men, Lt. (jg) John C. Lutz and Fireman Tom Edwards, belonged to UDT Eleven, and they served as the crew—the pilot and navigator—of the SDV. Their task was to deliver Dry and another SEAL, Warrant Officer One P. L. Martin, to the island and then return to the submarine. After two or three days they would repeat the process, picking up the two SEALs and replacing them with two more.
When everything was in readiness, the hangar door was opened, and Lutz slowly “flew” the nineteen-foot-long SDV off into the dark waters. The craft was an early model of the Mark 7 SDV, the first to go into service with the navy. It was little more than a prototype, intended for training rather than for a combat mission. With its four-man crew it had little positive buoyancy to spare for carrying weapons and other gear. Its navigation equipment amounted to little more than a clock and a compass.
As the SDV slowly made its way toward its target, the crew members became aware that they were fighting a much stronger current than they had expected, and that their batteries were running out of power. They weren’t going to make it. Before reaching the island, they were forced to surface and lie there, dead in the water. When Lutz and Edwards failed to return, the submarine sent a prearranged message: “Briarpatch tango.” This meant the SDV team was in trouble.
Shortly after dawn a helicopter was dispatched to search for the four men. Just east of the little island they were spotted in the water, alongside the black shape of the SDV. As the helo hovered overhead, the men were hoisted to safety. The helicopter crewmen were surprised to see how much equipment they were carrying: radios, survival gear, ammunition, M-16 rifles, and even communications equipment from the SDV.
As the last of the survivors was hoisted into the cabin, one of the helicopter’s crewmen swung the craft’s automatic machine gun into position and raked the SDV with bullets, sending it to the bottom. The frogmen were flown to the cruiser Long Beach.
On the following day, 5 June, the submarine radioed a message asking to have its “package”—the four men—delivered about midnight that night. The plan was for the sub to send a swimmer to the surface with an infrared lantern to signal his position. As the helicopter moved slowly overhead the frogmen would step out into the darkness, in a procedure called a helo cast. The man from the submarine would lead them back to the sub. One part of the message from the submarine was a mystery to officers on the cruiser. It said, “Will be conducting abbreviated ops.” Even though this didn’t make any sense, it was decided not to force the sub to compromise its position by pressing for an explanation.
The frogmen asked to be dropped from thirty feet, with the helicopter moving forward at five knots. This would be like jumping from the top of a three-story building onto water, which can be as hard as concrete from that height. In practice, it had been found that the forward momentum of the chopper would help the man maintain the proper body position so he would slice into the water rather than pancake. The thirty feet at five knots was a compromise from standard operating procedure, which called for matching the helicopter’s speed to its altitude: ten knots at ten feet, twenty knots at twenty feet, thirty knots at thirty feet, and so on. This compromise reflected the SEALs’ instinctive feeling that jumping out of a fast-moving helicopter was not a smart thing to do.
James L. (“Gator”) Parks, a plank owner of SEAL Team One and one of the navy’s most experienced SDV operators, says, “I’m not jumping out of any helicopter at thirty knots and thirty feet. I have done it, and I’m not ever going to do it again, I guarantee. That was SOP [standard operating procedure]. We were not smart enough to get the SOP changed.”
As the helicopter crewmen and the four frogmen emerged onto the deck of the Long Beach and prepared to board the helicopter, it became obvious that the fine points of helo casting were just so much theory. The night was dark and overcast, without even the hint of a horizon. The pilot said he’d try for thirty feet and five knots, but they had better plan on forty feet and ten knots.
Once airborne, the crewmen scanned the area ahead with an infrared detector, looking for a signal from the submarine. At one point, they saw a line of dim lights and flew toward them. Only as they swept in over the breaker line did they realize the light they saw came from candles, shining dimly from the windows of homes along the shore.
The pilot banked sharply back out to sea. But then, flying on instruments, he dipped so low that ocean water splashed onto the floor of the helicopter.
The infrared detector never did pick up the signal from the submarine. But the men in the helicopter saw several small, flashing strobe lights near where the submarine was supposed to be.
The pilot zeroed in on one of the strobes. Dry, still burdened with equipment, handed his rifle to Lt. Comdr. Edwin L. Towers, the officer in charge of the rescue attempt, and stepped into the darkness. The chopper was hovering, without the forward momentum that would have helped the men maintain the proper position to slice into the sea. Lutz, Martin, and Edwards followed quickly, in that order. As each man stepped out, the helicopter became lighter. By the time Edwards jumped, he may have been some one hundred feet from the water, equivalent to jumping from the top of a ten-story building.
As Edwards disappeared out the door, a startling message came from the sub: “Do not deliver my package! I say again, Do not deliver my package!”
The helo crew flashed back a message that the package had been delivered about thirty seconds before. The sub responded that it had detected a North Vietnamese patrol boat approaching and had to move.
The helicopter wheeled away toward a nearby amphibious ship, leaving the four frogmen alone in the darkness of the Gulf of Ton
kin until a search could begin at dawn.
Lutz was stunned by hitting the water, and some of his equipment was torn away by the impact, but he was not injured. He and Martin, also slightly dazed, soon located each other and then found Edwards, seriously injured and moaning. Martin inflated Edwards’s life vest, and Martin and Lutz called for Dry. There was no answer.
Soon, however, the three men made contact with four other swimmers in the water and learned the meaning of the mysterious strobe lights they had seen from the helicopter.
Although those aboard the Long Beach who were masterminding the operation didn’t realize it, the Grayback carried two SDVs. When the first craft failed to return, it was decided to send another SDV, with a two-man UDT crew and two SEALs to take up the surveillance mission on the island. This second SDV mission was the meaning of the enigmatic reference to “abbreviated ops.” But the SDV was improperly ballasted. As soon as it left the hangar deck of the submarine, it sank to the bottom. The four men were fortunate to escape before the sub, rolling gently, crushed the SDV.
Although their tiny craft foundered right beside the sub, the currents were so strong that the men were not able to get back inside. They began to flash their strobes, hoping that the helicopter coming to drop the package, consisting of the four men from the original SDV, would realize their predicament and pick them up.
The four men who had escaped from the second SDV—Lt. (jg) McGrath, Lt. (jg) Conger, Seaman McConnel, and Petty Officer Birkey—joined up with the three survivors from the first SDV. They were apparently caught in a giant whirlpool, for during the night Dry’s body floated into their midst.
When the helicopter returned to the area shortly after dawn, the crew members were startled to see eight, rather than just four, forms bobbing in the sea. As they got closer, they could see that one of the men was dead. Even though it strained the capacity of the helicopter, all seven men and Dry’s body were lifted from the sea and taken to the Long Beach.
Just after dawn on the morning of 9 June, alert lookouts on a U.S. destroyer spotted the wake made by a submarine’s snorkel. The crew had not been told of the presence of a friendly submarine, so they began firing with their five-inch gun. As soon as the destroyer radioed that the sub was under attack, the cease-fire order was flashed from the Long Beach. It was not until late that night, however, that the skipper of the Grayback felt comfortable coming to the surface and reporting that he had suffered no damage. He also said he would send a small rubber boat to pick up the six frogmen remaining after Edwards had been flown to a nearby aircraft carrier for treatment, along with Dry’s body.
It was not until three o’clock on the morning of 12 June that the rubber Zodiac boat from the sub, its outboard motor disabled, was paddled up to the Long Beach. Quickly, the six frogmen joined the two men in the boat and paddled off into the darkness. Why they felt such a strong urge to get back to the submarine, even though both the SDVs had been lost, is not clear. Perhaps it was the simple fact that they thought of the submarine as home.
The planners of Operation Thunderhead later learned that the prisoners had called off their escape attempt but had had no way to pass word of their change in plans. The official navy accident report on the death of Dry says the helicopter was hovering at about thirty-five feet when he jumped. But a number of SEALs familiar with the operation believe the helicopter, maneuvering on instruments in inky blackness and having, a few moments before, dropped so low that water splashed onto the flight deck, was at a much higher altitude when Dry stepped out the door.
Operation Thunderhead was not one of the U.S. Navy’s finest hours, and that may help explain why it long remained highly classified. But it was also the navy’s first chance to test in a combat environment a type of technology in which it had lagged, but which other nations had pioneered, on several occasions with spectacular success.
The leaders in the use of small submersibles were for many years the Italians, but the British were probably the first in modern times to give serious consideration to the use of combat swimmers. In 1909, a Royal Navy officer proposed a scheme in which men—human torpedo riders—would sit astride torpedoes and guide them toward enemy shipping. At the beginning of World War I in 1914, the concept was proposed to Winston Churchill, then first lord of the admiralty and a man with a well-developed penchant for the unusual and the unorthodox. But the idea of having men ride torpedoes into an enemy port was too much even for Churchill. He turned thumbs down on the proposal. In Italy, a similar suggestion was greeted initially with similar skepticism. But perhaps because Italy was not blessed with a navy as powerful as that of Britain, the Italian brass gave the go-ahead. The plan called for surface swimmers to be dropped from a mother ship, swim into an enemy harbor, plant mines on ships, and then swim back out again.
The scheme was workable, and on 1 November 1918, just days before the end of the war, it proved itself in combat. An Italian swimmer towed a mine into Pola Harbor, on the coast of what is now Yugoslavia, across the Adriatic from Venice. There he planted the explosive on an Austro-Hungarian ship, the Viribus Unitus, and sank her.
In World War I, Italy was one of the Allies, along with the United States, France and Britain. But by the mid-1930s, the British navy was seen as a major threat to Benito Mussolini’s plan to create a new Roman Empire. When II Duce launched his attack on Ethiopia in the winter of 1934-35, the Ethiopians, with their spears and primitive rifles, put up little resistance. But the British Mediterranean fleet could, at any moment, cut the Italian supply lines to Africa.
Two submarine officers, Lts. Teseo Tesei and Elios Toschi, revived the idea of using combat swimmers. Their proposal was very similar to that rejected by Churchill two decades before. But their torpedo riders would wear breathing devices as they rode into enemy harbors with their eyes just above the level of the water. Once inside the harbor, they would dive, attach the warhead to a ship, and set the timer. In theory, they would then ride the propulsion unit of the torpedo back out to sea. Practically, they would be lucky to be able to surface and surrender without being shot. Tesei and Toschi contemplated a major surprise attack that would sink or disable the bulk of the British Mediterranean fleet.
The plan was abandoned, and the small group trained by Tesei and Toschi was disbanded, after the British and French made a secret deal that gave Mussolini a free hand in Ethiopia, effectively removing the Royal Navy as an obstacle to his ambitions. But as war became more imminent, the plan was revived again in 1939, and by early 1940, Tesei and Toschi were learning to ride a twenty-two-foot-long torpedo with a detachable warhead containing 660 pounds of explosive. It was capable of a speed of two and a half miles an hour, had a range of ten miles and could reach a depth of one hundred feet. It was an awkward beast to ride, and the Italian swimmers dubbed it maiale (the pig). The goal of the plan was the same as it had been half a decade before: to disable the British fleet that dominated the Mediterranean.
The months that followed Italy’s entry into World War II on the German side on 10 June 1940 were frustrating ones for the Italian swimmers. Early tests forced them to concede that a lengthy period of intense training was needed. When they were finally ready to go to war, each of their first five attempts—at Gibraltar, Malta and Alexandria—failed. In the process, both Tesei and Toschi were captured. Finally, on the sixth attempt in September 1941, three British ships were sunk while at anchor at Gibraltar.
This was just a prelude to what the Italian frogmen accomplished on the night of 18-19 December 1941. An Italian submarine surfaced a little more than a mile off the Alexandria lighthouse and launched three maiali. Moving cautiously in the darkness, six men climbed aboard their aquatic steeds, two on each torpedo. As they approached the entrance to the harbor, luck was with them. The submarine nets were swung aside to let three British destroyers enter. The frogmen followed so closely behind that they were battered by the wake of the ships and became separated, but they were safely inside the first line of defense.
The team leader, Lt. Luigi Durand de la Penne, and his copilot, Emile Bianchi, cruised slowly through the harbor toward their target, the Valiant, a thirty-two-thousand-ton battleship. As they approached the ship the men were forced to push their torpedo over a torpedo net. In the process, their craft sank about forty-five feet from the ship, and they became separated.
Groping in the mud at the bottom of the harbor, de la Penne found the torpedo, detached the warhead, and tugged it through the mud to a position beneath the keel of the ship. He quickly set the fuze and then surfaced, panting for breath. He found Bianchi clinging to a buoy, but both men were soon spotted and captured. When they refused to reveal the location of the explosive, they were locked in a cabin in the bowels of the ship—directly above the warhead.
When the blast came, de la Penne and Bianchi were badly shaken up but not seriously injured. And they found the door of the room that could have been their death cell hanging from its hinges. They hurried to an upper deck in time to witness two more powerful explosions in the crowded harbor. Their teammates had sunk another battleship, the Queen Elizabeth, and a tanker.
In those few moments, six men had sunk two battleships and a tanker, totalling some eighty thousand tons. They had completely changed the balance of naval power in the Mediterranean, leaving the British without a battleship in that area for the next year. Although the British tried to hide the disaster, the Axis navies soon learned what had happened but failed to capitalize on their advantage.
The Italian swimmers continued their operations until Italy signed an armistice agreement in August 1943. They never repeated the success of the Alexandria raid—partially because they had reduced the number of highly lucrative targets—but they are credited with sinking or damaging ships totalling 150,000 tons in three years.
Even though the two Italian officers responsible for developing this formidable weapon were captives, the British did not learn of their role and the navy brass did not fully grasp the fact that a handful of men, riding torpedolike craft that were barely seaworthy, were capable of wreaking havoc with their navy—until the disaster at Alexandria. Shortly after that attack, Churchill wrote in a letter, “One would have thought we should have been in the lead.”