THE NAVY AT WORK.

New Zealand Herald, Volume LXVII, Issue 20598, 24 June 1930, Page 10

THE NAVY AT WORK.

DUNEDIN'S EXERCISES.

GUNS AND TORPEDOES,

CO-OPERATION BY AIRCRAFT. .TARGET ADRIFT IN GALE. / Varied and exceedingly interesting gunnery and torpedo exercises were carried, out in the Ilauraki Gulf during the past fortnight by H.M.S. Dunedin, flagship of the New Zealand Division of the Royal Navy. In a number of the practices valuable co-operation was given by the Now Zealand Air Force. Tho Dunedin, which reached Auckland on Saturday, was delayed in her return by a mishap off Tiri. Tho battlo practice target, which sho had in tow, broke adrift in tho darkness in a heavy easterly swell. Tho target i 3 a massive Structure weighing 275 tons, and manoeuvring the ship in a heavy sea to pick It Dp was a difficult and dangerous business. In such an emergency men have to be placed on the target and heavy towing wires shackled on while all the time the ship must bo so handled that the rolling and pitching monster does not crash into her and damage the projecting propellers. This was no light task in tho dark with half a gale blowing, and it added valuable seamanship experience to tho lessons learnt from tho gunnery and torpedo practices. H.M.S. Dunedin was under way during 12 days and carried out a comprehensive programme of day and night gunnery and torpedo firings. Naval Gunnery Problems. The gunnery programme included three 14 sub-calibre" shoots at a small target towed by H.M.S. Laburnum, four 6-inch full-calibre shoots and seven 4incli full-calibre shoots, two of which were at a " drogue target" towed by an aeroplane. Naval gunnery presents an entirely different problem from any other form of shooting, because both the target and tho firing ship are moving through the water, and tho firing ship is probably rolling and pitching to an uncomfortable degree, making a very unsteady "gun platform." The firing ship may be travelling at any speed up to 28 knots (31j miles an hour) and the target is usually from 15.000 to 12,0(30 yards away and also moving, so it can be realised that a very high degree of skill and constant training of every officer and man on board is neodod to ensure that hits are obtained quickly and continuously. Shells Filled With Salt. " Live" shell are not fired from tho 6-inch guns for these practices, as they wbuld be too expensive and do too much damage to the target; so "practice shell" of the same weight (1001b.), filled with salt, are used instead. They do not burst and do very little damage. For the preliminary " sub-calibre" practices a small gun firing a 51b. shell is put inside the 6-inch guns, again as an economy. The three 4-inch high-angle guns were fully exercised in their two principal functions, illuminating a target at night and repelling hostile aircraft. In tho first case a steady stream of "star-shell" is fired. These burst high in the air_ behind the target and release a brilliant parachute-supported " star,"_ that glides slowly into the sea, silhouetting anything that may be between its reflection in the >vater and the ship. The Torpedo Practices.

When firing against a target towed by aircraft "live" high explosive shells n.ra nsed, so the piano must tow the target on a very long span. This was the first time that "drogue target" firing has ever been carried out in New Zealand and the New Zealand Air Force deserve real congratulations for tho thoroughly efficient way in which they tackled this new and difficult job. During tho practice period 12 torpedoes were fired, all with success. Torpedoes are very different from shells in that, when fired into the water from the ship, they have to provide their own means of propulsion to reach their objective. They carry a charge of compressed air and engines which drive them on a straight course through the water for about eight miles.

Torpedoes have to be recovered at tho end of their run for use again—they cost £2ooo—and so their high explosive warheads are replaced by practice heads, filled with cork, which prevent damage to the target or the torpedo itself. In peace time tho charge of compressed air is so regulated that the torpedo will float at the end of its run and so allow itself to be picked up. A floating torpedo is not easy to see from a ship, and here, again, the Air Force rendered most valuable assistance in sighting and reporting the "fish." Firing Over Island. The last practice before coming in was a bombardment shoot, tho ship being anchored west of Motuora and the target placed about five miles east of the island, out of sight from tho ship. The shots whined their way over thu .island, to the surprise of the local cattle and, as their fall could not be seen from the ship, an observer reported their position by wireless from an aeroplane. The target would not have made a "desirablo residence" at the time. Auckland is the only port in Now ■Zealand where a target and a suitable "practice area" are available, so a very great deal of work has to be crammed into a very short space of time to enable tho New Zealand Division of the Royal Navy to maintain the sarno standard of lighting efficiency as the sister divisions at Home. NAVAL TRAINING SHIP. [RECONDITIONING OF HULL. HEAVY CROP OF MUSSELS. Twenty-five tons of mussels and a mat of sea grass a foot in depth were removed from the hull of the naval training ship, 11.M.5. Philomel, when the vessel was ' clocked yesterday for the first under-water oveihaill since 1926. Some of the mussels wero exceptionally large, but their hold or) tho steel sides was not so strong as to • call for mora than ordinary effort on tins part of the workmen, who weildcd huge scrapers similar to broad chisels on the end of long handles. With the scraping completed, tho bull will bo swept with strong fibred brooms before it is repainted. The shallowness of tho water at tho Philomel's berth at the naval base contributed to tho prolific marine growth during the past four years. The rubbish will lio lifted out of the dock by a crane and transported out of the harbour on a barge. [Yesterday's operations, on which 30 men were ..employed, revealed that the hull is in splendid order. The ship is expected <o come out of dock to-morrow. As tho old cruiser is without propellers, a tug was used to assist her into the dock. The Philomel was first commissioned in 1892, and in spite, of her years is remarkably well preserved. Prior to being brought to Auckland some years ago, the veteran training ship saw extensive active Eervice in many parts of the world, and was present at the bombardment of Zanzi- . During the Great War the ship was employed mainly in the Persian Gulf and & Hed Sea,