884 EXPLORATION GEOPHYSICS 



winch is driven from the truck engine by means of a side outlet power 

 take-off assembly installed in the truck. The winch line passes under the 

 truck bed and comes out between the guide sheaves (D) and the roller (E) 

 at the rear. The winch line, threaded around the guide sheave (F) and up 

 over the "A" frame sheave (C), is used for pulling casing from holes after 

 they have been shot in areas where casing is required. There are also guide 

 sheaves (G) at each rear corner of the truck, as the winch line is useful for 

 pulling this truck or the drill truck over short stretches of wet or swampy 

 ground or on sandy roads. 



Between the spare tire and the water tank is a 30-gallon auxiliary gaso- 

 line tank. On the left side of the water tank is a storage box for carrying 

 aquagell or other special mud additives. A drinking water can is mounted 

 directly in front of this mud box. There is space between the vertical guard 

 posts on either side of the truck bed to carry extra pieces of 10-foot drill 

 rod. The water tank itself is built with a luggage rail around the top for 

 tying down extra supplies on long hauls. The suction hose usually has one 

 end connected to the tank. The other end is inserted in a special pipe com- 

 partment where it is carried when moving. 



There are several methods used for filling the water tanks. One is to 

 equip the water truck with a small rotary-type water pump driven by a 

 power take-off from the truck engine. A second is to equip the water trucks 

 with a single-cylinder, double-acting, reciprocating-type plunger pump 

 driven by a power take-off from the truck engine and also arranged so that 

 it can be operated by hand. 



A third method is to use a separate portable gasoline-engine-driven 

 pumping unit, light enough to be carried by one man. This is a light-weight 

 centrifugal pump directly connected to a single cylinder gasoline engine. 

 This method is used when the source of the water is more than eighteen or 

 twenty feet below the lowest elevation that the water truck can reach, mak- 

 ing it impossible to lift the water by direct suction. The portable pumping 

 unit is carried down close to the water level where the water can be lifted by 

 direct suction, and is discharged under pressure up through a hose line into 

 the water tank. 



A fourth method is to have the water tank made air-tight so it can be 

 filled by means of a vacuum drawn from the intake manifold on the truck 

 engine. This method makes it possible to create a vacuum in the tank while 

 the truck is traveling to the location of the water supply, so that upon arrival 

 at the water source the tank can be very quickly filled by the vacuum already 

 created. A float-operated valve should be mounted on top of the tank to 

 break the vacuum when the tank is full, so that water cannot be drawn into 

 the engine intake manifold. In freezing weather the exhaust from the 

 engine is circulated around this float valve assembly to insure its proper 

 functioning. The quick full-opening valve at the rear has an air-tight 

 rubber seat. 



