LOCATION AND DESCRIPTION OF MAJOR COMPONENTS - continued

TM 9-2320-269-20-1

LOCATION AND DESCRIPTION OF MAJOR COMPONENTS - CONTINUED

DERRICK EXTERIOR - CONTINUED

The rotating turret mounts on top of the derrick mast, and the rotation gear is driven by a hydraulically powered motor. The

turret rotates to 360 degrees right and left direction only, non-continuous, and is controlled from the operator's station.

The derrick leg is attached to the rotating turret. The outer steel tube houses the fiberglass extension section and

hydraulically powered extension section. The derrick leg is elevated and lowered by the elevation cylinder which is

controlled from the operator's station.

The fiberglass insulating extension is housed inside the outer derrick leg. This fiberglass section is manually extended.

The fiberglass section insulates the steel hydraulic extension against contact with high voltage power lines when crew

personnel are working in the aerial baskets.

The hydraulic leg extension telescopes out and retracts hydraulically from the outer steel derrick leg tube. The hydraulic

leg extension is controlled from the operator's station and aerial basket.

The derrick leg elevation cylinder elevates and lowers the derrick leg assembly. The elevating cylinder is controlled from

the operator's station and aerial basket.

TA228519

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