Abstract: An arrangement for use in the inspecting and carrying out of maintenance on, for example, the undersurface of bridges and viaducts, including piers thereof, the arrangement being adapted for mounting upon a mobile frame, the arrangement comprising in combination a first elongated member adapted to be rotatably mounted upon the mobile frame; a second elongated member secured to the first member and adapted to extend therefrom; motor means for use in rotating the second member relative to the first member; a third elongated member hingedly secured to the second elongated member adjacent the free end thereof; fifth wheel means associated with the third elongated member for use in rotating the third elongated member relative to the second elongated member; and a fourth elongated member secured to the third elongated member and extendable therefrom so as to lie in spaced parallel relation to the first and second elongated members.

Abstract: A temporary, modular, self-erecting bridge which can be transported from place-to-place by collapsing the side, top and bottom elements about pivot points to achieve a narrow and shorter unit. Hydraulic jacks or other fluid actuated mechanisms are used to expand and contract the elements.