Hand counter pull
Hand counter trains are a special type of theater train . They belong to the upper machinery of the stage technology . Hand counter-hoists are operated manually and are used for a quick scenic transformation of the theater decoration. As a rule, they belong to the category of prospectus hoists and thus have a pull rod to which decorative elements or stage prospectuses can be attached.
In theaters that use manually operated overhead machinery , the trains are operated from the Schnürbodengalerie during rehearsals and performances . This gallery is usually located above the stage area, but sometimes also at stage level. The lacing master and his lacing staff are responsible for the maintenance and operation of the cables .
Working principle
Simple hand counter-pull
The rope floor personnel move the trains by means of the command ropes, which run down the side of the stage wall and are connected to the weight sled. This carriage is in the simple Handkonterzug with the counterweights loaded, which correspond to the weight in about to be moved decoration. The dead weight of the tie rods is balanced with a permanently installed basic weight. Thus, when the train is moving, the entire suspended load does not have to be moved by muscle power, only the friction has to be overcome.
In many theaters there is a weight gallery above the stage for the loading process, on which the weights are stored and can be placed on the counterweight sled.
Doubled hand counter-pull
The doubled hand counter- hoist works like a pulley block . It is used when the full platform height cannot be used for the counterbalance tracks, for example because a side platform is connected to the main platform. In the case of doubled trains, the counterweight track ends halfway up the stage.
The pulley principle is reversed with the doubled hand counter-hoist. Pulley blocks are commonly used to reduce the force required to lift a load. According to the golden rule of mechanics , the reduced force is bought at the cost of a rope path that is increased by the same factor. With the doubled hand counter pull, you don't want to reduce the force, but rather the rope distance. In return, the pulling force must be increased. Therefore, the weight of the counterweights must be twice as high as the load in the drawbar to counter the pull.
Spread and future
The manual counter trains can still be found as prospect trains in many theaters. However, they are hardly ever newly installed. Computer-aided upper machines with different drive technology, electric motor or hydraulic , are standard today and, due to their speed, programmability and load capacity, offer a multitude of options that are not available with manual counter-hoists.
literature
Stage technology, mechanical equipment, 4th revised. Edition / Bruno Grösel: R. Oldenbourg Verlag Vienna Munich 2007, ISBN 978-3-8356-3128-1