A few things are common to both buildings and bridges. Of these the balustrades, pylons, approaches and lamp brackets and posts can be mentioned. Bridge arches have little analogy to arches in buildings because they are usually much larger and serve an entirely different purpose. To some, unfortunately, an arch is merely an arch regardless of its special function. It will be found that the engineering properties of a bridge arch will frequently develop a pleasing outline. Constructed of reinforced concrete, the outline of the intrados and extrados of the arch can be made to conform
to any reasonable architectural demand without greatly violating economical limits. This is one of the advantages of reinforced concrete construction.
Aside from the balustrades, lamp posts, pylons and approach accessories, the parts of a concrete bridge are monolithic except for expansion joints which are infrequent. These joints can be hidden or be left frankly exposed because necessary. Designing on this hypothesis, a monolithic structure may or may not have the appearance of an articulated stone structure. The surfaces of a monolithic structure may consist of different planes separated
by offsets or mouldings. In this manner the desirable and necessary shadows can be obtained. Concrete is a plastic material cast in forms and should be designed in accordance with this quality.
The designing of bridges should be confined to those who are competent (I). Competency in bridge architecture is not necessarily the attribute of either architects or engineers and can be common to both. Responsible charge can be placed with each profession. It is as possible for the engineer to include a competent architectural designer in his organization as it is for an architect to
include a competent bridge engineer in his. This is not desirable in either case because there is not a sufficient volume of bridge work to justify many such organizations. The reasonable course seems to be the employment of both architects and engineers on an exactly equal basis. The selection of the engineer is a comparatively easy matter as his competency is manifest in successfully accomplished work. The ability of architects to design bridges as such and in suitable materials is a much more difficult problem owing to their lack of experience with that kind of structures. NORTH APPROACH, WASHINGTON MEMORIAL BRIDGE, WILMINGTON, DEL.
VANCE W. TORBERT, ARCHITECT—BENJAMIN H. DAVIS, ENGINEER
to any reasonable architectural demand without greatly violating economical limits. This is one of the advantages of reinforced concrete construction.
Aside from the balustrades, lamp posts, pylons and approach accessories, the parts of a concrete bridge are monolithic except for expansion joints which are infrequent. These joints can be hidden or be left frankly exposed because necessary. Designing on this hypothesis, a monolithic structure may or may not have the appearance of an articulated stone structure. The surfaces of a monolithic structure may consist of different planes separated
by offsets or mouldings. In this manner the desirable and necessary shadows can be obtained. Concrete is a plastic material cast in forms and should be designed in accordance with this quality.
The designing of bridges should be confined to those who are competent (I). Competency in bridge architecture is not necessarily the attribute of either architects or engineers and can be common to both. Responsible charge can be placed with each profession. It is as possible for the engineer to include a competent architectural designer in his organization as it is for an architect to
include a competent bridge engineer in his. This is not desirable in either case because there is not a sufficient volume of bridge work to justify many such organizations. The reasonable course seems to be the employment of both architects and engineers on an exactly equal basis. The selection of the engineer is a comparatively easy matter as his competency is manifest in successfully accomplished work. The ability of architects to design bridges as such and in suitable materials is a much more difficult problem owing to their lack of experience with that kind of structures. NORTH APPROACH, WASHINGTON MEMORIAL BRIDGE, WILMINGTON, DEL.
VANCE W. TORBERT, ARCHITECT—BENJAMIN H. DAVIS, ENGINEER