TM 5-3820-256-10
(13)
Frame Components.
(a) Frame lighting.
(b) Operator's and helper's platform.
(c)
Front and rear hydraulic leveling jacks.
(14)
Truck.
(a) Rear axle or front and rear axle drive.
(b) Air brakes.
(c)
6-cylinder diesel engine.
(d) Turbocharger.
(e) Five-speed transmission.
(f)
Two-speed transfer case.
(g) Power steering.
b.
Location and Description of Major Components.
(1) Mast (1, Figure 1-2). The mast is mounted to mast pivot brackets at the rear of the drilling rig. Hydraulic
cylinders raise and lower the mast to upright or transport positions. The mast's height (32') permits the use of 20' drill
pipe or'20' lengths of casing. The mast is equipped with a chain feed, hydraulic-motor powered pulldown system for
applying drilling pressure on the bit. A lighting system allows use of the drilling system at night.
(2) Mud Pump (2, Figure 1-2). The mud pump provides circulation of drilling fluid during drilling operations. It is a
duplex, double-acting, piston-type pump with removable, hardened-steel cylinder liners. The pump is driveshaft driven
from the sub-drive, by way of an air-clutch operated mud pump drive unit.
(3) Air Compressor (3, Figure 1-2). The air compressor provides air for air rotary drilling; it can also be used to
supply air for drilling large diameter holes using the foam method. The compressor is powered from the sub-drive
through an air clutch.
(4) Sub-Drive (4, Figure 1-2). The sub-drive assembly is a power transfer unit that receives power from the truck's
power take-off. One side of the subdrive delivers power to drive the drawworks and the air compressor; the other side
delivers power to drive the mud pump and the four hydraulic pumps used to deliver hydrostatic power to other rig
systems.
(5) Drawworks (5, Figure 1-2). The drawworks consists of three cable drums used for lifting drilling components at
the drilling site. The hoist drum supports the swivel, kelly, drill pipe, drill collars, and bits-elements that make up the "drill
string." The auxiliary drum is used to handle drill pipe when adding joints of drill pipe to the drill string. These two drums
have a relatively short length of cable, typically long enough for raising and lowering items the height of the mast. The
third drum has much more cable, of smaller diameter, and is used to lower tools and instruments to the bottom of the
hole. The drawworks is drive-shaft driven from the sub-drive, through a bevel gear box. Each drum is independently
operated by an air clutch.
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