The River Gorge Explorer, powered by
four Caterpillar C- 18 diesels rated 652 k W
each at 2200 r/min, topped 43 knots during sea trials in Bellingham, Washington,
U.S.A. The Tennessee Aquarium in
Chattanooga, Tennessee, U.S.A., owns
the 20 m vessel and uses it to conduct excursions to the “Tennessee Grand
Canyon” — an area almost inaccessible
except by the Tennessee River.
High-Speed Vessel
for Inland
Waterway Excursions
Until now, high-speed catamaran
passenger vessels had not been approved to work on the United States’
more than 40 000 km of inland waterways. However, that has changed with
the U.S. Coast Guard’s approval of the
River Gorge Explorer to conduct eco-tours on the Tennessee River near
Chattanooga, Tennessee, U.S.A.
The Tennessee Aquarium in Chattanooga owns the 20 m, all-aluminum
vessel. It will run up to five, 90-minute
excursions to the “Tennessee Grand
Canyon” — an area almost inaccessible
except by the Tennessee River.
The vessel is 7 m wide with a 0.9 m
draft and a 2 m depth. The Coast Guard
classifies the vessel under Subchapter
T regulations less than 100 gross tons.
The Tennessee River Gorge is a 43
km long, 610 m deep canyon through
the Cumberland Mountains south of
Chattanooga on the Tennessee River.
The gorge is home to more than 1000
Larry Pearson is a freelance writer based in
Kenner, Louisiana, U.S.A.
kinds of plants, trees and flowers and
184 species of birds, 63 types of mammals and 193 species of butterflies. A
naturalist will guide each tour.
The US$2.9 million vessel can navigate along the river at over 43 knots,
but for now speed is restricted to 30
knots by the Coast Guard for the first
few months of operation.
Built by All American Marine Inc. of
Bellingham, Washington, U.S.A., the
vessel was designed by Teknicraft
Design Ltd. of New Zealand — the
designer of all catamarans built by All
American Marine.
The vessel is actually a hydrofoil-assisted catamaran for a stable and
smooth ride even at high speed. “The
lifting effect produced by the Teknicraft
hydrofoil and signature hull shape
causes the River Gorge Explorer to draft
less than 1 ft. (0.3 m) of water,” said Joe
Hudspeth of All American Marine.
“The minimal draft reduces resistance
from the water, and enhances speed
and efficiency. The hydrofoil system
helps to displace one-third of the ves-
sel’s own weight, utilizing less horsepower and one-third less fuel. The fuel
savings alone make this vessel very relevant to the overall mission of the
Tennessee Aquarium,” Hudspeth added.
Propulsion Power for the 70-passen-
ger vessel comes from four Caterpillar C-
18 ACERT engines rated 652 k W each at
2200 r/min. The engines are connected
to four Hamilton HJ 403 waterjets.
Each of the Hamilton waterjets is
controlled by a Modular Electronic
Control System (MECS) for waterjet
steering and reverse, engine throttle
and gearbox control. Within MECS
there are two separate control subsys-tems and a hydraulic power unit. In addition, the system on the River Gorge
Explorer includes a handheld remote
(HHR) that acts in exactly the same
way as any other control station, except it is carried on a neck strap by
the pilot.
In addition, the port side catamaran
hull has a Northern Lights 25 k W gen-set for ship’s power as well as a
Superior Marine switchboard. Fuel for
the ship is carried in a pair of 1514 L
tanks — one in each hull. There is also
a 189 L water tank.
Since her debut from a dock in downtown Chattanooga adjacent to the
Tennessee Aquarium, the vessel has
been running almost full on five trips a
day, according to aquarium spokesman
Thom Benson.
