in keeping with the commanding position which it would occupy at the entrance to one of the most beautiful harbors in the world.

The other case, as indicated at the beginning of this chapter, is that of a proposed suspension bridge, having a single span of 1,750 feet which clears the entire width of river between the established harbor lines, to join the cities of Philadelphia and Camden.

Quite lately the author was struck with the idea that a transbordeur might serve all the traffic at the crossing and save considerable money as compared with a bridge, consequently he had his office prepare a layout, using a three-deck cage to carry street-cars, automobiles, and pedestrians; but a short preliminary economic study showed that the expense involved would be too great, consequently he prepared a two-deck layout that does not carry street-cars. These would run around a loop on each approach and would discharge and take on passengers close to the loading places of the cages. An estimate of cost was made for this layout based on the then-ruling prices of materials and labor, the grand total, excluding right-of-way, property damages, and interest during construction, amounting to $12,000,000. Then a layout was made for a bridge and its approaches, and a similar estimate of cost was prepared, amounting to $13,400,000.

As these two amounts differ so little, it was at once concluded that for this crossing there would be no real economy in adopting a transbordeur. The ratio of the said amounts is about 0.9, while the corresponding ratio for the New Orleans study was only 0.58.

From these figures it may be concluded that a long-span-suspension layout does not accommodate itself to the carrying of transbordeur cages as economically as does a layout of several shorter continuous spans. The explanation of this fact is that the piers for the two cases are about alike, that the approaches of the transbordeur are nearly but not quite as expensive as those of the bridge, and that while there is a large saving in the combined costs of superstructure and anchorages, it is largely offset by the cost of the cages, travelers, and pockets. In the New Orleans investigation the substructure of the transbordeur would cost but little more than one-half of that for the corresponding bridge, and the cost of the approaches to the former is a bagatelle when compared with that of those to the latter; but the total steelwork for the river spans, towers, bents, cages, travelers, and pockets of the transbordeur exceeds in value that of the river spans of the bridge.

Conclusion and Recapitulation

The title of this chapter indicates that it is intended to show both the possibilities and the economics of what in slang parlance might be termed the "glorified" transbordeur, i.e., the existing type of transporter bridge expanded and enlarged many fold so as to accommodate it to wide rivers, high  carrying  capacity,  and  rapid  transit.  Some of its possibilities have