SHIPS AND SHIP-BUILDING.
“Far as the breeze can bear, the billows foam,
Survey our empire, and behold our home.”
“Ships are but boards,” soliloquised the crafty Shylock, and were this
still true, yet this present period has seen wonderful changes in
construction.
The high castellated bows and sterns and long prows of _The Great
Harry_, of the seventeenth century, and its successors in the
eighteenth, with some moderation of cumbersome matter, gave way to
lighter, speedier forms, first appearing in the quick-gliding Yankee
clippers, during the first decade of the nineteenth century.
Eminent naval architects have regarded the proportions of Noah’s ark,
300 cubits long, 50 cubits broad and 30 cubits high, in which the length
was six times the breadth, and the depth three-fifths of the breadth, as
the best combination of the elements of strength, capacity and
stability.
Even that most modern mercantile vessel known as the “whale-back” with
its nearly flat bottom, vertical sides, arched top or deck, skegged or
spoon-shaped at bow and stern, straight deck lines, the upper deck
cabins and steering gear raised on hollow turrets, with machinery and
cargo in the main hull, has not departed much from the safe rule of
proportions of its ancient prototype.
But in other respects the ideas of Noah and of the Phœnicians, the
best of ancient ship-builders, as well as the Northmen, the Dutch, the
French, and the English, the best ship-builders of later centuries, were
decidedly improved upon by the Americans, who, as above intimated, were
revolutionizing the art and building the finest vessels in the early
part of the century, and these rivalled in speed the steam vessels for
some years after steamships were ploughing the rivers and the ocean.
Discarding the lofty decks fore and aft and ponderous topsides, the
principal characteristics of the American “clippers” were their fine
sharp lines, built long and low, broad of beam before the centre, sharp
above the water, and deep aft. A typical vessel of this sort was the
clipper ship _Great Republic_, built by Donald McKay of Boston during
the first half of the century. She was 325 feet long, 53 feet wide, 37
feet deep, with a capacity of about 4000 tons. She had four masts, each
provided with a lightning rod. A single suit of her sails consisted of
15,563 yards of canvas. Her keel rose for 60 feet forward, gradually
curved into the arc of a circle as it blended with the stern. Vessels of
her type ran seventeen and eighteen miles an hour at a time when steam
vessels were making only twelve or fourteen miles an hour, the latter
speed being one which it was predicted by naval engineers could not with
safety be exceeded with ocean steamships.
These vessels directed the attention of ship-builders to two prominent
features, the shape of the bow and the length of the vessel. For the old
convex form of bow and stern, the principal of an elongated wedge was
substituted, the wedge slightly hollowed on its face, by which the
waters were more easily parted and thrown aside.
A departure was early made in the matter of strengthening the “ribs of
oak” to better meet the strains from the rough seas. In 1810 Sir Robert
Seppings, surveyor of the English navy, devised and introduced the
system of diagonal bracing. This was an arrangement of timbers crossing
the ribs on the inside of the ship at angles of about 45°, and braced by
diagonals and struts.
Of course the great and leading event of the nineteenth century in the
matter of inventions relating to ships was the introduction of steam as
the motive power. Of this we have treated in the chapter on steam
engineering. The giant, steam, demanded and received the obeisance of
every art before devoting his inexhaustible strength to their service.
Systems of wood-working and metal manufacture must be revolutionised to
give him room to work, and to withstand the strokes of his mighty arm.
Lord Dundas at the beginning of the century had an iron boat built for
the Forth and Clyde Canal, which was propelled by steam.
But the departure from the adage that “ships are but boards” did not
take place, however, until about 1829-30, when the substitution of iron
for wood in the construction of vessels had passed beyond the
experimental stage. In those years the firm of John Laird of Birkenhead
began the building of practical iron vessels, and he was followed soon
by Sir William Fairbairn at Manchester, and Randolph, Elder & Co., and
the Fairfield Works on the Clyde.
The advantage of iron over wood in strength, and in power to withstand
tremendous shocks, was early illustrated in the _Great Britain_ built
about 1844, the first large, successful, seagoing vessel constructed.
Not long thereafter this same vessel lay helpless upon the coast of
Ireland, driven there by a great storm, and beaten by the tremendous
waves of the Atlantic with a force that would have in a few hours or
days broken up and pulverised a “ship of boards,” and yet the _Great
Britain_ lay there several weeks, was finally brought off, and again
restored to successful service.
Wood and iron both have their peculiar advantages and disadvantages.
Wood is not only lighter, but easily procured and worked, and cheaper,
in many small and private ship-yards where an iron frame and parts would
be difficult and expensive to produce. It is thought that as to the
fouling of ships’ bottoms a wooden hull covered with copper fouls less,
and consequently impedes the speed less; that the damage done by shocks
or the penetration of shot is not so great or difficult to repair, and
that the danger of variation of the compass by reason of local
attraction of the metal is less.
But the advantages of iron and steel far outnumber those of wood. Its
strength, its adaptability for all sizes and forms and lines, its
increased cheapness, its resistance to shot penetration, its durability,
and now its easy procurement, constitute qualities which have
established iron ship-building as a great new and modern art. In this
modern revolution in iron-clad ships, their adaptation to naval warfare
was due to the genius of John Ericsson, and dates practically from the
celebrated battle between the iron-clads the _Merrimac_ and the
_Monitor_ in Hampton Roads on the Virginia coast in the Civil war in
America in April, 1862.
Although the tendency at first in building iron and steel vessels,
especially for the navy, was towards an entire metal structure, later
experience resulted in a more composite style, using wood in some parts,
where found best adapted by its capacity of lightness, non-absorption of
heat and less electrical conductivity, etc., and at the same time
protecting such interior portions by an iron shell or frame-work.
One great improvement in ship-building, whether in wood or metal,
thought of and practised to some extent in former times, but after all a
child of this century, is the building of the hull and hold in
compartments, water-tight, and sometimes fire-proof, so that in case of
a leakage or a fire in one or more compartments, the fire or water may
be confined there and the extension of the danger to the entire ship
prevented.
In the matter of _Marine Propulsion_, when the steam engine was made a
practical and useful servant by Watt, and men began to think of driving
boats and ships with it, the problem was how to adapt it to use with
propelling means already known. Paddle-wheels and other wheels to move
boats in place of oars had been suggested, and to some extent used from
time to time, since the days of the Romans; and they were among the
first devices used in steam vessels. Their whirl may still be heard on
many waters. Learned men saw no reason why the screw of Archimedes
should not be used for the same purpose, and the idea was occasionally
advocated by French and English philosophers from at least 1680, by
Franklin and Watt less than a century later, and finally, in 1794,
Lyttleton of England obtained a patent for his “aquatic propeller,”
consisting of threads formed on a cylinder and revolving in a frame at
the head, stern, or side of a vessel.
Other means had been also suggested prior to 1800, and by the same set
of philosophers, and experimentally used by practical builders, such as
steam-pumps for receiving the water forward, or amidships, and forcing
it out astern, thus creating a propulsive movement. The latter part of
the eighteenth century teemed with these suggestions and experiments,
but it remained for the nineteenth to see their embodiment and
adaptation to successful commercial use.
The earliest, most successful demonstrations of screw propellers and
paddle wheels in steam vessels in the century were the construction and
use of a boat with twin screws by Col. John Stevens of Hoboken, N. J.,
in 1804 and the paddle-wheel steamboat trial of Fulton on the Hudson in
1807.
But it was left to John Ericsson, that great Swedish inventor, going to
England in 1826 with his brain full of ideas as to steam and solar
engines, to first perfect the screw-propeller. He there patented in 1836
his celebrated propeller, consisting of several blades or segments of a
screw, and based on such correct principles of twist that they were at
once adopted and applied to steam vessels.
In 1837-1839 the knowledge of his inventions had preceded him to
America, where his propeller was at once introduced and used in the
vessels _Frances B. Ogden_ and the _Robert E. Stockton_ (the latter
built by the Lairds of Birkenhead and launched in 1837). In 1839 or 1840
Ericsson went to America, and in 1841 he was engaged in the construction
of the U.S. ship of war _Princeton_, the first naval screw warship built
having propelling machinery under the water line and out of reach of
shot.
The idea that steamships could not be safely run at a greater speed than
ten or twelve miles an hour was now abandoned.
Twice Ericsson revolutionised the naval construction of the world by his
inventions in America: first by the introduction of his screw-propeller
in the _Princeton_; and second, by building the iron-clad _Monitor_.
Since Ericsson’s day other inventors have made themselves also famous by
giving new twists to the tail of this famous fish and new forms to its
iron-ribbed body.
_Pneumatic Propellers_ operated by the expulsion of air or gas against
the surrounding body of water, and chain-propellers, consisting of a
revolving chain provided with paddles or floats, have also been invented
and tested, with more or less successful results.
A great warship as she lies in some one of the vast modern ship-yards of
the world, resting securely on her long steel backbone, from which great
ribs of steel rise and curve on either side and far overhead, like a
monstrous skeleton of some huge animal that the sea alone can produce,
clothed with a skin, also of steel; her huge interior, lined at bottom
with an armoured deck that stretches across the entire breadth of the
vessel, and built upon this deck, capacious steel compartments enclosing
the engines and boilers, the coal, the magazines, the electric plant for
supplying power to various motors for lighting the ship and for
furnishing the current to powerful search-lights; having compartments
for the sick, the apothecary shop, and the surgeon’s hospital, the men’s
and the officers’ quarters; above these the conning tower and the
armoured pilot-house, then the great guns interspersed among these
various parts, looking like the sunken eyes, or protruding like the bony
prominences of some awful sea monster, is a structure that gives one an
idea of the immense departure which has occurred during the last half
century, not only from the wooden walls of the navies of all the past,
but from all its mechanical arts.
What a great ocean liner contains and what the contributions are to
modern ship-building from other modern arts is set forth in the
following extract from _McClure’s Magazine_ for September, 1900, in
describing the _Deutschland_. “The _Deutschland_, for instance has a
complete refrigerating plant, four hospitals, a safety deposit vault for
the immense quantities of gold and silver which pass between the banks
of Europe and America, eight kitchens, a complete post-office with
German and American clerks, thirty electrical motors, thirty-six pumps,
most of them of American and English make, no fewer than seventy-two
steam engines, a complete drug store, a complete fire department, with
pumps, hose and other fire-fighting machinery, a library, 2600 electric
lights, two barber shops, room for an orchestra and brass band, a
telegraph system, a telephone system, a complete printing establishment,
a photographic dark room, a cigar store, an electric fire-alarm system,
and a special refrigerator for flowers.”
We have seen, in treating of safes and locks, how burglars keep pace
with the latest inventions to protect property by the use of dynamite
and nitro-glycerine explosions. The reverse of this practice prevails
when those policemen of the seas, the _torpedo boats_, guard the
treasures of the shore. It is there the defenders are armed with the
irresistible explosives. These explosives are either planted in harbours
and discharged by electricity from the shore, or carried by very swift
armoured boats, or by boats capable of being submerged, directed, and
propelled by mechanisms contained there and controlled from the shore,
or from another vessel; or by boats containing all instrumentalities,
crew, and commander, and capable of submerging and raising itself, and
of attacking and exploding the torpedo when and where desired. The
latter are now considered as the most formidable and efficient class of
destroyers.
No matter how staunch, sound and grand in dimensions man may build his
ships, old Neptune can still toss them. But Franklin, a century and a
half ago, called attention to his experiments of oiling his locks when
in a tempestuous mood, and thus rendering the temper of the Old Man of
the Sea as placid as a summer pond. Ships that had become unmanageable
were thus enabled, by spreading oil on the waves from the windward side,
to be brought under control, and dangerous surfs subdued, so that boats
could land. Franklin’s idea of pouring oil on the troubled waters has
been revived during the last quarter of the century and various means
for doing it vigorously patented. The means have varied in many
instances, but chiefly consist of bags and other receptacles to hold and
distribute the oil upon the surrounding water with economy and
uniformity.
At the close of the century the world was still waiting for the
successful _Air-ship_.
A few successful experiments in balloon navigation by the aid of small
engines of different forms have been made since 1855. Some believe that
Count Zeppelin, an officer of the German army has solved the great
problem, especially since the ascent of his ship made on July 2, 1900,
at Lake Constance.
It has been asserted that no vessel has yet been made to successfully
fly unless made on the balloon principle, and Count Zeppelin’s boat is
on that principle. According to the description of Eugen Wolf, an
aeronaut who took part in the ascent referred to and who published an
account of the same in the November number of _McClure’s_, 1900, it is
not composed of one balloon, but of a row of them, and these are not
exposed when inflated to every breeze that blows, but enclosed and
combined in an enormous cylindrical shell, 420 feet in length, about 38
feet in diameter, with a volume of 14,780 cubic yards and with ends
pointed like a cigar. This shell is a framework made up of aluminium
trellis work, and divided into seventeen compartments, each having its
own gas bag. The frame is further strengthened and the balloons stayed
by a network of aluminium wire, and the entire frame covered with a soft
ramie fibre. Over this is placed a water-tight covering of pegamoid, and
the lower part covered with light silk. An air space of two feet is left
between the cover and the balloons. Beneath the balloons extends a
walking bridge 226 feet long, and from this bridge is suspended two
aluminium cars, at front and rear of the centre, adapted to hold all the
operative machinery and the operator and other passengers.
The balloons, provided with proper valves, served to lift the structure;
large four-winged screws, one on each side of the ship, their shafts
mounted on a light framework extending from the body of the ship, and
driven backward and forward by two light benzine engines, one on each
car, constituted the propelling force. Dirigibility (steering) was
provided for by an apparatus consisting of a double pair of rudders, one
pair forward and one aft, reaching out like great fins, and controlled
by light metal cords from the cars. A ballast of water was carried in a
compartment under each car. To give the ship an upward or a downward
movement the plane on which the ship rests was provided with a weight
adapted to slip back and forth on a cable underneath the balloon shell.
When the weight was far aft the tip of the ship was upward and the
movement was upward, when at the forward end the movement was downward,
and when at the centre the ship was poised and travelled in a horizontal
plane. The trip was made over the lake on a quiet evening. A distance of
three and three-quarter miles, at a height of 1300 feet, was made in
seventeen minutes. Evolutions from a straight course were accomplished.
The ship was lowered to the lake, on which it settled easily and rode
smoothly.
The other great plan of air navigation receiving the attention of
scientists and aeronauts is the aeroplane system. Although the cohesive
force of the air is so exceedingly small that it cannot be relied upon
as a sufficient resisting medium through which propulsion may be
accomplished alone by a counter-resisting agent like propeller blades,
yet it is known what weight the air has and it has been ascertained what
expanse of a thin plane is necessary without other means to support the
weight of a man in the air.
To this idea must be added the means of flight, of starting and
maintaining a stable flight and of directing its course. Careful
observation of the manner of the flight of large heavy birds, especially
in starting, has led to some successful experiments. They do not rise at
once, but require an initiative force for soaring which they obtain by
running on the ground before spreading their wings. The action of the
wings in folding and unfolding for maintaining the flight and
controlling its direction, is then to be noted.
It is along these lines that inventions in this system are now working.
An initiative mechanism to start the ship along the earth or water, to
raise it at an angle, to spread planes of sufficient extent to support
the weight of the machine and its operators on the body of the air
column, light engines to give the wing-planes an opening and closing
action, rudders to steer by, means for maintaining equilibrium, and
means when landing to float upon the water or roll upon the land, these
are the principal problems that navigators of the great seas above us
are now at work upon.