a SASGEN SINGLE DRUM LIGHT DUTY HOIST loaded with 2,000 feet of 5/l6 

 inch wire rope, and capable of piilling 2,000 pounds. The shed was 

 constructed to overhang the rear of the flat-bed truck section. A 

 trap door was located in the overhung section for lowering and rais- 

 ing oceanographic instruments. A canvas skirt pegged to the ice sur- 

 rounding the ice hole made it possible for a kerosene stove to main- 

 tain normal room temperature inside the shed. Figure ilC shows per- 

 sonnel working arotrnd the ice hole under the overhang. They are tie- 

 ing off a lowered current meter strung to a wooden cross-piece sup- 

 port, preparatory to moving the R/V THULE off station. 



While drilling a hole through the ice might sound like a rather 

 mundane task, it is both a necessary and difficvilt part of an ocean- 

 ographic operation carried out on an ice covered area. This phase 

 of the field operation is shown in Figures 5A and 5B. A small dia- 

 meter, hand-powered ice auger used for making ice thickness measure- 

 ment holes is shown in Figure 5A. A large diameter gasoline-powered 

 ice auger used for making instrument access holes is shown in 

 Figure 5B. 



Oceanographic measurements made through sea ice req\iire drilling 

 a relatively large hole in the ice. The dimensions of the hole de- 

 pend on the size of the equipment to be passed through the ice and 

 the type of measurement to be made. The technique described was used 

 to make holes large enough to pass through the ice, the Hydroproducts 

 and Geodyne current meters and the modified E., G., and G. sea floor 

 camera. The size of the hole reqtilred was 2l«-" by 2V' . Eight holes 

 were prepared, varying in size from 19" by 31" to 27" by 51", all of 

 which were adequate. The time for preparation varied from 15 minutes 

 to 1.5 hours. 



The following equipment was used to make the holes: 



(a) Ice thickness kit, (b) an ice auger, 52" long and 7" iii 

 diameter, powenred by a 5HP Tecumsh, 2 cycle engine (c) a shovel and 

 (d) an ice spiid. 



The procedure, in outline form, follows: 



1. Measure the ice thickness. 



2. Clear an area of 20 square feet, 



5. Drill 10 overlapping 7" diameter holes in the ice to within 

 V of the sea water. This configuration leases an "island" in the 

 center of the hole. 



h. Depending on the thickness of the ice, the "island" may be 

 broken up and cleared from the hole or may be removed in one piece. 

 Forty inch thick ice left an "island" that could be removed by 2 

 men. 



321 



