Figure Lr-21. 



The Van Veen sampler with modified 

 trigger. 



The dredge is operated from a heavy duty 

 winch or boom using i/o-inch diameter lowering 

 wire. During dredging operations, the ship is 

 lying to as the dredge is lowered ; then, the ship 

 slowly tows the dredge along the bottom at 2 or 

 3 knots. 



While the dredge is being towed, the deep sea 

 dynamometer must be watched for irregular 

 tension on the towing wire. If the tension is very 

 irregular, the dredge probably is skipping, and 

 more wire should be payed out to increase the 

 scope. Also, if rocky irregularities such as ledges 

 are encountered, the dredge will tend to foul. If 

 this occurs, the ship is stopped and, if possible, 

 reversed and maneuvered to free the dredge. If 

 this maneuver fails, a weak link in the dredge 

 bridle usually gives way, and upsets the ap- 



jjaratus dumping the sample and freeing the 

 dredge; thus, saving both the dredge and the 

 lowering wire. 



Rocks and representative samples of other 

 bottom material obtained should be packed in 

 wooden boxes, canvas bags, or sample jars, 

 labeled, recorded on the oceanographic Log 

 Sheet-M, and shipped in accordance with in- 

 structions contained in paragraphs Lr-39, L-40, 

 and L-41. 



Fiffwre Lr-22. Box shaped dredge. 



L-39 Oceanographic Log Sheet-M Bottom 

 Sediment Data. — The Oceanographic Log 

 Sheet-M is used for recording bottom sediment 

 samples. The following items of information 

 are recorded on the M-sheet; (fig. L-23) : 



Vessel. Enter the name of the ship from 

 which the sample is being collected. 



Cruise. Enter the number of the cruise or the 

 project designator. 



Checked hy. Enter the name of the person 

 checking M-sheet against core samples. 



Date Checked. Enter date, e.g., 12 Jan. 1965, 

 samples were checked against M-Sheet. 



Bottom Sediment No. (BS- ). Enter Bot- 

 tom Sediment Number assigned to Sample. 

 (This number must agree with sample number 

 on Sample Label.) 



Date (19 ). Enter year at top of column 

 and Day and Month, e.g., 10 Jan., for date 

 sample was collected. 



Sample Position {Latitude Longitude). En- 

 ter position of ship at time sampler reached 

 bottom. 



L-18 



