2Landing Craft Air Cushion (LCAC) HistoryCharacteristicsMaintenanceCrewMissionOperational Success
3Landing Craft Air Cushion (LCAC) MaintenancePlanned Maintenance SystemCorrectedPreventativePackagesOperational CostsWeldingMan-hours expended
4Landing Craft Air Cushion (LCAC) Craft CrewCabin CrewQualification ProcessRatings
5Landing Craft Air Cushion (LCAC) MissionReady for TaskingShip to ShoreOver The Horizon (OTH)Direct USMC SupportNon-Military utilization
6Landing Craft Air Cushion (LCAC) Operational SuccessNavy and Marine CorpHumanitarianKatrinaTsunamiLos Angeles Fire DepartmentSpecial Operations
7Landing Craft Air Cushion (LCAC) HistoryOriginal hovercraft conceptEarly yearsJEFF A/BHovercraft around the globeWar and PeaceTake Quiz and answer.
8HistoryA hovercraft is a craft capable of traveling over relatively smooth surfaces supported by a cushion of slow moving, high-pressure air, ejected against the surface below, and contained within a “skirt.” Although supported by the air, they are not usually considered to be an aircraft.The idea of using an air-cushion as a means or aid to acceleration and reduction in (hydrodynamic) drag was first explored by Sir John Thornycroft, a British engineer, who, in the 1870's built some experimental models on the basis of an air cushion system that would reduce the drag of water on boats and ships.In 1877 he successfully patented the idea and his theory was that if a ship's hull was given a concave bottom, which could be filled - and replenished - with air, it would create significant additional lift. And so the air cushion effect was born.Decades later scientists and inventors were still busy with his ideas but without any practical applications. With the coming of the airplane however, it was noticed that additional lift was obtained if the plane flew closer to land or water, creating a "funnel effect", a cushion of air.The next two decades saw little interest in air cushion development. World War 1 saw a huge increase in the development of the airplane as a military weapon and even though the ground effect was known, airplanes were designed for speed and maneuverability in the air rather than close to the ground
9Early YearsLighter Air Cushioned Vehicle - an air cushion vehicle craft that travels over water, beaches, soft or firm ground, snow or ice at speeds of up to fifty miles per hour. The craft has an open deck space with a total payload capacity of thirty tons. The LACV-30 is approximately 40 ft wide by 80 ft long, weighs about 65,000 lbs empty, can carry up to 60,000 lbs of cargo, utilizes gas turbines to power its twin propellers, and can cruise at speeds of up to about 60 mph. A major Army mission is to ensure the adequate flow of supplies and materiel to the various field elements deployed worldwide. With commercial shippers converting to containerized cargo, the Army realized that some of its then current watercraft would inhibit fast turnaround of container ships and thereby reduce productivity. The Army concluded that the air cushion vehicle concept should be developed for use in an over-the-shore logistics operation.
10Early YearsThe successful use of the air cushion effect was not lost on engineers after World War 2 was over and in the early 1950's British, American and Swiss engineers started to rethink Sir John Thornycroft's problem.The Englishman Christopher Cockerell, commonly seen as the father of the hovercraft, being retired from the army, settled into boat building where he soon got captivated by Thornycroft's problem of reducing the hydrodynamic drag on the hull of a boat by using some kind of air cushion.His theory was that, instead of using the plenum chamber - an empty box with an open bottom as Thornycroft had devised - air was instead pumped into a narrow tunnel circumnavigating the entire bottom, it would flow towards the center and form a more effective air cushion. This peripheral jet would cause the air to build up enough pressure to equal the weight of the craft and, as it would have nowhere to go, the pressure would force the craft up, clearing it off the ground altogether.Cockerell successfully tested his theory and filed his first patent in The year after he formed a company called Hovercraft Ltd. He further envisioned and partially worked out other problems of the hovercraft principle that still have to be fully exploited by modern hovercraft builders. One of these was to re-use the air for greater overall efficiency.Thinking that his air cushion vehicles would be eminently suitable as amphibious craft he approached the British Ministry of Supply, the government's defense equipment procurement authority with his findings. Soon after, in 1956, the air cushion vehicle was classified as "secret" and a construction contract was placed with a British aircraft and seaplane manufacturer. The result was the SR.N1 in 1959.The first SR.N1 weighed four tons and could carry three men. Its maximum speed was 25 knots (1 knot = 1.15 miles or 1.85 kilometres per hour) on calm water. It had a 6-inch (15 cm) rubberized skirt to make it easier to contain the air cushion on uneven ground.By this time the Americans, the French, Japanese and Swedes had begun to be interested in the air cushion vehicle and its possibilities and companies sprang up the world over. As far as experimental vehicles were concerned the Soviets, in their race for technological supremacy, were as prolific as the Americans in building craft of all sizes, shapes and types. Nothing was too weird or technologically theoretical but it was built. Especially after World War 2, during the 1950's and 1960's did experimental constructions reach extraordinary proportions.
11It took 25 charges to sink me! Jeff A/BIt took 25 charges to sink me!Jeff AJeff B
13RussianThis is the world’s largest military hovercraft and it belongs to the Russian army. It is armed with missiles, artillery and anti-aircraft defense guns and can carry a few heavy tanks at once. After approaching to the enemy coastline it can give a burst of fire to tear of such fierce force that can tear big military ship apart, then without any slowing down start moving on the shore advancing deep inside to unload the tanks and infantry.
14ChinaThe 540-ton Zubr LCAC, the world’s largest amphibious assault hovercraft, can reach speeds in excess of 60 knots, can travel 300 nautical miles and can shoulder various large loads: 130 tons of cargo, 500 troops, three 50-ton medium battle tanks, 10 BTR-70 armored personnel vehicles or eight BMP-2 infantry fighting vehicles.
15SwedenHovercraft 2000, which is the Swedish name of the vehicles, will perform the same function as defense Light Faith boats and so called Stridsbåt 90. First task is therefore transportation of troops. Hovercraft 2000 takes up to 50 troops / passengers, compared with Stridsbåt 90, which holds up to 16 people. Floats can easily be converted to freight traffic.
16Christopher Cockerell A fan draws air from the ambient atmosphere at pressure pa and compresses it to a stagnation pressure po in the reservoir inside the vehicle. The air then exhausts downward through a narrow slot of width w at the periphery of the vehicle (w<<R), creating a condition that maintains a positive gage pressure (an "air cushion") underneath the vehicle. This allows the vehicle to float at a height h above the ground.Air Flow4 Tons3 man crew25 Knots(1 knot = 1.25 mph: 25knots=28.8mphFirst HovercraftMilitaryTransportation
17War and PeaceHovercraft serve different missions depending the country and the climate. We have seen many countries have a flavor of hovercraft. The USA uses hovercraft routinely during war and peace.Vietnam. This hovercraft was used to clear areas of Vietnam in a matter of hours that would normally take weeks. Often traveling at speeds greater than 60 MPH, they carried both offensive and defensive weapons.Today. The hovercraft today are primarily used to transport troops and equipment to the beach and return to the “mother ship.” Not equipped to fight, their speed and agility are their only defense.
18Landing Craft Air Cushion (LCAC) Characteristics of an LCACSpecificationsDifferencesComparisonsTake Quiz
19Characteristics LCAC General Characteristic Builder: Textron Marine and Land Systems/Avondale Gulfport Marine.Date Deployed: 1982.Propulsion: Legacy 4-Allied-Signal TF-40B gas turbines (2 for propulsion / 2 for lift); 16,000 hp sustained; 2-shrouded reversible pitch airscrews; 4-double-entry fans, centrifugal or mixed flow (lift)SLEP 4–Vericor Power Systems ETF-40B gas turbines with Full Authority Digital Engine ControlLength: 87 feet 11 inches (26.4 meters).Beam: 47 feet (14.3 meters).Displacement: 87.2 tons (88.60 metric tons) light; tons ( metric tons) full load.Speed: 40+ knots (46+ mph; kph) with full load.Range: 200 miles at 40 kts with payload / 300 miles at 35 kts with payload.Crew: Five.Load: 60 tons / 75 ton overload (54.43/68.04 tonnes)Armament: mm MGs. Gun mounts will support: M-2HB .50 cal machine gun; Mk-19 Mod3 40mm grenade launcher; M-60 machine gun.Electronics: Radars, Navigation: Marconi LN 66; I band / Sperry Marine Bridge Master E.
20Characteristics Legacy – Original craft from 1983 SLEP – Service Life Enhancement ProgramFMP – Fleet Modernization PlanLACV – Light Air Cushion Vehicle
21Characteristics Comparisons of LCAC – Travel in excess of 50 knots Fuel of 300 NMCapable of carrying 60 – 75 ton payloadCrew of 5LCU – Landing Craft UtilitySelf-sustaining with accommodations and galley2 Detroit Diesel engines11 knots, 1200 NM range, carry 170 ton payloadCrew of 14
23DISCUSSION POINT RELATED INSTRUCTOR ACTIVITY 2. PresentationC. LCAC Characteristics/Systems(III) ComponentsSkirt System Identify all parts of the skirt system.
24Propeller SystemThere are two 11 foot, 9 inch diameter propellers on the stern of the craftMajor components consist ofShroud - 14 ft outside diameterPropeller spinnerDrive adapterPropeller assemblyPropeller controlsHydraulic system360 degree FOD screenThe propellers are controllable as far as the pitch angle is concerned. The angle can be changed from +40 degrees forward to -35 degrees reverse pitch
26OPERATIONAL TEMPERATURES DISCUSSION POINT RELATED INSTRUCTOR ACTIVITY2. PresentationD. LCAC Capabilities and Limitations Discuss LCAC minimum operational temperature and cold weather kit.Refer to SEAOPS Volume I, page 1-7 and to 1-70.-30° FAHRENHEIT(-34.4° CELSIUS)
27120 ° FAHRENHEIT (48.8° CELSIUS) DISCUSSION POINT RELATED INSTRUCTOR ACTIVITY2. PresentationD. LCAC Capabilities and Limitations Discuss LCAC maximum operational temperature and hot weather operations.Refer to SEAOPS Volume I, page 1-7.(48.8° CELSIUS)
28Landing Craft Air Cushion (LCAC) Maintenance (UNDER CONSTRUCTION)Planned Maintenance SystemPackagesCorrective and PreventativeOperational CostsWeldingMan-hours expended
33Craft Crew Cabin Crew (Starboard) Cabin Crew (Port) Craftmaster – Senior Enlisted Sailor who drives or “pilots” the LCAC.Engineer – Petty Officer Second or above with an engineering source rating.Navigator - Petty Officer Second or above with a Quartermaster or Operations Specialist.Cabin Crew (Port)Loadmaster – Typically a Petty Officer Third Class or above with a Boatswain mate source rating.Deck Mechanic – Junior Sailor with an engineering rate background.
34Craft Crew Qualification Process Initial Program Entry Qualification Process –Minimum aptitudeFive year program commitmentNo conviction at Non-Judicial Punishment (i.e., Captain’s Mast) in past 12 months.Medical screeningInitial and Follow-up TrainingCraftmaster, Engineer, Navigator (Starboard Cabin Crew) – six month school to include classroom, simulator, and hands-on and and night flight training. Must maintain proficiency of 20 hours a quarter, 10 must be night hours.Load Master and Deck Mechanic – 50 flight hours plus six weeks of classroom study.
36Landing Craft Air Cushion (LCAC) MissionReady for TaskingShip to ShoreOver The Horizon (OTH)Direct USMC SupportNon-Military utilization
37Mission Over the Horizon (OTH) Ready for Tasking (RFT) Ship to Shore Requirements for LCAC operations is derived from multiple operation plans (called “O Plans). These classified documents direct military insertion into hostile territories over a period of time. Minimum LCAC requirements within these O Plans dictate quantity of LCAC inventory should be RFT on a daily basis. However, because of equipment casualty and maintenance, actual RFT numbers may be below O Plan tasking, an average of 80% is realistic, if not higher.Ship to ShoreLCAC’s success stems from time and distance more than payload. As learned earlier there are other waterborne craft that can carry more resources longer distances but in a greater amount of time (LCU for example). For resupply after establishing base camp this is acceptable. LCAC’s provides immediate and rapid responses of Marines and cargo into a hostile landing zone in a fraction of the time.Over the Horizon (OTH)Benefit of LCAC speed and agility is OTH tasking. Naval ships can sit just OTH from shore, approximately 26 miles, and deliver troops and cargo to the beach. This keeps the enemy from engineering an attack on the delivery ships.
38Mission Direct USMC Support Non-Military utilization LCAC Delivery LCAC’s main mission, deliver Marines and cargo to the beach. The slogan, “No Beach Out of Reach” is a testimony of our mission and success. LCAC’s can transport tons of payload to include weapons systems, equipment, cargo and personnel of the assault elements of the Marine Air-Ground Task Force from ship to shore and across the beach. LCAC can also carry heavy payloads, such as an M-1 tank, at high speeds. The air cushion allows the LCAC to reach more than 70% of the world's coastline. Conventional landing craft can land at only 15% of coasts. To launch and recover conventional landing craft, the ship can ballast over 15,000t of seawater to allow these craft to float into and out of the well deck.Non-Military utilizationLos Angeles fire department entered into a memorandum of agreement to have LCAC’s delivery fire fighting vehicles throughout the coast, including Catalina Island, to reach difficult or impossible areas to access.LCAC DeliveryLCAC’s must be delivered via ship to their ultimate location. The following ships are designed to carry, repair, and fuel LCAC’s.LSDLHALPD 1LPD 17
39Mission LHD/LHA LPD/LSD WASP/TARAWA Class. Off the beach, landing craft are launched and recovered through the very large stern gate, which opens the well deck to the sea. This well deck is 267ft long, 50ft wide and is designed specifically for the fly-in / fly-out capabilities of the air-cushioned landing craft (LCAC).LPD/LSDAUSTIN/SAN ANTONIO Class. The LPD 4 Austin class of ship combines the functions of three different classes of ships; the landing ship (LSD), the tank landing ship (LST), and the attack cargo ship (LKA). The LPD 17 class program will be the replacement for three classes of amphibious ships that have reached the end of their service life – LPD 4, LSD 36, LST 1179.
40LSD 36 CLASS 2 LCAC Anchorage class 2 LCAC for normal ops can carry 3 if mezzanine ramp removed (not done on West coast)2 LCAC
41LSD 41 CLASS 4 LCAC Whidbey Island class 3-4 LCAC for normal ops 5 LCAC for admin loadNote: Spot 1 has wave guard4 LCAC
42LSD 49 CLASSHarpers Ferry class2 LCAC for normal ops2 LCAC
47Operation Success Navy and Marine Corp LCAC’s are used throughout the world. Since the first LCAC deployment in 1986, only one craft of the 91 inventory experienced a collision with injuries. The craft was later destroyed.HumanitarianKatrinaTsunamiLos Angeles Fire DepartmentSpecial Operations