mere personal convenience it must not be supposed that an average of
50 miles an hour will continue to meet the needs of travellers.
Already practical experiments have been made with two systems that
promise us an ordinary speed of 100 miles an hour and an express speed
considerably higher.
One of these, the monorail or single-rail system, will be employed on
a railroad projected between Manchester and Liverpool. At present
passengers between these two cities--the first to be connected by a
railroad of any kind--enjoy the choice of three rival services
covering 34-1/2 miles in three-quarters of an hour. An eminent
engineer, Mr. F. B. Behr, now wishes to add a fourth of unprecedented
swiftness. Parliamentary powers have been secured for a line starting
from Deansgate, Manchester, and terminating behind the pro-Cathedral
in Liverpool, on which single cars will run every ten minutes at a
velocity of 110 miles an hour.
A monorail track presents a rather curious appearance. The ordinary
parallel metals are replaced by a single rail carried on the summit of
A-shaped trestles, the legs of which are firmly bolted to sleepers. A
monorail car is divided lengthwise by a gap that allows it to hang
half on either side of the trestles and clear them as it moves. The
double flanged wheels to carry and drive the car are placed at the
apex of the gap. As the “centre of gravity” is below the rail the car
cannot turn over, even when travelling round a sharp curve.
The first railway built on this system was constructed by M. Charles
Lartigue, a French engineer, in Algeria, a district where an ordinary
two-rail track is often blocked by severe sand-storms. He derived the
idea of balancing trucks over an elevated rail from caravans of camels
laden on each flank with large bags. The camel, or rather its legs,
was transformed by the engineer’s eye into iron trestles, while its
burden became a car. A line built as a result of this observation, and
supplied with mules as tractive power, has for many years played an
important part in the esparto-grass trade of Algeria.
In 1886 Mr. Behr decided that by applying steam to M. Lartigue’s
system he could make it successful as a means of transporting
passengers and goods. He accordingly set up in Tothill Fields,
Westminster, on the site of the new Roman Catholic Cathedral, a
miniature railway which during nine months of use showed that the
monorail would be practical for heavy traffic, safe, and more cheaply
maintained than the ordinary double-metal railway. The train travelled
easily round very sharp curves and climbed unusually steep gradients
without slipping.
Mr. Behr was encouraged to construct a monorail in Kerry, between
Listowel, a country town famous for its butter, and Ballybunion, a
seaside resort of increasing popularity. The line, opened on the 28th
of February 1888, has worked most satisfactorily ever since, without
injury to a single employé or passenger.
On each side of the trestles, two feet below the apex, run two
guide-rails, against which press small wheels attached to the
carriages to prevent undue oscillation and “tipping” round curves. At
the three stations there are, instead of points, turn-tables or
switches on to which the train runs for transference to sidings.
Road traffic crosses the rail on drawbridges, which are very easily
worked, and which automatically set signals against the train. The
bridges are in two portions and act on the principle of the Tower
Bridge, each half falling from a perpendicular position towards the
centre, where the ends rest on the rail, specially strengthened at
that spot to carry the extra weight. The locomotive is a twin affair;
has two boilers, two funnels, two fireboxes; can draw 240 tons on the
level at fifteen miles an hour, and when running light travels a mile
in two minutes. The carriages, 18 feet long and carrying twelve
passengers on each side, are divided longitudinally into two parts.
Trucks too are used, mainly for the transport of sand--of which each
carries three tons--from Ballybunion to Listowel: and in the centre of
each train is a queer-looking vehicle serving as a bridge for any one
who may wish to cross from one side of the rail to the other.
Several lines on the pattern of the Ballybunion-Listowel have been
erected in different countries. Mr. Behr was not satisfied with his
first success, however, and determined to develop the monorail in the
direction of fast travelling, which he thought would be most easily
attained on a trestle-track. In 1893 he startled engineers by
proposing a Lightning-Express service, to transport passengers at a
velocity of 120 miles an hour. But the project seemed too ideal to
tempt money from the pockets of financiers, and Mr. Behr soon saw that
if a high-speed railway after his own heart were constructed it must
be at his own expense. He had sufficient faith in his scheme to spend
£40,000 on an experimental track at the Brussels Exhibition of 1897.
The exhibition was in two parts, connected by an electric railway, the
one at the capital, the other at Tervueren, seven miles away. Mr. Behr
built his line at Tervueren.
The greatest difficulty he encountered in its construction arose from
the opposition of landowners, mostly small peasant proprietors, who
were anxious to make advantageous terms before they would hear of the
rail passing through their lands. Until he had concluded two hundred
separate contracts, by most of which the peasants benefited, his
platelayers could not get to work. Apart from this opposition the
conditions were not favourable. He was obliged to bridge no less than
ten roads; and the contour of the country necessitated steep
gradients, sharp curves, long cuttings and embankments, the last of
which, owing to a wet summer, could not be trusted to stand quite
firm. The track was doubled for three miles, passing at each end round
a curve of 1600 feet radius.
The rail ran about four feet above the track on trestles bolted down
to steel sleepers resting on ordinary ballast. The carriage--Mr. Behr
used but one on this line--weighed 68 tons, was 59 feet long and 11
feet wide, and could accommodate one hundred persons. It was
handsomely fitted up, and had specially-shaped seats which neutralised
the effect of rounding curves, and ended fore and aft in a point, to
overcome the wind-resistance in front and the air-suction behind.
Sixteen pairs of wheels on the under side of the carriage engaged with
the two pairs of guide rails flanking the trestles, and eight large
double-flanged wheels, 4-1/2 feet in diameter, carried the weight of
the vehicle. The inner four of these wheels were driven by as many
powerful electric motors contained, along with the guiding mechanism,
in the lower part of the car. The motors picked up current from the
centre rail and from another steel rail laid along the sleepers on
porcelain insulators.
The top speed attained was about ninety miles an hour. On the close of
the Exhibition special experiments were made at the request of the
Belgian, French, and Russian Governments, with results that proved
that the Behr system deserved a trial on a much larger scale.
The engineer accordingly approached the British Government with a Bill
for the construction of a high-speed line between Liverpool and
Manchester. A Committee of the House of Commons rejected the Bill on
representations of the Salford Corporation. The Committee had to
admit, nevertheless, that the evidence called was mainly in favour of
the system; and, the plans of the rail having been altered to meet
certain objections, Parliamentary consent was obtained to commence
operations when the necessary capital had been subscribed. In a few
years the great seaport and the great cotton town will probably be
within a few minutes’ run of each other.
A question that naturally arises in the mind of the reader is this:
could the cars, when travelling at 110 miles an hour, be arrested
quickly enough to avoid an accident if anything got on the line?
The Westinghouse air-brake has a retarding force of three miles a
second. It would therefore arrest a train travelling at 110 miles per
hour in 37 seconds, or 995 yards. Mr. Behr proposes to reinforce the
Westinghouse with an electric brake, composed of magnets 18 inches
long, exerting on the guide rails by means of current generated by the
reversed motors an attractive force of 200 lbs. per square inch. One
great advantage of this brake is that its efficiency is greatest when
the speed of the train is highest and when it is most needed. The
united brakes are expected to stop the car in half the distance of the
Westinghouse alone; but they would not both be applied except in
emergencies. Under ordinary conditions the slowing of a car would take
place only at the termini, where the line ascends gradients into the
stations. There would, however, be small chance of collisions, the
railway being securely fenced off throughout its entire length, and
free from level crossings, drawbridges and points. Furthermore, each
train would be its own signalman. Suppose the total 34-1/2 miles
divided into “block” lengths of 7 miles. On leaving a terminus the
train sets a danger signal behind it; at 7 miles it sets another, and
at 14 miles releases the first signal. So that the driver of a car
would have at least 7 miles to slow down in after seeing the signals
against him. In case of fog he would consult a miniature signal in his
cabin working electrically in unison with the large semaphores.
The Manchester-Liverpool rail will be reserved for express traffic
only. Mr. Behr does not believe in mixing speeds, and considers it one
of the advantages of his system that slow cars and waggons of the
ordinary two-rail type cannot be run on the monorail; because if they
could managers might be tempted to place them there.
A train will consist of a single vehicle for forty, fifty, or seventy
passengers, as the occasion requires. It is calculated that an average
of twelve passengers at one penny per mile would pay all the expenses
of running a car.
Mr. Behr maintains that monorails can be constructed far more cheaply
than the two-rail, because they permit sharper curves, and thereby
save a lot of cutting and embankment; and also because the monorail
itself, when trestles and rail are specially strengthened, can serve
as its own bridge across roads, valleys and rivers.
Though the single-rail has come to the front of late, it must not be
supposed that the two-rail track is for ever doomed to moderate speeds
only. German engineers have built an electric two-rail military line
between Berlin and Zossen, seventeen miles long, over which cars have
been run at a hundred miles an hour. The line has very gradual curves,
and in this respect is inferior to the more sinuous monorail. Its
chief virtue is the method of applying motive power--a method common
to both systems.
The steam locomotive creates its own motive force, and as long as it
has fuel and water can act independently. The electric locomotive, on
the other hand, receives its power through metallic conductors from
some central station. Should the current fail all the traffic on the
line is suspended. So far the advantage rests with the steamer. But
as regards economy the superiority of the current is obvious. In
the electric systems under consideration--the monorail and
Berlin-Zossen--there is less weight per passenger to be shifted, since
a comparatively light motor supersedes the heavy locomotive. The cars
running singly, bridges and track are subjected to less strain, and
cost less to keep in repair. But the greatest saving of all is made in
fuel. A steam locomotive uses coal wastefully, sending a lot of latent
power up the funnel in the shape of half-expanded steam. Want of space
prevents the designer from fitting to a moving engine the more
economical machinery to be found in the central power-station of an
electric railway, which may be so situated--by the water-side or near
a pit’s mouth--that fuel can be brought to it at a trifling cost. Not
only is the expense of distributing coal over the system avoided, but
the coal itself, by the help of triple and quadruple expansion engines
should yield two or three times as much energy per ton as is developed
in a locomotive furnace.
Many schemes are afoot for the construction of high-speed railways.
The South-Eastern plans a monorail between Cannon Street and Charing
Cross to avoid the delay that at present occurs in passing from one
station to the other. We hear also of a projected railway from London
to Brighton, which will reduce the journey to half-an-hour; and of
another to connect Dover and London. It has even been suggested to
establish monorails on existing tracks for fast passenger traffic, the
expresses passing overhead, the slow and goods trains plodding along
the double metals below.
But the most ambitious programme of all comes from the land of the
Czar. M. Hippolyte Romanoff, a Russian engineer, proposes to unite St.
Petersburg and Moscow by a line that shall cover the intervening 600
miles in three hours--an improvement of ten hours on the present
time-tables. He will use T-shaped supports to carry two rails, one on
each arm, from which the cars are to hang. The line being thus double
will permit the cars--some four hundred in number--to run to and fro
continuously, urged on their way by current picked up from overhead
wires. Each car is to have twelve wheels, four drivers arranged
vertically and eight horizontally, to prevent derailment by gripping
the rail on either side. The stoppage or breakdown of any car will
automatically stop those following by cutting off the current.
In the early days of railway history lines were projected in all
directions, regardless of the fact whether they would be of any use or
not. Many of these lines began, where they ended, on paper. And now
that the high-speed question has cropped up, we must not believe that
every projected electric railway will be built, though of the ultimate
prevalence of far higher speeds than we now enjoy there can be no
doubt.
The following is a time-table drawn up on the two-mile-per-minute
basis.
A man leaving London at 10 A.M. would reach--
Brighton 50 miles away, at 10.25 A.M.
Portsmouth 60 " " 10.30 A.M.
Birmingham 113 " " 10.57 A.M.
Leeds 188 " " 11.34 A.M.
Liverpool 202 " " 11.41 A.M.
Holyhead 262 " " 12.11 P.M.
Edinburgh 400 " " 1.20 P.M.
Aberdeen 540 " " 2.30 P.M.
What would become of the records established in the “Race to the
North” and by American “fliers”?
And what about continental travel?
Assuming that the Channel Tunnel is built--perhaps a rather large
assumption--Paris will be at our very doors. A commercial traveller
will step into the lightning express at London, sleep for two hours
and twenty-four minutes and wake, refreshed, to find the blue-smocked
Paris porters bawling in his ear. Or even if we prefer to keep the
“little silver streak” free from subterranean burrows, he will be able
to catch the swift turbine steamers--of which more anon--at Dover,
slip across to Calais in half-an-hour, and be at the French capital
within four hours of quitting London. And if M. Romanoff’s standard be
reached, the latest thing in hats despatched from Paris at noon may
be worn in Regent Street before two o’clock.
Such speeds would indeed produce a revolution in travelling comparable
to the substitution of the steam locomotive for the stage coach. As
has been pithily said, the effect of steam was to make the bulk of
population travel, whereas they had never travelled before, but the
effect of the electric railway will be to make those who travel travel
much further and much oftener.
SEA EXPRESSES.
In the year 1836 the _Sirius_, a paddle-wheel vessel, crossed the
Atlantic from Cork Harbour to New York in nineteen days. Contrast with
the first steam-passage from the Old World to the New a return journey
of the _Deutschland_, a North German liner, which in 1900 averaged
over twenty-seven miles an hour between Sandy Hook and Plymouth,
accomplishing the whole distance in the record time of five days seven
hours thirty-eight minutes.
This growth of speed is even more remarkable than might appear from
the mere comparison of figures. A body moving through water is so
retarded by the inertia and friction of the fluid that to quicken its
pace a force quite out of proportion to the increase of velocity must
be exerted. The proportion cannot be reduced to an exact formula, but
under certain conditions the speed and the power required advance in
the ratio of their cubes; that is, to double a given rate of progress
eight times the driving-power is needed; to treble it, twenty-seven
times.
The mechanism of our fast modern vessels is in every way as superior
to that which moved the _Sirius_, as the beautifully-adjusted safety
cycle is to the clumsy “boneshaker” which passed for a wonder among
our grandfathers. A great improvement has also taken place in the art
of building ships on lines calculated to offer least resistance to the
water, and at the same time afford a good carrying capacity. The big
liner, with its knife-edged bow and tapering hull, is by its shape
alone eloquent of the high speed which has earned it the title
of Ocean Greyhound; and as for the fastest craft of all,
torpedo-destroyers, their designers seem to have kept in mind Euclid’s
definition of a line--length without breadth. But whatever its shape,
boat or ship may not shake itself free of Nature’s laws. Her
restraining hand lies heavy upon it. A single man paddles his
weight-carrying dinghy along easily at four miles an hour; eight men
in the pink of condition, after arduous training, cannot urge their
light, slender, racing shell more than twelve miles in the same time.
To understand how mail boats and “destroyers” attain, despite the
enormous resistance of water, velocities that would shame many a
train-service, we have only to visit the stokeholds and engine-rooms
of our sea expresses and note the many devices of marine engineers by
which fuel is converted into speed.
We enter the stokehold through air-locks, closing one door before we
can open the other, and find ourselves among sweating, grimy men,
stripped to the waist. As though life itself depended upon it they
shovel coal into the rapacious maws of furnaces glowing with a
dazzling glare under the “forced-draught” sent down into the hold by
the fans whirling overhead. The ignited furnace gases on their way to
the outer air surrender a portion of their heat to the water from
which they are separated by a skin of steel. Two kinds of marine
boiler are used--the fire-tube and the water-tube. In fire-tube
boilers the fire passes inside the tubes and the water outside; in
water-tube boilers the reverse is the case, the crown and sides of the
furnace being composed of sheaves of small parallel pipes through
which water circulates. The latter type, as generating steam very
quickly, and being able to bear very high pressures, is most often
found in war vessels of all kinds. The quality sought in boiler
construction is that the heating surface should be very large in
proportion to the quantity of water to be heated. Special coal,
anthracite or Welsh, is used in the navy on account of its great
heating power and freedom from smoke; experiments have also been made
with crude petroleum, or liquid fuel, which can be more quickly put on
board than coal, requires the services of fewer stokers, and may be
stored in odd corners unavailable as coal bunkers.
From the boiler the steam passes to the engine-room, whither we will
follow it. We are now in a bewildering maze of clanking, whirling
machinery; our noses offended by the reek of oil, our ears deafened
by the uproar of the moving metal, our eyes wearied by the efforts to
follow the motions of the cranks and rods.
On either side of us is ranged a series of three or perhaps even four
cylinders, of increasing size. The smallest, known as the
high-pressure cylinder, receives steam direct from the boiler. It
takes in through a slide-valve a supply for a stroke; its piston is
driven from end to end; the piston-rod flies through the cylinder-end
and transmits a rotary motion to a crank by means of a connecting-rod.
The half-expanded steam is then ejected, not into the air as would
happen on a locomotive, but into the next cylinder, which has a larger
piston to compensate the reduction of pressure. Number two served, the
steam does duty a third time in number three, and perhaps yet a fourth
time before it reaches the condensers, where its sudden conversion
into water by cold produces a vacuum suction in the last cylinder of
the series. The secret of a marine engine’s strength and economy lies
then in its treatment of the steam, which, like clothes in a numerous
family, is not thought to have served its purpose till it has been
used over and over again.
Reciprocating (_i.e._ cylinder) engines, though brought to a high
pitch of efficiency, have grave disadvantages, the greatest among
which is the annoyance caused by their intense vibration to all
persons in the vessel. A revolving body that is not exactly balanced
runs unequally, and transmits a tremor to anything with which it may
be in contact. Turn a cycle upside down and revolve the driving-wheel
rapidly by means of the pedal. The whole machine soon begins to
tremble violently, and dance up and down on the saddle springs,
because one part of the wheel is heavier than the rest, the mere
weight of the air-valve being sufficient to disturb the balance. Now
consider what happens in the engine-room of high-powered vessels. On
destroyers the screws make 400 revolutions a minute. That is to say,
all the momentum of the pistons, cranks, rods, and valves (weighing
tons), has to be arrested thirteen or fourteen times every second.
However well the moving parts may be balanced, the vibration is felt
from stem to stern of the vessel. Even on luxuriously-appointed
liners, with engines running at a far slower speed, the throbbing of
the screw (_i.e._ engines) is only too noticeable and productive of
discomfort.
We shall be told, perhaps, that vibration is a necessary consequence
of speed. This is true enough of all vehicles, such as railway trains,
motor-cars, cycles, which are shaken by the irregularities of the
unyielding surface over which they run, but does not apply universally
to ships and boats. A sail or oar-propelled craft may be entirely free
from vibration, whatever its speed, as the motions arising from water
are usually slow and deliberate. In fact, water in its calmer moods is
an ideal medium to travel on, and the trouble begins only with the
introduction of steam as motive force.
But even steam may be robbed of its power to annoy us. The
steam-turbine has arrived. It works a screw propeller as smoothly as a
dynamo, and at a speed that no cylinder engine could maintain for a
minute without shaking itself to pieces.
The steam-turbine is most closely connected with the name of the Hon.
Charles Parsons, son of Lord Rosse, the famous astronomer. He was the
first to show, in his speedy little _Turbinia_, the possibilities of
the turbine when applied to steam navigation. The results have been
such as to attract the attention of the whole shipbuilding world.
The principle of the turbine is seen in the ordinary windmill. To an
axle revolving in a stationary bearing are attached vanes which oppose
a current of air, water, or steam, at an angle to its course, and by
it are moved sideways through a circular path. Mr. Parsons’ turbine
has of course been specially adapted for the action of steam. It
consists of a cylindrical, air-tight chest, inside which rotates a
drum, fitted round its circumference with rows of curved vanes. The
chest itself has fixed immovably to its inner side a corresponding
number of vane rings, alternating with those on the drum, and so
arranged as to deflect the steam on to the latter at the most
efficient angle. The diameter of the chest and drum is not constant,
but increases towards the exhaust end, in order to give the expanding
and weakening steam a larger leverage as it proceeds.