IN A STEAMER'S ENGINEROOM

Otago Witness, Issue 2811, 29 January 1908, Page 13

IN A STEAMER'S ENGINEROOM

RECIPROCATING .ENGINES.

By Will Lawson.

I The wharf lights have faded astern and L are lost to sight behind the^ obtruding point of Land as the steamer's head is turned to the open sea. A keeii"~breeze is blowing, promising a nasty-^-roll outside, and from her tall smoke-spouting iunnel to' tfie seething foam that clings arid sweeps at her §ides ifte prospect is cold arid dispiriting. . But ' within the doorway of the engine-room, Nvhere three tireless tail-rods rise and sink in beautiful harmony, the warm air almost chokes the chilled lungs. This is the hottest part ot the engine-room, as the hiige cylinders radiate great heat, and all the hot vapours from the floor below rise to the exit provided by the skylight. Steel ladders descend with abrupt steepness into the gleaming, _ clanging engine-room.. The -bass in -the orchestra of sound 'is a heavy, humming, droning roar which dominates everything, while the steady thumping of the great piston-i'ods and cranks beats out the time. Ever and anon a harsh, loud cry, like the bleat of a motherless calf magnified enormously, echoes through the mass of machinery below. This is caused by a pump, the valves of which are worn. It is circulating water through the condenser and moves slowly, occasionally emitting its earsplitting bray. * Standing on the floor of the engineroom, the hugeness and the clangour of the mass of moving rods and rolling shafting make one take pause and consider the littleness of man — and the ; ' greatness of his brain and his' courage." Thump — thump — thump crash the down-, swinging cranks, to disappear into and emerge from the white-painted pits with uncanny' rhythm and regularity ; to rise and crash downward again. A dynamo purrs in a corner and the pump groans. Then, with appalling suddenness,- the great engines race, filling the place with a terrifying roar, and revolving so fast that their movement cannot clearly be seen. The engineer on watch leaps to the throttle and shuts off steam. The ship is feeling the long swell outside the Heads and has pitched her propeller out of the water. The pitching movement, unless very marked, is not noticeable in the engine-room, which is amidships, and consequently the engineer has been taken a little off his guard, though his promptness has saved the machinery from damage which might have resulted had the propeller entered the water again with a full head of steam spinning it frantically around. The twist and push exerted on the shaft of the propeller is, of course, considerable at any time ; and when an undue strain is put upon it in pitching, the propeller is sometimes a quarter of a revolution after the engine in its movement, and the lay shaft springs visibly. Various automatic devices have been tried to shiit off steam when the stern lifts, but it has been found that all are too slow in operation — the engines get ' away before the throttle closes and the propeller is well under water and preparing to rise again before steam is again admitted into the cylinders. So the work of regularity is done by hand, and a trying, wearisome task it is. One . of the devices above mentioned consisted of a sliding-bar moved by a swinging weight, and the engine-room staff of a steamer on which one of these inventions was fitted had a rather unique experience in mid-ocean. A greaser, ignorant of the nature of the contrivance, while cleaning, rubbed the bar with a handful | of waste, moving it slightly, and, being somewhat stiff, the bar remained as he left it. Simultaneously the engines stopped, though he did not connect their stoppage with his action. For 24 hours the engineers tried to discover the cause, even taking down the cylinders and examining the internal workings. At last the "third" thought of this automatic cut-off, and moved it as the greaser did but in the reverse direction. And away the engines went. The advent of the turbine is killing the romance of the engine-room. In the turbine all the working parts are covered, and the engine is driven from a footplate somewhat similar in appearance to that of a locomotive. There is nothing to see beyond various gauges arrayed in groups showing the pressure and vacuum in each chamber of the separate turbines, and the only indication of movement is in the regular motion of the counter which tells off the revolutions of the shafts. With reciprocating engines, the engine- ' room is all athrill with life and anima- ■ tion and the suggestion of immense power. All the drive is on one. or two, 1 shafts, as against the turbine's three or ' more, and "these consequently require i great attention. The difference between ' the two methods of marine propulsion [ may be likened to that between a four-in-j hand coach and a motor car. The one I all clash, and motion with a pleasant t sense of visibly applied energy. The 1 other silent, resistless, apparently inexp licable. | Eight bells chimes shrilly above the thunder of sound. The second engineer, I who Is just going off watch, is writing i up the rough log. which is kept on a j slate, recording the number of revoluI tions per minute made by the shaft duri ing his watch and everything of note 1 which has occurred during the last four I hours. When the ship "is running on j dead reckoning this record of revolution | is checked against the patent log which jis towed astern. From this rough record ( the chief engineer writes up the official ' log. The fourth, v/ho takes watch from 8 to 12, comes down the ladder and hears the second's comments on the working of the engines during his watch. Then the j second departs, and the fourth makes a 1 round of inspection of the whole " job,'' as engineers term the contents of an i «ngine-room. In the ordereel noise of

the engine room he appears to walk ratfooted, v. hile his shouted inquiry ol a greaser about a ceitti'm bearing comej-s to the -unpractised cay no meaimu, at all. The steamer cariies loir uiigiiietis and nine firemen, six trimmers and ihiee greasers — one, three, , ,iivo, a;*d one. respectively .iri ea,cb. watch, -chiefs engineer does -not .-stTau'd "ra"CJw*tc&.-'^zit!,' eight bells."' the*" greasers,, frlb Hbbe 1 ipil-ciipß,;, and it is not an easy task -fo'-a'ttsnTd" to : those on the revolving clanks, and" .or. thetossing crossheads. -;,-Tlie mfitiori~.bi..,-th,€C-oil can must be % .given ~ijro£nVsk£'lwfri&t; rather than from, tlie elbow-.- else 'the<bil* will be more likely to" fall lnto'~t>he_"pit than into the caps. _ Different parts of - the machinery are oiled at-frequent intervals varying from 20 minutes, to ,nn hour; one of the greaser^rttuti'es^e^uiringv^s&c^. tice rf the o'^th^^istqli-rods-with, jffily wagife"-s?hSte -they -perform their' regular leapirigY^-fchTUsiing^smoo^thHsifp-ping action. Th-isf-is „done^, done^ about- every half-hour. The motion of the ship is altering. The seas are taking her on the beam and she is beginning to roll. This is a trying -motion loxi the engineer, though it is not so severely felt as cmdeck. But there is always the danger of a slip or fall on the iron floor, and the presence of the swirling rods and cranks does not give reassurance. So the engineer hangs on to the handrail with one hand while he tends his engines. He passes through the watertight door into the long tunnel where the whitepainted shaft turns smoothly in its bearings, and putting the weight of its tremendous T>hrust against the - thrustblock which is situated immediately aft of the engine. This thrust-block is connected by frames and stays to every part of the ship, so that the push of the propeller is < - distributed ._ the steamer's hull. The lowef'pbrtion of the lilock is 'shaped in the J 'form of a trough, in which distilled water, oil, and washing sods .are placed to act as lubricants to this' heavily-burdened bearing. "me ; shaft--is in three sections, bolted together by means of bolts and flanges. •' Sometimes these joints are made flexible, to allow the shaft play when, the hull is working in heavy weather, 'for the hull of a vessel is not an absolutely rigid structure. When the shaft is rigid it may get out of alignment and cause heating of the bearings in the ,tunnel. These bearings are made so as to give the shaft some slight freedom to spring in heavy weather. At such times an engineer is placed on duty in the tunnel to watch the shaft — an unenviable and dangerous position, for space in the tunnel is cramped and the noise and vibration of the shaft and the propeller are not calcu- j lated to soothe the nerves of a man. Any flaw or phenomenal strain shows instantly by cracking the coat of white paint. j Round behind the engines are the j pumps, which need attention, and then he goes into the stokehold to see that the j required amount of water is in the boilers and the stokers are firing well. The stokehold' is forward of bhe engineroom, through a low doorway. So through his watch he moves about his work, his movements hampered by her j swing in the heavy sea. At midnight the "third" takes charge till 4 in the morning, when the " second" j agnin takes* xip the reins and the ' ' third ' | returns to his bunk to snatch what sleep he can before the crew begins hosing down the deck. This is the middle watch, the most unpleasant watch of all. He turns out at midnight and goes to bed at 4.

It is soon after 6 o'clock when the steamer makes port, her steadiness bespeaking her arrival in smooth water. The telegraph rings " Stand-by !" Before its echoes cease the fourth engineer comes tumbling below again. In making port always two engineers are on duty — the one to check the other.

The "second" stands at the throttle; the ' ' fourth " at the telegraph, near which is the slate

"Half speed!" The call is answered; the engines .slacken speed as the ijhrottle closes ; the order ancl the exact time it is received are recorded on the slate.

"Stop!" After s6 many hours of strenuous noise, a strangeness comes over the engine-room as the result of this order ; only the pumps and dynamo break the .stillness and the whirling of a fan.

"Slow astern-!" The shafting has been revolving slowly with the drag of the mobile propeller through the water. Now the .steam is admitted slowly into the cylinders" to act as a, brake to stop the propeller. Before the ensrines can go astern they must be stopped. When the white water boils np at the stern and along the sides of a slowing steamer the propeller is merely being held rigid and aoting as a brake. Then the pliant steam, rushing into the cylinders, tosses the great throws round and round and the snip moves backward. "Stop!" "Slow ahead!" "Stop!" Order after order comes over the wire, eachJßeing given*., effect to, acknowledged, 'and recorded.,- 1 In berthing a steamer, sometjmes as many as 32 distinct messages are transmitted to the engine-room, though this number is excessive. " And at last, comes the welcome zinc which tells that the ship is snugly laid alongside — " Finished with

engines