STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

598 Drilling and Well Completions
Table 4-34
Recommended Reeving Arrangements for 12-, lo-, 8-, and 6-Line
String-ups Using 7-Sheave Crown Blocks with &Sheave Traveling
Blocks and 6-Sheave Crown Blocks with 5-Sheave Travelina Blocks 1111
5. Location of deadline anchor, and its influence upon the maximum rated
static hook load of derrick.
Recommended Design Features
The proper design of sheaves, drums, and other equipment on which wire
rope is used is very important to the service life of wire rope. It is strongly urged
that the purchaser specify on his order that such material shall conform with
recommendations set forth in this section.
The inside diameter of socket and swivel-socket baskets should be + in. larger
than the nominal diameter of the wire rope inserted. Alloy or carbon steel, heat
treated, will best serve for sheave grooves. Antifriction bearings are recommended
for all rotating sheaves.
Drums should be large enough to handle the rope with the smallest possible
number of layers. Drums having a diameter of 20 times the nominal wire-rope
diameter should be considered minimum for economical practice. Larger
diameters than this are preferable. For well-measuring wire, the drum diameter
should be as large as the design of the equipment will permit, but should not
be less than 100 times the wire diameter. The recommended grooving for wirerope
drums is as follows:
a. On drums designed for multiple-layer winding, the distance between groove
centerlines should be approximately equal to the nominal diameter of the
wire rope plus one-half the specified oversize tolerance. For the best