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146 STRUCTURE AS ARCHITECTURE▲ 7.27 Stadelhofen Railway Station, Zürich, Switzerland,Santiago Calatrava, 1990. Escalator entrance structure.▲ 7.28 Upper cantilever-to-torsion-beam connection, withsmaller canopy cantilevers in the background.given the ‘sagging’ beam profiles. Zannos suggests that designers shouldavoid this type of structural detailing:If it is indeed true that we dislike forms that appear weak because theirshape is deformed or seems to have been deformed by loading, it is quite naturalthat we prefer forms that are in contrast to that shape. We may thuspropose the following law of aesthetics: a form . ..agrees with our aestheticintuition – and, hence, satisfies us aesthetically – if its shape contrasts theshape that would have resulted if the form had been deformed by loading. 9In this building, rather than the sagging beam soffits creating the senseof oppression that might be experienced in a more enclosed space, theylead the eye away from any potential visual heaviness towards the lightand the open space on either side of the building.The Stadelhofen Railway Station, Zürich, comprises a number of steeland concrete structures all of which to some degree illustrate detailingthat expresses structural actions. For example, consider an escalatorentrance structure (Fig. 7.27). The upper cantilever springs from ashort pier bolted to a concrete base whose top surface slopes parallelwith the cantilever. Immediately, by inclining its base Calatrava introducesa sense of dynamism to the structural form.Like all other cantilever beams in the station, the cantilever tapers to apoint, approximating the shape of its bending moment diagram. Near itsend it supports an unusually configured and orientated two-pinnedframe whose member profiles also match their bending moment diagrams.The form of this hanging lower structure recalls that of a swimmerdiving. Under each of the two canopies of the escalator entrance,smaller beams cantilever from tubular torsion-resistant beams. The circularbolted plates express the transfer of torsion into the main members(Fig. 7.28). Here, detailing not only expresses structural actions