Linking together preassembled formwork came after pouring an elevator’s slab

Initial formwork for new grain bins at Flagler in 1953.

Initial formwork for Tillotson Construction’s new annex of grain bins at Flagler, Colo., in 1953.

Editor’s note: The following explanation by Charles J. Tillotson helps to answer the question of how a grain elevator is built.

The excavation you see in the picture was dug for the foundation and floor slab of the annex at Flagler. Once the slab is poured, the forms that have been built are moved onto the slab where further carpentry is used to connect all the formwork together and construct the supplemental formwork such as horizontal ribs, jack yokes, et cetera, to make an integral form, all assembled into a uniform unit and capped entirely with a walking deck, also of wood.

Oftentimes the job site did not lend itself to building the major portion of the formwork simultaneously with the excavating and placement of the foundation (lack of space, topography, et cetera). So all of the formwork had to be built in place after the new floor was poured, which slowed the construction time of the overall build-out of the elevator.