Early construction: Boundary Channel Bridge Columbia Island (District of Columbia)

the dirigible uss akron flies on columbia island in 1931. below , right of airship s tailfins island, on extensive construction under way on great plaza , axial roads, boundary channel bridge, , memorial drive. note lack of bridges north (left in image).

bids construction of boundary channel bridge opened on july 18, 1928. project divided among several contractors. north carolina granite co. provided below-water granite, hallowell granite works provided granite voussoirs , facing on piers 10 feet (3.0 m) above mean low water level. woodbury granite co. provided coping granite , balustrades. hallowell delivered granite in may 1929, north carolina granite delivered june, , woodbury granite delivered half granite june 30, 1929. construction contract awarded n.p. severin company in october 1928.

nearly year passed before cfa approved pylon designs columbia island in march 1929. great plaza , roads on island needed further study.

work on boundary channel bridge began in spring of 1929, ran problems. unstable rock shelf 13 feet (4.0 m) thick lay under western abutment of arlington memorial bridge. rotten rock had not been revealed borings 2 years earlier, came light construction began on boundary channel bridge. additionally, thin layer of sand , gravel discovered lying atop bedrock of eastern abutment of boundary channel bridge. both obstacles had removed before construction proceed further. june 30, 1929, arlington memorial bridge s western abutment finished (except exterior masonry facing), , many of concrete columns boundary channel bridge finished.

by end of june 1930, additional filling in of columbia island needed finish arlington memorial bridge. no construction had occurred on columbia island great plaza, monumental columns, or 2 pylons cfa had still not approved final design these. additionally, work on western half of boundary channel bridge had come standstill. tracks of rosslyn branch of pennsylvania railroad ran along virginia shoreline. in order avoid at-grade crossing memorial drive, cfa proposed in june 1927 these tracks lower 20 feet (6.1 m). since meant extending boundary channel bridge, new engineering studies of bridge needed. corps , cfa still studying how depress pennsylvania railroad tracks 3 years later. informal negotiations had, end of june 1930, come agreement line moved closer river, , underpass through bridge (accommodating 2 side-by-side tracks) , depressed tracks should constructed first before railroad took title new line. permit uninterrupted rail service. pennsylvania railroad agreed cede old right-of-way government once new tracks , tunnel operational. otherwise, construction on boundary channel bridge complete.