from south to north, but there is no eddy or fall at the place where the
waters meet. The tide runs up the canal with great force, and there is a
difference of six or seven feet between high and low water: but the tide
does not extend beyond the Bitter Lakes, where it is gradually diffused
and lost. The colour of the current of water from Suez is said to be
green, whilst that portion fed by the Mediterranean is blue. Since the
Bitter Lakes have been filled the mean temperature of the districts on
the banks has fallen 5° Centigrade. It is also stated that, although the
canal swarms with sea fish they keep to their respective ends of the
canal, as if the Mediterranean fish would not consort with those of the
Red Sea, or, rather, make themselves at home in strange waters. There is
also, perhaps, another cause, and that is the very bitter nature of the
water at the northern end of the Bitter Lakes, which acts as a natural
barrier, through which the fish may decline to pass.
The bed of the Bitter Lakes is the only portion of the canal’s course in
which it was not necessary to make a cutting. Buoys are laid down to
mark the best channel, but such is the width and depth of the water that
vessels need not exactly keep within them. Quitting the Bitter Lakes we
again enter the canal proper. In order to reach the vast docks which the
Suez Canal Company has constructed on the western coast of the Red Sea,
the canal is now quitted, and the vessel crosses the neck of the Red
Sea. The Cairo and Alexandria Railway has been extended two miles, and
is carried through the sea on an embankment, which lands the train close
to the docks and quays of the canal, so that passengers by the overland
route are able to embark from the train on board the steamer, and thus
escape the troublesome transhipment of themselves and luggage.
_THE MANCHESTER SHIP CANAL._
The project of constructing a ship canal to connect Manchester with the
sea appears to have been started just before the railway era, but it was
then abandoned, as the opening of the Liverpool and Manchester Canal
brought about an immediate reduction in the rates of carriage. Perhaps
it was the success of the Suez Canal which caused the revival of this
scheme, in 1880, combined with the depression of the cotton trade at
that period, when the Liverpool dock dues and the comparatively high
railway rates proved a heavier tax than usual on the great Lancashire
industry. The first definite steps were taken two years afterwards, when
two plans were submitted for the selection of a committee. One scheme
proposed to construct the canal without any locks; but, as Manchester is
60 feet above the sea level, there would, it was felt, be certain
inconveniences in loading or unloading ships in a deep depression. The
other plan was submitted by Mr. Leader Williams, a well known canal
engineer, who proposed to take the canal from Runcorn, a distance of 20
miles, and making use of locks. When Parliament was applied to for
powers authorizing the prosecution of the enterprise, there was, of
course, much opposition offered by the various interests involved, and
the inquires before the Committees of each House of Parliament were
unusually protracted, for they extended in all to 175 days, and the cost
to the promoters is said to have amounted to £150,000. Then, when the
Bill had passed, it was found that the capital (£8,000,000) could not be
raised owing to the financial depression, and partly also to some want
of confidence in the soundness of the undertaking on the part of the
Lancashire capitalists. But the promoters submitted the whole scheme to
a representative committee, who should consider any possible objections.
This committee reported (after sitting almost daily for five weeks) upon
every point, and were unanimous in pronouncing the undertaking to be
perfectly practicable and commercially sound. After this there was no
difficulty in raising the required capital, which was subscribed by
corporate bodies as well as private persons. The contract was let for
£5,750,000, and the work was commenced in November, 1887, the contractor
undertaking to have the canal completed and ready for traffic by January
1st, 1892.
[Illustration:
FIG. 133.—_Western Portion._
]
[Illustration:
FIG. 134.—_Eastern Portion._
FIGS. 133 AND 134.—_Map of the Manchester Ship Canal._
]
The Manchester Docks of this canal will cover an area of nearly 200
acres at the south-western suburb of that city, and from there the canal
traverses the Valley of the Irwell, following, indeed, the general
course of the river, but not its windings, so that the bed of the river
is, in the distance of eight miles, or down to its junction with the
Mersey, repeatedly crossed by the line of the canal. From the confluence
of the rivers, the canal traverses the Valley of the Mersey, for this is
the name retained by the combined streams. The course of the river, in
its progress towards the sea, now makes wider bends, but the canal
proceeds, by a slight and nearly uniform curve, to Latchford, near
Warrington, passing to the south of which last named place it follows a
straight line to Runcorn, which is at a distance of 23 miles from
Manchester. Here it reaches what is now the estuary of the Mersey, but
the embankments are continued along the southern shore to Eastham, where
the terminal locks are placed. In this part of the canal, the engineer
had difficulties to overcome of a different nature from those
encountered in the upper part, where it was chiefly a matter of cutting
across the ground intervening between the bends of the river, so as to
form for its waters a new and direct channel everywhere of the requisite
breadth and depth. But when Runcorn has been passed, and Weston Point
rounded, there is the mouth of the River Weaver to be crossed, and this
is marked by a great expanse of loose and shifting mud. Other affluents
of the Mersey are dealt with by means of sluices, and in one instance
the waters of a river are actually carried beneath the course of the
canal by conduits of 12 feet in diameter. The total length of the canal
from Manchester to the tidal locks at Eastham is 35 miles.
[Illustration:
FIG. 135.—_A Cutting for the Manchester Ship Canal._
]
[Illustration:
FIG. 136.—_Blasting Rocks for the Manchester Ship Canal._
]
The minimum width of the canal at the bottom is 120 feet, its depth 26
feet. But for several miles below Manchester this width will be
increased, so that ships may be moored along the sides, and yet
sufficient space left for the up and down lines of traffic in the
middle. In this way, works and manufactories on the banks will be able
to load and unload their cargoes at their own doors, and it may be
expected that the advantages so offered will cause the banks of the
canal to be much in request for the sites of works of all kinds. At the
several places where the locks are placed there will be a smaller and a
larger one, side by side, so that water shall not be needlessly used in
passing a moderate sized vessel through the greater locks. As these last
are 550 feet long and 60 feet wide, they are capable of receiving the
largest ships, whilst the smaller locks are 300 feet long and 40 feet
wide. Again, both the larger and the smaller are provided with gates in
the middle, so that only half their length may be used when that is
found sufficient. Coming down the canal from Manchester, the first set
of locks will be at Barton, about three miles distance, just below the
place where the Bridgewater Canal is carried across the Irwell, which is
now to become the ship canal, by means of the aqueduct of 1760, by which
Brindley became so famous. There is a story told about Brindley being
desirous of satisfying the duke about the practicability of his plan,
and requesting the confirmatory opinion of another engineer. When,
however, this gentleman was taken to the place where it was proposed to
construct the aqueduct, he shook his head, and said that he had often
heard of castles in the air, but had never before been shown where any
of them were to be erected. This aqueduct is about 600 feet long, and
the central one of its three arches spans the river at a height of
nearly 40 feet above the water. But the Manchester Ship Canal requires a
clear headway of 75 feet, and Mr. Williams is going to replace the fixed
stone structure by a swinging aqueduct, or trough of iron, which can be
turned round, so as to give a clear passage for ships in his canal. This
trough, or great iron box, will have gates at each end, and gates will
be provided in the aqueduct at each side, so that no water will be lost
when the water bridge is turned aside. But more than this; hydraulic
lifts have been designed, so that, in a few minutes, vessels can be
lowered from the Bridgewater Canal into the Manchester Canal, or raised
from the latter into the former while still floating in water. The
supply of water for the canal will be ample, as it has the rivers
Irwell, Mersey and Bollin, with their tributary streams, to draw from.
It should be mentioned that the terminal locks at Eastham will be of
somewhat larger dimensions than those already referred to, and will be
three in number. The largest, which is on the south or landward side,
will be 600 feet by 80 feet, the middle one 350 feet by 50 feet, and the
smallest one 150 feet by 30 feet. These three locks will be separated by
concrete piers 30 feet wide, on which will be placed the hydraulic
machinery for opening and closing the gates. Besides the ordinary gates,
there will be provided for each lock at Eastham an outer pair of
storm-gates that will be closed only in rough weather. These gates will
shut from the outside against the lock sills, and, by resisting the
force of wind and waves, will protect the ordinary tidal gates from
being forced open. The lock gates throughout will be made of a wood
obtained from British Guiana, and known as _greenheart_. This timber is
the product of a large tree (_Nectandra Rodiœi_) belonging to the laurel
family. It is a very heavy and close grained wood, the strength and
endurance of which have been proved many years ago by its use in
ship-building, etc., and some of the logs imported for the canal are
remarkably fine specimens, being 22 inches square and 60 feet long. A
pair of the largest gates weigh about 500 tons. The gates of the tidal
locks at Eastham will all be open for half the time of each tide, when
there will be a depth of water, above the sills, greater by 11 feet than
that of any dock in Liverpool or Birkenhead.
[Illustration:
FIG. 137.—_Manchester Ship Canal Works, Runcorn._
]
The way in which the difficulty is overcome of crossing the several busy
lines of railway that intersect the course of the new canal, so that
their traffic shall not be impeded, is one of special interest in this
bold scheme. The London and North Western Railway crosses the Mersey at
Runcorn by a bridge that leaves a clear headway of 75 feet at high
water, and it was determined that this headway should be maintained in
the bridges over the canal. The use of swing bridges on lines of railway
over which trains are constantly passing being out of the question, it
is necessary that the railways be carried over the canal at the required
height. It is accordingly laid down in the Act of Parliament that before
the Canal Company can cut the existing lines of railway it shall
construct permanent bridges, and carry over them lines rising by
gradients not exceeding 1 in 135, and not only so, but these deviation
lines must be previously given up to the several railway companies for
six months to be tried experimentally in that period for goods traffic.
The cost of constructing these deviation lines, which, in all, will not
be far short of 12 miles of new railway, will not be much less than
£500,000. The traffic of the canal will probably have great feeders at
certain points in the other canals and the railway lines that reach it.
For instance, the Bridgewater Canal, now incorporated with the greater
undertaking, will bring traffic from the Staffordshire potteries, the
river Weaver brings salt laden barges from Cheshire, and at other points
the railways will bring the produce of the excellent coal fields of
South Yorkshire and South Lancashire, which will be automatically
transferred from the waggons into ocean going steamships.
[Illustration:
FIG. 137_a._—_The French Steam Navvy._
]
[Illustration:
FIG. 137_b_.—_The English Steam Navvy._
]
Though the general notion of the construction of the canal as a deep,
wide trench, or cutting following the course shown on the map, is
sufficiently simple, the operation of carrying this into practice
involves the exercise of great skill and ingenuity in dealing with
mechanical obstacles. Man’s operations in the world consist but in
changing the position of masses of matter; and the properties of
matter—its inertia, cohesion, gravitation, etc., are the forces that
oppose his efforts. The quantity of matter to be shifted in excavating
this trench of thirty-five miles long across the country was no less
than sixty millions of tons. The number of “navvies” employed at one
time has been 15,000; but even this army of workmen would have made but
slow progress with a cutting of this magnitude, had not the “strong
shouldered steam” been also called into operation for scooping out the
soil. The illustrations (Figs. 137_a_ and #137_b_:fig137b) will show the
arrangement of two forms of “steam navvies” that were much used on the
works. One (Fig. 137_a_) is similar to the dredgers used for clearing
mud out of rivers and canals: it consists of a series of scoops, or
buckets, mounted on an endless chain, so as to scrape the material from
an inclined embankment and tip it into waggons for removal. The other
(Fig. 137_b_) may be compared to a gigantic ladle made to scrape against
the face of a cutting in rising, and filling each time its bucket with
nearly a ton of the material. It is most interesting to witness the
perfect control which the man at the levers exercises over this machine,
the movements of which he directs with as much precision as if he were
handling a spoon. One of these steam navvies is able to fill 600 waggons
or more—that is, to remove 3,000 tons of material—in one day; and as
many as eighty of them have been simultaneously used on the Canal works.
The value of the plant employed by the contractor is estimated at
£700,000, and the length of temporary railway lines (see Fig. 137), for
transport of the “spoil,” etc., is said to exceed 200 miles. There is a
main line running through from one end of the canal to the other, and
known to the workmen as the “Overland Route.” From this diverge numerous
branches, some to the bottom of the excavations in progress, others to
embankments down which is tipped out the “spoil,” as the dug out
material is called; while others connecting with brickfields and
quarries, or with existing canals and railway lines, serve to bring
supplies of the materials used in the constructions. Some 150
locomotives are constantly at work on these temporary lines, and the
coal consumed by them, and by the steam navvies, steam cranes, pumping
engines, etc., is equivalent to about two train loads every day.
Though the Manchester Ship Canal is to be nearly twice as wide as the
Suez Canal, its width for some miles below Manchester will be still
greater, for there the banks will form long continuous wharves for the
accommodation of the works and factories that are certain to be
attracted to the spot. Indeed, so obvious are the advantages of ocean
shipment, and so extensive the industries of South Lancashire, that it
is not improbable the whole course of the canal may, in process of time,
be lined with wharves, and the two great cities of Manchester and
Liverpool may be united by a continuous track of dense population. Be
that as it may, there seems every reason to believe that the undertaking
will be a financial success. Calculation has shown that if the cotton
alone that enters and leaves Manchester were carried by the canal at
half the rates charged by the railways, there would result not only an
annual saving of £456,000 to the cotton trade, but a clear profit to the
canal company sufficient to pay more than 3 per cent. interest on its
own capital. And, again, the railway and other local interests that have
hitherto been opposed to this great enterprise can hardly fail to be in
the long run benefited by the enlarged prosperity and increased general
trade and manufactures it will develop. So that it will presently be
found that there is room enough and work enough for both canal and
railways.
The Manchester Ship Canal, so far from having been ready for traffic on
the 1st January, 1892, was not completed until the end of 1893, and it
was only on the 16th December, 1893, that the directors and their
friends made the trial trip throughout its entire length, accomplishing
the distance of 35½ miles in 5½ hours. The total cost of the canal was
greatly in excess of the estimates, which placed it at eight million
pounds, as fifteen millions is the sum actually expended upon it. With
such a vast capital expenditure, it may be some time before the ordinary
shareholders can look for dividends, especially as there has not been
any sudden rush of traffic, such as many sanguine people expected. On
the other hand, traffic is continuously and steadily increasing, and
there is reason to believe that this great work will ultimately prove a
commercial, as it has an engineering, success.
[Illustration:
FIG. 137_c._—_Sketch Map of The North Sea Canal._
]
_THE NORTH SEA CANAL._
Like several other canals for sea going ships this last addition to the
achievements of modern engineering is but the realisation of a project
conceived at a long past period. The idea of a canal to connect the
Baltic and the North Sea dates back into the Middle Ages, and indeed a
short canal was constructed in 1389, which by uniting two secondary
streams of the peninsula really did provide a waterway between the two
seas. The inefficiency of this means of communication may be inferred
from the fact of there having been proposed since that period no fewer
than sixteen schemes of canalisation between these two seas, of which
the recently completed North Sea Canal is the sixteenth, and it need
hardly be said the greatest, so that in comparison with it the rest
vanish into insignificance. The canal was commenced in 1887, and on the
20th of June, 1895, it was opened by the reigning Emperor of Germany,
William II., with a very imposing naval pageant in which nearly a
hundred ships of war from the great navies of the world took part. A
glance at the accompanying sketch-map will show the great importance of
this canal as a highway of commerce. The entrance to the Baltic has
hitherto been round the peninsula of Denmark and through the narrow
“belts” and “sounds” that divide the Danish Islands, a course beset with
imminent perils to navigators, for the channels abound in rocks and
dangerous reefs, to say nothing about the frequent storms and the
impediments of ice floes. Yet as many as 35,000 vessels have lately had
to take that course annually, these representing a total tonnage of no
less than 20,000,000 tons. The figures speak for the magnitude of the
Baltic shipping intercourse with the rest of the world; while the losses
incurred in traversing these forbidding waters may be gathered from the
statement that since 1858, nearly 3000 ships have been wrecked in them,
and a greater number much damaged. Indeed, for large vessels, there is
hardly a more dangerous piece of navigation in all Europe. The
importance of this canal must not therefore be estimated solely by the
saving of length in ships’ course, though that is great, as the map
shows.
The North Sea Canal is 61 miles long, 200 ft. wide at the surface, 85
ft. wide at the bottom, and it will admit of vessels of 10,000 tons
register passing through, the average time of transit being about twelve
hours. The estimated cost of this undertaking was nearly eight and a
quarter million pounds sterling, and about one-third of this sum was
contributed by Germany, for whom the canal is of the greatest strategic
importance in case of war, for her fighting ships need not then traverse
foreign waters. The construction was therefore pushed forward with
unusual energy, as many as 8,600 men having been engaged on the works at
one time. An important naval station already exists at Kiel, the Baltic
end of the canal, where there is a splendid harbour. The engineer and
designer of this water-way is Herr Otto Baensch, who has devised much
ingenious machinery in connection with the immense tidal locks at the
extremities of the canal, and the swing bridges by which several lines
of railway are carried across it. In the construction of this canal
there were no vast engineering difficulties to be overcome, and hence
striking feats of mountain excavation or valley bridging are not to be
met with in its course, though in places there are some deep cuttings.
The methods of excavating and of steam dredging that were made use of
have already been illustrated in relation to the other works described
in this article. The country through which the canal passes does not
present any unusually picturesque features.
_THE PANAMA AND NICARAGUA CANAL PROJECTS._
The several undertakings described in our chapter on Ship Canals are now
all completed and in active operation, and but for financial
mis-management and dishonest speculations, the same might probably have
been said of another great project, the name of which was on everyone’s
lips a short time ago, but in which public interest has lately waned;
perhaps from a mistaken impression that the construction itself is
involved in a common ruin with the fortunes of so many of its promoters,
or that the scheme was frustrated by some unforeseen and insurmountable
engineering difficulties. These assumptions have so little justification
that it is quite probable that Lesseps’ last great project may yet be
completed under more favourable auspices, and the Panama Canal unite the
Atlantic and Pacific Oceans. The Panama Canal Company still exists, and
possesses not only a very large part of the work almost quite finished,
but all the extensive plant in perfect condition for resuming
operations. The original scheme provided for a tidal water-way between
the two oceans, without the intervention of a single lock. The canal was
to be nearly 47 miles in length, 100 feet wide at the surface of the
water, 72 feet wide at the bottom, and 29 feet deep. The entrances are
at Colon on the Atlantic side, and at Panama on the Pacific. The latter
is the eastern extremity, and the western one is on the Atlantic side,
owing to the configuration of the isthmus which curves round the Panama
Gulf that opens to the south. A railway crosses the isthmus between the
points already named, and the route of the canal is laid down almost
parallel with this railway, from which it is nowhere far distant. For
the first 20 miles from the Atlantic side the land is only at a very
moderate elevation above the sea-level, say 25 or 30 feet, but the next
11 miles is more hilly, the elevations reaching at some points 150 to
170 feet, but these are only for short distances. A few miles farther
on, they rise still higher, until at Culebra the highest point is met
with, about 323 feet above the sea-level, and a cut of this depth, 1,000
feet long, would be required. Through this highest part it has been
proposed to drive a tunnel, but the total extent of the deep cutting at
this part of the canal would be nearly 2 miles in length. This would no
doubt be a work of the most formidable magnitude, for it has been
calculated that no less than 24,000,000 cubic yards of material,
consisting for the most part of solid rock, would have to be removed. It
is not supposed, however, to offer any great difficulty in an
engineering point of view. Doubtless it would be costly, and would take
some time to accomplish. Another heavy piece of work would consist in
constructions for controlling a mountain torrent called the Rio Chagres,
through the valley of which the canal passes. This stream is very
variable in the quantity of water it discharges, rising in the rainy
season 45 feet above its ordinary level, and sending down forty times as
much water as it does in the dry season.