The four components from this J40 mold are cast first. One casting results in a complete arch consisting of a left and a right side part.
The width of the piers to be built corresponds to the desired width of the bridge. A suggestion for the pillars is included in the instructions for the basic set SM32.
The center piece (the actual bridge) is assembled as a separate component. Depending on the desired width of the bridge, one or more bricks No. 1 or No. 2 (from the basic set) are placed crosswise at each end and the now created cavity between the two arches is filled with casting material. The filling is formed e.g. with a spatula parallel to the bridge arches.