A ‘NEW’ RANGATIRA

Dominion, Volume 29, Issue 199, 20 May 1936, Page 13

A ‘NEW’ RANGATIRA

Big Repair Job Nearing Completion AN INTRICATE WORK One Hundred Days In Floating- Dock The permanent repairs to Hie hull of the inter-island steamer Itangatira—the greatest work of the kind ever carried out iu New Zealand —are now practically completed, and it is expected that the ship will be brought out of the jubilee floating dock to-morrow or on Friday. The Itangatira last night completed her 100th day in dock, the vessel having been lifted on Sunday, February 9, Contrary to the belief held in many quarters, it can be stated that the repairs to the Itangatira are of a completely permanent nature, and that, as soon as the extensive internal repairs and overhaul are completed afloat, the ship will again be in first-class condition and will, probably, be recommissioned some time next month. The repairs to the ship are being carried out under the special survey and to the full requirements of Lloyd’s Register for a 100A1 classification.

Big repair jobs in past years have included the Ulimaroa. Kaipara, Knight of the Garter, Westmoreland, C. A. Larsen, Northumberland, and Huntingdon, the work in one or two cases being classed as “temporary." Moreover, most of these ships were “full-bodied" cargo carriers which simplified the work of repairing them. The work on the Rangatira’s hull, in addition to being more extensive, has been of a far more intricate nature, since, except for a comparatively small section of her bottom, her hull has practically no straight lines in it, and scarcely two frames are identical iu shape, due to the extreme fineness of her ends and her sharp curvatures from the midship section. Separate templates have had to be made for most of her floors and frames, and for all the shell-plates, except a few in the bottom of the ship. New Frames and Plates.

Approximately 100 tons of new material has been worked into the ship's hull, including some 40 tons of shell plating. Most of the shell plates were brought out from England in the Rangitane last month. Approximately 40 new plates, each measuring 28 feet in length by seven feet in width, have been used. A large number of the original shell plates were taken off and recoiled and “faired” in the shops at Evans Bay and have since been replaced. A goodly number of frames and floors and intercostal girders and frames were cut out, straightened and repaired, and have been rebuilt into the ship, but a large number of new ones have had to be fabricated and worked into the hull structure.

The centre-line girder, or keelson, some three feet in depth, forming virtually the ‘‘backbone - ’ of the ship, had to be completely renewed for a length of about 100 feet. The keel plates of the ship bad also to be renewed for a length of some 240 feet. The stem-bar and the heavy steel casting of the ship’s forefoot, which took the first impact when the Itangatira stranded, were taken out and “faired ’ up in the shop. Ten Tons of Rivets tseil.

More than 50,000 rivets o£ varying sizes and o£ a total weight o£ some 30 tons have been used in the repairs, and all have been driven in with pneumatic riveting-liaiiiiiiers, or “guns/’ Electric arc-welding lias been extensively employed in the repairs and in closing up joints and seams. I’nenmatic tools have been employed in caulking Ihe seams and overlaps o£ the shell plating and thousands of cubic feet of acetone gas have been used in the torches for burning out rivets and in cutting frames and plates, Jhe big job has employed JOO men by day and often far into the nights. During the last few days water has been tilled into the ship’s double bottom tanks, oil bunkers and other internal spaces for the purpose of testing the repair work for watertightness, and the job has stood up to the test remarkably well. In the case of the oil tanks, and especially of the feed-water tanks, the tests have been very exacting. The feed-water used for the highpressure water-tube boilers is doubledistilled and has to be completely free from salt or aeration, lienee the tanks have to be absolutely watertight. The last of the plates was placed in position and was being riveted up yesterday. This plate had been kept off till the last in order to give quick access to the interior of tlie ship and save the workmen from having to go “over the top.” The riveters were hard at werk yesterday completing their job and were being closely followed up by the painters. The numerous “passing-ln” holes, each about three inches in diameter, cut in the shell plates at convenient places to allow the white-hot rivets to be passed inside, are being closed up by a welded backing-plate and spigot. A Great Bow-Rudder. An object of interest on the dock floor is the ship’s bow-rudder. This is shaped to the form of the bow and weighs about nine tons. It measures lift. Gin. along each of its two straight sides, the oilier, of course, being curved, and It is more Ilian three feet in “thickness’’ on its rounded after side, the diameter of its shaft being 12in. The rudder will be hoisted and fitted into place this afternoon. During the time she has been In dock, the forepart of the ship has been supported by 2-1 huge ironbark shores, twelve on either .side, the keel blocks having had to be removed to enable work to be carried out under the vessel, the bottom of which is little more than four feet off the floor. To ensure that, no undue stress was taking place, in the hull a series of “sighting” posts were placed on her upper deck and at least twice a day the “sights” have been carefully checked. During the 100 days not the slightest sign of “bending” in the ship’s structure has been detected. As the keel plates have been riveted in the keel blocks have been replaced and tightly wedged When the Rangatira comes oft tin, dock she will be taken to a berth at Clyde Quay. where 1,10 . oE ternal overhauling and refitting will be completed.