Edgetech 2000-DSS, Руководство пользователя по оборудованию

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TOWING CHARACTERISTICS
This section includes graphical plots representing the towing characteristics of the 2000-DSS Tow Vehicle
for various cable lengths, tow vehicle speeds and tow vehicle depths. There are a total of 32 plot
configurations as listed in
T
ABLE
C-1 . These plots are available for equipment selection purposes only. In
addition, when selecting a particular plot, it should be verified prior to being used for detailed survey
planning.
NOTE: Some of the plots reference tow vehicle operating depths that are
greater than the maximum depth rating of the 670D Tow Vehicle. These
plots are for illustrative purposes only. The 670D Tow Vehicle should
never be deployed at a depth that exceeds its 2000-meter depth rating.
The plots have been generated under the following assumptions:
• Sea State = 0 with no vessel heave motion
• Ocean current = 0
•
Steady state tow vehicle speeds of 2–8 knots in 1-knot increments
•
Armored cables A320327 - 0.32", A301241 - 0.68", and A302799 - 0.45"
•
Cable lengths of 500–10,000 meters
Ocean currents will be a factor for virtually all cases in which the tow vehicle is used. By using the
equations below to calculate tow vehicle relative speed, the existing plots can be used for approximating
the tow vehicle depth when ocean currents are present and assuming that the current is uniform with
depth.
For the tow vessel moving into the current:
Tow Vehicle Relative Speed = Tow Vessel Speed + Ocean Current
For example, for a tow vessel speed of 5 knots and an ocean current of 1 knot, the tow vehicle relative
speed is 6 knots. Therefore use the 6-knot plot in the selected graph.
For the tow vessel moving into the current:
Tow Vehicle Relative Speed = Tow Vessel Speed - Ocean Current
For example, for a tow vessel speed of 5 knots and an ocean current of 1 knot, the tow vehicle relative
speed is 4 knots. Therefore use the 4-knot plot in the selected graph.