The Captive Air Amphibious Transporter (CAAT) an enabler for Ultra-Heavy lift Amphibious Logistic Operations in Extreme Environments
Authors: Kline Jeff , Shimozono Gary , Schmidt Terrence 
Published: December 2012

The Captive Air Amphibious Transporter (CAAT ®) is a new amphibious vehicletechnology that enables heavy-lift, logistics transport at considerable speedover land, open water, shallow water, surf-zone, beach and mud-flats, andobstacles to potentially include sea ice. Unlike an air cushion vehicle, whichuses lift fans and a " non-sealed" flexible skirt cushion to keep the craftafloat and propel it, the CAAT uses a " captive" or " sealed air cushion" in theform of a buoyant belt which translates around the vehicle providing bothbuoyancy and propulsion. This approach enables the CAAT to provide the liftcapacity and versatility of a traditional Landing Craft Utility (LCU) whileexceeding the amphibious mobility of a Landing Craft Air Cushion vehicle(LCAC). The CAAT's low ground pressure (less than 2 psi) supportsenvironmentally sensitive ecosystems and enables it to traverse environmentsthat would typically stop an equivalently-loaded tracked or wheeled vehicle(ground pressures of 15 to 20 psi). Of particular importance, the CAAT's methodof propulsion eliminates collisions with floating debris or ice fields. Formobility in open-water cluttered with ice-fields, the CAAT's propulsion tracksystem provides a zero knot relative speed to the water surface. Thisperformance is unique to the CAAT technology and results in the CAATessentially " walking-on-water" as opposed to plowing through it like atraditional marine craft. Additionally, the CAAT technology projects to offer a30% improvement in operational cost ($/ton-nm) relative to an LCU and a 300%improvement relative to an LCAC.

The CAAT technology affords the natural resource development industry aheavy-lift logistics amphibious transport capability that is compatible withenvironmentally sensitive coastal regions. For the arctic region in particularthis will increase logistics transportation cost-effectiveness by eliminatingthe seasonal dependency of ice road infrastructure and respective environmentalrestoration.

Description Navatek Ltd. (www.navatekltd.com) proposes our CaptiveAir Amphibious Transporter (CAAT ®) as a candidate arctic connector for ship toshore or broader arctic amphibious mission requirements. Our CAATtechnology is the basis for the on-going Ultra Heavy-lift Amphibious ConnectorProgram for the US Navy's Office of Naval Research (ONR) and the DefenseAdvanced Research Projects Agency (DARPA). Illustrated in Figure 1, theCAAT has unique capabilities useful in the exploration of remote and unimprovedarctic areas. As shown in Figure 2, the CAAT technology has the ability tonavigate open water, mudflats, beaches and breach ice sheets (simulated byclimbing over a floating pier and dry-dock). Unlike an air cushion vehicle(ACV), which uses lift fans and a " non-sealed" flexible skirt cushion to keepthe craft afloat and propel it, the CAAT uses a " captive" or " sealed aircushion" in the form of a buoyant belt which translates around the vehicleproviding both buoyancy and propulsion. This approach eliminates the highpowered, complex and costly lift system of the ACV as well as enabling the CAATto breach obstacles and inclines 3 to 5 times as high as an ACV. The CAAT's lowground pressure (less than 2 psi) enables it to traverse sand-bars and tidalmud-flats and arctic ice that would typically stop an equivalently-loadedtracked or wheeled vehicle (ground pressures&gt; 20 psi). The CAAT technologyenables transiting at considerable speed over land, open water, shallow water, tidal mudflats, and obstacles to potentially include sea ice.