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SHIPBUILDING INDUSTRY AND CONSTRUCTION
carrying capacity of these schooners, the largest Steel Steamships.-- The modern ocean liner of which are engaged almost entirely in the for freight and passengers, as built of steel, has coal-carrying trade, is exceedingly large. Thus, a length over all of 630 feet; breadth, 73 feet the five-masted schooner is 318 feet in length, 6 inches; molded depth from keel to upper 44.feet beam, and 21/2 feet in depth. The ves- deck, 56 feet. On a draft of 33 feet the dissel will carry 4,000 tons of coal on her maxi- placement is 33,000 tons, and on a maximum mum drast. A six-masted schooner is 330 feet draft of 361/2 feet, to which the vessel can be in length, 48 feet in beam, and has 22 feet loaded whenever the depth of the harbors will depth of hold. On her maximum draft of 24 admit of it, the displacement will be 37,000 feet she will carry 5,500 tons of cargo. Her The space occupied by machinery is the lower masts are each 116 feet in length, and her smallest practicable, so that space for cargo may topmasts 58 feet.
be as large as possible. In order that cargo may The seven-masted steel schooner of modern
be readily stowed, the ordinary type of hold build has a bar keel of forged steel three and pillar has been dispensed with, and large boxone-half inches in width by 12 inches in depth, shaped columns are fitted, supporting heavy which extends from stem to sternpost. There girders which run longitudinally under the transis a cellular double bottom with a continuous, •verse beams which carry the decks. These single, vertical, keel plate weighing 22.5 pounds columns are widely spaced, and in some cases to the square foot. The upper bilge-strake is only one is fitted in a hold, whereas by the older of 2834-pound plate for two-thirds of the method 10 pillars would be required. A longilength. The middle bilge-strake is of 30 pounds tudinal bulkhead is fitted the whole length of weight for the same distance and the lower the ship; this divides each hold into two sepabilge-strake 25 pounds. The bottom strake
rate compartments, and, therefore, the hatches is of 20-pound plate, while the garboard strake are fitted in pairs, one to each hold. Some of is of 29-pound plate for two-thirds of the
the hatches are so large that bulky freight, such length. All of the plating reduces to 1834
as a locomotive or freight car, or large marine pounds at the ends of the vessel, except in the
or land boilers, can be lowered directly into the case of the garboard strake, which will reduce
hold. Every hatch can be loaded or discharged to 25 pounds at the ends. There are three com- simultaneously if desired. The cargo-handling plete decks, which are of steel plating, the upper
plant on such a vessel is very complete, and deck, forecastle and poop-deck being wood
designed so as to cut down the number of men covered. A collision bulkhead is worked in at
to a minimum. Two winches and two booms a suitable distance from the stem. The lower
are fitted to handle cargo at each hatch. The masts throughout the vessel are built of steel,
booms, 34 in number, are built of steel. Two with lapped edges, flush butts, and stiffening
heavy booms are fitted to lift weights of from angles extending inside for the full length. The plates are single-riveted at the edges and double
30 to 50 tons. The winches for cargo handling riveted at the butts. The plating is double and
are 34 in number, all electrically operated. One
hold in the ship is devoted to carrying frozen stiffening, double at the mast-partners and at
meat, and is completely insulated; its capacity the hounds. The masts are all 135 feet in length
being about 2,500 tons. The insulation is so from the mast step to the top of the upper band, and they have a uniform diameter throughout of
arranged that ordinary cargo can be carried on 32 inches. The topmasts are of Oregon pine.
return trip. The coal bunkers are located above
the boilers; the ends of the bunkers being inThey are 58 feet in length over all, tapering from
clined in such a manner that the bulk of the 18 inches in diameter to 10 inches, except the foremast, which is 64 feet in length and 20
coal will gravitate through chutes and be deinches at its point of greatest diameter. The
posited on the firing platform. The capacity of booms of the first five masts are 45 feet in
the permanent bunker is over 4,000 tons, and a length by 14 inches in diameter, the spanker
reserve bunker is fitted contiguous to the boiler boom being 75 feet in length by 18 inches in
room, having a capacity for about 2,000 tons of diameter. The total sail area of the lower sails
coal. The boilers have a working pressure and topsails is 40,617 square feet. All of the
of 260 pounds per square inch. They will supstanding rigging, and in special cases the run
ply steam to two main engines of the triplening rigging for the lower sails, are of a high
expansion type, arranged side by side, workquality of wire rope. Although this vessel is
ing separate shafts. The propeller wheels are propelled entirely by sails, she carries quite a
20 feet in diameter, and revolve 78 times per considerable instalment of machinery, including
minute. The horse power of the engines would one 9-inch by 10-inch Hyde double-cylinder ship
be about 10,000, and will drive the ship at a engine, and five 6-inch by 8-inch Hyde hoist
speed of about 14 knots per hour. To realize ing engines. There are two vertical boilers 56
the great size of the ship, one must but recainches in diameter by 90 inches high, one in the
pitulate the various decks, platforms, etc., from forward house and one in the after house. the keel to the top-most bridge. First there is The boilers were built for a working pressure of
the outer bottom of the ship; 6 feet above that 100 pounds to the square inch. There are two is the inner bottom or floor; then within the 8-inch by 4-inch by 6-inch duplex pumps and
molded or plated structure of the vessel are two direct-acting steam pumps, with steam and the orlop, lower, between, main, and upper decks. water cylinder, each 12 inches in diameter by All of these decks are of steel plating, and the 12 inches stroke. As the result of the installa- whole structure of the ship from the bottom tion of steam power on board for the purpose to the upper deck is 56 feet in height, the of hoisting anchors and sails the number of upper deck running in an unbroken sweep the hands necessary to work this large vessel is con- whole 630 feet length of the vessel. Above the siderably reduced, the total number required upper deck are the promenade deck, the upper being only 19 men. The total cost of the ves- promenade deck, and the boat deck, this last sel delivered was about $250,000.
being about 30 feet above the kecl, while eight
SHIPBUILDING INDUSTRY AND CONSTRUCTION
feet above this, or 88 feet above the keel, is merchant marine with that existing immediately the captain's bridge. Now, since the vessel at previous to the outbreak of the war. In June her lightest draft draws 17 feet of water, the 1914 the total gross tonnage under the United captain's bridge, when the vessel is running States' fag, including the coastwise shipping light, will be over 70 feet above the water, and and the fleet on the Great Lakes was 4,287,000 the passengers on the topmost upper deck will tons. In 1920 the gross tonnage was 12,406,123 be between 60 and 70 feet above the water. tons, an increase of 283 per cent. The larger See Ship.
part of this increase has been in ocean-going
vessels. The United States Shipping Board.— When
The steam tonnage of the United the United States entered the World War in States is now about 25 per cent of the entire 1917 the preponderant demand of the army
tonnage of the world.
At the close of August 1919 the Shipping was for ships to transport men and materials
Board reported the delivery of 899 steel steamto Europe. The United States Shipping Board was formed to control generally the increase and
ships, of 5,733,622 deadweight tons; 378 wooden operation of the necessary ocean-going fleet,
steamships of 1,339,103 deadweight tons; and and this board established as a subsidiary the
15 composite ships of 32,500 deadweight tons Emergency Fleet Corporation. The govern
- a total of 1,292 ships aggregating a deadment advanced $50,000,000 capital to the latter
weight tonnage of 7,125,225 tons. There were body, taking the entire issue of stock to that
fitting out in wet basins 408 steamships aggreamount. The duty laid upon the corporation
gating 1,920,000 deadweight tons. There were was the providing of the largest possible ship
on the ways in the several yards under the tonnage in the shortest possible time. It began
board's control 497 ships, aggregating 3,286,105 its labors by taking over a large number of the
deadweight tons, and 227 steel steamships of existing shipyards of the country and entering
a combined tonnage of 1,476,610 tons are still
under contract but have not been begun. upon the construction of new ones in all sec
At the close of August 1919 the Shipping tions of the country whence ships could be brought to deep water. Besides these activities
Board had a total fleet of 1,280 ships under its the structural steel works everywhere were set
control, with a combined tonnage of 7,706,400 to work fabricating parts of ships which were
deadweight tons. See, also, AMERICAN SHIPlater to be assembled at the shipyards. In
BUILDING; NAVAL ARCHITECTURE. August 1918 the corporation had under its con- Ship Construction.— As the first step in trol more than 200 shipyards, half of which the building of a ship' is the designing of it had built. These were distributed over 27 it, the use to which it is to be put must first different States, and aggregated nearly 900
be decided on. What cargo is it to carry and ways with a maximum capacity for fabricated how much? And what speed is desired? The ships of 5,400 ships per annum. The actual answer to these questions will go far to deteroutput was held down to about half of this mining the ship's dimensions — length, beam figure owing to inability to get materials fast and depth - and to a large extent the shape or enough, and the necessity of training the large lines” of the under-water body and the horse forces of unskilled labor. Advantage was power of its propelling machinery. The availtaken also of yards formerly in use for the able depth of water in the harbors the ship is building of wooden ships, especially in the designed to visit is another controlling factor. South and on the Pacific Coast, where ship As the dimensions of the ship are not known, timber was plentiful and within easy reach. a trial design is first calculated upon the basis The largest of these new yards was that at
of the tonnage required; say, for example, Hog Island near Philadelphia where nearly 10,000 tons. The designer makes a calculation 30,000 men were employed. Efforts were made of a hull which will afford the space for 10,000 to celebrate the Fourth of July 1918 by the deadweight tons... The displacement of the launching of 100 ships throughout the country.
completed ship will be the deadweight tonnage While the goal was not quite reached, more than plus the weight of a hull to contain it. From 90 ships were actually sent into the water on experience and experiment is has been found that day. As an instance of the remarkable
that about 64-100ths of the whole carrying caefficiency attained in some yards the Tuckahoe pacity, (including engines, fuel, stores, etc.) may be cited. This vessel was a 5,500-ton steel must be added for the vessel itself. The ship collier of the fabricated type, and was erected carrying 10,000 tons will, therefore, have a in 27 days at a Camden (N.J.) shipyard. On displacement of about 16,400 tons. It devolves the 40th day from the date the keel was laid this then upon the designer to determine length, vessel put to sea with a full cargo.
beam and depth for his vessel from this total At the yards on the Great Lakes the possible displacement. Into this problem enters first, size to which ocean-going ships might be built if at all, the available depth of water in the was limited by the size of the locks in the harbors where the ship will trade. The shalWelland Canal to a length of not more than lower the possible draught, the greater, rela261 feet and a beam not exceeding 42% feet. tively, the beam. Aside from this the desired These limitations were overcome in part by speed determines the proportion of length to building a ship in two sections and assembling breadth. The longer the ship -- and the narthe parts when they reached tidewater in the
- the speedier will she move for the Saint Lawrence. However, the width of the same engine power. A trim underwater body ship inexorably held them do to a limited
with long gently flowing curves will require less length, not exceeding 350 feet and limited the horse power for a given speed than a body tonnage to about 6,000 tons.
which is full and roomy well up to the bow and The work accomplished by the United States back to the stern. Shipping Board is best comprehended by com- For all of these calculations constants and paring the present tonnage of the American "coefficients are available to the constructor,
SHIPBUILDING INDUSTRY AND CONSTRUCTION
and his ship of 16,000 tons will, in ordinary sponding effect. This economic speed can be course, figure out a length of between 450 and very closely calculated by the shipbuilder from 470 feet and a beam of 55 to 60 feet, a draught the under-water lines of his model for the load of 25 to 28 feet, with a total depth of about of cargo it is to carry. He is thus able to 40 feet. With engines of 4,000 horse power decide upon the size of the propeller or prothis vessel should show a speed of about 12 pellers needed - their diameter and pitch, and knots.
the number of revolutions they must make In the planning of the ship the established per minute to drive the ship at the desired rate. rules of the several Lloyds” and classification Engines powerful enough to turn the propeller committees must be strictly adhered to in order easily and without strain the calculated numthat the vessel may be duly registered.
ber of revolutions may then be designed. One The chief factor in the hull of the ship is more problem remains, that of so attaching the the shell plating. All other constructive parts engines to the ship that they actually form of the ship, that is, the framing, are to be con- an integral part of its construction. The whole sidered as practically the support and stiffening problem of propulsion is one of delicate adof the shell. In a large vessel the pressure of justment. The engine will run best at a certain the water upon its exterior shell is enormous, speed, and the vessel will run best at a certain the tendency being to cause a collapse. This speed. The closer these two conditions can be pressure is tremendously increased by the vio- matched, the more successful and the more lent blows of storm waves, and from the pitch- durable the ship. In most vessels nothing ing and rolling sustained in rough water. better than a compromise is reached. The inHerein lies the demand for the knowledge of stances in which hull and engines are really the skilled engineer, that the metal of which mated are so rare as to excite admiration and the ship is constructed shall be so disposed as incidentally to mark the possibilities to be to afford abundant strength and resistance to achieved. every possible stress and strain from without. The reciprocating engine is of satisfactory Another series of strains arises from the load efficiency for moderate speeds, ranging up to carried by the vessel, and acting from within, 0.88 for triple expansion and 0.92 for quadof great magnitude when the waves are high ruple expansion engines. The latter are more and the ship is subjected to a hogging strain economical of fuel, but require so much more when lying across the crest of a great wave, engine room that little if any advantage is or to a sagging strain when lying across the gained on the average voyage. The steam turtrough between two waves. It is customary bine is equal in efficiency to the quadruple exto regard the ship as a section of a tubular pansion reciprocating engine, and does equal bridge, so far as the amidship's part is con- work with considerably less fuel, but, as it cerned. The ends of the vessel from their cannot be run astern, a second turbine must wedge-shaped construction are from that con- be provided_for this purpose, or a transformer dition relatively stronger and may safely be employed. Furthermore the turbine is of great more lightly built. The art of the shipbuilder efficiency only, at high speeds - too high to is in the skilful adjustment of material to its allow of its being connected directly to the propurpose, so disposing it as to afford abundant peller shaft. A combination of reciprocating strength, without interfering with generous engines and the turbine has worked well, where cargo capacity.
the turbine has been of the low pressure type In the more recent development of ship con- and runs by the exhaust steam of the reciprostruction the system most approved is the longi- cating cylinders. With triple screws on large tudinal, as opposed to the transverse; the vessels (20,000 tons and upward) the two former having the advantage of stiffening wing shafts are operated by reciprocating enthe plating against transverse buckling as well gines and the centre shaft by the turbine. as against fore-and-aft compression, a feat not
Turbines of the high speed type are successattained by the transverse method of construc- fully utilized when employed to run electric tion except by an undue and undesirable generators which, in turn, operate the shafts by thickness of the plating and a close placing of electric drive. the side frames -- thus adding unprofitable It is quite impossible in the limits of space weight and diminishing cargo space.
available in this work to even touch upon the The division of the hull into watertight com
multitudinous details of practical ship conpartments is a feature of present shipbuilding
struction. For this information the student is regarded as indispensable, particularly as referred to the excellent and complete treatises gards the collision bulkhead,” placed near
named below. See SHIP; SHIPBUILDING TERMS. the bow, to keep out the sea in case the bow Bibliography.-- Baker, G. S., Ship Form, is broken by collision. The requirements of Resistance and Screw Propulsion' (New York the Lloyds associations are that the compart- 1915); Biles, J. H., (The Design and Construcments shall be of such a limited size that the tion of Ships) (2 vols., London 1919); Holms, vessel may still float safely if two of them are A. C., Practical Shipbuilding) (2 vols., London breached. This provision demands at least eight 1916); Kelly, R. W., and Allen, F. J., The transverse bulkheads in the ordinary passenger Shipbuilding Industry (Boston and New York liner. The compartments are connected by 1918); Marvin, W L., The American Merchant water-tight sliding doors which are operated by Marine) (New York 1902); Nelson's Encyclocompressed air from the bridge, in case of pedic Library. Ships and Shipping' (London emergency
1914); Simpson, G., The Naval Constructor) Given the hull, the remaining problem is its (New York 1918); Taylor, D. W., The Speed propulsion. A certain model of hull will be and Power of Ships (New York 1910); Tompfound to have a definite economic speed. Above kins, A. E., Marine Engineering' (London this speed the engines labor without corre- 1908)