Page:Professional papers on Indian Engineering (second series).djvu/199

 No. CCXCIX.

BOAT BRIDGE OVER THE RIVER RAVI AT CHICHAWATNI, PANJAB.

[Vide Plates I.-III.]

By Rai BAHADUR Kuniya Lall, Assoc. Inst. C.E., Exec. Engineer, P. W. Dept., Panjab.

The above boat bridge was formerly straight, of the old usual construction, viz., boats supported against the stream by munj cables and anchors.

In the heavy rains of 1876 it was swept away, and was reconstructed in 1877, in a new curved form with boats supported on a strong iron chain, without any anchors in the river on the up-stream side.

It has eight anchors, or one to every alternate boat, on the down-stream side with munj cables, and about 20 feet of 4-inch chain to each, at the end attached to the boat, to prevent the bridge being blown up against the river by high winds.

Plate No. I. shows the present general form of the bridge, and Plates Nor. II., III., contain the constructive details.

The up-stream chain is a one inch short linked iron chain called "crane chain," and the down-stream chain a 4-inch stud chain.

The bridge consists of 16 boats in the cold weather, and 18 boats in the rains. The boats are large, of standard pattern, and the superstructure is also of standard pattern, on plan and specification published in Roorkee Professional Papers, see Vol. IV. of 1st Series, Paper No. CLXVIII.

The ends of the trussed girders are cased with sheet-iron, see figure 7, Plate No. III., to protect them against rapid wear and tear.

The chains are fastened to the boats at bow and stern, by means of stout