A compressible, rubber rim that is used around the edge of a lift, to stop the lift in case of an emergency, thereby protecting limbs that could get trapped. The safe edge may be monitored by contacts closing as the edge is compressed or by resistance change, in which case the system will be programmed to fail.
Axes that are linked to a single piece of scenery but may have differing speeds or paths. This type of group contains an inherent safety relationship so that if one axes fails then they all stop (see also ‘Free groups’ and ‘Locked groups’).
The load which a lifting device or arrangement can safely lift, suspend or lower. The load represents a mass or force which is much less than that required to make the lifting equipment fail.
The ratio of the maximum stress or load which something can withstand to the stress or load which it was designed to withstand under normal operation.
A safety integrity level (SIL) is a measure of safety system performance, in terms of the probability of failure on demand. There are four discrete integrity levels, SIL 1-4. The higher the SIL level, the higher the associated safety level and the lower the probability that a system will fail to perform properly.
Usually flat panels of scenery tracked to run across stage manually or automated. Many slider formats have been used in the past with differing sizes, shapes and effects.
Stands for 'sliding, lifting, opening, automated trap'
Member of stage or automation crew who watches particular equipment moving in order to communicate to the operator if anything is out of the ordinary or if a particular effect needs to be ‘clear to run’.
A toothlike projection arranged on a wheel rim to engage the links of a chain.
A false stage floor which is built over the existing stage floor. A stage deck is generally used if machinery or effects are required to be built into the floor (such as floor tracks or smoke effects). This is often employed during tours as the floor contains all machinery and cable runs required for the touring show and remains discrete from the host theatre’s stage floor.
Rails in the stage floor or stage deck along which scenery, props, trucks or wagons can be pushed or pulled using automation or manual effort.
A moveable platform that accommodates a 3-D stage set for scene changes and usually runs along stage tracks in the stage deck or stage floor. Radio- controlled trucks are free-moving and are not limited by the positioning of stage tracks.
A type of stage truck which is larger and usually installed as a permanent feature of the infrastructure of a venue. For example, at the Royal Opera House in London wagons are used to deliver a complete built set to the stage from a storage or rehearsal position.
A section of stage floor which can be opened to bring up or take down a performer quickly using a counterweighted or automated elevator under the stage. Originally in the form of upward hinging flaps in a ‘star’ pattern enabling the performer to burst through with dramatic effect – these days drop and slide traps are more usually employed.
In automation programming terms, a pre-recorded sequence of motion (also see ‘Cue’).
A cable made of twisted steel, often used to replace hemp ropes due to its durability. The rope can be in an array of formations made up with differing numbers of strands and twists (e.g. 7 by 19 referring to 7 groups of 19 strands). Each group is twisted together and then the groups twisted around each other, to increase tensile strength. In modern theatres, steel wire rope may be replaced by Dyneema rope or Kevlar rope.
Striking the set (usually referred to as the 'get out' in modern touring theatre) is the dismantling of the set.
A computer that provides central data storage facilities.