In a traditional hemp and sandbag rigging system the clew is used to join the several ropes which support the batten to a single control line. This control line is then tied to the belaying pin on the pin rail, or counterbalanced with sandbags.

The reason the clew is necessary is because older theatres often used wooden battens. On a wide stage several ropes were needed to support this batten. Without the clew to join ropes each rope would have to be individually sandbagged. Moving a single batten would require as many riggers as there are ropes. With a clew, one single rope can control the series of ropes,thus allowing the lineset to be operated by just one person.

Part of the Stage Rigging metanode