counterweight

An object with a particular mass to offset the mass of another object it is attached to, in an effort to balance it or keep it in a particular position.

In a theatrical rigging system counterweight (also called bricks or pig iron) counterbalances the load of the batten. Typical couterweights are made of lead or steel and come in units of 22, 33, and 44 pounds. Larger bricks may exceed 100 pounds.

Each brick is grooved to allow it to slide onto the rails of the arbor. Typically opposite corners of the bricks are notched. When stacking bricks on an arbor, a rigger alternates the direction of these notches creating room for finger grip below the brick.

Part of the Stage Rigging Metanode