Mexborough and Swinton Times March 3, 1906

The New Railway Bridge at Denaby
How the Feat was Performed in a Day
Engineers Description

Supplementing our description last week of the engineering feat of throwing a bridge across the river Don, in the course of a single day, we have received from Mr R.H.Clayton, the resident Engineer of the Dearne Valley Railway, the following lucid description of the structure and the manner in which it was placed place across the river.

The Lancashire and Yorkshire Railway Coal are constructing a branch line from the Dearne Valley Railway to the Denaby Main Colliery at Conisborough. This line crosses the river Don by a bridge of three openings, the centre one over the river and towing path being 106 feet span, the other two being small side spans of 22 feet each.

The bridge will carry a single line into the Denaby Main Colliery Co’s sidings, and gives a clear headway over the river of 19 feet for navigation purposes. The main span of the river consists of two outside braced girders, with cross girders and flooring, all of steel, resting on two cast iron cylinders on each side of the river, with brick abutments for the side spans. The cylinders 6 feet in diameter, are composed of a number of cast iron rings 1 inch thick and 6 feet deep, bolted together. These were sunk by compressed air onto rock foundations, and then filled with cement concrete to ground level, and brickwork set in cement above, completed with a stone cap bolted down to the brickwork in which the girders rests.

The two main girders and a portion of the flooring for the centre span, were built on rollers on the embankment on the Denaby side of the river, and pushed out over other rollers fixed on the two cylinders on this side, until the ends projected about 10 feet over the river. A barge upon which a trestle had been constructed, was loaded with about 20 tons of steel rails, and floated underneath the projecting ends of the girders.

Some of the weight was then taken out until the barge rose and the girders rested on the trestle. On Sunday, February 18, four steel ropes were fastened to the barge, two being worked by crabs on each side of the river; the other two ropes were attached to the girders themselves, and carried across the river to crabs on the embankment on the opposite side. Additional ropes were also fixed, staying the girders and the barge.

The bridge then rested for the greater portion of its length on rollers on the Denaby side of the river, with one end on the trestle. The barge with its load was then hauled across the river by the above-mentioned ropes. The ends of the girders were then attached to chains hung from blocks fixed to two derricks previously erected on the towing path and lifted off the barge which was floated away. The bridge was then let down on to its final position on the cylinders. The weight of the bridge carried by the barge was at no time greater than 40 tons, and the total weight when completed will be about 130 tons.
The work was carried out under the supervision of Mr D.C.Rattray, chief engineer of the Lancashire and Yorkshire Railway, Mr R.H.Clayton, being the resident engineer.
The contractors are Messrs. Gates and Hogg and the subcontractors for the steelwork Messrs. Francis Morton and co-Ltd, Liverpool.

The bridge had been erected by Messrs. J.H.and W.Bell Ltd, Liverpool and it is expected will be completed and opened for traffic very shortly.