Airboat

Airboats are essentially flat-bottomed vessels propelled in a forward direction by an aircraft-type propeller and powered by either an aircraft or automotive engine. The engine and propeller are enclosed in a protective metal cage that prevents objects, e.g., tree limbs, branches, clothing, beverage containers, or wildlife, from coming in contact with the whirling propeller, which could cause devastating damage to the vessel and traumatic injury to the operator and passengers.

The propeller produces a rearward column of air that propels the airboat forward. Steering is accomplished by forced air passing across vertical rudders. There must be a forceful airflow in order for the vessel to be steered. Airboats do not have brakes and are incapable of traveling in reverse. Stopping and reversing direction are dependent upon good operator/pilot/driver skills.

The operator/pilot/driver and in most instances the passengers, are seated in elevated seats that allow visibility over swamp vegetation. The improved visibility permits the operator and passengers to observe floating objects, stumps and animals in the airboat's path.

The characteristic flat-bottomed design of the airboat, in conjunction with the fact that there are no operating parts below the waterline, permit the vessel to be easily navigated through shallow swamps and marshes, in canals, rivers and lakes as well as on frozen lakes. The airboat's design makes it the ideal vessel for flood and ice rescue operations.

Steering the airboat is accomplished by swiveling vertical rudders positioned at the rear (stern) of the vessel. The propeller produces a column of air that produces forward momentum. That column of air passes across the rudders, which are directed through the forward and backward movement of vertical "stick" located on the operator's left side. The "stick" is attached to the rudders via teleflex cable or linked rods. Overall steering and control is a function of water current, wind, water depth and propeller thrust. The sound produced by an airboat's propeller and engine can be loud; the majority of the sound is produced by the propeller. Modern airboat designs and modern technology have significantly reduced the sound that an airboat produces. Modern airboat engines are equipped with mufflers and multi-blade carbon-fiber propellers that greatly reduce the sound emitted by the airboat. Airboats vary in size from 10-foot hunt/trail boats, with a two- to three-passenger capacity, to large 18-passenger and greater tour boats.

Airboats are a very popular means of transportation in the Florida Everglades, and Louisiana Bayou, where they are used for fishing, bowfishing, hunting and eco-tourism.

Public Safety

In recent years airboats have grown in popularity in the area of public safety. Airboats have proven to be indispensable for flood, shallow water and ice rescue operations. During the flooding of New Orleans following Hurricane Katrina, August, 29, 2005, airboats from across the United States rescued thousands of flood victims. Thirty airboats evacuated over 3,000 patients and medical staff from four downtown New Orleans hospitals in less than 36 hours.

Numerous articles have been published in fire-rescue trade journals, i.e., Fire Engineering, National Fire and Rescue Magazine, describing the advantages, capabilities and benefits of using airboats for water rescue operations, and in depth descriptions of actual water rescue incidents, including the flooding of New Orleans. [Rescuing New Orleans - Nov./Dec. 2005] [The Evacuation of New Orleans, After the Levees Broke - April 2006] [Rescue on the Chatahoochee - January 2006] [The Use of Airboats in Ice and Water Rescue Emergencies - March 2004] ["You Want To Buy A What" - March/April 2004] [Saving Lives Across America - August 2004]

Airboat engines and powerplants

Airboats are powered by either an aircraft or large block automotive engine, ranging from 125 to over 600 horsepower. Replacement parts and ease of repair make the automotive engine the preferred powerplant. Also, high octane automotive gas is less expensive than aviation gas required by the aircraft engines. An automotive engine powered airboat generally has more power to push through high grass or carry heavy loads. An aircraft engine powered airboat may still be preferred in situations where a light boat or greater maneuverability is desired.

afety

Knowledge of operational safety is essential when operating an airboat. The average airboat produces a 150 mile-per-hour prop wash behind it and if a tree branch gets into a propeller the spray of material could be devastating, causing damage to the vessel and injury to the boat's occupants. Modern commercially manufactured airboat hulls are made of aluminum or fiberglass. The choice of material is determined by the type of terrain in which the vessel will operated. Airboat manufacturers tend to be small, family run businesses that assemble built to order boats; airboats are also manufactured in Russia and Australia. Normally a truck or airplane engine is positioned on the back of the boat with a wood or carbon fiber propeller. Importation to European Union is difficult due to the high cost of the CE mark test, which all new and imported used boats need from outside the EU.

History

The first airboat, called the Ugly Duckling, was built in 1905 in Nova Scotia, Canada by a team lead by Dr. Alexander Graham Bell. It was used to test various engines and prop configurations. An associate of Dr. Bell, Glenn Curtiss (of airplane manufacturing fame) is reported to have registered the first airboat in Florida, USA in 1920. It was called the Curtis Scooter [Dreamers, Schemers and Scalawags By Stuart B. McIver: Chapter 28, Who Invented the Airboat?] and it had a closed cockpit design.

By the 1930s homemade airboats began appearing in the swamps and marshes of Florida and Louisiana. One company in Florida claims to have been providing airboat rides as entertainment since the mid 1930s. Over the years a variety of designs were tried and. through trial-and-error, the standard design used today arose: an open, flat bottom boat with an engine mounted on the back, the driver sitting in an elevated position, and a cage to protect the propeller from objects flying into them. One well documented case of a homemade design (though not the first) was an airboat built by staff at the Bear River Bird Refugee near Brigham City, Utah in the 1940s. It appears to have involved collaborative efforts by three employees of the refuge - Leo young, G. Hortin Jensen and Cecil Williams.

A story in Ducks Unlimited magazine in 1987 mentioned Young and Jensen and dated the building of the first boat in 1950. Refuge records, however, show the first boat came into use in 1943, with several photos of running air boats dated 1947. Prior to the introduction of the airboat, refuge biologists had to either walk through shallow water and deep, sticky mud or push unpowered flat-bottom boats with long poles. Staff had experimented with a boat called the "Mud Queen," which had small paddle wheels on either side that pushed the boat. They build their first airboat nicknamed "Alligator I" from a flat-bottom boat pushed along by an aircraft engine purchased for $99.50. Young reported that he called the first airboat an "air-thrust boat." Once word got out about the boat, Leo Young built and sold boats all over the world.

Note

It is worth noticing that in early aviation history the term "airboat" was applied to seaplanes or flying boats, amphibian aircraft capable of taking off and landing on water surfaces.

References

See also

* Hovercraft
* Aerosan
* Hydrocopter
* American Airboat Search and Rescue Association