The "Savannah" measured three hundred and fifty tons, and was
constructed by Crocker & Fickett, at Corlear's Hook, N. Y. She was purchased
by Mr. Scarborough, of Savannah, who placed Captain Moses Rogers, previously
in command of the "Clermont" and of Stevens's boat, the "Phoenix,"
in charge. The ship was fitted with steam machinery and paddle-wheels, and
sailed for Savannah, April 27, 1819, making the voyage successfully in seven
days. From Savannah, the vessel sailed for Liverpool, May 26, and arrived
at that port June 20. During this trip the engines were used eighteen days,
and the remainder of the voyage was made under sail. From Liverpool the
"Savannah" sailed, July 23, for the Baltic, touching at Copenhagen,
Stockholm, St. Petersburg, and other ports. At St. Petersburg, Lord Lyndock,
who had been a passenger, was landed; and on taking leave of the commander
of the steamer the distinguished guest presented him with a silver tea-kettle,
suitably inscribed with a legend referring to the importance of the event
which afforded him this opportunity. The "Savannah" left St. Petersburg
in November, passing New York December 9, and reaching Savannah in fifty
days from the date of departure, stopping four days at Copenhagen, Denmark,
and an equal length of time at Arundel, Norway. Several severe gales were
met in the Atlantic, but no serious injury was done to the ship.
The "Savannah" was a full-rigged ship. The wheels were turned
by an inclined direct-acting low-pressure engine, having a steam-cylinder
forty inches in diameter and six feet stroke of piston. The paddle-wheels
were of wrought-iron, and were so arranged that they could be detached and
hoisted on board when found advisable. After the return of the ship to the
United States the machinery was removed, and was sold to the Allaire Works,
of New York. The steam-cylinder was exhibited by the purchasers at the World's
Fair at New York, thirty years later. The vessel was employed as a sailing-vessel
on a line between New York and Savannah, and was finally lost in the year
1822.
Later, the "Enterprise" made a voyage (1825) to India, under steam
and sail as the weather and circumstances permitted ; and still other vessels
were built, using "auxiliary" engines, as they were called; but
even as late as 1838 there were grave doubts expressed by eminent authorities
of the feasibility of making long voyages by steam alone. These doubts were,
however, set at rest in that year by the crossing of the Atlantic by two
steamers almost simultaneously, - the "Sirius and the "Great Western."
The latter was a large vessel for those days, and nearly double the size
and power of the other. The "Great Western" was of 1,350 tons
burden and 450 horse-power; the "Sirius" was of 700 tons and 250
horse-power.
The "Sirius" sailed from Cork on the 4th and the "Great
Western" from Bristol on the 8th of April, both arriving in New York
on the same day, - April 23, 1838, - the one in the morning, the other
in the afternoon. These vessels were placed on the route in the interests,
respectively, of the British and American Steam Navigation Co., and of the
Great Western Railway of Great Britain. Both ships returned safely, making
good time; and the larger was kept on the line for some years, making many
successful voyages. The other craft was deemed too small for the route and
was taken off and placed on a line between Dublin and Cork. Other ships
were soon built for this trade, and the transoceanic lines were gradually
established, never again to be given up. As may well be imagined, the appearance
of the two pioneers in New York harbour was a most impressive event, and
awakened the greatest enthusiasm on both sides the Atlantic. The formation
of the still-existing Cunard Line immediately followed; its first vessel,
the "Britannia," sailing for New York on the 4h of July, 1840.
Three sister ships followed; and the four steamers continued in service
until the success of the enterprise was so far assured as to justify the
building of larger and more powerf~ vessels. These four ships had an aggregate
of about forty-six hundred tons burden, - about one half the tonnage of
single vessels now on transatlantic lines. These vessels and the ships of
the first large American company, the Collins Line, organized about 1850,
were all paddle-steamers with side-lever engines, like that illustrated
in figure 21. They were first built, it is said, by Messrs. Maudsley, Sons,
& Field, about 1835; but that here illustrated was designed by Mr. Charles
Copeland, of New York, for the "Pacific," one of the Collins steamers.
This steamer was built at New York, - the hull by William Brown, and
the machinery by the Novelty Iron Works. The length of the hull was 276
feet, its breadth 45 feet, and the depth of hold 31.5 leet. The width over
the paddle-boxes was 75 feet. The ship measured 2,860 tons. The form of
the hull was such as best adapted the ship for high speed. The main "saloon"
was about 70 feet long, and the dining-room was 60 feet in length and twenty
feet wide. The staterooms accommodated 150 passengers. These vessels inaugurated
our present wonderful system of passenger~transpbrtation. The engines were
of the side-lever type, as illustrated in Figure 21.
In this engine the piston-rod was attached to a cross-head, from which,
at each side, links BC, connected with the side-lever, D B F. The latter
vibrated about a main centre at B; from its other end a connecting-rod,
B; led to the cross-tail, W, connected to the crank-pin, L The condenser,
M; and air-pump, Q, were between the cylinder, A, and the crank, IJ.
The Collins Line proved a failure; but it was very largely a consequence
of a series of inisfortunes, for which neither the management nor the officers
of the ships were held accountable. Ship after ship was lost, and the costs
of operation in competition with the British lines, which were subject to
far less expense, proved to be unexpectedly large. It is also probable that
the general introduction of the screw, after these ships had been built
as paddle-steamers, had something, perhaps much, to do with the final breaking
down of so expensive and burdensome a line. The screw-propeller had by this
time become an undeniable success in competition with the paddle in ocean
steaming; and screw-vessels now rapidly displaced those propelled by paddle-wheels.
The screw-propeller, proposed by Bernouilli and by Watt, used successfully
by Fitch and by Stevens and Smith, and a little later (1812) by Trevithick,
- was finally brought into use for general purposes by Francis Pettit Smith
in Great Britain, and by John Ericsson in the United States, after the latter
had made an experimental success but a commercial failure of it in England.
Ericsson's patent on his screw was issued from the British patent office
in 1836. His boat, built in that year, was found to be capable of doing
- good work as a "tug" on the Thames, making ten miles an hour,
running free, and towing large vessels at the rate of five to seven miles
an hour. The British Admiralty, with customary conservatism, refused to
adopt Ericsson's plans, and he was persuaded by Captain Stockton, an enterprising
American naval officer, to go with him to the United States, and there endeavour
to interest the Navy Department in his inventions. A screw-vessel, the "Stockton,"
was accordingly built in England and sent over to the United States in 1839;
and Ericsson followed, to build other vessels for Stockton and his partners
in the venture. The "Stockton "remained in service on the Delaware
and Raritan Canal, under the name of the "New Jersey," for many
years.
After the departure of Ericsson a company was formed in England to work
the patents of Smith; and this company built the "Archimedes,"
the trial-trip being made October 14 of that year. This boat made nearly
ten miles an hour; and the British Admiralty at last began to take some
interest in the subject, and subsequently adopted the screw for naval purposes.
Meantime, also, Congress had authorized the construction of new vessels,
and Ericsson was allowed to introduce his screw and his engines into one
of them, - the "Princeton." This was the first steamer built
for war purposes which was fitted with a screwpropeller. She was large for
the time, - about one thdusand tons displacement, - and all the machinery
was placed under the water-line for the first time also.
In reporting on the performance of this ship, Captain Stockton, who was
the first commander, recites the advantages possessed by the steamer in
consequence of the facts that her machinery is out of reach of shot; that
no paddles are in sight; that she has clear decks; and that, burning anthracite
coal, no smoke is visible; he then goes on to repeat, substantially, the
idea of Fulton, saying, "The improvements in the art of war effected
on board the 'Princeton' may be productive of more important results than
anything that has occurred since the invention of gunpowder. The numerical
force of other navies, so long boasted, may be set at naught; the ocean
may again become neutral ground; and the rights of the smallest, as well
as the greatest nations, may once more be respected." The hull of the
vessel was condemne in 1849, and the ship broken up. A second hull was built,
fitted with the same machinery, and given the same name, in 1851, but was
less satisfactory, performed little service, and was sold out of the service
in 1867. Since the days of the "Princeton," all navies have adopted
the screw-propeller, and all naval fleets are steam-fleets.
The screw was found to possess many advantages over the paddle-wheel. The
cost of machinery was greatly reduced; the expense of maintenance in working
order was, however, somewhat increased. The latter disadvantage was, nevertheless,
compensated by an immense increase in the economy of power for ship-propulsion,
which marked the substitution of the new machinery.
When a ship is under way, the motion of the vessel creates a current of
water in the direction in which the ship is moving, following the ship for
a time, and finally losing all motion by contact with the surrounding mass
of water. All the power expended in the production of this great stream
is, in the paddle-steamer, lost. In screw-steamers, however, the propelling
instrument works in this following current; and the tendency is to bring
the fluid to rest, taking up, and thus restoring usefully, a large part
of that energy which would otherwise have been lost. The screw is covered
by the water, and acts with comparative efficiency iii consequence of its
submersion. The rotation of the screw is rapid and smooth also, and this
permits the use of small, light, last-running engines. The latter condition
leads to economy of weight and space, and saves not only the cost of transportation
of the excess of weight of the larger kind of engine, but leaving so much
more room for cargo, the gain is found to be a double one. Still further:
the quick-running engine is, other things being equal, the most economical,
and thus expense is saved, not only in the purchase of fuel, but in its
transportation; and additional gain is derived from the increased amount
of paying cargo which the vessel is thus enabled to carry.
Since the days of Ericsson's great success in the introduction of the screw-propeller
and the organization of steam-fleets, there have been two great improvements
in the steam-engine, and two important changes in naval construction. The
first two are the general introduction of the surface-condenser, and the
use of the compound engine at sea; the second two are the building of the
iron-clad fleet, and the construction of Ericsson's greatest invention,
the "Monitor." During these fifty years, also, the steam-fleets
of the merchant navies of the world have become enormously increased in
numbers, their vessels have grown to tremendous size, and their machinery
has more than proportionally gained in power, driving their great hulls
through the heaviest seas with the speed of the railway train on land.
The change from the side-lever single-cylinder engine, with jet-condenser
and paddle-wheels, to the direct-acting compound engine, with surface-condenser
and screw-propellers, has occurred within this period. Builders slowly learned
the principles governing expansion in one or more cylinders; and the earlier
engines were often made with a high and low pressure cylinder working on
the same rod, each machine consisting of four steam-cylinders. It was at
last discovered that a high-pressure single-cylinder engine exhausting into
a separate larger low-pressure engine might do as well, and the compound
engine became as simple as the type of engine which it displaced.
The advantage of introducing such engines at sea is considerably greater
than on land. The coal carried by a steam-vessel is not only an item of
great importance in consequence of its cost, but it represents so much non-paying
cargo, and is to be charged with the full cost of transportation in addition
to first cost and the loss of profit on the freight that it displaces. To
this saving of cost on fuel account, by the use of the later type of engine,
is to be added the gain in wages and sustenance of the labour required to
handle that coal.
At sea, rise of steam-pressure was for a considerable time retarded by the
serious difficulty encountered in the tendency of the sulphate of lime to
deposit from the sea-water in the boiler. When steam-pressure had risen
to twenty-five pounds per square inch, it was found that no amount of "blowing
out" would prevent the deposition of seriously large quantities of
this salt. The introduction of surface-condensation was attempted as the
remedy for this evil, but it was long doubtful whether its disadvantages
were not greater than its advantages. It was found difficult to keep the
condensers tight; and boilers were injured by corrosion, evidently due to
the presence of the surface-condenser. The simple expedient of permitting
a thin scale to form in the boiler was, after a time, hit upon as a means
of overcoming this difficulty. Once introduced, the surface-condenser removed
the obstacle to further elevation of steam-pressure, and the rise from twenty
to sixty pounds pressure, and more, soon occurred. John Elder and his competitors
on the Clyde were the first to take advantage of the fact when these higher
pressures became prac ticable.
Extreme lightness in modern machinery has been largely the result of skilful
designing, of intelligent construction, and of care in the selection of
material. Today, the engines of heavy iron-dads are models of good proportions,
excellence in materials, and of workmanship. The weight per indicated horse-power
has been reduced from 400 or 500 pounds to a fraction of that amount. This
has been accomplished by forcing the boilers, by higher steam-pressure,
higher piston-speed, reduction of friction of parts, reduction of capacity
for coal-stowage, and careful proportioning. The reduction of coal-capacity
is compensated by increase of economy secured by high pressure, by increased
expansion, elevation of piston-speed, and the introduction of the c6mpound
engine with sufface-condensation.
A good marine steam-engine of the form considered standard about 1860, having
low-pressure boilers carrying steam at 20 or 25 pounds pressure, expanding
twice or three times, and with a jet-condenser, would require about 30 or
35 pounds of feed-water per horse-power per hour; substituting surface-condensation
brought down the weight of steam used to from 25 to 30 pounds. Increasing
steam-pressure to 60 pounds, expanding from five to eight times, and combining
the special advantages of the superheater and the compound engine with surface-condensation
reduced the consumption of steam to 20, and with 100 to 150 pounds pressure
in the "triple-expansion engine, in some cases to 15 pounds of steam
per horse-power per hour.
The next engraving illustrates the modern compound engine. Here, the cranks
Y Z are coupled at an angle of ninety degrees, only two cylinders, A B,
being used; and an awkward distribution of pressure is avoided by having
a considerable volume of steam-pipe, or by a steam-reservoir, 0 P, between
the two cylinders. The valves, y y, are set like those of an ordinary engine,
the peculiarity being that the steam exhausted by the one cylinder, A, is
used again in the second and larger one, B. In this combination, the expansion
is generally carried to about six times, the pressure of steam in the boiler
being usually between sixty and seventy-five pounds per square inch.
The latest form of marine engine is the "quadruple. expansion"
engine, in which the steam, taken from boilers carrying a pressure of one
hundred and fifty to two hundred pounds per square inch, is worked through
a series of steam-cylinders, expanding continually to lower pressures as
it goes, until it is finally discharged into the condenser at a pressure
far below that of the atmosphere, all its energy converted, so far as the
laws of nature allow, into working power. Thus expanding the steam to sixteen
or twenty times its original volume, each of the four elements of the engine
doing its share of the work, this machine is found capable of vastly more
effective use of steam than the older types of engine, in which the wastes
within the cylinders were increased with increasing expansion in far higher
proportion than the gain by expansion itself. In the various compound engines,
the wastes of one steam-cylinder are utilized more or less completely in
the next, thus making the total waste approximately, for the series, only
that of one of its cylinders. Otherwise stated, the physical wastes of heat
and steam in the " multiple-cylinder" engine of extreme expansion
is approximately that only of a single cylinder, with a fraction of that
degree of expansion. This is, in simple terms, the secret of the gain by
the use of the compound engine. This change of type has been slowly going
on, both on land and sea, ever since the time of Watt, whose contemporary
and rival, Horablower, first endeavoured to introduce the now standard system.
It has now so far progressed that the marine engine demands only from one
and a quarter to one and a half pounds of fuel of good quality per horse-
power and per hour. In special instances, on land, where the conditions
of operation could be made exceptionally favourable, the economy of the
engine is claimed to have been made even greater. Even the locomotive engine
is now in process of conversion into a compound engine, with good results
in many cases.
As the compound engine revolutionized the methods and results of the work
of the engineer in steam-navigation, so the entrance of the modem iron-clad
upon the scene, about the middle of the century, revolutionized many of
the methods and the results of naval contests. The idea was by no means
new; but like all great inventions, time had been required for it to become
matured, and especially for the world to make ready for it. The Stevens
Battery was probably the first real armoured war-vessel proposed and planned,
and actually placed on the stocks; but the first use of the iron-clad of
which we have authentic knowledge was during the Crimean War, when the French
and English fleet was reinforced by a few iron-clad craft, small and rude,
crude in design and thin of plating, but which were sufficient to indicate
the probability that such vessels might find place in modern fleets. Today
all fighting ships are plated, and their dimensions have increased, and
the thickness of their armour has been made correspondingly greater, until
they are now the largest of ships, and their plating withs~ands the shock
of guns throwing shot weighing many hundred pounds, with a velocity of nearly
a half-mile in a second; but they are nevertheless still vulnerable when
attacked by Fulton's method of submarine warfare with torpedoes.
Modern fleets include, in some countries, part of the more efficient
and the larger merchant-vessels; and in Great Britain all the largest and
fastest transoceanic ships are retained, under the laws of the naval code,
for use by the Government in time of war, thus making an enormous and important
addition to the unarmoured fleet. Lloyd's Register of Shipping of the "War-ships
of the World," for 1890, gives statistical and other information regarding
all navies, which will be interesting in this connection:
| Britain | United States | France | Germany | Italy | Russia | |
|---|---|---|---|---|---|---|
| Number of first-class armour-clads (18-in. armour and above) | 19 | 13 | 10 | 7 | ||
| Other sea-going arour-clads | 41 | 27 | 16 | 11 | 17 | |
| Cruisers and sloops (above 900 tons) | 166 | 47 | 63 | 35 | 22 | 32 |
| Gun vessels (over 600 tons) | 47 | 3 | 11 | 4 | 17 | 4 |
| Gunboats (over 200 tons) | 81 | 2 | 37 | 10 | 22 | 14 |
| War-vessels over 14 knots | 169 | 19 | 75 | 44 | 55 | 28 |
| Merchant ships to each cruiser or sloop | 39 | 9 | 8 | 21 | 10 | 7 |
| Merchant tonnage to each cruiser or ship | 49,000 | 11,000 | 13,000 | 26,500 | 13,600 | 5,000 |
| Merchant ships to each war-vessel | 38 | 22 | 7 | 17 | 4 | 8 |
The speed of the several classes of war-vessels are as follows:
| Britain | France | Germany | Italy | Total, incl. other Nations | ||
|---|---|---|---|---|---|---|
| Over 20 knots | Number | 50 | 5 | 2 | 17 | 94 |
| Tons displacement | 135,900 | 24,280 | 640 | 12,300 | 238,663 | |
| Number of guns | 290 | 48 | 16 | 350 | ||
| Over 19 knots | Number | 24 | 10 | 9 | 3 | 61 |
| Tons displacement | 96,510 | 30,030 | 10,870 | 7,900 | 208,210 | |
| Number of guns | 196 | 58 | 10 | 26 | 375 | |
| Over 18 knots | Number | 9 | 11 | 8 | 9 | 61 |
| Tons displacement | 46,660 | 4,980 | 57,260 | 71,310 | 232,800 | |
| Number of guns | 107 | 5 | 56 | 72 | 334 |
The largest vessels included in the British 20-knot list are the "Blake"
and "Blenheim," of 9,000 tons, and 22 knots speed, with 9.25-inch
guns. France's largest are the "Dupuy de Lome" and "Amiral
Jaures," of 6,300 tons and 20 knots speed. Germany has two small torpedo-catchers
of 22 knots, and Italy several of 21 knots, while Austria has three of 23
knots speed. Spain has the "Reina Regente," of 21 knots speed,
and two sister ships. It seems that sixteen merchant-vessels are able to
steam over 19 knots, several of them at 21 knots. Of this number nine are
Atlantic vessels, three Hamburg-American liners, two White Star, two Inman,
and two Cunard liners, while the remainder are paddle-steamers on the Channel,
- eight between England and the Continent, and two to the Isle of Man.
Several steamers have since been added to the list.
Among the most famous of the great steamers of recent years, - the "ocean
greyhounds," as they have been well named, - are the Cunard steamers
"Umbria" and "Etruria; " the still faster vessels of
the Inman line, - the ' City of New York" and the "City of Paris;"
and the later ships of the White Star line, - the "Majestic "
and the "Teutonic." They are all ships of 8,000 to 10,000 tons
burden, and of from 15,000 to 20,000 horse-power. The "City of Paris,"
for example, cost to build over L350,000, or about $1,750,000. Her length
is 580 feet, and breadth of beam 63 feet, while her two complete sets of
engines are of the triple expansion type, and of about 20,000 horse-power.
A manufacturing establishment requiring engines of 1,000 horse-power is
considered a great enterprise, but this steamer's engines are nearly twenty
times as great. The consumption of fuel averages about 350 tons a day. She
has a crew of 370 men, and accommodations for 1,450 passengers. One thousand
electric lamps are required to furnish light. 'I'his wonderful vessel has
crossed the Atlantic repeatedly in less than six days, and perhaps with
the exception of the "'Feutonic" has held a first place among
the fastest steamers on the ocean up to the present time (1891).
The sister ships "Teutonic" and "Majestic" are of
about 16,000 tons displacement, that is, their weight at sea is that amount,
- and are the fastest ships in a fleet of about 85,000 tons total belonging
to one company. The "Teutonic" has made the trip from Queenstown
to New York in five days, nineteen hours, and five minutes, at a speed averaging
20.2 knots, or about 23.25 miles an hour, a speed only rivalled by the sister
ship and by the "City of Paris," which made its fastest trip in
five days, nineteen hours, and nineteen minutes. These ships are of 10,000
tons burden, registered, and their engines are of 17,000 horse-power. They
are 582 feet long, 57.5 feet wide, and 39 feet deep, of finest steel for
ship construction, and can carry over 1,300 passengers, 3,000 tons of fuel,
and 4,000 tons of cargo. There are twenty-five engineers, sixty firemen,
and forty-eight coal-passers or trimmers, with supernumeraries, etc., which
bring up the total engineer's roll to one hundred and sixty-eight persons.
The crew consists of about forty men. There are twenty-five cooks and sixty"
stewards." A full passenger-list gives a total of about sixteen hundred
persons on board when at sea.
The engines of these great ships are of the triple-expansion variety, two
independent sets being employed to drive twin screws. Their condensers contain
twenty miles of brass tubes. The fires are forced by blowing-fans, which
in the aggregate -fourteen in number - are capable of supplying about 225,000
cubic feet of air per minute. One hundred and twenty tons of water are converted
into steam each hour, and at a pressure of one hundred and eighty pounds
per square inch.
This would be sufficient for the supply of a city of over twenty-five
thousand people, allowing twenty-five gallons per day to each. About 320
tons of fuel are required to convert the water into steam, each day, and
the air needed for its combustion weighs about 275 tons. In the condensation
of the steam about 4,000 tons of sea-water are passed through the condensers
every hour, - the equivalent of the water-supply to a city of three-quarters
of a million people.
The outlook, in the direction of higher speeds and better accommodation
in river and ocean navigation, judged by the knowledge which we now possess
and from the standpoint of the engineer, may be said to be, practically,
today, what it has been for many years, - a gradual and steady, though probably
now comparatively slow, progress in both directions. The gradual increase
of size of vessel, of power of machinery, and the improvement in form of
the ship's lines, may be expected to go on, more and more slowly as we approximate
more and more toward a limit set by Nature to further extension and to that
continually met with in the financial problem involved. As the costs of
such growth increase in a high ratio, it is always the fact that it will
not pay, at any given moment, to very greatly increase speeds or improve
accommodations; but the state of the art of steam-navigation now reached
is such that it is not likely that many will be found to mourn the fact
that we advance no more rapidly. As the writer has elsewhere remarked:
"The primary conditions are very readily determined and specified;
but the working out of these conditions to a satisfactory result involves
the application of principles which are the fruit of some of the most abstruse
mathematical investigations, of the most ingenious and elaborate systems
of experiment, and of the most extended and varied experience. In certain
directions we are to-day probably very near the limit of perfect construction;
but the conditions controlling the problem are so different where different
ends are sought, and these differences lead to such apparently opposite
lines of improvement, and to such varied forms of vessel, that it has been,
and still is, to a certain extent, very difficult to reach correct formulas
of application; and probably few naval architects have been able to acquire
very distinct views of the best principles of design for specified purposes."
The obvious conditions of maximum speed, irrespective of other desiderata,
as comfort, handiness, ease in a seaway, stability (all which must be considered
to a greater or less extent by the naval architect in designing a vessel),
are -