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

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Model 865-A Deep Sea Acoustic Release/Transponder M-855-009
Benthos, Inc.
2
APPLICATION NOTE #865-001
SUBJECT : 865-A Acoustic Release
Definition of Load Ratings
The Benthos Model 865-A Acoustic Release was designed as a deep water/high load releasing device.
The current data sheet and manual state the "...load capacity is 4,540 kg (10,000 lbs.).
This statement necessitates the definition of load rating.
All loads discussed are assumed to be axial. Prior to shipment, all units are tested in a load-frame in our hydrostatic
pressure chamber to 10,000 psi (6,700 meter depth) which induces a load of 6,600 lbs. (3,000 kg) and the unit is
acoustically commanded through the chambers' wall as a second check of the release mechanism under hydrostatic
conditions. The units have been tested to failure and, typically, the release lever will fail at around 17,000 lbs. (7,730
kg).
What does all this mean? Conventional oceanographic mooring design typically employs hardware which will either
experience static or dynamic loading. Static loads typically incorporate a 2:1 safety margin by their users, and dynamic
loads usually have a 5:1 factor of safety on design.
The 10,000 lb. (4,540 kg) rating is applied to the maximum load under any conditions. Therefore, if you anticipate only
static loading and wish to work within a 2:1 safety margin, the maximum working load should be 5,000 lbs. (2,270 kg).
For dynamic situations, the maximum working load should be 2,000 lbs. (900 kg).
Any specific concerns should be addressed to Benthos where we can perform calibrated testing under static load
conditions.