Scaffolding arrangement for attaching to a bridge or similar deck structure, comprising - a set of arms including a carrier beam for carrying working levels and support structures needed in work, - an attachment frame for attaching the set of arms to an upper surface of the deck structure, - at least one platform (103, 104, 105) for forming at least one of the working levels, characterized in that the arrangement comprises a) a locking mechanism (401, 402, 403, 404) for locking the at least one platform (103, 104, 105), used for forming the at least one of the working levels to two adjacent carrier beams of the scaffolding arrangement so that the locking mechanism (401, 402, 403, 404) allows enough play so that the at least one platform (103, 104, 105) can be tilted in relation to the longitudinal axis of the carrier beams, and b) at least one support shelf formed on each of the carrier beams for supporting the at least one platform (103, 104, 105), c) whereby the at least one platform has end profiles with protruding lower edges, whereby one of the protruding edges is resting on the at least one support shelf, which support shelf has turned edges for holding the one of the protruding lower edges of the of the at least one platform (103, 104, 105), d) whereby the at least one shelf is dimensioned wide enough to allow tilting of the at least one platform (103, 104, 105) to form a working level to follow the curvature of an edge of said bridge or similar deck structure, wherein the locking mechanism (401, 402, 403, 404) further comprises - a locking guide formed at the end profiles of the platform (103, 104, 105), - a hole in the carrier beam, - a locking hook and a locking nail whereby the locking hook is adapted to be slid into the locking guide and to be passed through the hole, where after it is adapted to slide sideways when locking nail is pushed into the locking guide next to it - while the hole is dimensioned so that it allows the desired tilting movement. - a set of arms including a carrier beam for carrying working levels and support structures needed in work, - an attachment frame for attaching the set of arms to an upper surface of the deck structure, - at least one platform (103, 104, 105) for forming at least one of the working levels, a) a locking mechanism (401, 402, 403, 404) for locking the at least one platform (103, 104, 105), used for forming the at least one of the working levels to two adjacent carrier beams of the scaffolding arrangement so that the locking mechanism (401, 402, 403, 404) allows enough play so that the at least one platform (103, 104, 105) can be tilted in relation to the longitudinal axis of the carrier beams, and b) at least one support shelf formed on each of the carrier beams for supporting the at least one platform (103, 104, 105), c) whereby the at least one platform has end profiles with protruding lower edges, whereby one of the protruding edges is resting on the at least one support shelf, which support shelf has turned edges for holding the one of the protruding lower edges of the of the at least one platform (103, 104, 105), d) whereby the at least one shelf is dimensioned wide enough to allow tilting of the at least one platform (103, 104, 105) to form a working level to follow the curvature of an edge of said bridge or similar deck structure, - a locking guide formed at the end profiles of the platform (103, 104, 105), - a hole in the carrier beam, - a locking hook and a locking nail