A BRIDGE FOR NEW ZEALAND RIVERS.

Lyttelton Times, Volume XVII, Issue 983, 12 April 1862, Page 3

A BRIDGE FOR NEW ZEALAND RIVERS.

To the Editor of the Lyttelton Times,

Sik, —Permit me through your columns to draw attention to the ' Illustrated London News' of the 18th of January last, page 68. Engineers will probably find there an easy solution of the question how we are successfully, and at a cost within our means, to bridge over large Canterbury snow rivers like the Rangitata and Rakaia, as well as the minor streams, having wide shingle beds and subject to heavy freshets. The page 68 contains the view of a wrought iron, lattice girder bridge, built in May, 1861, across the river Ebro in Spain, for the Pamplona and Zaragoza railway. The length of the bridge is 2014 feet. The distances from pier to pier, about 100 feet, in all 21 spaces. The piers are iron cylinders, of 6 and 8 feet diameter, sunk through the bed of the river, about 30 feet to the rock. The work was completed in about 8 months, mainly during winter, in a year of very severe floods, the current running at times 15 miles per hour.

The view given of the river Ebro is such as—with the omission of the bridge—l have seen scores of times on our New Zealand rivers, especially on this island. The material and mode of construction of this work do not suggest the idea of enormous costliness, as a suspension bridge does; and this latter is the kind of bridge which has mostly been talked of as the only one with which we should be able to carry a road-way across a stream like the Rakaia.

It may probably be well worth sending hofne to enquire into the cost of an iron lattice girder bridge, with a view to trying one across some small stream like the Ashley, as an experiment.

Mr. Marshman was some years in the Royal Engineer Department, and would be a competent agent to enquire and give an opinion on the subject.

I am, sir, Yours obediently, H.