Conceived by Douglas C. Webb and supported by Henry Stommel and others, the class of Slocum Gliders is named after Joshua Slocum, the first man to single-handedly sail around the world.
The Slocum Glider is a uniquely mobile network component capable of moving to specific locations and depths and occupying controlled spatial and temporal grids. Driven in a sawtooth vertical profile by variable buoyancy, the glider moves both horizontally and vertically.
The long-range and duration capabilities of Slocum gliders make them ideally suited for subsurface sampling at the regional scale. Carrying a wide variety of sensors, they can be programmed to patrol for weeks at a time, surfacing to transmit their data to shore while downloading new instructions at regular intervals, realizing a substantial cost savings compared to traditional surface ships.
The small relative cost and the ability to operate multiple vehicles with minimal personnel and infrastructure will enable small fleets of gliders to study and map the dynamic (temporal and spatial) features of subsurface coastal waters around the clock and around the calendar.
- This report presents the design features, computer-simulated and actual field trial gliding and autopilot performance of the first two
models in the ongoing evolution of the SLOCUM glider vehicle. The vehicle mission is to gather oceanographic data while performing
autonomous, gliding dives to 1800 m depth at typical glide path angles of 45° with the horizontal, and a sink rate of .33 m/sec.
The ascent/descent portions of the dives are driven by the vehicle's ability to slightly (typ IIOO g) change its net buoyancy at the
inflection points of the dive. The energy to power these buoyancy changes will eventually be provided at zero on-board energy cost by a
heat engine that exploits the ocean's thermal gradient between the warm surface and cold deep layers of the ocean. The first two units
described in this report employed mechanical, energy consuming means of buoyancy change.
The glider is a faired cylinder with fixed vertical and horizontal wings at the aft end. These provide gliding lift as well as stability
and steering moments. The cylindrical fuselage also provides some lift. The vehicle pitch angle is changed by longitudinal movement of
an internal weight. The vehicle roll angle is changed by rotation about the vehicle centerline of the same radially aSYIDIDetric, internal,
moveable. weight ..-.This causes the fixed wings.to rotate and produce a net lateral yawing moment due-to their
vertical/horizontal aSYIDIDetry; as a result, the vehicle changes its heading. Once per day, the
vehicle will assume a vertical, antenna-up position at the surface and -
eventually engage in two-way satellite communication. This maneuver is
accomplished by activating approximately 0.7 liter of additional surface buoyancy in the vehicle nose and by movement of the vehicle's
center of gravity aft-ward and on-centerline. Power to activate the surface buoyancy will be provided at no on-board energy cost by a
second heat engine. This engine will operate on a different thermodynamic cycle than the drive buoyancy engine. The long-term
deployment target is 5 years.
A basic description of the design features and field trial environment of the first two glider models
is a battery electric ASV (Autonomous Solar Vessel), a trimaran with an extremely
active hull that runs on solar
power = energy from nature. This hull form has never been
before, nor has the use of wind energy been used in such manner for crew
complete onboard autonomy). A fleet of such vessels could be the basis of an
international peacekeeping, and/or emergency rescue force.
| Paints | Screens | Diving
Estimates | Record Attempt | PR Events
| Alloys | Timber | Composites | Navigation | Hydraulics
| Electronics | Solar
Panels | Propeller | Transmission | Tooling | Life Support
Construction) & Results
design of the Solar Navigator boat
has been licensed for use in
John Storm series of books by