Steam-ships : The story of their development to the present day by R. A. Fletcher
CHAPTER X
2897 words | Chapter 128
THE BUILDING OF STEEL SHIPS
As early as 1853 mild cast steel had been suggested for shipbuilding,
and in 1855 Howell introduced it as “homogeneous metal,” but
shipbuilders took little notice of the suggestion for some years.
Robert Napier and Sons received orders in 1858 for some high-pressure
boilers and marine machinery where lightness combined with strength
was of the utmost importance, and it was proposed to use “homogeneous
metal” for the one and puddled steel for the other instead of the
wrought iron which was ordinarily employed. Steel as then made was
very brittle and many attempts were made to remedy this defect. David
Kirkaldy made a series of important experiments which lasted three and
a half years and attracted the attention of the Scottish Shipbuilders’
Association. His principal service was the discovery and placing on
record of the effects of oil hardening upon the properties of steel.
The _Ma Robert_ is said to have been the first steel steamer ever
built; she was constructed by Laird’s for the Livingstone expedition to
the Zambesi. High tensile steel was used with a limit of elasticity of
about twenty-three tons, which is very similar to the metal used in the
_Mauretania_ and _Lusitania_ where stresses are to be met. Strength
and lightness were essential in the _Ma Robert_ and therefore the new
material was used. The little vessel was 73 feet long, 8 feet wide, and
3 feet deep, and was flat-bottomed and of very little draft. But the
hull corroded badly and leaked very much, and the steamer came to grief
on a sandbank in the Zambesi.
The _Rainbow_, built of steel plates in 1858, was a smart, handsome
paddle-boat, schooner-rigged, and carrying two very tall masts. She
had a high-pressure engine and her steam-pipe emitted the energetic
snort which was peculiar to the locomotive of the time. Indeed her
high-pressure machinery made such a noise that she could be heard from
one side of the Mersey to the other. She was intended for the Niger
Exploration expedition, and on her trial attained a speed of between
twelve and thirteen miles an hour. She was 130 feet long by 16 feet
beam. Although her plates were only one-eighth of an inch thick she
had the stiffness and rigidity of a strong ship, and there was almost
an entire absence of vibration from the engines. Her boilers, which
were of puddled steel plates, were proved up to 200 lb. on the square
inch, though they were only worked at 50 to 60 lb. The engine was of
60 nominal horse-power, working up to 200 indicated. The hull was
divided athwartship and longitudinally by bulkheads into ten or twelve
water-tight compartments.
It must be remembered that these experimental steel boats were intended
for inland navigation, and being taken to Africa were withdrawn from
the observation of practically every one who was competent to judge
of the relative merits of iron and steel. Certainly no one attempted
to build a steel boat for the ocean for some years afterwards, and it
was not until 1875, when the Admiralty, acting upon observations made
in the dockyards of France where steel was being used, represented to
British manufacturers the importance of improving the quality of steel,
that the Siemens-Martin process was brought out, and in consequence two
cruisers were constructed of steel produced in this way.
[Illustration: THE “BRITANNIC” (WHITE STAR LINE, 1874).]
[Illustration: THE “UMBRIA” AND “ETRURIA” (CUNARD).]
With the launching of the _Rotomahana_, an ocean steel steamer of 1777
tons gross built by W. Denny and Bros. in 1879 for the Union Steamship
Company of New Zealand, the iron age of the steamer may be said to
close and the age of steel to begin. It has been shown how iron slowly
but surely replaced wood in construction; when the superiority of steel
to either had been practically demonstrated the change from iron to
steel was rapid. In 1891 over 80 per cent. of the steam-ships under
construction were of steel.
The _Rotomahana_ was followed in 1881 in the transatlantic trade by
the Allan liner _Buenos Ayrean_. The Allan Line has always been to the
fore in the provision of first-class steamers. They were the first to
have a steel ocean steamer; the first to adopt bilge keels on vessels,
the _Parisian_ in 1884 being fitted with them; and they were the first
to make the experiment with turbine-driven steamers for ocean traffic
in the _Victorian_ and _Virginian_ in 1903. These two vessels are 540
feet in length by 60 feet in breadth, and 40 feet 6 inches in depth.
They are of 12,000 tons register, and have a speed of 17 knots. Besides
these, the company has five twin-screw boats of tonnages ranging from
9000 to 11,000 tons, and twenty-two screw boats from 3000 to 5395 tons.
The Cunard Line’s first steel steamer was the _Servia_, built by
Messrs. J. and G. Thomson, and completed in 1881. She was 515 feet in
length, and of 7392 gross tonnage, and her engines, of 10,000 indicated
horse-power, gave her a speed of 17 knots. Incandescent electric lamps
were fitted in her, she being the first of the fleet to carry them. The
_Aurania_, of slightly less length, but of equal speed, and also of
steel, was built in 1883. After her came the _Umbria_ and _Etruria_,
steel single-screw steamers, with engines of 14,500 indicated
horse-power, giving them a speed of 20 knots. The sisters _Campania_
and _Lucania_, steel twin-screw vessels of 12,952 tons, were added for
the New York trade, and later the _Caronia_ and _Carmania_. They were
sisters except in their engines; the latter being the company’s first
turbine experiment, and having triple propellers. They are each 675
feet in length by 72 feet 6 inches beam, and 43 feet 9 inches moulded
depth.
The _Etruria_ was sold in 1909 to the shipbreakers for £16,750, and
with her there ended another chapter in the history of the navigation
of the North Atlantic. She was a “flyer” only a few years before being
disposed of, her record passage from Queenstown to New York being 5
days 20 hours 55 minutes, and her eastward passage 6 days 37 minutes.
She was built to outstrip the _Oregon_, a vessel built for the Guion
Line in 1883 by John Elder and Co., and known from her speed of 18
knots as “the greyhound of the Atlantic.” The same builders were
ordered by the Cunard Company to eclipse her, and constructed two
steamers, the _Etruria_ and _Umbria_, which for many years were the
fastest ships afloat. Before they left the builders’ hands, however,
the _Oregon_ was acquired by the Cunard Company. The two Cunarders had
the largest compound engines in existence. These boats were 500 feet
between perpendiculars, 57 feet 3 inches beam, and 40 feet moulded
depth. They were each of 8127 tons gross, and had engines of 14,500
indicated horse-power, giving them an average speed of 19 knots. It
was stated of them at one of the meetings of the Cunard Company that
“no ships ever gave their owners less uneasiness than these two, and
no ships have done such an extraordinary amount of good work. They
are monuments that cannot lie to the skill of the design and the
faithfulness of the labour that went to their accomplishment.”
[Illustration: THE “MAURETANIA” (CUNARD, 1907).]
[Illustration: THE “CAMPANIA” (CUNARD, 1892).]
The Cunard express steamer _Mauretania_, sister ship to the
_Lusitania_, launched at Clydebank, was constructed on the Tyne by
Messrs. Swan, Hunter, and Wigham Richardson, Ltd., who were already
represented in the Cunard fleet by the _Ultonia_, _Ivernia_, and
_Carpathia_. A description of the _Mauretania_ given by the builders
and the Cunard Company states that the flat keel-plate is five feet
wide and three and three-quarter inches thick, and forms a portion of
the bottom of the ship. Associated with this flat keel is a vertical
keel, five feet high and one inch thick, and to this vertebra are
attached, directly or indirectly, the frames and beams which make
up the skeleton. The double bottom is divided by this vertical keel
and the transverse frames into compartments in which water-ballast
may be taken. The tops of these tanks are carried well round the
turn of the bilge, so that should the bilge keels be torn away and
the hull pierced, the entering water would be confined between the
inner and outer bottoms. As a further precaution towards securing
insubmersibility, the lower deck is made completely water-tight. Below
it are the orlop and lower orlop decks, and above are the main, upper,
shelter, promenade, upper promenade, and boat decks--nine decks in all.
Automatically closing water-tight doors are fitted in the bulkheads,
and can be closed from the navigating bridge in a few seconds. The
_Mauretania_ has 175 water-tight compartments, so that it is claimed
for her that she is as unsinkable as a ship can be.
“The steel plates which cover the ribs or framing of the vessel or
are used for the decks, bulkheads, and casings, or in other ways,
number 26,000, the largest being about 48 feet in length, and weighing
from four to five tons. To secure these plates to each other and the
structural framework of the ship, over 4,000,000 rivets have been used,
aggregating in weight about 500 tons. The largest rivets are used in
the keel-plate, and these are eight inches in length and weigh 2³⁄₄
lb. The main frames and beams placed end to end would extend thirty
miles; the rudder, which has two sets of steering gear, both of which
are below the water-line, weighs 65 tons, and the diameter of the
rudder stock is 26 inches. The castings for the stem, stern-post, shaft
bracket and rudder together weigh 280 tons. Her ground gear is, with
that manufactured for her sister ship, the _Lusitania_, the strongest
yet made. The three anchors each weigh ten tons, while the 1800 feet of
cable is composed of 24-inch links, the iron in which is 3³⁄₄ inches
in diameter and the weight of each link about 1¹⁄₂ cwts. This mighty
harness has been vigorously tested, sample links and shackles emerging
successfully from a test strain of 370 tons.
“The principal measurements of the _Mauretania_ are:
Length 790 feet.
Breadth 88 „
Depth (moulded) 60 „
Gross tonnage 32,500 tons.
Displacement tonnage 45,000 „
Load draught 37 ft. 6 ins.
Height of funnels 155 feet.
Diameter of funnels 24 „
Height of masts 216 „
“Figures, however, convey but a bare idea of the great size. A
favourite standard of comparison in shipping is the leviathan of
Brunel, the _Great Eastern_, the mammoth steamer, which, born before
its time, yet solved in her construction many of the most difficult
problems with which the modern builders of big ships have to grapple;
yet the _Mauretania_ quite dwarfs the gigantic _Great Eastern_, as the
following figures show:
_Great Eastern._ _Mauretania._
Length 692 feet. 790 feet.
Breadth 80 „ 88 „
Displacement 27,000 tons. 45,000 tons.
Paddle, screw, and sail. Quadruple screws.
Speed 13 to 14 knots. 25 knots.
“The _Great Eastern_ was an experiment, but there is nothing of the
experiment about the _Mauretania_ and her sister, the Clyde-built
ship _Lusitania_. The valuable data obtained from the running of
the 20,000-ton turbine Cunarder _Carmania_ has afforded a valuable
object-lesson in adapting the turbine method of propulsion to liners of
the leviathan class, demonstrating the suitability of the steam turbine
to the largest type of vessel.
“The _Mauretania_ is propelled by turbine engines of about 70,000
indicated horse-power, driving four shafts, each of which is fitted
with one three-bladed propeller of manganese bronze. The outermost
shafts are each connected with a high-pressure turbine, the inner
shafts being rotated by the low-pressure turbines.
“The boilers and turbine engines of the _Mauretania_ were
constructed by the Wallsend Slipway and Engineering Company, Ltd.,
of Wallsend-on-Tyne. There are twenty-three double-ended and two
single-ended boilers, and one hundred and ninety-two large furnaces.
The boiler plates are the largest yet made. The steam is conducted from
the boilers into the turbines, of which there are four.” The turbines
contain about 3,000,000 blades, rotating four shafts, the united length
of which is close upon 1000 feet with a weight of about 250 tons,
each shaft carrying 17,000 or 18,000 indicated horse-power. Under the
covenant with the Government made at the time she was arranged to be
built, she is fitted for an armament of 12 six-inch guns. Her rudder
and both sets of steering-gear are below the water-line, and in the way
of the engine and boiler rooms there are side bunkers which, filled
with coal, are equivalent to an armour-belt round the vulnerable
portion of the ship.
Although the _Mauretania_ and _Lusitania_ are usually spoken of as
sisters, there are some differences in the design. They are the same
length, but the former is six inches deeper, which adds about 500 tons
to her registered tonnage. Special high tensile steel was used to a
greater extent in the construction of the _Mauretania_, making that
vessel something like 1000 tons lighter. Her lines are slightly finer,
and it has been claimed to account for her speed that there is some
superiority in her engines.
In regard to the structure of the _Lusitania_, it is stated that with
the whole structure of mild steel Lloyd’s accepted a stress of ten
tons to the square inch, and that in view of the strains thrown upon
the upper works a high tensile steel of less scantling was adopted for
those parts; a material having been discovered with a tensile strength
20 per cent. greater than mild steel, a reduction of 6 per cent. in the
scantlings was allowed from those for mild steel. The Cunarders were
not the first vessels by many years in which high tensile steel of a
strength of thirty-six tons was used, as it was introduced twenty-three
years ago in the steam-ship _America_.
Whether the great Cunarders pay in the financial sense is known only
to the management of the line, but there is no denying that they are
a great national asset. A detailed estimate, published at the time
they were about to make their first voyages, placed the expenditure at
£17,990 per voyage, and the income, allowing for a full passenger list,
at £31,350.[91] But this did not profess to be more than a general
estimate and in no sense official. The question has been raised in
various quarters whether an equal speed could not have been obtained
from reciprocating engines with a less consumption of coal; as a reply
to this view it has been pointed out that the sizes that would have
been required for the ingots, &c., for the machinery were beyond the
capabilities of our steel manufacturers, and thus, as so often has
happened, the new set of conditions was met by the new development of
invention.
[91] _Liverpool Courier_, November 18, 1907.
KAISER
CAMPANIA. OCEANIC. BALTIC. WILHELM II. LUSITANIA.
Displacement 20,000 26,100 33,000 26,000 41,500
Draught 30 30 30 30 32
Speed 22 20 16¹⁄₂ 23¹⁄₂ 25
I.H.P. 30,000 29,000 16,000 38/40,000 65,000
Consumption }
of coal, tons } 485 400 260 660 840
per day }
Length, b.p. 598 685 709 684 760
Breadth 65 68·3 75·6 72·3 88
Depth 43 49 49 52·6 60·5
Gross tonnage 12,950 17,274 23,800 19,360 28,830
Number of } {12 double}
boilers } 13 16 8 { 7 single} 24
Total cost £615,000 £739,000 £800,000 £927,200 £1,250,000
“The above table shows at a glance the ships that have come between
the _Campania_ and the _Lusitania_. The _Baltic_ shows the type of
steamer that pays the best, going across at a moderate speed sufficient
for most people while at the same time carrying an enormous amount of
cargo.”[92]
[92] _Shipping World_, January 2, 1907.
Alterations have been made in the propellers of both these steamers
with a view to finding the size, pitch, number of blades, material,
weight, and number of revolutions per minute and the other details upon
which efficiency depends, but the result is carefully guarded. Such
tests are expensive.
In 1889 the White Star Company built the _Teutonic_ of 10,000 tons,
which, like her sister ship the _Majestic_, was intended to be an armed
mercantile cruiser. These two vessels, which each took nearly three
years in building, were at that time the finest the world had seen, and
the speediest, and were regarded with such wonder that at the naval
review in 1889, one of them was visited by the German Emperor and the
late King Edward (then Prince of Wales) and many distinguished officers
of the Navy. The _Majestic_ soon brought the record from Queenstown to
New York down to 5 days 18 hours 18 minutes, but this was reduced by
the _Teutonic_ to 5 days 16¹⁄₂ hours.
The second _Oceanic_, also of steel and a twin-screw boat, was placed
in the Liverpool and New York service in 1899. She was 704 feet in
length and was the first vessel to be built longer than the _Great
Eastern_, but in other respects she was smaller, her beam being 68·3
feet, her gross tonnage 16,900 and her displacement tonnage 26,100. The
indicated horse-power of the _Oceanic_ was 29,000 as against the 11,000
of the _Great Eastern_, and her speed was 21¹⁄₂ knots as compared with
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