seminars
and colloquia

special events

technology,
archaeology,
and the deep sea
conference '02

toward a new
synthesis
conference '99

SEMINARS AND COLLOQUIA

Remotely Operated Vehicle Technology
Jim Newman, Institute for Exploration
May 20, 1998

Jim Newman on the development of ROV technology:

Remotely Operated Vehicle - a neutrally buoyant, thruster-controlled, cabled underwater vehicle that carries no people.

Early manned vehicles included:

- Trieste - a submersible from the 1960s that controlled buoyancy via a large bladder filled with aviation fuel

- Alvin - 1964, stainless steel sphere (later titanium sphere) to house crew of three, buoyancy provided with syntactic foam

ROVs - 1960s-70s carried small video cameras.

An example is the US Navy's CURV, a salvage ROV that played a role in the recovery of a hydrogen bomb lost off Palomares, Spain.

Technologies to consider in ROV building:

ROV cables can be either soft tethers, nowadays kevlar-wrapped and neutrally buoyant, or armored with steel.

Easy technologies to incorporate include

• Solid state video
• Syntactic foam
• Acoustic navigation linked to Global Positioning System navigation on the surface
• Video telemetry and data transmission
• Fiber optics

Higher technologies include

• Closed loop position control of the ROV
• Image mosaicking
• Bathymetric mapping at fine scales (< 1 m)
• Manipulation

Some starting points for an archaeological ROV include a vehicle such as the MaxRover, and technologies developed on the Jason ROV at Woods Hole Oceanographic Institution. These systems are more expensive than technologies usually employed in archaeology. For instance, a 1000 meter capable MaxRover vehicle with cable and winch system costs in the neighborhood of $250,000.

Assumptions for the vehicle under development:

• Fiber optics
• Armored cable
• Depressor weight to decouple ROV from surface motion (like the Jason - Medea tandem at WHOI)

Likely enhancements include:

• Doppler velocity log
• Side scan sonar, possibly on a separate tow body
• Elevator system for navigational beacon deployment and artifact recovery procedures

Possible enhancements include:

• Side scan sonar mounted on the ROV
• High-frequency subbottom profiling sonar

The ROV will be a sensor platform. Perhaps other sensing technologies could be brought to bear on underwater archaeological sites. Optical and acoustic systems are already planned.

Justin Manley, MIT Sea Grant, ventures that florescence or some other techniques not yet considered may prove useful for archaeological investigations.

Deep Water Archaeology Research Group Massachusetts Institute of Technology 77 Massachusetts Ave. Rm e51-194 Cambridge, MA 02139