FLOATING MACHINE SHOP

Auckland Star, Volume LVI, Issue 190, 13 August 1925, Page 10

FLOATING MACHINE SHOP

REPAIR SHIP MEDUSA. A MARVEL OF COMPLETENESS. DOES EVERYTHING BUT DOCK A SHIP. The U.S. repair sliip Medusa is the largest foundry afloat. From top to bottom of her seven decks she is a vast engineering shop, and a centre of highly technical craftsmanship. The activities of the ship range from repairing the most intricate stop watches used in--the navy and delicate range-finding and navigation instruments, to casting and fittinge for the engines and fighting machines of the big battleships. Just before the present cruise was begun the battleship Tennessee was overhauled (with the exception of the docking and scraping of the bottom of the hull) by the Medusa's crew, in co-operation with that of the Tennessee. The work occupied approximately a month. On the way out the flagship Seattle wirelessed to the repair ship that a certain section of her electrical equipment had broken down. Sizes of the parts were wirelessed to the Medusa, and when the ship reached Melbourne thr> new parts "were taken over to the flagship and replaced. Why is this ship necessary? Visitors to the vessel wondered. The United States navy, it is explained, unlike trie British fleet, has to travel long distances to undertake manoeuvres, and there are no bases where extensive repair work can be carried out. This ship trails the fleet. Another reason for her existence is, as an oflicer explained, sn that the navy will not be subject to the vagaries of land workmen. Many Experts. She is not the only repair ship in the American navy, but she is by far the largest, and has been in commission for about twelve months. Another one ie being constructed now for attachment to the Atlantic division. The Medusa was ordered during the war, but was not available in time. Her present-day cost to build and equip is about 2,0(10,000 dol. (£500,000). Every man on the Medusa, though most of them are young, is a Specialist, and there are experts in charge of the department* who have s\ fine reputation ashore in the States. The navy hates to lose them, but the* temptations on shore, combined with the fact that the navy cannot compete for men as a business firm would, aro proving great, and when the men's time expires a large percentage leave as experts in their particular line. The Medusa, in another sense, is a huge technical school afloat. At the preseut time there are vacancies on the vessel, but bo high is the standard of service demanded "that the officers, to iome extent, pick the eyes out. of tho navy for their complement of men. ■which is about 500, including twelve officers and 23 warrant officers. In times of great pressure—and it is sometimes more frequent than the heads of departments like —other temporary hands are put on. Youths of between 18 and 21 years mostly join the service, and whea one shows aptitude in any mechanical direction he is sent to a specialist to he trained if his class of work, is not embraced at one of the many naval schools. He still has to do a certain amount of naval training. Men on other boats have their opportunity of getting on to the Medusa if they show their talents and desire the move. It is possible for the mechanics on the repair vessel to graduate to the position of chief engineer oi one of the biggest battleships. Experimental Work. A tour of inspection of the Medusa is interesting, and those of an engineering turn of mind would be fascinated by the magnitude of the work and the works. On the upper deck is located the light sheet metal workers' branch, and in another little room just oli it the elec-tro-plating department, where electrical fittings, t3 r pewriters and other equipment is nickel-coated to protect it from the detrimental effects of the sea air. Huge searchlight mirrors, some 3ft in diameter, are resilvered an<l polished. In.another section of this deck is a shop where pipes 14 and lOin in diameter are cut, threaded, and in other ways lixed up for installation in ships. A little f-urther along towards the line quarters are radio rooms. It is here that experiments carried out in Washington are put into operation throughout the navy. A specification is sent from headquarters as the result of the experiments, and the men on the Medusa have to see that they are carried out. As a matter of fact, experiments iv all engineering branches are carried out on the Medusa. It is sometimes found that a part is not effective or that a little alteration carried out to some other apparatus would wake it more effective. Washington is just informed that it has been done, and after further experiments it is generally approved, hi many case.s the parts are manufactured. Among the Machines. Down on the well-deck the electric and acetelyne welding sets are located, and one, and often the two, are operating all the time, and many processes of ■welding various metals arc undertaken. In the stores of the ship there are portable sets together with the power, including electric motors, so that th«-y can bo taken aboard another ship to effort repairs. Near this department is ■the blacksmith's shop, the modern equip- ' ment of which includes a combination steam and hydraulic press, which, by a ! pressure of 150 tons, tears quickly { through heated metal. It is quite different from the many hydraulic ham- ' mere used, It is an intricate piece of 1 machinery, and the pressure is obtained ' by a combination of methods. ' The boiler shop occupies a section of ' this deck, and it is here that the heavy sheet metal work is performed. Another ( corner finds the ship's fitter, the "handy man," who does all the odd jolw from 1 building gangways to repairing a hole ' in. the Hide of the vcnsel. CJn the iirst ' deck the carpenters occupy one Hide, ana a little further along there is the pattern Bliop. There are four cupola furnaces in the foundry. Further forward is the easting shop, where parts of all descriptions are moulded from sand-baked patterns roasted in an electrical oven. On the other side of the gulh-ry is the machine shop, where men work at 13 lathes and milling machines of different type. Included in this shop aro two production lathes, which are the latest appliances, and may be set-to automatically perform twelve different operations at once. Each one of the machines on this floor has its own electric motor, so that overhead shafts aro entirely eliminated, lv fact, all the machinery is electrically operated. Behind netting and with flooib locked there are two precision lathes, by which it ie possible to work to ono-thousaudth part of au inch.,

Those machines are the latest of their kiud. At one end of the gallery there is an office, and on the other side the electrical shop, where everything in connection with the electrical plant on the fleet, and that is considerable, is attended to, including the remaking of armatures. The Tool Room. In one corner there is the tool room, where every kind of implement for use on the machines is kept. It is not postiblc to obtain a screw driver without leaving a little identification disc by which it can be traced if not returned. No risk is taken in leaving tools about tho shops. Many of the implements have I'een made on the ship, including a set of spiral bevel gear cutters. In another wire-netted room magnetos are tested, charged, and the coils renewed under a modern system. The electrical shop is interesting, for it is a scene of activity in the repair of apparatus, which is sent out again as good as new. The lathes and other machines here are modern inventions. On the third deck is the fitting shop. Two lloors underneath it are stores. These are at the bottom of the vessel, and all kinds of material, including some very costly metals, and 2(3 different kinds of tungsten steel rods are kept. These materials are chemically tested before they are placed on board the boat. One piece of steel aiiout 0 feet in length neighed over a ton and a-half, and the dente in the thick iron floor underneath the hatch, which runs up through the. different shops, indicated some of the heavy weights that are lifted into the .-toreroom by a crane on deck, which has a lifting power of 35 tone, or, if necessary, by certain strengthening, up to 50 tons. In the machine shop just above the stores, an electrically operated travelling crane, capable of lifting three tons, runs along the centre of the ship, with small overnead hand-cranes along the sides. Amongst the many big lathes were noticed one which is capable of turning j a piece of steel 5 feet in diameter. In another part of the ship there is what is termed turret lathes of similar dimensions. A Titan planer, power saws and hydraulic presses perform remarkable tasks. The boring machine is a contrivance capable of dealing with a large steel shaft. Aeroplane Work. One of the storerooms has lwen allotted to the aviation department, which lias been kept busy since it left America attending to the seaplanes attached to the larger vessels. Included in the work of this branch has been the rebuilding of four planes, one of which was smashed to pieces, and repairing some others. Spare pontoonn, wings and other parts, as well as several engines, are kept on the ship, and in order to maintain the aircraft the seaplanes are examined so frequently that two engines are nearly always being overhauled. Forward of the well deck there is Rn engineering ship, where periscopes, range finders, binoculars, compasses, aeroplane instruments, telescopes, gyroscopes, watches, typewriters and intricate instruments are dealt with. Miniature lathes purr and the whole atmosphere immediately suggests delicate operations. Officers do not hesitate to say that this is the most overworked branch of the service, and it seldom gets clear of work. The Medusa is fitted with two antiaircraft guns of three-inch and four-inch broadside guns. Some oi the machinery which is not quite modern is being made so during the trip, when work accumulated in port is done. The Medusa's place in the navy is to do everything but dock a vessel.