9) consists of a steel braced tower, on which revolves a large horizontal double **cantilever**; the forward part of this **cantilever** or jib carries the lifting crab, and the jib is extended backwards in order to form a support for the machinery and counter-balance.

The Taff is spanned by two bridges, one a four-arched bridge rebuilt in 1858-1859 leading to Llandaff, and the other a **cantilever** with a central swinging span of 190 ft.

There are two high-level footways for use when the bascules are raised, the main girders of which are of the **cantilever** and suspended girder type.

- Typical **Cantilever** Bridge.

(e) **Cantilever** Bridges.

The exceptional local conditions at the site of the Forth bridge led to the adoption there of the **cantilever** system, till then little considered.

The length of the **cantilever** bridge is 5330 ft., made up thus: central tower on Inchgarvie 260 ft.; Fife and Queensferry piers each 145 ft.; two central girders between **cantilevers** each 350 ft.; and six **cantilevers** each 680 ft.

This is due to the half weight of centre girder, the weight of the **cantilever** itself, the rolling load on half the bridge, and the wind pressure.

(4) The Red Rock **cantilever** bridge over the Colorado river, with a centre span of 660 ft.

21 shows a typical **cantilever** bridge of American design.

The girder spans are 525 ft., the **cantilever** spans 547 ft., and the shore spans 201 ft.

The central double **cantilever** is 360 ft.

The **cantilever** rests on two river piers 120 ft.

The counterweight is a depressed **cantilever** arm 12 ft.

Since the erection of the Forth bridge, **cantilever** bridges have been extensively used, and some remarkable steel arch and suspension bridges have also been constructed.

The great **cantilever** bridges have been erected in the same way, and they are specially adapted for erection by building out.

58, 5 q and 60 show an independent girder, a **cantilever**, and a **cantilever** and suspended girder bridge.

The **cantilever** and suspended girder types are as economical and free from uncertainty as to ' ??` the stresses.

In long-span ¦ bridges the **cantilever** system permits erection FIG.

Farther down the river are two railway bridges, the Michigan Central's **cantilever** bridge, completed in 1883, and the (lower) single steel arch bridge (completed in 1897, on the site of John A.

The Pasig river is crossed by two modern steel **cantilever** bridges.

The river is spanned here by a **cantilever** railway bridge 1895 ft.