VER SALES, INC.
The methods of reeving tackle blocks will vary with the applications. With heavy lift cargo booms, cranes and so forth, where blocks with four sheaves or more are required, a number of lead blocks have to be considered. The Brewer- Titchener engineering department will be happy to assist on such applications.

Method of Figuring "Parts of line"

L
------ =E
P

L = Load lifted in pounds
P = Line pull in pounds
E = Efficiency

For example: To figure "Parts of Line
required when load lifted "L" and line pull "P" are known.

32,000 Ibs.
(load lifted "L")
---------------- = 5.3 ("E")
6,000 Ibs.
(line pull "P")

You can see in the table below that an "E" factor of 5.3 requires 6 "Parts of Line".
1 2 3 4 5 6 7 8 9 10 11 12
"E" Factors Bronze
Bushed		 0.96 1.85 2.8 3.6 4.4 5.2 5.9 6.6 7.3 7.9 8.5 9.1
Roller
Bearing		 0.98 1.9 2.9 3.8 4.7 5.6 6.5 7.3 8.2 9.0 9.8 10.6