| 摘要 |
A transportable bridge is provided which may be erected across a wide, e.g. 150 foot, depression, and with access to only one bank of the depression. The bridge comprises a pair of abutments and a plurality of deck units. The abutments are laterally extensible, and erectible, from a collapsed state; they each comprise a base, a pair of backstays pivoted to one end of the base, and a pair of beam columns pivoted to the other end of the base, the backstays and beam columns being at small, acute angles to the plane of the base in the collapsed position, and being erected to form a triangle in the use position. Connecting means at the free ends of the backstays and beam columns are automatically engaged upon erection. A pair of reaction beams each has one end pivoted to a beam column, intermediate its ends, and extends over the base and past the one end of the base: anchoring means anchor the reaction beams to the ground. The reaction beams have inwardly extending haunches, which form between them and the base a passage for the deck units.
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