US NAVY BEACH JUMPER UNITS
Beach Jumpers were US Navy special warfare units, which specialized in commando style operations, deception and misdirection to confuse the enemy. The Navy had active Beach Jumper units from 1943-1946 and 1951-1972. Their basic mission was “To assist and support the operating forces in the conduct of Tactical Cover and Deception in Naval Warfare”. To reach their goal, they learned to simulate very large amphibious landings with very few resources, of which crash boats became an essential part. Using specialized deception equipment, a few dozen Beach Jumpers could make the enemy believe they were a large amphibious landing force, when in fact the actual assault force would usually attack many miles away.
The initial announcement to naval personnel stated “The Navy is requesting volunteers for prolonged, hazardous, distant duty for a secret project”. The first group of 15 recruits reported to the Amphibious Training Base at Camp Bradford, Virginia in March 1943, and formed Beach Jumper Unit 1 (BJU-1). They were housed in tents on the perimeter of the base to try to keep them segregated from other units based there. Training continued at the base until December 1943, when it was moved to the isolated Advanced Amphibious Training Base at Ocracoke Island, North Carolina where they carried out full-scale exercises.
The volunteers were taught seamanship, boat-handling, pyrotechnics, demolition, ordnance, gunnery and meteorology, and were trained to be able to operate in any of the boat’s crew positions. Weapons training covered everything from the standard issue pistol up to the 40mm cannon. They learned to use smoke generators and how to use smoke screens. All together this package of deceptive skills was put together to simulate an amphibious assault.
Initially they were assigned just ten 63ft Aircraft Rescue Boats powered by Hall-Scott engines. It is unclear how the 16 model 168 Packard powered 63ft Aircraft Rescue Boats ordered in 1942 fit into this group but it seems obvious that they were intended for “special ops”. Each crew totaled seven, just one less than a standard crash boat crew but certainly with a specialized skill set.
Deception gear on the BJU craft consisted of a multi-component audio transmission system known as a “Heater” which took six men to carry. It consisted of two “Presto” disc wire-recorders – using glass discs similar to 78 rpm records on acetate bases. The amplifier was 5-phase with a 1000-watt horn speaker with generators for power installed in the boat to both record and emit pre-recorded sounds of amphibious landings. Sound effects were either recorded in the harbour area of ship and boat activities or on army training grounds of tank engines etc. Sound tests were carried out which showed that the acoustic deception was most effective at a distance of 2000 feet from the target. Later raids in the Mediterranean put the Beach Jumpers that close to the enemy shore batteries.
Electronic deception was achieved by using jammers i.e. transmitters which would drown out the normal radar echo. In simple terms – normally a target would appear as a vertical spike on the radar, but by generating random noise (jamming) on the radar frequency the real target would be lost in a multitude of false echoes known as “grass”. This became one of the Beach Jumpers main deception techniques. There were two basic types of jamming, Spot or Barrage but “Barrage” jamming was the general broad frequency jamming method. The transmitters were pre-tuned evenly to cover all the known enemy frequency bands thus blocking as many as possible. Operators were not needed for this method. By late 1944 the Beach Jumpers had several “Jammer Transmitters” to use.
The radar deception illusion was enhanced by another type of deceptive technique – radio countermeasures or communications deception, especially manipulative deception. This entailed the transmission, in the clear, of a scripted dummy voice or code traffic simulating actual assault force communications. Beach Jumper specialists used this to fool the Germans and the Japanese into believing that, rather than small boats operating offshore, they were a large amphibious force preparing to launch assault troops in landing craft; that they were the real attacking force. Operations were executed to a pre-determined script, which helped to make the deception quite realistic. False signals, radar reflections, smoke screens, and sound effects were timed so that they gave the impression the small BJU force was a much larger enemy assault force.
When deployed on missions, Beach Jumper Units were frequently deployed with PT boats and British crash boats. There is documentation indicating that USAAF crash boats participated in these composite units in the Mediterranean. OSS operators later moved to the C.B.I. theater where they formed a composite group with the AAF 7th ERBS. Their operations are covered further into this page and there are several photos in the World War II album in the Photos & Missions.
TYPICAL MODIFICATIONS FOR BJU OPERATIONS
The standard Model 314 craft and the model 152 variant, were stripped of unnecessary equipment such as the tripod mast, 9ft dinghy, handrails etc. and then modified for Beach Jumper operations. The boat would carry the RCM 3.5 inch rockets (two launchers, one each starboard & portside) on the fore deck, and the standard twin .50 caliber machine guns in tubs. On the former dispensary roof, the speaker was mounted on a turntable for the “Sound” equipment, with smoke pots on the main deck, just forward of the dispensary cabin and the cylindrical smoke gas generator at the stern. A small mast at the forward end of the cockpit replaced the larger tripod mast, probably for a communications aerial.
The Model 293 Sub-chaser or flush-deck variant was stripped of unnecessary equipment much as those above and then rigged, as many boats were, with lattice mast and SO-1 radar. They were also fitted with the RCM 3.5 inch rockets (two launchers, one each starboard & portside) on the fore deck and the .50 caliber machine guns in tubs, as well as a single 20mm cannon amidships. They were also fitted with the speaker for the sound equipment aft, and an assortment of other smoke generator related stores. The amplifier equipment, normally located in the well deck in other versions, was on the main deck aft of the 20mm canon. Some also carried additional machine gun mounts aft.
OPERATION HUSKY – INVASION OF SICILY
As a pre-requisite for the operation Allied Forces seized the small island of Pantelleria. In preparation for the invasion, BJU crews prepared and tested their equipment and loaded it aboard the ARBs. Speakers for the “Heaters” were swivel mounted on the sterns of the boats so that they could be turned towards the beach no matter what direction the boat was travelling. The electric generators were set up with the wire recorders in the cockpit. To simulate 20mm gunfire, roman candles were mounted on pieces of 2 x 4 lumber nailed in an “X” shape, with jury rigged pyrotechnics – these were lit and floated off into the sea from the ARBs.
At 10:00PM on July 11, 1943 the British boat ARB-39 positioned 1000 yards ahead of British 63 ft boats 48,49 and 69, was laying a thick smoke-screen as PT-213 closed the beach firing all its weapons, and then circled back out to sea behind the smoke screen. The sound boats ran up and down the coastline playing their pre-recorded “invasion” sound effect recordings and sending out phoney inter-ship messages, the decoys creating the effect of an armada of large vessels standing offshore. ARB-39 was laying more smoke pots when suddenly they were caught in the beam of a searchlight from Cape San Marco – so they moved away but later returned at high speed to fire rockets at the beach.
The deception had worked as the coastal defenses had opened up on the imaginary fleet. On their return, orders were received to continue the deception the following day, but this time combining the theatrical deception with an electronic package. The next day the BJU crews intermittently jammed the known radar frequencies, while others sent out scripted radio signals between the landing craft of the imaginary invasion force.
The success of the mission was undeniable. German news reported on July 13th that their forces had repelled a landing attempt between Sciacca and Mazzara de Vallo. The few weeks after this operation were spent conducting coastal patrols before returning to Bizerte. After WW II, captured documents and reports from prisoners proved that the date and scale of the landings had been a big surprise, and that an entire German reserve division had been held in place because of the deception tactics.
Beach Jumper Units, often combining U.S, and British boats, were active in the Mediterranean during WW II, including OPERATION AVALANCHE, in the Gulf of Gaeta where they captured 90 German soldiers at a radar installation. They also operated out of the island of Vis, off the coast of Yugoslavia, from which they captured the island of Solta and its German garrison. They also participated in OPERATION BRASSARD, the landing on Elba.
Prior to the Normandy invasion it was determined that we would not have the resources available to simultaneously invade southern France. Beach Jumpers were deployed in OPERATION ANVIL-DRAGOON to convince the Germans that we were planning to invade Southern France at the same time as the Normandy invasion. After the successful Normandy landing the Beach Jumpers were assigned to OPERATION BIGOT-ANVIL with the task of convincing the Germans that the Allies would leap-frog up the coast of Italy to Genoa, rather than landing in Southern France. This caused the Germans to withdraw troops from Southern France and shift them toward Genoa, thinning out the defenses in the Cannes -Toulon area of Southern France, making the inva
O.S.S. OPERATIONS AROUND ITALY
AAF rescue boats P-568 and P-584 were assigned to the OSS with OSS crews. It is unclear as to whether these men were actually AAF crew assigned to the OSS, or totally independent operators. However, the second skipper of the AAF crash boat P-568 was a LTjg T. A. Morde, and Lt Ward Ellen USNR, was the skipper of P-584; both men held Navy ranks. The boats were based in Bari, Italy and first operated in the Adriatic. Later they were moved to the waters off the west coast of Italy.
The OSS worked with the 63’ crash boats out of La Maddalena and Bastia, off the west coast of Italy and southeast of France. The boats worked with several groups of OSS operators but were not assigned to the OSS. By late 1944, with activities in the area winding down, the P568 and P-584 and their crews were slated to be moved to the Southeast Asia Command (SEAC). However, there was an explosion aboard P-584 on January 13, 1945 and she was transferred back to the AAF. Because of shipping delays P-568 was returned to the AAF as well.
O.S.S. & 7th ERBS IN THE C.B.I.
I have not been very successful in collecting data about the 7th ERBS, stationed in the C.B.I. (China, Burma, India) theater of operations. I have come to understand why it is known as the “Forgotten War”. For the U.S. the primary war was in Europe, the secondary war was in the Pacific, and finally our efforts in the CBI were primarity to tie-up Japanese troops in the CBI, especially China. However, just recently some information has come to me from two authors, Phil Garn & Al Ross preparing an article on OSS operations, including the C.B.I. Rescue operations did not start in the C.B.I. until probably late 1943 as the C.B.I. theater was primarily a British area of responsibility.
By late 1944 Beach Jumper and OSS operations in the Mediterranean were winding down. In both the Med and the C.B.I. operations were conducted by the British, U.S. Navy and the OSS (Office of Strategic Services) which was the predecessor of the CIA. The new maritime focus of the OSS was the C.B.I, and the 7th ERBS, although both had been in the C.B.I. since at least late 1943. From what I have found, the 7th ERBS and the O.S.S. effectively formed an unofficial composite unit. They were so intertwined that it has been difficult to determine who was 7th ERBS and who was O.S.S.. The O.S.S. pulled men from the Navy, Army, Coast Guard and even a few Marines. Generally, the “Coasties” were O.S.S. operational swimmers a.k.a. frogmen, several of whom were legendary prewar Santa Monica Beach, LA City and LA County lifeguards.
Crash boats conducted their normal functions of rescuing and recovering downed air crews, whether from Jap fighters defending Japanese occupied territory in Burma or from mechanical issues that developed while flying combat missions or supplies to the Chinese. The 7th ERBS was also very active in inserting and recovery of spies, operational swimmers (predecessors to UDT & SEAL teams) and guerrilla units (Merrill’s Marauders) along the Burma Coast.
Walter Mess and the O.S.S.
In 1943 Lieutenant Walter Mess, an Army Quartermaster Corps officer and pre-war intelligence operative was recruited by William Donovan, considered the father of the modern C.I.A. and an advisor and friend to President Franklin D. Roosevelt. Mess attended rescue boat training along with future crash boat crew members in the Gulf Mexico, the Florida Keys and Cuba. Upon completion of training and other maritime operations, in 1944 Mess would oversee the modification and loading of P-564 & P-563 on a liberty ship that transported the crash boats as deck cargo across the South Pacific to Ceylon via Australia & Calcutta.
Walter Mess would become the senior Flotilla officer in the O.S.S. MU (Maritime Unit) in the CBI or SEAC and work with O.S.S. Operational Groups, Secret Intelligence as well as Operational Swimmer (OS) teams, crossing the Bay of Bengal on many missions. The O.S.S. men also used submarines and PBYs on these missions, thus utilizing sea, air and land resources, all the resources of modern navy special warfare. Mess’s O.S.S. air sea rescue boat P-564 numbered over 36 missions with other boats of the unit across the Bay of Bengal for official O.S.S. MU operations ferrying Operational Groups and Operational Swimmer teams; They also returned over 220 downed pilots & crewmen from pickup points on Burma coast.
Dr. Christian Lambertsen was a Captain in the US Army/O.S.S. and the inventor of the first American combat SCUBA re-breather, the Lambertsen Amphibious Respiratory Unit (LARU) and reported to Lt. Cdr. D.A. Lee, USNR, Commanding Officer of the Maritime Unit, CBI Theater Under SEAC Command, as did Walter Mess. In fact Lambertson coined the acronym SCUBA, also frogman, swim pairs and naked warriors came into the world’s lexicon through the O.S.S.. The LARU was superior to both the Axis units and the British copies of the Axis units. In January 1945, P-564 became the primary boat for Dr Lambertsen and swimmers for combat evaluation of systems resulting in swimmers becoming an integral part of O.S.S. OG (operational groups) and SI (secret intelligence) missions. During the period Mess and his crew undertook sensitive missions for joint US and British CBI Theater commanders, sinking Japanese merchantmen (These would be the first American operations using combat swimmers for limpetter attacks as well as the first combat applications of the Sleeping Beauties swimmer delivery vehicles.)
In the Spring of 1945, members of the O.S.S. MU, along with British units executed a number of raids on the retreating Japanese in Burma. One of these raids was on a Japanese occupied oil refinery at Yenangyoung in June/July 1945. The raiding party, delivered to the launch point by rescue boat, consisted primarily of Operational Swimmers and Commonwealth commandos. Once near the refinery, the raiders used two Sleeping Beauties (motorized submersible canoes) piloted by the OS’s with LARUs to recon the site about an hour before insertion. The raiders used Sleeping Beauties armed with machineguns to hold the flanks, while the OS teams infiltrated on paddleboards and Waterlilies (motorized air mattresses) to get their demolitions to shore. After destroying the refinery, they were able to safely exfil. This was another successful combat operation in American history using the revolutionary Sleeping Beauty wet submersibles. This operation would foreshadow future Special Operation by Americans and their allies.
P-564, along with P-563 and P-565, all Herreshoff built 85 footers, were highly modified for their C.B.I. service. Phil Garn, who has been very helpful in putting together information about O.S.S. operations in the C.B.I. learned in early 2021 that Walter Mess and other O.S.S. people set up a finance system where the standard services were reimbursed for equipment so it became O.S.S. property and the parent service (Navy or Army) could not capriciously get it back.
The research into modifications was prompted by an email from Frank Hollinger, son of US Army Lt Sherard F Hollinger, who served as chief engineer on P-563. He was concerned by my statement elsewhere on the website that "While PT-boats had an option to muffle their engines by routing the exhaust underwater, no such option was on either the 63' or 85' rescue boats, so with straight pipes, stealth operations were never an option"
Frank pointed out, “that according to published interviews with 1st Lt Walter Mess (skipper of sister boat P564) and recollections of what my father told me, the two boats (and later P565 which was only used on training missions in Ceylon) were equipped with "muffled / underwater exhaust" systems. I realize that when the boats came out of engine installation at Herreshoff this was not the case. My father had told me that when they first went over, they had to rely on Trincomalee Royal Navy dockyard which was the Brits head naval station for the East Indies. From written accounts, at least some of the British "launches" were "muffled", so it's logical to assume "modifications" could be accomplished at their yard.” Since the British did not have 85s, their muffled boats included Motor Launches, Motor Gun Boats and Motor Torpedo Boats.
According to research done by Phil Garn, the 85s were heavily modified after leaving Herreshoff’s yard where they were built. During interviews, Walter Mess said they were heavily modified i.e. souped-up and silenced. Phil saw reports of top speeds quoted in 50 kt range. There was a lot of insulation and likely some ducting of exhausts and silencers (mufflers). In one of the deck logs the silencers were replaced in theater. It is unclear at this point where the initial modifications were done, whether in the U.S. or in the C.B.I. but the 50 kt. figure matches the comments of Lt. Sherard Hollinger to his son Frank. That is a tremendous increase in performance.
I am still hoping to learn the details of the muffling system. The muffling system used on the PT boats may have been adapted, but it would have entailed significant modifications to the 85 footer’s system. The addition of insulation might have been to control the heat off of the exhaust pipes or it might suggest a muffler in the engine room. At this point any description of the exhaust mods is pure speculation. Unless very surprising new information is found, it is extremely unlikely that the muffler system was in use at high speed.
The Kanmon Tunnel Caper - OSS
John D. Mitchell was based in St. Petersburg, FL assigned to a special unit and wrote an article that is the basis of this article. - Our unit was comprised of AAF Crash Boats (85s) with AAF, Coast Guard and Navy personnel. We had a compliment of six 85s (total was to be 12, plus an Air Arm of 6 B-17s). Our boats were radio controlled from the B-17s and we were equipped with a TV camera on the bow. The B-17s were equipped with two G-stick (sic) controllers in the bomb bay/ radio room area. We would take practice runs in Tampa Bay and the skipper would stand by the wheel while the B-17 would guide us, then release us. MacDill had a 35’ J-boat for initial training of B-17 operators.
The mission, the original project was named CAMPBELL, was an OSS project to develop high speed boats that could be packed with explosives and be remotely controlled from B-17 bombers and targeted against enemy-held harbors and shipping. According to a report from September 1944, “the mission of CAMPBELL is the sabotage of enemy targets inaccessible to other methods of attack. These targets, protected by inner and outer harbor defenses, are best approachable by operational ruse and deception.” The targets were to include ships, piers and bridges.
Originally the plan called for fast, low silhouette boats of approximately 35 ft. that would carry a television camera for navigation from a nearby ship or airplane. Television was a new technology that was being developed simultaneously with this project. The TV camera was to be steadied on the moving boats by a standard Army Ordnance tank-gun stabilizer. What appears to be the same project is, in different documents, referred to as project JAVAMAN. I have not been able to determine if they were actually the same project, different projects, or different elements of the same project.
As the project progressed, as with most things military, the size of the boats grew bigger and more expensive. From Hacker-Craft models A-2 and A-3, of approximately 36 ft., the plans later grew to include the 85ft. rescue boat. Each of the three boats could be disguised as locally used water craft. During development the explosive payload grew from 5,000 lbs. of TORPEX explosive for the Hacker-Crafts to 50,000 lbs. for the rescue boats.
Conceived by the OSS in March of 1944, perhaps earlier, the CAMPBELL project’s first testing took place on 5-6 April at the Army Mine Command Headquarters, Little Creek VA. In August of 1944 a Hacker-Craft was successfully tested in the Gulf of Mexico, off Pensacola against a 5,000-ton, 300 ft. freighter, the S.S. San Pablo, sinking her in two minutes.
The conversion and preparation of the 85s was critical. During September of 1944 tests were conducted with the P-654, an 85’ rescue boat, and due to the costs in developing the control mechanism, it was recommended that no other type of boat be considered.
By mid-March 1945, 152 people, including John Mitchell, had been assigned to the project’s secret base at St. Petersburg, FL. The plan was to approach to within 20 miles (1/2 hour from the target), bring her up to full speed and jump off, although distances as far away as 85 miles showed promise with the B-17s flying at 20,000 ft. The B-17 would take over and direct her to the tunnel entrance area and cut the engines, let out a bow and stern anchor, blow smaller bow and stern charges letting her sink on to the tunnel, then blow the main charge, caving in the tunnel.
In May of 1945, the war in Europe ended. In Japan, the twin tubes of the Kanmon tunnel were vital transportation links between Japan’s southern island of Kyushu and its main island of Honshu. Intelligence was reporting that large quantities of raw materials such as coal and iron ore continued to be shipped from China and Korea as well as from Kyushu to the main island of Honshu. There weapons were manufactured, many of which were returned to Kyushu, in a last-ditch effort to defend the homeland. At the time it was estimated that 50% of the total tonnage of material passing between these islands flowed through the Kanmon Tunnel. Thirty-five percent of the total supply of Japanese steel and coal coming from Kyushu, Korea and China, flowed northward through the tunnel to Honshu. Flooding the tunnel would force the shipping of materials and goods by boat, which would be easy targets for our fighter-bombers.
The tide of the war in the Pacific had long since turned against Japan. She was taking a nightly beating from American B-29s and plans were beginning to take shape for the final assault on the home islands of Japan, known as Operation Olympic. The BAGPIPE Project was the very special project for 85 ft. rescue boats, although in some documents it was still to referred to as JAVAMAN. Perhaps the OSS was trying to confuse the Japanese as successfully as they confused me. BAGPIPE, was to precede the invasion of Japan by blowing up the Kanmon Tunnel between the island of Kyushu and the main island of Honshu. The resulting cave-in would disrupt north and south rail traffic passing beneath the Straits of Shimonoseki, the narrow seaway separating the two islands. In spite of references to the AAF’s “pinpoint bombing” we really were not very good at hitting bridges and could not expect better results trying to hit a submerged tunnel, boats seemed to be a possible solution.
The loading of the 50,000 lbs. of standard Navy demolition units (packages of TORPEX, complete with electrically detonated fuse, weighing 55lbs. each) on the rescue boats was critical. The packages would be tightly packed together to eliminate any air pockets, in a metal cage, in the large compartment that replaced the galley and officer’s quarters. The mass of explosives would be braced and secured in place to prevent shifting in high seas and to enable detonation as a single charge. It was extremely important that they blow as a single charge for greatest effect. There was some concern that 50,000 lbs. of TORPEX might not be enough to get the job done as late as 14 July 1945 since the tunnel was perhaps 25 ft. below the floor of the strait and not just two tubes sitting on the strait’s floor. Various methods of detonation were considered and, in the end, three different types of detonators (impact, timed and magnetic) were to be used.
To scuttle the boats at just the right moment and position above the tunnels, a network of Primacord was placed along the bulkheads from stem to stern. Primacord is a plastic explosive formed in rope-like sections and simply pressed together, end to end, forming a single explosive along any line chosen. It was critical that the cage land either between the two tubes or on at least one tube and much consideration was given to tides, current and drift of the sinking explosives. There was concern that rescue boats were difficult to scuttle so enough Primacord was to be used to completely shatter the hull. Large concentrations should be wrapped around the hull just fore and aft of the main charge to completely sever the bow and stern from the charge. Basically, they were going to blow the crew bunk room and the engine room away from what had been the galley and officers’ quarters, as well as shatter the hull enough for the explosive charge and two heavy anchors to drop quickly to the bottom. The anchors would be secured to the explosive cage with 60 feet of chain. There was some concern about the gas tanks in the boat blowing-up and setting off the charges prematurely.
If one of the 12 boats John Mitchell referred to early in his article made it to the target and blew as planned, the mission would be accomplished. The crews would be picked-up by submarines or other crash boats. As finally defined, the operation was to launch from Okinawa involving only four explosive boats and two 85-ft. escort boats to pick-up the crew that were to jump off the explosive boats. The explosive boats were also going to be booby trapped and armed as the crew jumped off each boat. If anyone should board the boat from any position it would detonate the main explosive charge. With 25 tons of explosive going off, there would be no secrets lost to the Japanese.
Of course, with the dropping of the atomic bombs and Japan’s surrender, the plan was never executed. The book, “The Army Air Forces In WW-II” indicates that the plan was abandoned before the dropping of “The Bomb” but an official dispatch from the OSS labelled “Top Secret” cancels the project on 18 August 1945, almost two weeks after the first bomb and three days after VJ Day. Total cost of the projects was $1,554,200 according to official records. Leroy W. Gardner, a volunteer (retired) at the National Archives in College Park, MD contributed substantial information, once “Top Secret”, for this article.