Investigators subsequently determined that the wooden formwork did not meet industry standards.

The overall frame of the building is in raw concrete, with clear markings of the wooden formwork.

In a partially successful experiment, he used wooden formwork to imprint a texture onto the concrete (but he chose to cover it up).

Thus a large scale systematic and reusable formwork was developed, with the wooden formwork panels being produced and shipped from the Amstetten company.

It has been claimed that the board of the Great Western Railway did not believe that the arches would stay up under the weight of the trains and ordered Brunel to leave the wooden formwork used to construct the arches in place.

Its double-shell construction of bricks locked together in herringbone pattern (re-introduced from Byzantine architecture), and the gentle upward slope of its eight stone ribs made it possible for the construction to take place without the massive wooden formwork necessary to construct hemispherical arches.