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tons, was launched in December of 1907, and is one of the most
notable productions of recent years. She is spar-decked throughout,
with magnificent lines and a handsome appearance, whilst retaining
the more conventional stem-plus-bowsprit. She has exceptional
accommodation, all connected by corridors and vestibules with no
fewer than a dozen state-rooms for guests. She is driven by two sets
of triple-expansion engines actuating twin-screws, which, to minimise
vibration, are at a different pitch, and run at varying speeds. She can
carry sufficient coal to allow her to cruise for 6,000 miles, and both in
internal and external appearance is as handsome as she is capable.
Her genesis begins when the future owners resolve to have her
built. Before any plans are drawn out there must first be decided the
dimensions, the displacement and the general features which she is
to possess, whether she is to be a slow ship, a fast ship, engaged in
passenger work, cargo-carrying, on the North Atlantic route, for the
East through the Suez Canal, and so on; for all these factors
combine to determine the lines on which she is to be built. Before we
progress any farther, let us get into our minds the nine different types
which separate the generic class of steamships. If the reader will
follow the accompanying illustrations, we shall not run the risk of
being obscure in our argument. Fig. 1, shows the steamship in its
elementary form, just a flush-decked craft, with casings for the
protection of the engines as explained on an earlier page. This
represents the type of which the coasting steamer illustrated
opposite page 134 is an example. This casing in the diagram before
us is, so to speak, an island on the deck, but presently it was so
developed that it extended to the sides of the ship, and, rising up as
a continuation of the hull, became a bridge. At the same time a
monkey forecastle and a short poop were added to make her the
better protected against the seas. This will be seen in Fig. 2. This is
known as the “three-island” type for obvious reasons. It must be
understood that on either side a passage leads beneath the bridge-
deck so as to allow the crew to get about the ship. But from being
merely a protection for the bows of the ship, the monkey forecastle
became several feet higher, so that it could accommodate the
quarters of the crew, and this “top-gallant” forecastle, as it is known,
will be seen in Fig. 3. At the same time, the short poop or hood at the
stern has now become lengthened into something longer. But in Fig.
4 we find the lengthened poop becoming a raised quarter-deck—that
is, not a mere structure raised over the deck, but literally a deck
raised at the quarter. This raised quarter-deck was the better able to
withstand the violent force of the sea when it broke over the ship. In
Fig. 5 we have a still further development in which the topgallant
forecastle is retained as before, but the long poop and the after end
of the bridge are lengthened until they meet and form one long
combination. This is one of the “well-deck” types, the “well” being
between the after end of the forecastle and the forward end of the
bridge-deck. This well was left for the reason that it was not required
for carrying cargo, because it was not desirable to load the ship
forward lest she might be down at the head (which in itself would be
bad), whilst at the same time it would raise the stern so that the
propeller was the more likely to race. But in the modern evolution of
the steamship it is not only a question of trim and seaworthiness that
have been taken into consideration, but also there are the rules and
regulations which have been made with regard to the steam vessel.
Now, this well-space not being reckoned in the tonnage of the ship
(on which she has to pay costly dues) if kept open, it was good and
serviceable in another way. Considered from the view of
seaworthiness, this well, it was claimed, would allow the prevention
of the sweeping of the whole length of the ship by whatever water
that broke aboard the bows (which would be the case if the well were
covered up). If left open, the water could easily be allowed to run out
through the scuppers. But this type in Fig. 5 is rather midway in the
transition between the “three-island” type and the shelter-deck type.
The diagram in Fig. 6 is more truly a well-decker, and differs from the
ship in Fig. 5, in that the one we are now considering has a raised
quarter-deck instead of a poop. She has a top-gallant forecastle, a
raised quarter-deck and bridge combined, and this type was largely
used in the cargo ships employed in crossing the Atlantic Ocean. It is
now especially popular in ships engaged in the coal trade. The
advantages of this raised quarter-deck are that it increases the cubic
capacity of the ship, and makes up for the space wasted by the shaft
tunnel. By enabling more cargo to be placed aft, it takes away the
chance of the ship being trimmed by the head.
With these different types before us, we may now go on with our
main subject. Having settled the question as to the type and
character of the steamship to be built, the next thing is to design the
midship section, which shows the general structural arrangements
and scantlings of the various parts. In the drawing-office the plans
are prepared, and the various sections of the ship worked out by
expert draughtsmen attached to the shipbuilding yard. This
necessitates the very greatest accuracy, and the building is usually
specially guarded against those who might like to have an
opportunity of obtaining valuable secrets. The plans having been
worked out on paper, there follows the “laying off” on the floor of an
immense loft, called the “mould floor,” where the plans are
transferred according to the exact dimensions that are to be
embodied in the ship. In many cases the future owner insists on a
wooden model being submitted in the first instance, by the builder,
so that a fair idea may be obtained of the hull of the proposed ship.
Each vessel is known at the shipbuilder’s by a number and not
by her name. The keel is the first part of her to be laid, which
consists of heavy bars of iron laid on to blocks of wood called
“stocks,” and the line of these slants gently down to the water’s
edge, so that when, after many months, the time arrives for the
launching of the great ship, she may slide down easily into the sea
that is, for the future, to be her support. After these bars have been
fastened together, then the frames or ribs are erected, the ship being
built with her stern nearest to the water, and her bow inland, except
in the few cases (as, for example, that of the Great Eastern), where
a vessel, owing to her length in proportion to the width of the water-
space available, has to be launched sideways. These ribs are bent
pieces of steel, which have been specially curved according to the
pattern already worked out. Let us now turn to the accompanying
illustrations which show the steamship in course of construction.
These have been specially selected in order that the reader might be
able to have before him only those which are of recent date, and
show ships whose names, at least, are familiar to him.
THE “GEORGE WASHINGTON” IN COURSE OF CONSTRUCTION.
Showing Framing from the Stern.
From a Photograph. By permission of the Norddeutscher Lloyd Co.
After the plates have been all fastened by rivets to the frames,
and the outside of the ship has been given a paint of conventional
salmon pink, the time approaches for her to be launched. During her
building the ship has been resting on the keel blocks where her
centre touches, but her bilges have been supported by blocks and
shores. These latter will be seen in the illustration of the Mauretania
already considered. As the day for launching approaches, so also
does the anxiety of the builders increase, for at no time in her career
is the ship so seriously endangered. On the day of the launch the
weight of the vessel is gradually transferred from the stocks on which
she has been built, to the cradle, being lifted bodily from the keel-
blocks by means of an army of men driving wedges underneath her
bottom. This cradle is constructed on the launching ways, and the
ship herself, being now “cradle-borne,” is held in place only by a
number of props called “dog-shores.” At the right moment the signal
is given for these to be knocked aside, and at the first symptoms of
the ship in her cradle showing an inclination to glide, the bottle of
wine is broken against her bows by the lady entrusted with so
pleasant an honour. With a deep roar the ship goes down the ways,
and as soon as the vessel becomes waterborne the cradle floats.
The ship herself is taken in charge by a tug, whilst numerous small
boats collect the various pieces of timber which are scattered over
the surface of the water. Two or three days before the launch, the
cradle which has been fitted temporarily in place, is taken away and
smeared with Russian tallow and soft soap. The ways themselves
are covered with this preparation after they have been well scraped
clean. In case, however, the ship should fail to start at the critical
moment after the dog-shores have been removed, it is usual now to
have a hydraulic starting ram (worked by a hand-pump) under the
forefoot of the ship. This will give a push sufficiently powerful to start
the great creature down her short, perilous journey into the world of
water which is to be her future abiding-place.
But it can readily be imagined that such a ponderous weight as
this carries a good deal of impetus with it, and since in most cases
the width of the water is confined, precautions have to be taken to
prevent the ship running ashore the other side and doing damage to
herself—perhaps smashing her rudder and propellers, or worse.
Therefore, heavy anchors have been buried deep into the ground,
and cables or hawsers are led from the bows and quarters and
attached thereto, or else to heavy-weights composed of coils of
chain, whose friction over the ground gradually stops the vessel. Not
infrequently the cables break through the sudden jerk which the
great ship puts on them, and the anchors tear up the slip-way.
Perhaps as many as eight cables may be thus employed, each being
made fast to two or three separate masses of about five to fifteen
tons, but with slack chain between so that only one at a time is
started. As soon as the ship has left the ways, all the cables become
taut, and they put in motion the first lot of drags. Further on, the next
lot of drags receive their strain, then the third, so that no serious jerk
may have been given, and the ship gradually brings up owing to the
powerful friction. Lest the force of the ship going into the water
should damage the rudder or the propeller, these, if they have been
placed in position, are locked so as to prevent free play. After this the
ship is towed round to another part of the yard where her engines
are slung into her by means of powerful cranes. The upper
structures are completed, masts stepped and an army of men work
away to get her ready for her builders’ trials. Carpenters are busy
erecting her cabins, painters and decorators enliven her internal
appearance, and upholsterers add the final touches of luxury to her
saloons and lounges.
STERN FRAME OF THE “TITANIC,” FEB. 9, 1910.
From a Photograph. By permission of Messrs. Ismay, Imrie & Co.
One of the most important events of the ship’s life is her trial trip.
Before this occurs the ship’s bottom must be cleaned, for a foul
underwater skin will deaden the speed, and give altogether
erroneous data. The weather should be favourable also, the sea
calm, and the water not too shallow to cause resistance to ships of
high speed, while a good steersman must be at the helm so as to
keep the ship on a perfectly straight course. Around our coasts at
various localities are noticeable posts erected in the ground to
indicate the measured mile. To obtain the correct data as to the
speed of the ship, she may be given successive runs in opposite
directions over this measured mile; a continuous run at sea, the
number of revolutions being counted during that period, and a
continuous run past a series of stations of known distances apart,
the times at which these are passed being recorded as the ship is
abreast with them. For obtaining a “mean” speed over the measured
mile, one run with the tide and one against the tide supply what is
required. During these trials, the displacement and trim of the ship
should be as nearly as possible those for which she has been
designed. But besides affording the data which can only show
whether or not the ship comes up to her contract, these trials are
highly valuable as affording information to the builder for subsequent
use, in regard both to the design of the ship herself and the amount
of horsepower essential for sending her along at a required speed.
The amount of coal consumption required is also an important item
that is discovered. This is found as follows: Let there be used two
bunkers. The first one is not to be sealed, but the latter is. The
former is to be drawn upon for getting up steam, taking the ship out
of the harbour, and generally until such time as she enters upon her
trial proper. This first bunker is then sealed up, and the other one
unsealed, and its contents alone used during the trial. After the trial
is ended, the fires being left in ordinary condition, the second bunker
is again sealed up, and the first bunker drawn upon. By reckoning up
the separate amounts it is quite easy afterwards to determine the
exact quantity which the ship has consumed during a given number
of knots in a given time. Finally, after every detail has been
completed, the ship is handed over to her owners and steams away
from the neighbourhood of her birth. Presently she arrives at her
port, whence she will run for the next ten or twenty years, and before
long she sets forth with her first load of passengers, mails and cargo
on her maiden trip across the ocean. To begin with, she may not
establish any new records for speed; for a ship takes time to find
herself, and her officers to understand her individualities. “Know your
ship” is one of the mottoes which an ambitious officer keeps ever
before him, and if this is true on the navigation bridge, it is even still
more true down below, where the engines will not show their full
capabilities for several passages at least.
LAUNCH OF THE “ARAGUAYA.”
From a Photograph. By permission of the Royal Mail Steam Packet Co.
LAUNCH OF A TURRET-SHIP.
From a Photograph. By permission of Messrs. Doxford & Sons, Sunderland.