Response of the depressor (with a flap gain of 6.6 deg/m) to a sine wave con- 

 trol input is shown in Figure 11. The depth response is not meaningful as noted 

 earlier. However, the tension response has very little distortion which indicates 

 that the depressor and control system are performing satisfactorily. 



AT-SEA EVALUATION 

 A one-day, at-sea towing evaluation of the depressor was conducted out of 

 Bermuda in Nov 1979 aboard USNS KANE (AGS-T27) to examine hydrodynamic performance 

 in an operational environment. The CTD electronics were not installed, nor was the 

 performance of the remote sensor mounts examined during the evaluation. The equip- 

 ment, procedures, and results are discussed below. 



EQUIPMENT 



Equipment consisted of the following: 



1. The depressor ballasted with a 44.5 N weight in the nose to simulate the 

 expected weight of the CTD electronics; 



2. The standard towcable; 



3. A handling winch provided by NAVOCEANO; 



4. An overboarding sheave (suspended below the fantail A-frame) also provided 

 by NAVOCEANO; 



5. A towcable clamp to transfer the towing tension from the winch to a hard- 

 point on the ship deck; 



6. A 22.2-kN (5000-lb) capacity load cell with an estimated overall accuracy 

 of + 100 N located at the cable clamp for measurement of towing tension; and 



7. The depressor control electronics which provided depth control as well as 

 measurement of control-flap angle and body depth. 



Tension, flap angle, depth, and the difference between initial set depth and 

 actual depth (Delta depth) were recorded on a series of single-channel strip chart 

 recorders provided by NAVOCEANO. Ship speed was obtained from a speed calibration 

 curve based on propeller turning rate. 



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