Bottom crawler
A bottom crawler is an underwater exploration, research and work vehicle.<ref name=TR>Template:Cite web</ref> It is designed to sink to the bottom of a body of water, where it uses the traction of its wheels or tracks against the bottom and can move a load.<ref name=TR/> It can be manned or unmanned.<ref name=TR/> It can tethered to a surface ship by a cable or cables providing power, control, video, and lifting capabilities, but this is not essential.
Applications
Such devices have been proposed for use in deep sea mining.<ref>Template:Cite journal</ref>
It was considered as a platform for nuclear missiles, but was rejected because it is restricted to essentially two dimensions, unlike a ballistic missile submarine.<ref>DA PAM (Department of the Army Pamphlet) issue 27, 1977, p. 177. Accessed 16 July 2025.</ref>
Limitations
Its use is limited by the composition of the bottom; unless it is firm, the crawler can become immobilized by sinking into sediment.<ref name=TR/> Another serious problem is that the tracks or wheels can stir up the sediment, causing it to seriously degrade vision.<ref name=TR/>
Its power source can be internal (batteries) or external (cable), but each presents problems.<ref name=TR/> Batteries are heavy and have limited capacity for sizable loads, while power cables can impede mobility.<ref name=TR/>
Remote Underwater Manipulator
In 1958, Victor Anderson began constructing the 10-ton, unmanned Remote Underwater Manipulator (RUM) for the Scripps Institution of Oceanography which was based on a United States Marine Corps self-propelled rifle carrier.<ref name=Scripps>Template:Cite web</ref> He attached a boom and claw which enabled it to manipulate objects up to Template:Convert away.<ref name=Scripps/> RUM was initially powered by a gasoline engine, but it was replaced by two electric motors.<ref name=Scripps/> It is paired with the Ocean Research Buoy (ORB), a barge with a center well.<ref name=Scripps/> RUM is lowered by crane, then a coaxial cable is attached for power and sensor signals.<ref name=Scripps/>
RUM has taken core samples at depths down to Template:Convert and has recovered equipment from Template:Convert.<ref name=Scripps/>
See also
- Benthic lander, an autonomous observational platform that sits on the seabed