DCHP-1 Online
bull block Lumbering 
a large pulley through which the main line (def. 3) passes in yarding operations.
See also: main line (def. 3)
- 1943 In ground lead logging, at first the main line rubbed or siwashed around a stump in order to spool it onto the drum, but when the bull block was invented, ground lead logging prospered by leaps and bounds, and its inventor, "Tommy" Moore, was crowned with a wreath of salal and made immortal among loggers who know their stuff.
- 1952 Next [after the spar tree is otherwise rigged] the bull block is fastened securely in place at the top of the spar tree with steel cable and iron tree-plates. Through it runs the main line which pulls the logs in front of the forest.
- 1963
There's where you'll hear the mainline hum
Through the bullblock, hanging high. . . .
- 1943 In ground lead logging, at first the main line rubbed or siwashed around a stump in order to spool it onto the drum, but when the bull block was invented, ground lead logging prospered by leaps and bounds, and its inventor, "Tommy" Moore, was crowned with a wreath of salal and made immortal among loggers who know their stuff.