A NEW FORT

Evening Post, Volume CXL, Issue 56, 4 September 1945, Page 8

A NEW FORT

City Defences

WARTIME SECRET REVEALED

Far down below the surface of the earth, underneath a Wellington peak is to be found the nerve centre of the city's most powerful fortress. From here would go the directions for the opening1 of fire on any hostile vessel which ventured to approach the city either for the purpose of a morale bombardment, or to destroy its shippingor its most vital military target—the floating* dock.

Few people have any conception of the magnitude of the undertaking which has turned the interior of the peak into a maze of concrete tunnels. Few, also, appreciate the enormous labours necessary to ensure that the big guns on top of the hill would be able to do their job properly if they were called upon to engage enemy targets. Now that the war is over some of the secrets of the fortress may be revealed, and a "Post" reporter was today given an opportunity of inspecting the gun positions and the enormous subterranean chambers. All are familiar with photographs of the great Maginot Line. These photographs immediately spring back to mind as the tunnels of this site are entered. The long concrete passages, lined with cables and hydraulic power lines, flights of concrete steps between higher and lower levels, the steel doors, and the spacious vaults crammed with switchboards and powerful Diesel and electric motors, all these bring back to mind the great French system of fortifications. This huge .engineering feat, constructed at a feverish pace when the threat of Japan was imminent, has altered very little the topography of the area. For obvious reasons, it is desirable that the maximum protection should be given to the equipment and personnel, and also that the whole system of defences should be as inconspicuous as possible from the air. All that can be seen above ground are the two huge coastal guns, a few small sheds and shelters, and the concrete cowls of the extensive ventilation and compressed air systems. LONG-RANGE FORTRESS. Coastal artillery defence is divided into three main categories. These are "counter bombardment" or long-range equipment, close defence, which includes the entrances and approaches of harbours, and anti-submarine and motor torpedo boat defences, which are sited mainly to cover' booms erected across the inner entrances to harbours. The guns in the battery visited are long-range weapons, designed to fight off any vessels which might approach sufficiently close to attempt a bombardment of the city and harbour. Moreover, by virtue of their elevation and their all-round traverse, the big guns can also be brought to bear on the harbour entrance and the harbour itself. On arrival at the site the immediate impression is that something is wrong. One is almost inclined to ask "What's the use of these guns up here? You can't see the sea, or at least what you can see of it is very little." It is not necessary these days, however, to be able to see your target. Shells can be fired over the seeminglyencircling hills to hit almost any target in deep water in a huge semi-circle in Cook Strait. • SPOTTING THE TARGET. Spotting is by forward observation posts spread around the coast in suitable positions and containing rangefinders and other equipment either visually or radar-controlled. Any two of these (or if radar is used, one alone) are sufficient to provide bearings. These bearings are passed by various means to the plotting-room, 60ft below ground, and transferred to the fortress plotter, which provides, automatically, the co-ordinates of the target in accordance with a standardised military grid of the area. These co-ordin-ates are passed to another plottingroom (the battery plotting-room) and handled by further instruments which turn out the present range and bearing necessary to hit the enemy vessel from the battery. That present range and bearing go through more instruments which accept all sorts of additional information, such as course of target, time of flight of shells necessary meteorological data, and other details, and send to the guns the future range and bearing of the target. The guns are laid in accordance with these instructions, and when the shells have finished their flight they should plunge straight on the unfortunate craft which has been presumntuous enough to come within range CRUISER ATTACKS. When the policy was being laid down for New Zealand coastal fortifications it demanded guns at the main ports which would be capable of discouraging sporadic raids by cruisers in addition to being able to handle attacks by submarines, motor torpedoboats, and other light surface craft The 6in gun was for mc:ny years the standard bombardment gun. but as cruisers began to mount Bin guns of1 improved performance and with more highly developed control gear, it was realised that something more powerful was necessary. A heavier gun was the answer. At the outbreak of the war Wellington's defences consisted of a lonCTrange battery of 6in guns, limited in their arc of fire. For close defence there were 6in guns and 4in. guns

Inside the entrance were 12-pounders. An "examination gun" was manned several days before the outbreak of war, and personnel for the remainder were called up by radio immediately on the outbreak of hostilities. Early arrangements were made to increase the existing equipment by the addition of other guns, but pending their arrival field artillery pieces were pressed into service. At that stage, too, New Zealand, being far removed from the theatre of combat, was well down the priority list for coast artillery, which was urgently needed at places such as Malta and Gibraltar. As submarine warfare increased the need was seen to develop anti-sub-marine weapons, in which this country was then comparatively weak. Twin 6-pounder rapid-fire guns, already ordered for Wellington, were lost at sea, and any hope of immediate replacements was siim. Further guns, handed over by the Navy, were installed, and arrangements were made to increase the size of the 6in. battery. THE PEAK PERIOD. June, 1943, was the peak period for Wellington's coastal defences, and at this time the Japanese threat was very close to us, it was known that enemy submarines were operating in the Pacific and the Tasman. At that stage the defences were augmented by thickening them up with 40mm. Bofors guns and 6-pounder anti-tank guns, both of which could also be used seaward. By now, however, additional 6in 4in, and 12-pounders were in process of installation. The new 6-pounder twin equipment had almost arrived, and work on the emplacement had already started. . The first move to provide Wellington with the latest type of heavy counter bombardment was made before the war, and they were finally ordered in 1941. Once again, however, priorities interfered, and it was not until early in 1942 that the first equipment started to arrive. The search for a site was of prior importance, and there were many headaches before one was finally decided upon as a situation from which the whole area desired could be covered. Hundreds of men set to work, the-above-groundjob being done by Public Works employees, and the tunnelling by a private engineering firm which has had long experience in this type of work. At last the site was ready for the installation of the big guns, and the huge pieces of metal were hauled up the hill. The barrel of one of these guns —the heaviest part—weighs 28 tons. One of the most impressive portions ol the installations is the engine-room, where huge Diesels provide electric power for the whole tort and for the camp attached, as well as hydraulic power by which the guns are manipulated and fed. The fort which could derive electricity from the city system, |is absolutely self-supporting in the matter of providing every type of power. Rather than risk the delay which would occur were experts to be brought from England, New Zealand sent a picked team of Army officers and non-commissioned officers to Australia to learn the problems of installing the guns and their accompanying equipment. There they helped to install similar guns, and used their practical experience on their return. Very little went wrong, the main problems encountered being those of ventilation and air supply to the Diesels, and the bugbear of seepage. Both have been satisfactorily overcome. One- of the innovations at the installation is a "miniature range." In a special building, by virtus of having all the area concerned plotted out on accurate maps on the floor, officers can follow an electrically-controlled target by means of instruments representing forward observation posts around the coast The resultant information is automatically sent to the plotting rooms, and the guns trained accordingly. Even the theoretical final fall ot shot is recorded, so that, apart from the noise (and the expense), everything proceeds as in a normal shoot. Some live shoots will still be necessary to bring training up to its required standard, but the device, which was perfected with the assistance of the Department of Scientific and Industrial Research, is regarded as an enormous help in the training of recruits. , , At its height, Wellington's coastal artillery was manned by 750 men and women; soon there will be only 41 on I the job, keeping it in order. ! Defences are installed to deter an enemy in the first instance from making an attack. Should, however, they fail in this object the defences must be capable of resisting such attack as the enemy may make. Accordingly it might well be said that a coast gun which may not have "fired in anger, had, through being a deterrent to attempted action on a port, fully justified its installation and manning in time of war. . • ,