To keep the Rover from sinking into the soft seafloor mud, the engineers outfitted the vehicle with large yellow blocks of buoyant foam that will not collapse under extreme pressure. This foam gives the Rover, which weighs about 1,400 kilograms (3,000 pounds) in air, a weight of only about 45 kilograms (100 pounds) in seawater.
Other engineering challenges required less high-tech solutions. In constructing the Rover's tractor-like treads, the design team used a decidedly low-tech materialcommercial conveyor belts. After watching the Benthic Rover on the seafloor using MBARI's remotely operated vehicles (ROVs), however, the researchers discovered that the belts were picking up mud and depositing it in front of the vehicle, where it was contaminating the scientific measurements. In response, the team came up with a low-tech but effective solution: they removed the heads from two push brooms and bolted them onto the vehicle so that the stiff bristles would clean off the treads as they rotated.
The team also discovered that whenever the Rover moved, it stirred up a cloud of sediment like the cloud of dust that follows the character "Pig-Pen" in the Charlie Brown comic strip. This mud could have affected the Rover's measurements. To reduce this risk, the engineers programmed the Rover to move very, very slowlyabout one meter (3 feet) a minute. The Rover is also programmed to sense the direction of the prevailing current, and only move in an up-current direction, so that any stirred-up mud will be carried away from the front of the vehicle.
|Contact: Kim Fulton-Bennett|
Monterey Bay Aquarium Research Institute