The Crab system The Crab system consists of a self-locking wedge key attached to a stirrup. Once a ledger comes into contact with a stirrup, the wedge key pivots automatically to form an instant connection. A single blow to the wedge key ensures the strength of the connection. When wedging is carried out along the main axes, it is guaranteed that the ledgers will be connected at right angles. A ledger may also be installed in any direction, without any dead angle. The Crab node can be used to fit 8 components simultaneously: 4 ledgers and 4 diagonal braces. The Crab system allows a ledger to have a single centre distance, irrespective of post diameter (49, 57 or 60 mm). This feature means that identical ledgers, diagonal braces and planks are used on all of our systems fitted with the Crab node. The Crab system is used on Multicrab scaffolding using Ø 49 mm diameter tubes, on Crabétai shoring using Ø 57 mm diameter tubes and on Crabtour and Touréchaf shoring using Ø 60 mm tubes. The use of common scaffolding and shoring components makes equipment management easy. The Crab system is able to mix and match standards with different diameters according to the load-bearing requirements. For example, Ø 57 mm Crabétai standards can be used for the bottom of very tall Ø 49 mm Multicrab scaffolding. = = Use this QR code to view the on-line Crab system presentation video. Entre-axes poteaux 1,00 m Poteaux Ø 49 mm Poteaux Ø 57 ou Ø 60 mm A ledger attached to a stirrup can be oriented in any direction, without any dead angle. Example with a 1.00 m ledger. 2 Ø 60 mm standard Ø 49 mm standard