A tubular transom (300, 300A) for temporary structures having vertical and horizontal structural members connected together in nodes by means of locking devices fixed at intervals on the vertical members, such as scaffolding or falsework, the tubular transom (300, 300A) having ends configured to be connected to the verticals at sections of the nodes, where each end (320, 320', 320A, 320A') of the transom (300, 300A) comprises a fastening device with an integrated profile part (200, 200A), releasably attached to an opening (100, 100A) at the ends (320, 320', 320A, 320A') of the tubular transom (300, 300A), wherein - the tubular transom (300, 300A) comprises a first (121, 121A) and at least second (122, 122A) elongate, parallel and hollow tube elements, interconnected at each end - the opening (100, 100A) at the ends of the transom (300, 300A) having at least partly a shape complimentary to the shape of the profile part (200, 200A) for receiving an end of the profile part (200, 200A) into an interior end part of the first and second tubes (121, 121A, 122, 122A), wherein - the first and the at least second elongate, parallel and hollow tube elements (121, 121A, 122, 122A) are interconnected by means of intermediate integrated web plates (123, 123', 123A, 123A') rigidly fixed to said at least two tube elements (121, 121A, 122, 122A), and - a contact surface (111, 111', 111A, 111A') of the opening (100, 100A) in the first tube (121, 121A), is transversally arranged relative to said web plates (123, 123', 123A, 123A'), - a contact surface (112,112', 112A, 112A') of the opening (100, 100A) in the second tube (122, 122A) is transversally arranged relative to said web plates (123, 123', 123A,123A'), and wherein - the contact surface (111, 111', 111A, 111A') in the first tube (121, 121A) is oppositely facing the contact surface (112, 112', 112A, 112A') in the second tube (122, 122A) and both contact surfaces are arranged for at least partially engaging respectively with first faces (211, 211', 211A, 211A') and second faces (221, 221', 221A, 221A') of the profile part (200, 200A), - and wherein the fastening device at each end of the transom (300, 300A) is adapted for engaging with the locking device in the nodes of the temporary structure characterized in that - an opening (125, 125A) extends through said intermediate integrated web plates (123, 123', 123A, 123A') and is ended at one end in said first tube element (121, 121A) and at an opposite end is ended in the second tube element (122, 122A). - the tubular transom (300, 300A) comprises a first (121, 121A) and at least second (122, 122A) elongate, parallel and hollow tube elements, interconnected at each end - the opening (100, 100A) at the ends of the transom (300, 300A) having at least partly a shape complimentary to the shape of the profile part (200, 200A) for receiving an end of the profile part (200, 200A) into an interior end part of the first and second tubes (121, 121A, 122, 122A), wherein - the first and the at least second elongate, parallel and hollow tube elements (121, 121A, 122, 122A) are interconnected by means of intermediate integrated web plates (123, 123', 123A, 123A') rigidly fixed to said at least two tube elements (121, 121A, 122, 122A), and - a contact surface (111, 111', 111A, 111A') of the opening (100, 100A) in the first tube (121, 121A), is transversally arranged relative to said web plates (123, 123', 123A, 123A'), - a contact surface (112,112', 112A, 112A') of the opening (100, 100A) in the second tube (122, 122A) is transversally arranged relative to said web plates (123, 123', 123A,123A'), and wherein - the contact surface (111, 111', 111A, 111A') in the first tube (121, 121A) is oppositely facing the contact surface (112, 112', 112A, 112A') in the second tube (122, 122A) and both contact surfaces are arranged for at least partially engaging respectively with first faces (211, 211', 211A, 211A') and second faces (221, 221', 221A, 221A') of the profile part (200, 200A), - and wherein the fastening device at each end of the transom (300, 300A) is adapted for engaging with the locking device in the nodes of the temporary structure - an opening (125, 125A) extends through said intermediate integrated web plates (123, 123', 123A, 123A') and is ended at one end in said first tube element (121, 121A) and at an opposite end is ended in the second tube element (122, 122A).