LCAC (Landing Craft Air Cushion)

History of LCAC (Landing Craft Air Cushion)

WWII Allied forces invaded Europe in Normandy on June 6, 1944, with thousands of landing craft of various types ashore for transport.

To date, this operation is the largest deployment of landing craft recorded in history. LSTs (Landing Craft, Tanks) are large vehicles used to bring tanks and armored vehicles ashore, while LCIs (Landing Craft, Infantry) are built to carry up to 200 soldiers and LCAs (Landing Craft, Assault) are used to carry a The train dispatched 31 infantrymen. At 6:55 a.m. at Omaha Beach, one of the five beachheads designated during the first wave of the invasion, the 116th Regiment of the 29th Division was 99 percent dead in just 15 minutes. As the second wave approached the blood-stained beach, the landing craft took off artillery and mortar shells fired from German land positions, hitting some directly and killing everyone on board. When some LCAs reached the beach, the access ramps along the front of the hull were lowered, and the infantry was immediately exposed to the waiting enemy, with machine guns aimed at the masses.

It was only a matter of time before German machine gun fire blew these men to pieces. As other LCAs approached the beach, some helmsmen, unable to see through the smoke covering the beach and disoriented, plunged their ramps into deep water, forcing troops to wade ashore in chest-deep water. Many would fall into the sea and drown under the weight of their gear and weapons.

Clearly, World War II-era landing craft were far from capable of landing people and supplies safely on enemy shores.

In 1977, the U.S. military's amphibious prototype design was evaluated - a program that would culminate in the production of the Landing Craft Air Cushion (LCAC) vehicle. The ambitious purpose of this new design is to provide U.S. war planners with a vehicle that can effectively use troops, equipment and supplies to conduct amphibious assaults when launched from ships on the "horizon".

The boat will wade through the sea to shore, and if necessary sail beyond the beach and beyond. The chosen prototype was a design sponsored by Bell Aerospace of New Orleans, Louisiana, which has experience building hovercraft tested in the Vietnam War.

Funding began in 1982, with the first LCAC 1 deployed aboard USS Germantown (LSD-42) in 1987. The last LCAC 91 was delivered to the US Navy in 2001. The largest deployment of these vehicles to date has been 11 prototypes deployed during Operation Desert Storm in the Gulf War in 1991.

However, none of these have been battle tested.

LCAC can be launched from any US Navy surface ship with a "well deck". To operate the car, she needs a basic crew of five employees. The vehicle is 87 feet long, 11 inches (26.4 m) long and 47 feet (14.3 m) wide. Their torso is supported on a pad of high-pressure air that is expelled to the surface below and restrained by the apron. The LCAC is powered by four main engines that provide lift and propulsion, giving the LCAC six dimensions of motion, similar to a helicopter.

The engine is an Avco Lycoming TF40B gas turbine delivering 16,000 shaft horsepower. Two are used for lifting and the remaining two are used for propulsion. For propulsion, the LCAC is equipped with a 2 x 4-blade reversible-pitch propeller that is 11.75 feet in diameter and navigates the craft like a rudder system. For buoyancy, there are 4 x 2 inlet dual outlet centrifugal fans up to 63 inches in diameter.

The crew who steered the ship was called the "Craftmaster" - a yoke used in conjunction with the foot rudder controls to move the ship in any direction. Downward air is surrounded by a flexible rubber canvas skirt system that allows the hull to hover four feet above any surface.

LCAC has 5,000 gallons of internal fuel, while Thirsty Girl needs 1,000 gallons per hour to run. Each LCAC deploys two ramps - 28.8 feet wide at the bow and 15 feet wide at the stern.

Personnel and equipment are unloaded simultaneously to allow LCACs to return to the fleet for additional personnel or supplies. The vessel can reach 40 knots (47 mph) under load, making it a valuable and fast transport and capable of going ashore on 70% of the world's coasts. She can traverse and traverse ice, soft sand, gravel, and swamps.

The vehicle requires 500 yards to stop and 2000 yards to turn. The downdraft of the LCAC creates high concentrations of dust that make it difficult for the vehicle to tow when deactivated. She displaces 170 tons when fully loaded, weighs 87.2 tons when light, and allows 82.7 tons of cargo to be transported in the 1,809-square-foot bay.

This weight limit supports 180 fully equipped troops or Abrams main battle tanks, as well as various armored vehicles or cargo.

In 1996, plans were drawn up to modernize the LCAC. A standard Service Life Extension Program (SLEP) was approved in 2004 and calls for upgrading and extending the useful life of all LCACs in service by approximately 30 years at approximately $20 million per vessel.

The service plan includes onboard electronics upgrades and replacement of new buoyancy tanks for each of the 74 vessels. The new extended life is expected to run from 2014 to 2027 (based on the vehicle's original release date).

The main amphibious assault vehicle deployed by the USMC (as of 2010) is the AAV-7A1. This armored track system can hold 25 soldiers and can also be launched at 43 knots from a well-covered vessel, but only into 17% of the world's coastline and has a range of 300 miles.

However, unlike the LCAC, the AAV is not a "super-horizon" attack vehicle, which is still the main feature of the LCAC.

Given today's globally available ground-based defense weapon systems, launching LCACs 50 miles offshore is proving to be a clear security concern for the U.S. Navy fleet.

If the LCAC moved inland to a controlled staging area - supported by overhead helicopters - the enemy would divert their attention from the fleet itself. A high-speed craft capable of achieving possible tactical surprises while towing troops and supplies and not exposing the fleet to enemy fire on the beach is the task of the LCAC.

However, of course, safety in every combat situation is beyond control, and we have a history of seeing amphibious assault vehicles fail in past wars.

LCACs had a number of drawbacks; they were made of rubber and canvas and had no armor to protect the crew or troops on board. A very large vehicle also produces a very large radar image. Once on land, her speed and maneuverability are greatly reduced to 6 knots. The six gas turbines are thought to be very loud and can be heard from a distance. A damaged LCAC proved difficult to tow, and backing up was tiring for the driver.

Due to LCAC turnaround times, naval shelling will extend beyond the initial landing and land build-up to support combat forces, and supplies will be slow.

It should be noted that LCACs and the men and women who depend on them have not been tested in combat.

LCAC Specifications (Landing Craft Air Cushion)

Basic

Roles

Dimensions

Weight

Performance

Performance

ARMAMENT

AIR WING