Dead hang

A dead hang is a load suspended straight down from one attachment, with nothing pulling sideways. The point sees only the weight, the arithmetic is the weight, and there is no geometry to calculate.

It is worth naming because it is the thing a rigger is trying to achieve and the thing a plot gets redrawn to allow. Every alternative is more expensive in some currency: a bridle costs tension and horizontal force, ground support costs floor and engineering, and moving the load costs a sightline or a seat.

This is why the useful question early in planning is not where the lighting should hang but where the building will allow it to hang straight down. A venue’s steel runs in one direction on a fixed spacing, and a rig laid out on that spacing is a rig of dead hangs. A rig laid out on a designer’s preferred spacing without reference to the steel is a rig of bridles.

The same logic applies to a single heavy item. A video wall placed a few feet to one side so that it lands under a beam is straightforward; the same wall centred on a room with no beam above the centre line becomes a bridled hang with horizontal forces on two members, and an engineering question that did not previously exist.

Staging and rigging — owned inventory, our own crew, and a site survey before anything is specified.

• Bridle Two legs run from separate attachments to a common point, used when the hang position does not line up with a beam — and a geometry that multiplies tension rather than sharing it.
• Rigging point One place where a load is attached to the building — counted and rated individually, because the building cares where the weight is, not how much is in the room.
• Point load The force delivered into one attachment — the number a building is rated against, and the reason total rig weight is the wrong thing to quote a venue.