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VI. SETTING AND RETRIEVING GEAR 
16, "One-dimensional" fore and aft rig 
As has been mentioned previously most of the work was done with a one 
dimensional fore and aft rig, which allowed gauges to be placed on two sides 
of the charge on two straight lines 180° apart, This rig was very simple to 
set and recover even in the event of a misfire. 
(a) Setting the gear, — For setting the gear all the various com- 
ponents were laid out from stern to bow on the port side of the RELIANCE in 
the order in which they would go overboard (Fig. 31). The heavier components 
such as the composite gauge blocks were lifted over the side and snubbed 
just above the water line by means of the manila recovery line. The charge 
was armed and prepared for launching. Then it was lifted by the hoisting 
boom by means of a pendant led through the supporting ring for the charge 
with the two ends of the charge hooked on to the hoisting boom tackle. 
When these preparations were complete, the large float nearest the sea anchor 
was throvm over-board and allowed to drift back away from the vessel, During 
the entire operation of sctting the gear the vessel was kept underway and 
also stcered slightly to port to keep the gear away from the propeller, 
After the sea anchor ball had been payed out the sea anchor itself was put 
over=board and opened. The small weight near the sea anchor was then put 
over, and that part of the gear was payed out by the line which lead up to 
the sternmost gauge block. When small ball-crusher gauge blocks were 
located at great distances from the charge, the line was made of 5/16=in. 
wire rope. However, when such gauge blocks were hot used, the line was 
usually of manila, When the line became taut on the sternmost gauge block, 
the block was slowly lowered by means of the manila safety line snubbed 
around a cleat on the deck of the RELIANCE, Due to the proximity of this 
gauge block to the next composite gauge block forward, the spacer cable 
between the two soon became taut and the lowering of the second composite 
gauge block was begun, snubbing with the rope recovering line over a cleat 
as in the first case. As these two gauge blocks were being lowered the strain 
came on the sternmost of the momentum gauge rigs. These momentum-gavge 
rigs were then lifted over the sides and lowered, snubbed again by means 
of the manila recovery linc. 
Before the strain reachod it the charge was lifted by means of the 
hoisting boom tackle and swung over. the side. The weight of the charge was 
then taken up by a manila snubber line, and the pendant by which the charge 
had been lifted was removed. Another rope snubber line, one end of which 
was made fast to the vessel, was passed through an iron ring just forward 
of the forward momentum-gauge rig, and was used to take the strain of the 
after part of the gear until the charge was fairly well dovwm in the watere 
As the gauge blocks and charges neared their final depth, their sup= 
porting floats were thrown overboard, and the snubber lines quickly throvm 
off the cleats. While the charge was being lowered the other components 
were lowered simultaneously, keeping all lincs tight. The spacer linc 
forward of the charge (carrying the piezoelectric gauges, and for the early 
= 38 - 
