Figure 3. Sensor Insertion System (SIS) with instrumented boom deployed during storm conditions
shop, dive locker, and general work
increased by 3 m (10 ft) to 11 m
operated in waves up to 2 m (7 ft)
space. The 40-m- (130-ft-) tall
(35 ft), sufficient to pass around the
high. Many operations at the FRF
climbable observation tower to sup-
pier, and it became a permanent
have only been possible because of
port video remote sensing observa-
part of the FRF in 1981. The CRAB
the CRAB. In recognition of the
tions and to hold radio antennas
is an aluminum tripod powered by a
value of the CRAB to surf zone
was added in 1986. With great cere-
lightweight diesel engine that drives
operations, Dutch researchers, after
mony, the tower was christened with
the variable stroke pump that
visiting the FRF, have constructed a
a bottle of champagne dropped from
powers the three hydraulic wheel
similar mobile platform, the WESP
the top deck, and bets were taken
motors (Figure 4). It is modeled after
(http:// www.frw.ruu.nl/fg/wesp.html).
as to whether it would break or
a similar looking vehicle designed by
Two reconditioned LARC-V
not--it did.
R.A. Stearn Inc. (Sturgeon Bay, WI)
(Lighter Amphibious Resupply
and constructed by Marine Travelift
The FRF is probably best known
Cargo) vehicles support operations
and Engineering for monitoring
for the CRAB or Coastal Research
in deeper water or remote from the
beach nourishment projects. Though
Amphibious Buggy (Birkemeier and
FRF. Originally built for the U.S.
primarily serving as a survey vehi-
Mason 1984). Designed and con-
Army to transport cargo between
cle, the CRAB supports other tasks
structed by the U.S. Army Engineer
ships and land, these vehicles sup-
in the nearshore, such as: instru-
District, Wilmington, the CRAB
port diving operations; tow sidescan
ment deployments and maintenance;
arrived at the FRF in 1978 to con-
and sub-bottom seismic instruments;
sand sampling and vibracoring;
duct some of the first surveys of the
lay and retrieve cables; and deploy
cable laying and retrieving; towing
bathymetry near the pier. At that
and maintain buoys and instruments.
instrumented sleds; conducting
time it was not tall enough to drive
One LARC has been converted from
sensor maintenance, and functioning
around the pier, and became stuck
the original mechanical drive to
as a mobile platform for diving oper-
on occasion trying to go under it.
hydraulic drive for greater speed and
ations. Top speed of the CRAB is
The height of the CRAB was later
reliability. It has also been equipped
3 kph (2 mph) and it can be
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