OUR HARBOUR DEFENCES.

Star (Christchurch), Issue 6647, 11 September 1889, Page 2

OUR HARBOUR DEFENCES.

Report of Mr A, D, Bell. [Compiled SpeoxaiiLy *ob "The Star."] Mr Arthur Dillon Bell, Engineer for Defences, deals with the subject of tha construction of harbour defences m a short report. Referring to the employment of CONVICT LABOUR upon defanoo works, he mentions that a temporary prison will shortly be erected to accommodate the prisoners on Bipa Island, and thus remove the necessity for the men being taken from and to Lyttelton daily. The general result of the employment of convict labour has been satisfactory. , THE TEAR'S "WORK. The record of the year shows a substantial advance in the efficiency of the defence works. The comprehensive attention de- ' voted by General Schaw to the Colony's defences, and his invaluable advice, had enabled operations to be conducted and the available labour to be employed on definite lines. "Recent experience has proved," Bays Mr Bell, " that the surest reliance in fortification must be placed on mother earth. While, therefore, it is at once advisable and necessary that gunpifca and magazines, and suoh other bomb-proof accommodation as may be required for the protection of artillery stores and the shelter of the garrison, should be solidly constructed in concrete, masonry, or brick, it is equally essential that as little as possible of thisclaea ofi work should be in any way exposed or even visible, and that the retaining walls and other massive outlines, and the enclosed and walled Bpaces, as well as the neatly formed and trimmed counterslopes, and merlons of recent systems should be conspicuous by their absence." Every effort had been made to apply these principles to the construction of our forts as well as the nature of the sites would allow. The shores of our harbours are singularly devoid of the extended area of fairly even-lying ground required for a fort of modern type, hence there had been difficulties in laying out the works. A casual visitor would not be able to perceive the progress made, as a completed battery had only the form of an irregular mound ; nor could the extent or solidity of the subterranean galleries ba estimated in their artificial light. WORKS UNFINISHED. It is not pleasant to learn that " there axe still a few main batteries and several | accessory works embraced in the accepted I scheme of defence which lie unfinished, or for which the ground has not yet been broken, although their armament is to hand in the Colony." These, Mr Bell thinks, should be " kept steadily in view." The reasons given for the delays are difficulties in acquiring sites, the fact that, . prison labour was not available, and want of funds to employ contract labour. HIGH-ANGLE FIRING AND MXNEH. The use of high-angle firing gusß/tis mentioned &3 showing that the development of meanß of defence for harbours appear to reach no final Btage. The accurate and destructive effects attained by high-angle i fire from guns of an elongated howitzer description against hostile vessels has, Mr Bell says, recently been brought into prominence. There are good sites for some of these guns, and the collateral works necessary are inexpensive. The whole of the guns ordered have been delivered in the Colony. Fair progress has been made with the completion and equipment of the various submarine mining stations, and with the study and preliminary surveys and preparation of the mme -fields. Mr Bell pointed out that in future harbour warfare submarine mining will play the more important and decisive part. It is, proposed, therefore, if possible, to devote a fair proportion of such funds aB may ba available during the ensuing year to the proper completion of the stations, and of the surveys and accessories of the actual mine-fields. The total expenditure on harbour dafences from the initiation of the works till March 31, 1889, is £448,491 3s 3d. Of thil the material ordered from England absorbed £236,792 14s Id, and the works in the Colony .£211,698 9s 2d.