Oroua River, Otaki River, and Waikanae River Bridges.

These bridges are all on the Auckland-Wellington Main Trunk line between Wellington and Marton. The type of bridge adopted in the reconstruction is similar in all three cases, viz., 60ft. deck plate girder spans on mass concrete piers supported on reinforced concrete piles.

The Oroua bridge will have ten spans, the Otaki nineteen, and the Waikanae three. The construction of the steel plate girders (approximately 700 tons of steelwork) is now being carried out at the Hutt Railway Workshops, the steel plates and shapes being imported from Great Britain.

The Waikanae bridge is being reconstructed on the site of the present bridge, and it was, therefore, impracticable to consider letting a contract for the work, which has to be carried out under traffic conditions. Railway gangs have now been at work for some weeks on the construction of the new foundations.

The Otaki and Oroua bridges are each being reconstructed a short distance upstream from the existing bridge. In order to obtain easy curves on the approaches, so that maximum speeds can be run on the deviations, the new centre lines are slightly divergent from the lines of the present bridges.

The construction of the embankments on the approaches to both these bridges has been completed. At Otaki a steam shovel and work train were employed, and the work was carried cut very expeditiously. For the purpose of facilitating the transport of materials and carthwork, and to enable the girders to be run out on trucks from the shops into position alongside the new piers, and thence lifted by page 38 cranes direct from the trucks into their final positions, temporary tracks, with light bridging over the main channels, were laid across the wide riverbeds. This arrangement will make for fast and cheap construction.

The concrete foundation work is in the hands of contractors. Rapid progress cannot be made with this work, however, because of the hard driving encountered in putting down the reinforced concrete piles in the shingle riverbeds. The contractors for the Otaki bridge foundations are Messrs. Christiani and Nielsen, and for Oroua, Mr. C. Wesley.

In the South Island, during the past year, the strengthening of the Teremakau River and Crooked River bridges, on the Westland section, was completed, and two weak bridges (Nos. 10 and 13) on the Addington-Waiau line were also strengthened up.

From the foregoing it will be seen that quite a comprehensive programme of bridge-work has been carried on during the last twelve months.