[Footnote: Paper read before the Institution of Mechanical Engineers.]
By M. DECAUVILLE, Aîne, of Petit-Bourg (Seine and Oise), France.
Narrow gauge railways have been known for a very long time in Great
Britain. The most familiar lines of this description are in Wales, and
it is enough to instance the Festiniog Railway (2 feet gauge), which has
been used for the carriage of passengers and goods for nearly half a
century. The prosperous condition of this railway, which has been so
successfully improved by Mr. James Spooner and his son, Mr. Charles
Spooner, affords sufficient proof that narrow gauge railways are not
only of great utility, but may be also very remunerative.
In Wales the first narrow gauge railway dates from 1832. It was
constructed merely for the carriage of slates from Festiniog to
Port-Madoc, and some years later another was built from the slate
quarries at Penrhyn to the port of Bangor. As the tract of country
traversed by the railways became richer by degrees, the idea was
conceived of substituting locomotives for horses, and of adapting the
line to the carriage of goods of all sorts, and finally of passengers
also.
But these railways, although very economical, are at the same time very
complicated in construction. Their arrangements are based upon the same
principles as railways of the ordinary gauge, and are not by any means
capable of being adapted to agriculture, to public works, or to any
other purpose where the tracks are constantly liable to removal. These
permanent narrow gauge lines, the laying of which demands the service of
engineers, and the maintenance of which entails considerable expense,
suggested to M. Decauville, Aîne, farmer and distiller at Petit-Bourg,
near Paris, the idea of forming a system of railways composed entirely
of metal, and capable of being readily laid. Cultivating one of the
largest farms in the neighborhood of Paris, he contemplated at first
nothing further than a farm railroad; and he contrived an extremely
portable plant, adapted for clearing the land of beetroot, for spreading
manure, and for the other needs of his farm.
From the beginning in his first railroads, the use of timber materials
was rigidly rejected by him; and all parts, whether the straight or
curved rails, crossings, turntables, etc., were formed of a single
piece, and did not require any special workman to lay them down. By
degrees he developed his system, and erected special workshops for the
construction of his portable plant; making use of his farm, and some
quarries of which he is possessed in the neighborhood, as experimental
areas. At the present time this system of portable railways serves all
the purposes of agriculture, of commerce, of manufactures, and even
those of war.
Within so limited a space it would be impossible to give a detailed
description of the rails and fastenings used in all these different
modes of application. The object of this paper is rather to direct the
attention of mechanical engineers to the various uses to which narrow
gauge portable railways may be put, to the important saving of labor
which is effected by their adoption, and to the ease with which they are
worked.
The success of the Decauville railway has been so rapid and so great
that many inventors have entered the same field, but they have almost
all formed the idea of constructing the portable track with detachable
sleepers. There are thus, at present, two systems of portable tracks:
those in which the sleepers are capable of being detached, and those in
which they are not so capable.
The portable track of the Decauville system is not capable of so coming
apart. The steel rails and sleepers are riveted together, and form only
one piece. The chief advantage of these railways is their great
firmness; besides this, since the line has only to be laid on the
surface just as it stands, there are not those costs of maintenance
which become unavoidable with lines of which the sleepers are fixed by
means of bolts, clamps, or other adjuncts, only too liable to be lost.
Moreover, tracks which are not capable of separation are lighter and
therefore more portable than those in which the sleepers are detachable.
With regard to sleepers, a distinction must be drawn between those which
project beyond the rails and those which do not so project. M.
Decauville has adopted the latter system, because it offers sufficient
strength, while the lines are lighter and less cumbersome. Where at
first he used flat iron sleepers, he now fits his lines with dished
steel sleepers, in accordance with Figs. 1 and 2.
[Illustration: Fig. 1. Fig. 2.]
This sleeper presents very great stiffness, at the same time preserving
its lightness; and the feature which specially distinguishes this
railway from others of the same class is not only its extreme strength,
but above all its solidity, which results from its bearing equally upon
the ground by means of the rail base and of the sleepers.
In special cases, M. Decauville provides also railroads with projecting
sleepers, whether of flat steel beaten out and rounded, or of channel
iron; but the sleeper and the rail are always inseparable, so as not to
lessen the strength, and also to facilitate the laying of the line. If
the ground is too soft, the railway is supported by bowl sleepers of
dished steel, Figs. 3 and 4, especially at the curves; but the necessity
for using these is but seldom experienced. The sleepers are riveted
cold. The rivets are of soft steel, and the pressure with which this
riveting is effected is so intense that the sleepers cannot be separated
from the rails, even after cutting off both heads of the rivets, unless
by heavy blows of the hammer, the rivets being driven so thoroughly into
the holes made in the rails and sleepers that they fill them up
completely.
The jointing of the rails is excessively simple. The rail to the right
hand is furnished with two fish-plates; that to the left with a small
steel plate riveted underneath the rail and projecting 1¼ in. beyond it.
It is only necessary to lay the lengths end to end with one another,
making the rail which is furnished with the small plate lie between the
two fish-plates, and the junction can at once be effected by fish-bolts.
A single fish-bolt, passing through the holes in the fish-plates, and
through an oval hole in the rail end, is sufficient for the purpose.
With this description of railway it does not matter whether the curves
are to the right or to the left. The pair of rails are curved to a
suitable radius, and can only need turning end for end to form a curve
in the direction required. The rails weigh 9 lb., 14 lb., 19 lb., and 24
lb. per running yard, and are very similar to the rails used on the main
railways of France, except that their base has a proportionally greater
width. As to the strength of the rail, it is much greater in proportion
to the load than would at first sight be thought; all narrow-gauge
railways being formed on the principle of distributing the load over a
large number of axles, and so reducing the amount on each wheel. For
instance, the 9 lb. rail used for the portable railway easily bears a
weight of half a ton for each pair of wheels.
The distance between the rails differs according to the purpose for
which they are intended. The most usual gauges are 16in., 20 in., and
24in. The line of 16 in. gauge, with 9 lb. rails, although extremely
light, is used very successfully in farming, and in the interior of
workshops.
[Illustration: Fig. 3. Fig. 4. Fig. 5.]
A length of 16 ft. 5 in. of 9 lb. steel rail, to 16 in. gauge, with
sleepers, etc., scarcely weighs more than 1 cwt., and may therefore be
readily carried by a man placing himself in the middle and taking a rail
in each hand.
Those members of the Institution who recently visited the new port of
Antwerp will recollect having seen there the portable railway which
Messrs. Couvreux and Hersetit had in use; and as it was these works at
the port of Antwerp that gave rise to the idea of this paper, it will be
well to begin with a description of this style of contractor's plant.
The earth in such works may be shifted by hand, horsepower, or
locomotive. For small works the railway of 16 in. gauge, with the 9 lb.
rails, is commonly used, and the trucks carry double equilibrium
tipping-boxes, containing 9 to 11 cubic feet. These wagons, having
tipping-boxes without any mechanical appliances, are very serviceable;
since the box, having neither door nor hinge, is not liable to need
repairs.
This box keeps perfectly in equilibrium upon the most broken up roads.
To tip it up to the right or the left, it must simply be pushed from the
opposite side, and the contents are at once emptied clean out. In order
that the bodies of the wagons may not touch at the top, when several are
coupled together, each end of the wagon is furnished with a buffer,
composed of a flat iron bar cranked, and furnished with a hanging hook.
Plant of this description is now being used in an important English
undertaking at the port of Newhaven, where it is employed not only on
the earthworks, but also for transporting the concrete manufactured with
Mr. Carey's special concrete machine.
These little wagons, of from 9 to 11 cubic feet capacity, run along with
the greatest ease, and a lad could propel one of them with its load for
300 yards at a cost of 3d. per cube yard. In earthworks the saving over
the wheel-barrow is 80 per cent., for the cost of wagons propelled by
hand comes to 0.1d. per cube yard, carried 10 yards, and to go this
distance with a barrow costs ½d. A horse draws without difficulty,
walking by the side of the line, a train of from eight to ten trucks on
the level, or five on an incline of 7 per cent. (1 in 14).
One mile of this railway, 16 in. gauge and 9 lb. steel rail, with
sixteen wagons, each having a double equilibrium tipping box containing
11 cubic feet, and all accessories, represents a weight of 20 tons--a
very light weight, if it is considered that all the materials are
entirely of metal. Its net cost price per mile is 450_l_., the wagons
included.
Large contracts for earthwork with horse haulage are carried on to the
greatest advantage with the railway of 20 in. gauge and 14 lb. rails.
The length of 16 ft. 5 in. of this railway weighs 170 lb., and so can
easily be carried by two men, one placing himself at each end. The
wagons most in use for these works are those with double equilibrium
tipping boxes, holding 18 cubic feet. These are at present employed in
one of the greatest undertakings of the age, namely, the cutting of the
Panama Canal, where there are used upward of 2,700 such wagons, and more
than 35 miles of track.
A mile of these rails of 20 in. gauge with 14 lb. rails, together with
sixteen wagons of 18 cubic feet capacity, with appurtenances, costs
about 660_1_., and represents a total weight of 33 tons.
This description of material is used for all contracts exceeding 20,000
cubic yards.
A very curious and interesting use of the narrow-gauge line, and the
wagons with double equilibrium tipping-box, was made by the Societe des
Chemins de Fer Sous-Marins on the proposed tunnel between France and
England. The line used is that of 16 in. gauge, with 9 lb. rails.
The first level of the tunnel, which was constructed by means of a
special machine by Colonel Beaumont, had only a diameter of 2.13 m. (7
ft.); the tipping boxes have therefore a breadth of only 2 ft., and
contain 7¼ cubic feet. The boxes are perfectly balanced, and are most
easily emptied. The wagons run on two lines, the one being for the
loaded trains, and the other for the empty trains.
The engineers and inspectors, in the discharge of their duties, make use
of the Liliputian carriages. The feet of the travelers go between the
wheels, and are nearly on a level with the rails; nevertheless, they are
tolerably comfortable. They are certainly the smallest carriages for
passengers that have ever been built; and the builder even prophesies
that these will be the first to enter into England through the Channel
Tunnel.
One of the most important uses to which a narrow gauge line can be put
is that of a military railway. The Dutch, Russian, and French
Governments have tried it for the transporting of provisions, of war
material, and of the wounded in their recent campaigns. In Sumatra, in
Turkestan, and in Tunis these military railroads have excited much
interest, and have so fully established their value that this paper may
confine itself to a short description.
The campaign of the Russians against the Turcomans presented two great
difficulties; these were the questions of crossing districts in which
water was extremely scarce or failed entirely, and of victualing the
expeditionary forces. This latter object was completely effected by
means of 67 miles of railway, 20 in. gauge, 14 lb. steel rails, with 500
carriages for food, water, and passengers. The rails were laid simply on
the sand, so that small locomotives could not be used, and were obliged
to be replaced by Kirghiz horses, which drew with ease from 1,800 lb. to
2,200 lb. weight for 25 miles per day.
In the Tunisian war this railroad of 20 in. gauge, 14 lb. rail, was
replaced by that of two ft. gauge, with 14 lb. and 19 lb. rails. There
were quite as great difficulties as in the Turcoman campaign, and the
country to be crossed was entirely unknown. The observations made before
the war spoke of a flat and sandy country. In reality a more uneven
country could not be imagined; alternating slopes of about 1 in 10
continually succeeded each other; and before reaching Kairouan 7½ miles
of swamp had to be crossed. Nevertheless the horses harnessed to the
railway carriages did on an average twelve to seventeen times the work
of those working ordinary carriages. In that campaign also, on account
of the steep ascents, the use of locomotives had to be given up. The
track served not only for the conveying of victuals, war material, and
cannon, but also of the wounded; and a large number of the survivors of
this campaign owe their lives to this railway, which supplied the means
of their speedy removal without great suffering from the temporary
hospitals, and of carrying the wounded to places where more care could
be bestowed upon them.
The carriages which did duty in this campaign are wagons with a platform
entirely of metal, resting upon eight wheels. The platform is 13 ft. 1
in. in length, and 3 ft. 11 in. in width. The total length with buffers
is 14 ft. 9 in. This carriage may be at will turned into a goods wagon
or a passenger carriage for sixteen persons, with seats back to back, or
an ambulance wagon for eight wounded persons.
For the transport of cannon the French military engineers have adopted
small trucks. A complete equipage, capable of carrying guns weighing
from 3 to 9 tons, is composed of trucks with two or three axles, each
being fitted with a pivot support, by means of which it is made possible
to turn the trucks, with the heaviest pieces of ordnance, on turntables,
and to push them forward without going off the rails at the curves.
The trucks which have been adopted for the service of the new forts in
Paris are drawn by six men, three of whom are stationed at each end of
the gun, and these are capable of moving with the greatest ease guns
weighing 9 tons.
The narrow-gauge railway was tested during the war in Tunis more than in
any preceding campaign, and the military authorities decided, after
peace had been restored in that country, to continue maintaining the
narrow-gauge railways permanently; this is a satisfactory proof of their
having rendered good service. The line from Sousse to Kairouan is still
open to regular traffic. In January, 1883, an express was established,
which leaves Sousse every morning and arrives at Kairouan--a distance of
forty miles--in five hours, by means of regularly organized relays. The
number of carriages and trucks for the transport of passengers and goods
is 118.
The success thus attained by the narrow-gauge line goes far to prove how
unfounded is the judgment pronounced by those who hold that light
railways will never suffice for continuous traffic. These opinions are
based on certain cases in the colonies, where it was thought fit to
adopt a light rail weighing about 18 lb. to 27 lb. per yard, and keeping
the old normal gauge. It is nevertheless evident that it is impossible
to construct cheap railways on the normal gauge system, as the
maintenance of such would-be light railways is in proportion far more
costly than that of standard railways.
The narrow gauge is entirely in its right place in countries where, as
notably in the case of the colonies, the traffic is not sufficiently
extensive to warrant the capitalization of the expenses of construction
of a normal gauge railway.
Quite recently the Eastern Railway Company of the province of Buenos
Ayres have adopted the narrow gauge for connecting two of their
stations, the gauge being 24 in. and the weight of the rails 19 lb. per
yard. This company have constructed altogether six miles of narrow-gauge
road, with a rolling stock of thirty passenger carriages and goods
trucks and two engines, at a net cost price of 7,500l., the engines
included. This line works as regularly as the main line with which it is
connected. The composite carriages in use leave nothing to be desired
with regard to their appearance and the comforts they offer. Third-class
carriages, covered and open, and covered goods wagons, are also
employed.
All these carriages are constructed according to the model of those of
the Festiniog Railway. The engines weigh 4 tons, and run at 12½ miles
per hour for express trains with a live load of 16 tons; while for goods
trains carrying 35 tons the rate is 7½ miles an hour.
Another purpose for which the narrow-gauge road is of the highest
importance in colonial commerce is the transport of sugar cane. There
are two systems in use for the service of sugar plantations: