The family of light amphibians for supplying US cargo includes three types of light amphibians capable of moving by land and sea LARC V, LARC XV and LARC LX capable of carrying payloads of 5, 15 and 60 tons, respectively. The light amphibious supply vehicle (LARC V, Lighter, Amphibious, Resupply, Cargo) is a small amphibious vehicle designed mainly for the transport of standard containers (CONEXE) and other cargo placed on pallets. The LARC XV amphibious supply vessel is slightly larger than the LARC V, but is used for the same purposes as the LARC V. The largest of the three LARC LXs was used extensively in Vietnam. She was able to carry two 20 'containers or one 40' container. LARC-5 and LARC-15 transported up to three quarters of all necessary cargo, LARC-60 the remaining quarter. By the mid-1980s, most of these amphibians were put into reserve and withdrawn from service. Although they are no longer in production, three sizes of amphibians (LARC-5, LARC-15 and LARC 60) are still in service in both the army and the "capitalist economy".
Brigadier General Frank Schaffer Besson began World War II with the rank of engineer lieutenant. Among other things, he organized the railway transportation of equipment supplied to the USSR under Lend-Lease. For his remarkable abilities by the end of the war, he rose to the rank of brigadier general. Upon returning to the United States in 1948, he served as Deputy Chief of Army Transportation for nearly five years. Besson was promoted to Major General in 1950 and took over command of the Army Transport School at Fort Estis in 1953. In this position, he initiated numerous projects related to improving the efficiency and effectiveness of the army's transport system. In particular, it has introduced the active use of standard containers, craneless loading and unloading (RO-RO) vessels, and improved the ability to unload cargo from transport vessels on the coast. In addition, it is largely thanks to him that the transport aviation and even the US expressway network developed. Noteworthy projects include cable cars connecting with cables a special barge with a 25-meter tower to the shore on the principle of ski lifts, as well as prefabricated demountable berths, which are still in use. However, he paid the most close attention to the army's ability to deploy its forces directly from ships to an unprepared shore using amphibians. Thanks to him, the LARC (Light Amphibians for Cargo Supply) was created. Major General Besson commanded the army transport from 1958 to 1962 and was instrumental in the purchase of the BARC (Barge, amphibious, resupply, cargo, amphibious transport-cargo barge), named "Besson's Ark". Frank Besson became the first four-star general in the history of the U. S. Army Transport Corps. Now the large landing ship USAV GEN Frank S. Besson, Jr. bears the name of Besson. (LSV-1) Logistics Support Vessel.
LARC-60 / LARC-LX / BARC
The BARC amphibious transport and cargo barge, later called LARC LX (light amphibious for supplying cargo, the Roman numeral LX also means carrying capacity) is designed to carry up to 60 tons of cargo and was used to transport wheeled and tracked vehicles, including engineering equipment for preparing a bridgehead landing. This was the only amphibious at the disposal of the army, capable of landing on the coast during the surf. BARC was loaded onto cargo ships with heavy-duty cranes for transportation overseas to the deployment area. BARC could operate on shaky soils with a gross weight of 145 tons (with a payload of 55 tons). This was enough to transport 40-foot containers, which could then be unloaded from the LARC using a crane, narrow container trucks, or on rollers similar to those used when unloading transport aircraft.
The first BARC trials were conducted at Fort Lawton, Washington in 1952. The four experimental BARCs were built by LeTourneau Inc, which specialized in manufacturing much more equipment than BARCs, including offshore oil rigs. BARC was designed to transport one 60-ton tank or infantry company with full uniforms (120 people) from a ship to an unprepared shore or back. In emergency cases, it could carry up to 100 tons of cargo (limited overload, limited overload) or up to 200 people (according to the memoirs of Vietnam War veterans, they managed to load up to 130 tons). The dimensions of this car are impressive, length 19.2, width 8.1 and height 5.9 meters. The empty weight of the BARC was 97.5 tons, the diameter of each of the four wheels was 3.2 meters, which provided a ground clearance of 0.9 meters. To load equipment and personnel on their own, the front of the amphibian could be lowered, and was also equipped with a folding ramp. A 12.7-ton winch located in the rear of the cargo compartment allowed one 12-meter (20-foot) or two 6-meter (20-foot) containers to be independently dragged into the cargo compartment along roller guides. BARC itself could be transported on semi-submersible ships, in the dock chamber of landing craft.
BARC is powered by four GMC 8-cylinder two-stroke diesel engines with a volume of seven liters and 165 horsepower each (at 2100 rpm). On land, each of these engines powered one wheel through a three-speed automatic transmission. On the water, two engines from each side were driven by one double propeller with a diameter of 1.2 meters. The maximum speed was 32 kilometers per hour on land and seven and a half knots on the water. The driver was located in a small cockpit on the left side in the rear of the vehicle. In total, the power plant included 12 gearboxes, 2 air compressors, 8 hydraulic pumps and 2 generators. All engine control systems were pneumatic and steering was hydraulic. Air compressors were a big problem. They were located below in the engine room next to the propeller gearbox. The mechanics often had to tinker with these compressors. The entire system hung on air pressure, and after both air compressors failed, serious trouble arose.
On the first versions of the BARC with tail numbers from 6th to 20th, the cockpits (wheelhouses) were located in the bow of the amphibian. In order to improve handling on the water on the next versions, the cabin was moved to the stern. However, when driving an amphibian on land, the driver, located in the cockpit in the stern, had practically no vision in front of the car, and therefore he had to rely only on the gestures of the signalman located in the bow. Everything on the BARC can be controlled from the cockpit, with the exception of the front ramp, which was controlled from the bow of the amphibious.
Each of the wheels with a diameter of 3200 mm could be independently controlled. BARC could skid ("crab") to the right or left by 30 degrees, could be controlled either by the front or rear pair of wheels, or all at the same time. But even despite this, the turning radius of this amphibian was 23 meters, which is not at all bad for such a large car. The problem with the wheels was sticking to the hub. This is a common problem with amphibians, but since the wheels on the BARC were huge, there were corresponding problems with them. To detach the wheel from the hub, several hydraulic jacks were used at the same time, as well as a cable tied to a fuel truck, and only in this way it was more or less normal to pull off the wheel. It is noteworthy that the BARC had a rigid suspension, in other words, it simply was not there. The wheels were rigidly fixed to the body. The damping function was successfully performed by low pressure and large diameter tires.
The LARC first took part in the fighting in Vietnam, where they were sent to support the 101st Airborne Division in 1967, and then the 1st Armored Cavalry Division in 1968. In July 1968, in Wunder Beach, BARCs were working twenty-four hours a day. The equipment of the 5th Mechanized Division: jeeps, trucks, M113 armored personnel carriers and M-60 tanks arrived from America aboard large ships called Seatrain. The ships dropped anchors close to the coast, BARC moored at the sides, where they were loaded on an M-60 tank or two M113 armored personnel carriers, after which BARC promptly delivered them to the shore, where the equipment went to the coast of Vietnam through the open ramps of BARC.
BARC maintenance proved to be very simple. It was only necessary to change the fuel, oil and air filters, and then the barge worked flawlessly. However, three BARCs were lost in Vietnam, all due to mechanical problems. When they got stuck on the beach in the sand, there was no way they could be pulled out. The soldiers tried everything, including bulldozers and helicopter-cranes, but it was already impossible to pull out the heavy BARC that had sat in the sand.
When deployed in Vietnam, when transporting cargo from Vung Ro to Tui Hoa, amphibians traveled about ten miles, and they always did this in pairs. For those designed for transporting cargo from ship to shore, it was a long voyage and, just in case, the crews always took with them a 15-meter air hose. Nevertheless, the BARC was the only amphibian capable of operating even in waves of 4 points and landing even during the surf. The overall survivability of the amphibian was also satisfactory, it was able to move even after losing two engines, and afloat even losing three engines out of four.
High-ranking military officials have stated at least twice that the LARC-LX has certain advantages over the LACV-30 hovercraft and that it should be considered as an alternative to the new amphibious. In 1979, the army already had 36 LARC-LX amphibians at its disposal. In its technical report number 225, the army reported that despite its low speed, the LARC-LX does not have serious flaws and is perhaps the most versatile light amphibious. Fuel consumption with its 60-tonne carrying capacity was significantly lower than that of the 30-ton LACV-30. At rated load, the LARC-LX had 144 liters of diesel fuel per hour compared to 984 liters of jet fuel per hour for the LACV-30. The LARC-LX could carry two army vans or one 40-foot commercial container, and could also carry a tank or any other cargo weighing up to 100 tons in a limited reloading mode, which the LACV-30 could not do. The LARC-LX was unaffected by slight inclines and rough terrain causing steering and maneuverability problems for the LACV-30. In addition, BARC was able to climb a gradient of 60%. The amphibious LARC-LX could be controlled by an ordinary soldier, which cannot be said about the LACV-30 hovercraft, where crew members and mechanics were specially selected from the "especially gifted" ones. "The complexity and high cost of the LACV-30 suggests that some systems must be operated by 'gifted' and highly trained combatants." In addition, the four engines in the LARC-LX provide greater survivability compared to the two engines in the LACV-30. Finally, the initial cost and maintenance cost of these amphibians was very different not in favor of hovercraft. The report also criticized the dust storms raised by the LACV-30 when entering the military base.
BARCs were under construction at Treadwell Construction Co Midland, Pennsylvania, Great lakes Engineering works in River Road, Michigan and Transval Electronic Corporation. In total, about 60 of them were built. The name BARC was changed to LARC in 1960. Fort Storey became the LARC-60 maintenance site. In the 1950s, this base was first used as a maintenance site for BARC barges, which ended in 1964. In 1982, the LARC-60 service base was modernized, a huge concrete platform was built to service and wash BARC. Today BARC can be found in museums, in particular in the General George Marshall Museum in Liberty Park Overloon in the Netherlands or in army dumps. Amphibians on the move are also put up for sale, such a device can be purchased for only $ 65,000.
The performance characteristics of LARC-60 / LARC-LX / BARC
Crew: 2
Weight: 100 tons
Body material: welded steel
Power plant: 4 diesel engines GM 6-71 with a capacity of 265 hp each
Fuel capacity: 2x 1135 liters
Cruising range: 240 km
Cruising range: 121 km
Length: 19.2 m
Width: 8.1 m
Height: 5.9 m
Wheelbase: 8.7 m
Ground clearance: 0.9 m
Power supply: 24 V
Travel speed (on water): empty - 12.1 km / h; 60 tons - 11 km / h; 100 tons - 10.5 km / h
Speed (on land): empty - 24.5 km / h; 60 tons - 23 km / h; 100 tons - 20.52 km / h; in reverse: 60 tons - 4.5 km / h
Turning radius: 23 m
Gradient overcome: 60%
Operating temperature range: -30 ° C to + 50 ° C
LARC-XV / LARC-15
The 15-ton light amphibian for supplying cargo LARC-15 (or LARC-XV where the Roman numeral XV also means carrying capacity) was introduced in 1960. Just like the LARC-LX, the amphibian is designed to transport cargo from ships to an unprepared shore and further to its destination by land. It is capable of carrying 13.5 tons of cargo at wave heights of up to 3 meters. Typical cargo may include a 155mm Ml14 towed howitzer. At the same time, the second LARC-15 usually carries the crew of a 2.5-ton tractor (6x6) howitzers and ammunition. The amphibious LARC-15 (like the smaller model LARC-V about which will be described later) was designed by the Ingersoll Kalamazoo division of Borg-Warner Corporation, and production was established at the Freuhauf Corporation factories. The main difference between the LARC-5 and the LARC-15 is the location of the engine compartment and controls aft of the LARC-15. This is done to enable the placement of a hydraulically operated bow ramp for loading and unloading tracked and wheeled vehicles.
Tests of the LARC-15 took place at Fort Storey from 1959 to 1967, as a result of which it was highly appreciated and was approved for mass production. An important indicator was a high degree of unification in many units and assemblies with LARC-V, which greatly facilitated logistics, repairs and somewhat reduced the cost of both machines.
The LARC-15 is powered by two 270 horsepower Cummins diesel engines each. Both engines with all auxiliary systems are located under a fully enclosed cab, which can be removed entirely if required. The engines are connected by cardan drives through torque converters to reverse gearboxes used to change the direction of travel (forward or backward) on land and water. The two-stage differential transfer case is equipped with a power take-off for one 4-blade propeller with a diameter of 914 mm, located in a guide nozzle in a recess in the aft part of the hull. The propeller thrust is 34.3 kN. Torque to the propeller is supplied from both engines through the transfer case and power take-off. Through the transfer case, the torque is directed to the final drives with cross-axle differentials and brakes from which, by means of cardan gears, to the bevel final drives of each wheel and then to the axle axles of the wheels. In order to reduce fuel consumption, front-wheel drive can be disabled.
The amphibian is equipped with two independent hydraulic systems. The main system serves power control mechanisms, bilge pump drives and bow ramp power cylinders. The auxiliary system serves all other servomechanisms of the amphibian, including the mechanisms of the braking system. For pumping out the seawater in the bottom part of the hull, there are three water-pumping pumps with hydraulic drives.
In order to reduce weight, the amphibian hull was made of aluminum alloy sheets. It has four wheel arches, a lowered nose with a 2.75 meter wide ramp lowered by means of a hydraulic drive, which is used for loading and unloading wheeled and tracked vehicles and other goods under their own power.
Like the LARC-60, this amphibian does not have a soft suspension and low pressure tubeless tires measuring 24.00x29 act as shock absorbers when driving on land. And just like in LARC-60, both pairs of wheels can be steered independently, either only the front wheels can be turned, or all four wheels can be turned in the opposite direction, or all wheels can be turned in the same direction and at equal angles for skidding or the so-called "crab" …
The closed control cabin is located in the stern of the amphibian. Movement on land is carried out stern forward. For this purpose, the adjustable seat, steering wheel and brake lever are located in a special way. When the amphibian moves through the water, a second seat is used with the control levers facing the nose of the car. In this regard, the instrument panels provide reading of their readings from any side. If necessary, control of the amphibian on the water can be carried out while standing. In this case, a special hemispherical lamp made of organic glass is mounted above the driver's workplace.
The amphibian is controlled on the water by simultaneously turning the wheels and a three-blade water rudder located behind the propeller. The sides of the platform are equipped with removable reinforced bulwarks made of rubberized fabric to protect the cargo platform from splashing through the low freeboards. For loading and unloading cargo from the sides using a forklift truck, the bulwarks are dismantled.
Due to the use of structural parts made of aluminum alloys, the car turned out to be too expensive and only half the price of the giant LARC LX. The cost of the LARC-XV was 165 thousand dollars in June 1968 prices. LARC XV did not become a mass amphibian, as a result, less than 100 units were produced. In addition to the US Army, the LARC-XV was in service with the Bundeswehr.
The performance characteristics of the LARC-15
Crew: 2 people
Total weight: 34.1 ton
Carrying capacity: 13.6 tons or 53 people
Length with lip raised: 13.7 m
Internal ramp width: 2.7 m
Length with ramp down: 15.8 m
Width: 4.47 m
Height: 4.67 m
Freeboard: 0.38 m
Awning height: 4.55 m
Frame height: 4.2 m
Powerplant: Two 270 horsepower Cummins diesel engines each
Body material: aluminum
Fuel capacity: 1360 liters
Cruising in store: 482 km
Navigation range: 160 km
Coolant volume: 123 liters per engine
Maximum speed on land: 48 km / h
Maximum speed on water: 15.3 km / h
Economy speed: 11-14 km / h
Maximum permissible wave height: 3.5 m
Gradient overcome @ 1.6km / h: 40%
Average draft in water: 1.5 m
Turning circle on water: 23.5 m
Turning radius on land: outer 11.1 m, inner 8 m
Ground clearance under the propeller: 0.4 m
Wheelbase: 6.25 m
Cargo platform dimensions: 7.28x3.6x0.98 m
Operating temperature range: -32 ° C to + 52 ° C
Power supply: 12 V
Number of batteries: 4
LARC-V / LARC-5
The 5-ton light amphibious vehicle for supplying cargo LARC-5 (or LARC-V where the Roman numeral V also means carrying capacity) is an army amphibious vehicle originally used in the 1960s to transport non-self-propelled cargo from ships to the unprepared shore and further to the deployment sites … In addition, the goals and objectives of LARC V include: search and rescue operations in the coastal zone, pulling cables for towing floating and stranded watercraft, removing obstacles to navigation, installing navigation aids, evacuation, transporting people (troops, prisoners of war,refugees and casualties), coastal firefighting, diving platform use, hydrographic assistance, flood relief and other emergency situations.
The head of Transportation Corps, Paul Yount, was tasked in 1956 to build a boat that could also move on land. The prototype was built in July 1959 and the final design was approved in 1963. Serial production was carried out at Consolidated Diesel Electric Corporation. Between 1962 and 1968, about 950 cars were produced. In addition to the US Army, LARC-5s were in service in Australia, Argentina, Portugal and the Philippines. They took part in the invasion of the Falkland Islands in 1982, but not directly in the fighting.
LARC V is a single-rotor, four-wheel, self-propelled diesel amphibious vehicle. The body is made of aluminum alloy and is not equipped with tempering sides, but only lateral tensioned rubberized fabric. The driver's cab, open at the rear, is located in the bow, and the power plant is in the stern. The cab is equipped with seats for the driver and two passengers and is equipped with a magnetic compass, radio station, heater, windshield defroster and portable fire extinguisher. If necessary, the rear of the cab can be covered with a waterproof cloth. The transmission components are located under the bottom, which is why the amphibian turned out to be quite high and does not allow vehicles to be loaded and unloaded on their own (this is possible only from a special apron). The engine compartment is completely closed and equipped with a fire extinguishing system.
The first samples of amphibians were equipped with a gasoline engine, later they were replaced by diesel ones. The amphibian is powered by a 4-stroke, eight-cylinder Cummins V-903C diesel engine with a capacity of 295 horsepower at a maximum 2600 rpm, idle speed of 650 rpm. She is able to navigate overland in a 4x4 or 4x2 scheme (while saving fuel). On the water, the amphibian is propelled by a four-blade propeller with a diameter of 0.762 m and a thrust of 14.52 kN located in the aft tunnel of the welded aluminum hull. The propeller is equipped with a nozzle to increase efficiency. The engine is located aft above the propeller, connected to a transfer case located in the center of the amphibian, transmitting torque to all four drive wheels and / or to the propeller. To pump out the seawater in the bottom part of the hull, there are three hydraulically driven bilge pumps, as well as manual bilge pumps.
LARC V has a carrying capacity of 4.5 tons and is capable of carrying up to 20 fully equipped soldiers. The cargo platform is completely open at the top, however, to protect the cargo from splashes on the sides, you can install sides made of rubberized fabric stretched over a cable frame. The amphibian can also be equipped at the rear of the cab with a hydraulically powered cargo boom with a lifting capacity of up to 2.5 tons.
The cruising range is 360 km on land and 40 miles on water. She is capable of speeds up to 48 kilometers per hour on land and 8.5 knots at sea. Currently, 12 LARC Vs are stationed aboard the Advance Storage Force (MPF) vessels. Due to its small size, the LARC V could independently enter the LARC LX.
The amphibian is capable of operating in temperate, tropical and arctic climates, on sandy and coral coasts, rough terrain, off-road and maneuvering at 3-meter waves.
Like its larger counterparts, the amphibian was equipped with a rigid suspension (that is, there was simply no suspension as such and the wheels were rigidly connected to the body) and low-pressure tires 18.00x25 inches ply acted as shock absorbers. Thanks to large wheels and a ground clearance of 0.406 meters, as well as the presence of a downshift, the amphibian has good maneuverability.
Handling on land was provided by the classic scheme with front steerable wheels. The minimum radius of the gate is 8 meters. The amphibian is controlled on the water by simultaneously turning the wheels and a three-blade water rudder located behind the propeller. The minimum circulation radius is 11 meters.
The combat transport companies that have adopted the LARC V are 165th, 305th, 344th, 458th, 461st. The cost of LARC-5 was $ 44.2 thousand in 1968 prices. When writing the terms of reference, it was assumed that LARC V will be used mainly in river estuaries. Despite this, the amphibian was actively used at sea, and therefore the loads it experienced led to increased wear of systems and mechanisms, as well as structural elements. As a result, the LARC V encountered traction problems and some mechanism failures. Also, the cost of maintenance was constantly growing, and some parts by that time were simply discontinued. At some stage, the question arose about the expediency of further use of these amphibians and the question of their write-off and replacement was considered. Many LARC Vs were assigned to 35 reserve companies. The amphibians are over 35 years old and require major overhaul. The thin aluminum body, the absence of a second engine could not but affect the survivability of the amphibian. As a result, out of almost 1000 built vehicles, no more than three hundred LARC V remained in service.
The performance characteristics of LARC-5 / LARC V
Crew: 2 people
Total weight: 13.6 tons
Empty weight with fuel and crew: 8.6 tons
Carrying capacity: 4.5 tons (ogranichenno do 5 tonn) or 20 people
Length: 10.6 m
Width: 3.05 m
Height: 3.1 m
Freeboard: 0.254 m
Powerplant: Cummins diesel engine, 295 horsepower each
Body material: aluminum
Fuel capacity: 2x 272 liters
Fuel consumption: 75 liters per hour
Cruising range: 402 km
Navigation range: 151 km
Coolant volume: 123 liters per engine
Maximum speed on land: 48 km / h
Maximum water speed: 9.5 knots
Economy speed: 12.8 km / h
Maximum permissible wave height: 3.5 m
Gradient overcome @ 1.6km / h: 60%
Average draft in water: 1.5 m
Turning circle on water: 23.5 m
Turning radius on land: outer 11.1 m, inner 8 m
Ground clearance: 0.9 m
Ground clearance under the propeller: 0.4 m
Wheelbase: 4.88 m
Cargo platform dimensions: 7.25x2.97x0.7 m
Operating temperature range: -32 ° C to + 52 ° C
Power supply: 12 V
A total of 968 amphibians were built. At least 600 of these were flooded when the United States left Vietnam in the 1970s. On October 15, 2001, the 309th Transport Company (LARC LX) of the 11th Transport Battalion was disbanded. It was the last amphibious company in the US Army. The army is now completely dependent on conventional landing craft.
