So the year is 2015, and you're in a serious disaster – one that requires the immediate provision of food, water, medical care, and shelter for a hundred thousand people. In other words, not something that a few airlifts will handle. If there is navigable water anywhere nearby, you could be saved by a future version of one of DARPA's new toys: the Captive Air Amphibious Transporter (CAAT).

Part of DARPA's Tactically Expandable Maritime Platform (TEMP) program, CAAT is a tool for enabling rapidly organized and executed ship-to-shore operations. In essence, the concept is to load standard shipping containers on a vehicle that operates close to shore which is equipped with an amphibious drive. CAAT is designed to provide a flexible and modular capability for solving supply problems cropping up during unconventional warfare scenarios, and also to assist during humanitarian disasters.

DARPA program manager Scott Littlefield said, "to allow military ships and aircraft to focus on unique military missions they alone can fulfill, it makes sense to develop technologies to leverage standard commercial container ships."

DARPA's CATT prototype swimming through the ocean (Photo: DARPA)

CAAT is essentially a tank with air-filled treads that supply buoyancy and amphibious propulsion to a cargo of multiple shipping containers. This enables CAAT to roll over water and debris in the water while also being able to drive on land. These vehicles are intended both to carry cargo and, when conditions allow, to tow much larger cargo-laden rafts to the shore.

There are certain tasks which must be dealt with to properly react to a major disaster. You have to know what the situation is, how much damage has been caused, where survivors are located, and the condition of the sustaining infrastructure. Another crucial task is quickly finding the material and equipment needed to supply and/or evacuate survivors and preparing it for transport. But once these tasks are underway, you have to transport an enormous quantity of supplies to the right places in the disaster area. Transportation is often the most difficult part of disaster relief and recovery.

The best way to quickly move huge quantities of supplies and equipment from one point to another is by water. A single mid-size container vessel can carry five thousand 20-foot cargo containers, or about 100,000 tons of cargo. The draft (depth of the hull) is rather small in container ships, so many are also able to deliver supplies inland to sites along navigable rivers and lakes. In addition, many container ships carry their own loading cranes, so that remote unloading can be accomplished in a timely manner.

Still, disasters have a way of rendering harbors temporarily non-navigable. Consider Katrina or Fukushima – in the aftermath the seaport facilities were damaged and flooded, and an enormous amount of flotsam and debris clogged the coastal waters for days or weeks. DARPA perceived a need for a rugged amphibious transport that could transfer supplies from a container ship a safe distance from shore to onshore locations where the supplies were needed.

The video below shows how a one-fifth scale prototype performs in the sort of conditions described above. Note that this prototype is not a remote control toy – it is over ten meters (33 ft) in length and weighs four tons. A full-scale CAAT will be half the length of a football field but weighs only 450 tons, leaving plenty of capacity for hundreds of tons of cargo in shipping containers. The CAAT is also equipped with a snorkel so that it can run in the roughest of seas and storms if necessary. It is safe to say that CAAT would be a valuable addition to the disaster relief toolbox.

Source: DARPA via PopSci