BEFORE Sir John Wolfe Barry was called into consultation, the main outlines of the Tower Bridge had already been decided upon. Sir Horace Jones, the City Architect, had submitted several designs to the Bridge House Committee, which, evolving through several stages, finally assumed a form not unlike the actual building. It may be of interest to study some of Mr. Horace Jones’s preliminary sketches, because these throw light upon the aesthetic problem which required to be solved. Figure 3 shows his first design for a bascule bridge, while Figure 4 was the one which held the field when Sir John Wolfe Barry was appointed engineer to the scheme. It was considered that any arched form of construction (such as Figure 3)across a span to be used by masted ships was inadmissible, and that whatever headway was given should be absolutely free of obstruction throughout the whole of the span. Sir Horace Jones, unfortunately, died in 1887, when the foundations had not made much progress, and up to that time none of the architectural designs had proceeded further than such sketches and studies as were barely sufficient to enable an approximate estimate to be made of the cost. After the death of Sir Horace Jones, the general architectural features of the Parliamentary sketch designs were preserved, but it will be seen that the structure as erected differs largely therefrom both in treatment and material. The width and, consequently, the weight of the bridge was increased by the requirements of Parliament, and the span of the central opening was enlarged from 160 feet, as originally intended, to 200 feet. At the same time the provision of lifts and stairs to accommodate foot passengers when the bridge was open was felt to be a necessity. It thus became apparent that it would not be possible to support the weight of the bridge on towers wholly of masonry, as in the first design, unless they were made of great size and unnecessary weight. It was therefore necessary that the main support should be of iron
or steel, which could, however, be surrounded by masonry, so as to retain the architectural character of the whole structure. It was clear that in any event a large part of the steelwork of the towers must be enclosed in some material, for the moving quadrants project upwards some forty feet from the level of the roadway, while the stairs and lifts also required protection from the weather. It thus became a question of surrounding the towers either with cast-iron panelling or with stone, and eventually a granite facing with Portland stone dressings was adopted.
A. Tryston Edwards