Training Walls.

This difficulty Sir John Coode intended should be rectified by the construction of training walls of stone which, by confining and directing the currents of both tides and floods, and being assisted by dredging, would deepen and maintain the depth of the river alongside the wharves, and out to the bar.

The training wall on the original plan extends for 12,300 feet, containing 120,000 tons of stone, and is estimated to cost £43,000; the cost was not included in the original estimate, being left for consideration as the trade of the port grew. The trade has grown, and the wall is now required to maintain the deep channel in the position required by the traffic. In the upper part of the wall a difficulty occurs which has been referred to Sir John Coode. The difficulty is that the wall, as shown on plan shuts out the deep channel of the river, and before the wall can be made, a new channel must be cut for the river through a large shingle spit which is too hard and compact to be scoured by the current The quantity to be removed from the shingle spit to give the river the same amount of waterway shut out by the training wall would be 200,000 cubic yards, and the cost would be about £10,000. But to dredge and scour the amount required to give the depth shown on Sir John Coode's longitudinal section would require the removal from this spit of about 500,000 cubic yards.