Benthos 865-A, Instructions For The Installation, Operation And Maintenance

Page: 23 / 68

Model 865-A Deep Sea Acoustic Release/Transponder M-855-009
Benthos, Inc.
15
4.3 Deployment
Before deployment be sure the following has been done:
n Inspection for damage, inside and out
n
O-rings inspected and lightly greased
n Battery voltage tested and battery changed if necessary
n
New anode properly installed and tightened
n Functional test complete.
The unit may now be attached to the mooring assembly to be deployed. The mooring assembly should
have been designed with the following considerations:
n
Maintain electrical isolation between the 865-A and the rest of the assembly to avoid corrosion
problems. The 865-A and spare links are fitted with plastic (Delrin) bushings for this purpose.
n Have a long enough tether between the 865-A and the anchor to avoid damage due to overshoot
when the anchor hits the bottom.
n
Provide a clear acoustic path to the surface from the transducer of the 865-A.
WARNING:
Be sure that the 865-A is switched to ON-ARMED before
deploying.
After the 865-A, with its instrumentation and mooring packages is deployed, the deck unit can be put
into RANGING MODE Repetitive STOP/START ENABLED. (Please refer to the DS-7000 manual
for a detailed discussion of this feature.) Now a constant update of SLANT RANGE will be
maintained until the maximum range is reached.
NOTE : The 865-A will stop replying at the end of the programmed enable time. See Section 6.3.1 for
details.
4.4 Recovery
Using surface navigation techniques, return to the general area of the mooring. Then stop the vessel and
lower the deck unit transducer over the side, as deep as possible. Chances are by this time the ENABLE
timer has run out, so first send an ENABLE command. Then send a single transpond and verify that the
release does reply. Read the slant range off the deck unit and move the ship if you wish to get closer.