The locomotive worked an average of 4 days per week, hauling an average
of 28 tons each day, and burning 1¾ cwts. of coal at a cost of 1s. 9d.
Full particulars of the hauling powers of the locomotive are given at the
end of this section, where it will be seen that 70 tons a day can readily
be dealt with, and that, in an emergency, 100 tons would be quite within
reasonable compass.
It is required, at Eaton, that the engine should meet the wants of
several independent departments on the estate, and in different
directions, added to which only a limited number of men are usually
available for loading. In effect, instead of matters being arranged
primarily with a view to the economy of the working of the railway, the
railway is made an instrument for the economical working of the various
departments supplied by it. There is doubtless much to be said for the
view that, as the driver’s wages have to be paid, he may as well have his
engine in steam as often as required. But, notwithstanding this easy mode
of working the traffic, the cost of haulage is 3d. per ton per mile less
than the average cost of carting, including interest on capital as well
as working expenses.
I may say that the line is kept in the most admirable order, clean, well
packed, and neatly ballasted, and that, under the astute direction of the
Hon. Cecil Parker, the Duke’s agent, the painstaking Superintendent of
the line, Mr. Forster, records with the greatest accuracy the weight of
every truck load of goods hauled, and the exact amount of all expenditure
on the railway, thus giving a value to this somewhat novel experiment
which it would not otherwise possess.
It should be mentioned that the amount expended on platelayers’ wages
during 1896 exceeded the probably normal sum spent in 1897, on account of
the road not having become till the latter year properly consolidated.
The cinder ballast, though admirably porous, has proved somewhat
deficient in solidity, and the sleepers have required a good deal more
packing than should have been necessary.
Since the completion of the line in May, 1896, some additions have been
made to the rolling-stock, with a view of obviating the necessity for the
immediate unloading of every wagon. There was a strongly expressed idea
among the employes that tip wagons would be more serviceable than the box
wagons with loose “tops” supplied by me. I have always felt that the
greater dead-weight of the former class of wagons in proportion to the
load carried, and also their increased cost, heavily discounted their
only advantage: celerity in unloading. In order, however, to bring the
question to a definite proof, I constructed six tip wagons entirely of
steel and cast iron which are fully described in Section VI. In practice
these were found to work as well as it is possible for a tip wagon to do,
but, nevertheless, the unloading advantages were wholly incommensurate
with the drawbacks of greater dead-weight and less capacity. There was
the further disability that a wagon of this class could not be used, as
can the others, for the conveyance of timber or other bulky goods. In the
end I removed all but two, which were left as samples, and replaced them
with wagons of the original type.
I conclude this account of the Eaton railway by giving particulars of the
trial trips of the small four-wheeled locomotive and of its hauling
powers, and also of a test day’s work on time line.
The trials of No. 4 locomotive at Eaton were carried out in Sept., 1896,
and the particulars were as follows (all weights being accurately taken
on the weighbridge):—
Weight of engine in working order, with two men on the footplate, 3 tons
5 cwt.; weight of brake-van, with two men and a boy, 14 cwt.; pressure of
steam throughout trials, 155 to 165 lbs. per sq. in.; ruling gradient
between Balderton (G.W.R.) and Eaton, 1 in 70 rise from Balderton to
Eaton, 51 ft.; rise from lowest to highest point, 63 ft.
Trip 1.—Balderton to Eaton, distance 3 miles exactly. To show that engine
could haul its guaranteed load of 15 tons gross, exclusive of own weight.
Coal train of thirteen wagons and van:—
Tons. cwt. qrs.
Coal 10 10 3
Thirteen wagons 4 18 1
Van 0 14 0
—
Gross load 16 3 0
Engine 3 5 0
—
Total weight of train 19 8 0
Time from start to stop, 17 mins.; speed. 10 miles per hour. In all
cases trains have to stop dead on a rising gradient of 1 in 100 before
crossing the high road one mile from Balderton.
Trip 2.—Eaton to Balderton. To test capacity of engine for fast running.
The same train as above, empty. Time from start to stop, 12 mins.; speed,
15 miles per hour.
Trip 3.—Balderton to Eaton. To determine maximum speed at which average
weight of train could be run. Gross load, exclusive of engine, 14 tons;
time from start to stop, 15 mins.; speed, 12 miles per hour.
Trip 4.—Eaton to Balderton. To test power of engine to haul a long train
round the curve of 60 ft. radius on a gradient of 1 in 60, with which the
line starts from Eaton. Gross load, exclusive of engine, 14 tons,
consisting of 33 vehicles. The gradient was surmounted without
difficulty. No time taken.
Trip 5. Balderton to Eaton. To test maximum capacity of engine.
Coal train of 20 wagons and van:— Tons. cwt. qrs.
Coal 14 6 2
Twenty wagons 7 13 0
Van 0 14 0
—
Gross load 22 13 2
Engine 3 5 0
—
Total weight of train 25 18 2
Time from start to stop, 21½ mins.; speed, 8½ miles per hour. The first
mile, fairly level, was run at 6¼ miles per hour only. The long gradient
up to Eaton was run at just under 10 miles per hour, the steam blowing
off freely with injector full on and damper three-quarters closed nearly
all the last mile-and-a-half.
Trip 6:—From 1¼ to 2¼ mile posts, chiefly up gradient of 1 in 80. To test
maximum running speed with light trains. Load: bogie passenger-car and
van only. The maximum speed was attained on passing the 1½ mile post, but
fell off slightly after passing the 1¾ post. Time by stop watch, from 1½
to 2 mile post, 1½ mins. exactly. Average speed, 20 miles per hour.
It is to be noted, since the 15 in. gauge is almost precisely one-quarter
that of the standard railway gauge, and since possible speed is in direct
proportion to gauge, that 10, 15, and 20 miles on the one equal 40, 60,
and 80 on the other. Thus the average speed of 10 to 12 miles per hour
usually maintained, including the road-crossing stop, by the mineral
trains on the Eaton line is considerably in excess of the proportionate
speed of similar trains on the standard railways.
In August, 1897, arrangements were courteously made at my request by the
Hon. Cecil Parker and by Mr. W. A. Forster, to enable me to test the
weight of minerals that could be transported in a full day’s work, over
the three miles of line from Balderton to Eaton. Care was taken to
obviate any delays in loading and unloading, but every truck had to be
weighed separately on leaving Balderton, a process occupying about ten
minutes with each train. Six trips were run during the day, and 69 tons
of coal and road-metal were transported. There were four loaders at
Balderton, and two unloaders at Eaton. The trains consisted of 12 wagons
and van. The average gross weight, exclusive of engine, was about 17
tons, and the weight of minerals, or paying load, 12 tons. The speed was
just under 10 miles per hour for the loaded trains, and 11.5 miles per
hour for the empties. The engine left the shed at 8.15 a.m., and returned
at 5.45 p.m., with a delay of 55 minutes for dinner. The weather was as
bad as possible, slight showers all through the day making the rails so
greasy as to necessitate the constant use of sand up the inclines. Time
was also wasted in an extra journey for empty wagons, and in other
unavoidable delays. About 1 hour 10 minutes was the average time taken
over a trip out and back, reckoning to the time of next start. It is thus
apparent that, with a little more arrangement, eight trips could have
been run in the day. In the earlier trips, the gross loads hauled were
only about sixteen tons, increasing later in the day to eighteen and
nineteen tons. These larger loads might just as well have been also
hauled on the earlier trips and it was apparent that, under less adverse
conditions, 100 tons of paying load could have been transported in the
day. Only 3 cwt. of coal was burned, including lighting up. The total
distance run was 41 miles, and the average consumption of coal per mile,
including that burned while standing, was 83 lbs. For Eaton Railway
Regulations see Appendix C.
V.
LOCOMOTIVES.
THE first locomotive put upon my line was completed in 1875. This engine
was constructed, not so much as a model of what a small locomotive should
be, as to provide the requisite motive power for the experiments I
desired to carry out. No great care was, therefore, observed in the
details, and in its construction a good deal of material which happened
to be at hand was utilized to save time and expense; this much in excuse
of the want of proportion in some of the dimensions, which will be found
in detail under the head of No. 1 in the table of locomotive dimensions
on page 31.
The boiler was of the launch type, a cylindrical shell with a cylindrical
fire-box terminating in tubes. This pattern of boiler, though giving less
heating surface for its size than one of ordinary locomotive design, has
the great merit of having no fire-box projecting below the barrel, thus
enabling the over-hang of the frame beyond the wheel-base to be equalised
at each end, a matter of the first importance in small tank engines. Its
low first cost and the ease with which it can be kept in order are
additional advantages. So well was I satisfied with the working, that in
the four boilers since designed for my locomotives I have adhered to the
original plan, which was copied from some shunting engines made by Mr.
Ramsbottom for the London and North Western Railway. I go so far as to
think that, without getting rid of a depending fire-box, no really
satisfactory tank engine can be constructed for a small gauge railway
unless idle wheels are introduced, a proceeding that cannot too strongly
be deprecated. The gradients, which are almost invariably the
concomitants of these small lines, make it essential that the whole of
the available weight should be utilized for adhesion.
The difficulty of carrying on four wheels a boiler of sufficient length
for a more powerful engine, and the unsuitableness of an ordinary
six-coupled engine to the sharp curves in which narrow-gauge lines
generally abound, led me, in 1877, to work out a design by which the
wheel-base of an engine of the latter type could be made to accommodate
itself to any required degree of curvature. At this time I was in
communication with officers engaged in promoting a scheme for an army
field railway, where great power conjoined with perfect flexibility was
essential. As the result, I constructed the engine of which the
dimensions are given under No. 2 in the table, this being put to work in
1881. While avoiding the complication of the double-bogie system, this
engine possesses most, if not all, of its advantages. It is six-coupled
in the ordinary way, the axles having outside bearings and cranks. The
wheels, of cast steel, are not fixed upon the axles, but each pair is
keyed upon a cast iron sleeve, through which the axle passes. The sleeve
upon the middle axle is capable of sliding 1 in. in each direction
laterally, but cannot revolve upon its axle thus, when the engine reaches
a curve, the arc of the rail draws the middle wheels on their sleeve to
an amount equal to the versed sine of the arc, without interfering with
the rigid position of the axle. The leading and trailing pairs are
likewise mounted on sleeves, but here the connection of the sleeve with
the axle is by means of a ball joint at the centre, so constructed as to
leave the sleeve free to radiate in any direction, but obliging it to
revolve with the axle. The middle sleeve is so connected by external
hoops and links with the leading and trailing sleeves that, when the
former makes a lateral diversion, the two latter are radiated precisely
to the required curve, providing it is within the limit of the travel of
the middle sleeve, which, in this case, is arranged for a radius of 25
ft. This engine excited considerable interest among visitors to my
railway at the time of the Royal Agricultural Show in Derby in 1881, but
the opinion was expressed that the arrangement would not stand hard work.
A few years later, however, when some officers of the Royal Engineers
were trying the engine with a view to adopting the plan on the military
railway at Chatham, they subjected it to very severe tests, loading it up
steep inclines to its utmost capacity; stopping it with the steam brake
almost dead when travelling at various speeds and over the most awkward
places; and, finally, giving it a fifty mile run with all the load that
could be got together, at an average speed of seven and a half miles an
hour, stops being made for water, &c., for twelve minutes in each hour.
This was followed, shortly after, by a continuous run with a similar load
for an hour and thirty-five minutes, the extreme limit to which the water
in the tanks would hold out.
There was no heating of any part during the trials, nor failure of any
kind. After eight years’ work, chiefly on gradients of 1 in 10 to 1 in
12, where sand has to be used freely, the engine came into the shops to
be overhauled. During this time there had been no mishap or breakage
whatever, nor had a wheel ever left the rails, except on one occasion in
descending the steep incline, when, owing to the slippery state of the
rails, and sand failing, the engine slid away and left the road; less
than an hour, however, sufficing to get it running again.
On removing and examining, shortly after this, the working parts of the
radiating gear, they were found in perfect order, the tool marks being
still visible in the ball joints; and in August, 1895, the engine, which
was then sent over to do the ballast work on the Eaton Railway, where it
worked for thirteen months, showed still a clean bill of health. The
engine is now rebuilding, and it is proof of the excellence of the
radiating gear that this part is being put together again without
re-adjustment of any kind. There is thus no doubt of the success of this
radiating principle.
This engine is fitted, as already noticed, with a steam brake, which can
also be applied by hand but the latter alone is far too slow in action
for the abrupt stops necessary on a line like mine.
The space between the frames being occupied by the radiating
arrangements, the valve gear is necessarily outside, and, to avoid
overhung eccentrics, I designed a modification of one of Mr. Charles
Brown’s Swiss valve gears, which are also the parents of what is known in
this country as Joy’s gear. I venture to think that my plan, in which
nothing projects below the connecting-rod, is better suited to small
engines where the motion is almost always near the ground than any yet
produced. The gear is extremely simple, and has worked without any
trouble, the only setting required being the adjustment to length of the
valve spindles, and the setting of one fixed centre on each side of the
engine.
The springs consist of rubber pads placed between the axle-box and the
horn-block. They are simple to fit, take up no room, never get out of
order, and last many years. I have no steel-carrying spring on any of my
stock.
The safety-valve spring is entirely within the boiler, so that it cannot
be tampered with or injured by accident.
The connecting-rod brasses are peculiar. In order to avoid the twist to
the slide bar when the driving axle, owing to inequalities in the road,
fails to preserve its horizontal parallelism with the frame, the brasses
are shaped circular, so as to turn slightly in their straps, the latter
being bored out in the direction of their length instead of slotted. This
plan not only relieves both crank-pin and slide-bar of torsion, but also
forms a much more rigid union between the strap and the rod end.
The steam jet is worked by the regulator handle, the valve being so
arranged that when the handle is moved beyond the point at which steam is
shut off, the jet is opened. A spring stop prevents the jet being opened
inadvertently. Thus when steam is put on, the jet is by the same action
closed, steam is saved, and two motions are performed in one.
An important point in this, as in all the locomotives I have built, is
that the over-hang at the two ends is equal, and the weight also on both
leading and trailing axles practically the same, when the driver is on
the foot plate. A further arrangement of value is that in all my engines
the cranks are counter-balanced. It is impossible to effect the
counter-balancing on the wheels, nor, even if feasible, will the result
be so good, as counter-balance weights on the wheel are not at the same
distance from the axle centre as the disturbing weights, and therefore
not equable in their effect at different speeds.
This engine was built for tractive power, not speed, and eighteen miles
an hour is the highest rate registered over the short straight course
available. The previous engine, with 15½ in. wheels, reached a speed
equal to 23 miles an hour, the time being in both cases taken over a
measured distance with a stop watch. About 11 miles an hour is the usual
average speed with passenger cars, which, owing to the severe curves, it
is not deemed wise to exceed.
The net cost of the engine under consideration was £309, exclusive of
drawings and patterns. At the time it was built a joiner and occasionally
a labourer were my only assistants; the work consequently proceeded but
slowly, occupying altogether two years and a half. Reducing the time to
hours, the whole of my own labour was almost precisely equal to that
worked in one year by an artisan, and that of my assistants together to
about half the amount. This includes the time occupied in moulding, for
all the castings were made on the premises, with the exception of the
steel wheels.
The boiler, frame-plates, and some of the brass fittings, were purchased,
but the whole of the machine work and fitting was executed on the spot.
The cost of all material, the hours of labour and engine power, interest
on tools, &c., were all carefully booked, and it will probably not be far
from a fair trade price for the engine if 10 per cent, for drawings and
patterns, and 20 per cent, for profit, are added to the cost given above,
thus bringing the amount to about £400.
The working of the radiating gear of engine No. 2 proving so
satisfactory, I elaborated the principle so as to apply it to an
eight-wheeled locomotive. (No. 3 in the table.) In this case both of the
middle pairs of wheels have the traversing motion already described, but,
instead of the leading and trailing wheels being radiated from one
central pair, the second pair of wheels radiates the leading pair, and
the third pair of wheels the trailing pair, thus forming a mechanism
practically equal to a double bogie. By this arrangement an eight-coupled
engine is obtained capable of passing round curves as severe as may be
necessary. In the present instance, the travel is constructed for a
minimum radius of 25 ft. The details of the engine are similar to those
of No. 2, but numerous improvements have been effected, into all of which
it would be tedious to enter. It may, however, be mentioned that the ends
of all the crank pins are boxed in by the connecting and coupling rod
brasses, to exclude dirt. A steam water-lifter has also been added, by
which the tanks can be filled without delay during frost.
The blast-nozzle is made adjustable by raising or lowering an internal
cone. Owing to the steep gradient before alluded to, it was impossible to
get a fixed size of nozzle that would keep up steam with a light load on
the level, without being so contracted as to lift the fire off the bars
on the incline.
The boiler fittings have been made as symmetrical as possible, and
circular nuts have been substituted for hexagon, as more easy to clean.
The water-gauge glasses are put in through the top cock and fastened by a
single cap nut, thus doing away with the usual external glands. The steam
brake has a 5 in. cylinder, and the rigging is arranged to swing with the
traversing wheels.
The locomotive for the Eaton Railway (No. 4 in the table) was built as an
example of a four-wheeled engine for use where the traffic was small and
the gradient reasonable. With the exception of radial axles, it is fitted
up precisely as No. 8. It has not, however, been altogether a success.
From the data of its hauling powers, it will readily be seen that there
is no deficiency in this respect; indeed, the maximum load handled
exceeded all my expectations. In its working, for now nearly two years,
nothing has gone amiss, nor has there been any trouble. On the contrary,
the engine has on all these points given full satisfaction. But it is
with regard to its effect on the road that I have my doubts. The running
is steady enough, and 20 miles an hour has been attained without undue
oscillation, yet nevertheless the road suffers as it never suffers under
the six and eight-wheeled engines. The long and short of my experience is
that I should not again recommend a four-wheeler except for very short
distances and low speeds. Nothing but the experience I have had with this
engine could have impressed so forcibly on me the very distinct
advantages of such a radial action as I have adopted in my other
locomotives, which enables them to go round a considerably sharper curve
than the four-wheeler with an ease and absence of grinding quite
remarkable, to say nothing of the saving to the road by the distribution
of weight over more points. The relief seems to be by no means so much in
the lessening of the weight per axle, which is not very great, as in the
increased number of points of support. I am well aware this is not a new
discovery, but it has come home to me with a practical force that leads
me to insist somewhat strongly upon its importance.
The whole of the foregoing locomotives have been entirely made in my
workshops, with the exception of the boilers and steel castings. The
former have been chiefly supplied to me of excellent workmanship by
Messrs. Abbott and Co., of Newark, and the latter by the Hadfield Steel
Foundry Co., of Sheffield.
The last locomotive in the table (No. 5) is now being commenced, and will
combine all the advantages of the previous ones in a less costly engine
than No. 8 which was built specially with a view to see how powerful and
fast travelling an engine could be put on the 15 in. gauge. No. 5, with
its smaller wheel, is not very inferior in hauling power to No. 8, and
the expense of the extra axle is saved. This is the engine that, if I had
to build another for the Eaton Railway, I should certainly recommend in
preference to the four-wheeled No. 4.
The wheels of such little locomotives, since speed is no object, should
be kept as small as possible, and the stroke should be of the greatest
length. The nearer the stroke can be extended to half the diameter of the
wheel, the more successful will the engine prove on steep inclines. Good
sand-boxes, front and back, of ample capacity are essential, but it is
not advisable to fit any steam sanding apparatus, for, owing to the low
position of the motion, a good deal of the sand will rebound into the
joints and bearings, as I found by experiment.
Cabs on such small engines are to be avoided as unbearably hot in summer,
dangerous in case of emergency, and inconvenient at all times on account
of the contracted dimensions. A stout mackintosh is cheaper and far
better for the driver.
A steam water-lifter is a convenience in frosty weather when the water
supply above ground may be frozen up, but in summer the engine tanks get
so hot from their proximity to the boiler that the water, which becomes
lukewarm in the process of being raised by the lifter, is then very soon
at a temperature which makes the action of the injectors precarious.
I may say that in all my locomotives I use Holden and Brooke’s restarting
injector, which, after experiment with many types, I find takes the
hottest water and is in all ways most reliable. I place brass wire
strainers in both steam and water-supply pipes close to the injector,
which is invaribly fixed below the tanks, so that when the injector is
overheated the water will run through by gravity and cool it; a most
important advantage.
NUMBER, DATE OF COMPLETION, No. 1. 1875. No. 2. 1881. No. 3. 1894. No. 4. 1896. No. 5.
AND NAME OF ENGINE. “EFFIE.” “ELLA.” “MURIEL.” “KATIE.”
Diameter of cylinders 4 in. 4⅞ in. 6¼ in. 4⅝ in. 5½ in.
Length of stroke 6 in. 7 in. 8 in. 7 in. 8 in.
Diameter of wheels 1 ft 3½ in 1 ft 1½ in 1 ft. 6 in. 1 ft. 3 in. 1 ft. 4 in.
Length of wheel-base 2 ft. 6 in. 4 ft. 6 in. 6 ft. 3 ft. 5 ft.
Number of wheels (all 4 6 8 4 6
coupled)
Length over framing 7 ft. 8 ft. 8 in. 10 ft. 9 in. 8 ft. 10 ft.
Overhang at each end 2 ft. 3 in. 2 ft. 1 in. 2 ft. 4½ in. 2 ft. 6 in. 2 ft. 6 in.
Width over framing 2 ft. 3 in. 3 ft. 10 in. 3 ft. 10 in. 3 ft. 10 in. 3 ft. 10 in.
Length of boiler 4 ft. 6 in. 6 ft. 6 in. 8 ft. 3 in. 5 ft. 8 in. 7 ft. 8 in.
Diameter of boiler 1 ft. 10 in. 2 ft. 1 in. 2 ft. 1 in. 2 ft. 1 in. 2 ft. 1 in.
Length of firebox (flue) 1 ft. 9 in. 2 ft. 3 in. 3 ft. 2 ft. 3 in. 3 ft.
Diameter of firebox 11 in. 1 ft. 3¼ in. 1 ft. 3¼ in. 1 ft. 3¼ in. 1 ft. 3¼ in.
Number of tubes (brass, 1⅜ 23 57 57 57 57
in.)
Heating surface 23 sq. ft. 70 sq. ft. 91 sq. ft. 53 sq. ft. 80 sq. ft.
Grate area 1.25 sq. ft. 2.12 sq. ft. 3 sq. ft. 2.12 sq. ft. 3 sq. ft.
Capacity of tanks 18 gals. 50 gals. 84 gals. 49 gals. 77 gals.
Working steam pressure per 125 lb. 160 lb. 160 lb. 160 lb. 160 lb.
sq. in
Weight in working order 1 ton 3 cwt. 3 tons 15 5 tons 3 tons 5 4 tons 5
cwt. cwt. cwt. (?)
Co-efficient of adhesion at 3.6 4.7 4.5 4.9 lb 4.3 (?)
145 lb. mean pressure
Tractive power per lb. 6.2 lb. 12.3 lb. 17.3 lb. 9.9 lb. 15.1 lb.
pressure in cylinders
If diameter cylinder2 = 1, 207 425 336 356 381
ratio heating surface =
If diameter cylinder2= 1, 11.2 12.8 11.0 14.2 14.3
ratio grate area =
Load (exclusive of engine) 15 tons. 35 tons. 49 tons. 28 tons. 44 tons.
on level.
(These are up 1 in 100 9 tons. 21 tons. 30 tons. 17 tons. 27 tons.
average
working
loads which
can be
considerably
exceeded on
the easier
gradients.)
up 1 in 50 6.4 tons. 14.6 tons. 21 tons. 11 tons. 18 tons.
up 1 in 25 3.8 tons. 8.3 tons. 12 tons. 6.5 tons. 11 tons.
up 1 in 12 1.8 tons. 3.4 tons. 4.9 tons. 2.5 tons. 4.4 tons.
VI.
WAGONS AND CARS
THE wagons first put upon my line measured only 4 ft. by 2 ft. inside. It
soon became apparent, however, that a gauge of 15 in. could carry with
safety a much larger vehicle. In fact it may be taken as a reasonable
rule that the floor area of narrow gauge wagons should not be less than
four times the gauge in length and twice the gauge in width. I have found
such a wagon very handy for light work, but on the Eaton Railway I
adopted an over measurement of 6 ft. by 3 ft. with 1 ft. 3 in. depth of
side. The wheel base is, in all cases, half the length of the wagon. The
larger wagon above described carries 16 cwts. of coal, and from 20 to 22
cwts. of sand, road metal, bricks, etc., and weighs about 7½ cwts., or
one-fourth of its total gross loaded weight, _i.e._, it carries three
times its own weight. The axles in this case are 2 in. diameter. For
heavier loads I have made the wagons with 2¼ in. axles to carry 30 cwts.
which is the standard I have finally adopted; and also with 2½ in. axles
to carry two tons. Two of these last were built for the Eaton line, on
which logs of timber up to 30 in. square and 60 ft. long have to be
conveyed from the G. W. Railway to the Estate works. Each end of the log
rests on a “timber fork,” which can be fitted on to any wagon, and in
this way, not only timber, but any kind of lengthy goods can be carried
with the greatest ease. My resident engineer at Eaton gave me an amusing
account of the arrival from Messrs. Handyside & Co. of the ironwork for
the coal store at Eaton. This included a number of long and awkward
shaped pieces, and the foreman sent by this firm to erect the shed was in
despair at seeing the toy wagons provided for the transport of pieces
that with some difficulty had been loaded in the main line wagons. To his
surprise the 15 in. gauge handled them with far greater facility than the
4 ft. 8½ in., owing to length being no drawback.
My standard wagons are constructed of pitch pine with angle-iron rims,
and the box sides are framed together independently of the wagon itself,
thus a flat wagon is converted into a box wagon by merely placing this
frame upon it. These sides, or “tops” as they have come to be called, are
about 15 in. deep, and the wagons being constructed to a standard size,
are interchangeable. An iron rim on each enables two or three of the tops
to be placed one above another upon any wagon, to give an extra depth. To
empty the wagon, two men readily lift off the top, and, if necessary,
turn it over sideways, sufficiently to shoot off the contents; or the
load may be upset without removing the top. This mode is almost as rapid
as emptying a tip wagon, which, though convenient to unload, is a fraud
as to capacity, and cannot be designed to carry more than one-and-a-half
times its own weight; and even then there is the objection that the
centre of gravity is far higher than in the box wagon.
For carrying timber or other lengthy loads swivelling carriers can be
placed on any two wagons; and if a greater length is required, these two
wagons can be set a distance apart, with or without other wagons placed
between them. By adopting the flat wagon as a standard, it is possible to
adapt each one to any class of work, without the necessity of keeping a
large variety for various purposes. A narrow gauge is said not to lend
itself advantageously to the carrying of bulky material, but by loading a
train of wagons without break from end to end, I clear hay off land, to
which it happens that carts cannot have access, with great despatch.
There is, therefore, no valid objection on this score. The cost of these
wagons is from 80s. to 85s. per cwt. In the two years the Eaton line has
been at work they have proved convenient in every way and show no signs
as yet of wear.
In addition to a number of wagons, some of which are fitted with brakes,
there are on my line seven bogie passenger cars and a bogie van; also a
variety of miscellaneous stock, such as workmen’s car, screw and roller
rail-benders, dynamometer car, and various small trolleys. The
dynamometer car is constructed to indicate the tractive effort of the
engine, the speed, and the distance travelled. The roller rail bender is
worked by three men, two of whom work the winch which draws the rail
through the rollers, while the third adjusts the pressure to produce the
required curvature. The screw bender has two thrust blocks, opposite
which works a horizontal screw, which straightens or bends rails with
great accuracy, but in long or sharp curves the roller bender is more
rapid and efficient, as elsewhere noted.
The passenger stock, which, like everything else, was built on the
premises, requires a somewhat more detailed notice. There are four open
cars, holding sixteen persons each, two abreast. These are 19 ft. 6 in.
long and 8 ft. 6 in. wide, and are carried on two bogies of 1 ft. 6 in.
wheel base, the total wheel base being 16 ft. 6 in. A foot brake is
fitted to one bogie on each car. The weight of these cars is 20 cwt.;
they therefore only weigh 1¼ cwt. per passenger seat, and reckoning
sixteen persons to the ton, the proportion of live to dead weight is as 1
to 1. On the main lines it is more than 1 to 5. The cost of these cars,
stained, varnished, and lined with linoleum, was £37 each.
In order to demonstrate the capabilities of even so small a gauge, a
closed car of the same dimensions as those already described was
constructed, which has doors and windows of the usual kind. Lest it
should be supposed that the space is unduly cramped, I may mention that a
visitor 6 ft. 3½ in. in height, when seated, found ample clearance for
his tall hat. The cost of this car was £67, and the weight is 24 cwt.
Here the proportion of live to dead weight is as 5 to 6.
As a further test of the capacity of a 15 in. gauge, I have built a
dining car and a sleeping car of the same dimensions as the cars already
described. The former seats eight persons and carries a suitable cooking
stove in a compartment to itself. The latter contains four berths 6 ft. 6
in. long and 1 ft. 10 in. wide, with a lavatory and other fittings. This,
though hardly an essential accompaniment to a line under one mile in
length, can be utilised as an overflow bedroom for my boys when the house
is full of guests. I am unable to state the exact cost of these two
vehicles, but exclusive of fittings, it is little, if at all in excess of
that of the closed car already quoted. The weights are somewhat greater,
owing to the bogie truck frames being of cast iron instead of elm.
A closed luggage van, 15 ft. in length, but otherwise of the same pattern
as the cars, concludes the list, and is used to convey luncheons, teas,
etc., for large parties, to the station where refreshments are served.
The extreme height of the closed cars is 6 ft.
All the wagons and cars are carried on chilled iron wheels, 13½ in.
diameter, cast in my foundry. The axles, as has been stated, vary from 2
in. to 2½ in. in diameter, and on to these the wheel on one side is
forced by a hydraulic pressure of about 15 tons, while the opposite wheel
runs loose to reduce the curve friction. The journals run in cast-iron
boxes, which are lubricated by sponges placed in oil receptacles below.
The horn-blocks and axle-boxes, with a rubber block between them to form
the spring, and a cover to the oil reservoir, are secured together by a
single bolt, after the insertion of which no part can come loose. The
castings are put together as they come from the foundry, without
machining or fitting of any kind, the axle bedding well into the
cast-iron box after a few days’ wear. For the Eaton railway, however, I
bored out the boxes, but have not found any advantage to result. These
bearings require oiling only at intervals of several weeks, and although
some of them have been in use more than eighteen years, there has been no
case of heating or other failure. The cost of each complete bearing,
including horn-block box, cover, spring, and bolt, is only 5s., 1s. of
which goes for the rubber.
The buffers and couplings are central. A single east-iron buffer, which
in the case of the cars is mounted on a spring draw-bar, has a coupler of
the same metal hinged to it by a bolt. The latter is self-coupling or not
as desired; but, when turned back so as not to couple, the driver can, by
bringing the buffers smartly together, cause it to fall and couple up.
These couplers allow the wagons and cars to be shunted out of the train,
when the engine is either pushing or drawing, by a quick manipulation of
the points, the hook sliding laterally from its hold as the vehicles
diverge on different lines. I designed some cast-steel coupler-buffers of
this type lately for the Royal Engineers’ 30 in. gauge experimental field
railway, near Chatham, which, though for reasons unconnected with their
construction not adopted, are reported as the only ones of several types
experimented with ‘which fulfilled the necessary requirements. In the
bogie stock the coupler-buffers are fitted to the bogie, and not to the
car frame, on account of the severe curves. In the construction of the
wagons and cars almost every part is made to gauge, and put together
without fitting.
The aim throughout has been to make the details of all the rolling-stock
as simple, cheap, and efficient as possible, which has been principally
achieved by adopting designs and modes of construction largely at
variance with commonly accepted notions. The totally different conditions
under which minimum-gauge lines work, as compared with ordinary railways,
renders this possible without any sacrifice of safety or durability.
In Section IV. mention was made of tip-wagons supplied as an experiment
to the Eaton line. These consist of steel tubs, U shaped in section, hung
at each end on two trunnions riding in cast-iron pedestals, the latter
being bolted to an under-frame of channel steel fitted with cast iron
ends rivetted in, and so formed as to carry a drawbar with rubber
cushions, to the end of which the coupler-buffer is attached. These
wagons cost £20 as against £12 for the standard box wagon. They weigh 11½
cwts., and carry about this weight of coal, or a little more. Loaded with
coal, they average a trifle under 24 cwt., exactly the same as the box
wagon, which weighs 7½ cwt., and carries 16 to 17 cwt. of coal. Thus the
paying loads of the two are as 3 to 4 for the same hauled weight. For
short distances, where the emptying bears a greater proportional relation
to the running time, or where the load must be got rid of in a
particularly short space of time, tip-wagons may answer. For such
purposes as my experience has had to deal with, they are a drawback,
which, as I have previously pointed out, is increased by their
inadaptability to the carriage of bulky goods. One of my strong
contentions is that, on a small line, to avoid expense in rolling stock,
every vehicle should be available for every purpose.
VII.
THE DUFFIELD BANK WORKSHOPS.
A BRIEF account of my little works will be of some interest to engineers.
I have already, in Section I., given an outline of my progress as a
mechanic.
I will now describe the machinery by which the locomotives, carriage and
wagon stock, and permanent way fittings have been constructed.
The machine-shop contains an 11 in. lathe for wheel turning, cylinder
boring, and the heavier work; an 8 in. lathe for surfacing, sliding, and
general work; a 7 in. lathe for screw-cutting and fine work; a 4 in.
Pittler universal lathe, with a variety of automatic and other fittings,
chiefly used for the smaller brass work, such as cocks, glands,
lubricators, &c.; a 3 in. sliding and screw-cutting lathe, for very light
work; a planing machine to take work 4 ft. by 1 ft. 6 in. by 1 ft 6 in.;
an 8 in. stroke double-table shaping machine, fitted for hollow and
circular shaping, specially used for machining coupling rods, &c.; a 4½
in. shaping machine with circular motion, for light work; a milling
machine; a 9 in. stroke slotting-machine with compound table, for heavy
work; a 2½ in. spindle drilling and boring machine; a 1¾ in. drilling
machine, for general work; a screwing and tapping machine, to 1½ in. for
bolts and to 2 in. for pipes; a cold-sawing machine, to cut iron up to 2¼
in. square; a slot drilling machine; a twist-drill grinding machine; two
grindstones, three bench vices, and complete sets of screwing tackle and
fitters’ tools.
The smith’s shop contains two fires, of which one is blown by a fan, and
is suited for the heavier work; anvils for ordinary purposes and also for
the treatment of angle iron, &c.; a 2½ cwt. gas hammer; a punching and
shearing machine; a bench vice, and complete set of smiths’ tools.
The erecting shop contains an overhead travelling crane; an engine pit; a
30-ton hydraulic press for putting axles into wheels, crank pins into
cranks, testing samples, &c.; a hand screwing and tapping machine to ¾
in. for bolts and to 1 in. for pipes; standards for fitting up
frame-plates; a rivet heating forge; two bench vices, and tools for tube
extracting and other special processes connected with the construction
and repair of locomotives.
The iron-foundry contains a 16 in. cupola worked through a double tuyère
by a “Root’s” blower; an overhead travelling crane; a core stove;
charge-weighing scales; a large supply of boxes for general purposes, and
special ones for cylinders, chilled-wheels, sleepers, gutters, &c., with
all ladles and other appliances suitable for producing castings up to
half-a-ton weight. Especial pains have been taken to turn out chilled
wheels (13½ in. diameter), for the rolling stock, of perfect smoothness
and of even depth of chill.
The brass foundry contains a furnace, a metal moulding bench, and the
usual fittings.
The carriage shop has two lines of 15 in. gauge formed of cast plates
bolted together and bedded in concrete, and contains a wood-morticing and
boring machine; fitters and joiners’ vices, with every convenience for
erecting, finishing, and painting two of the long 20 ft. bogie cars
simultaneously, or eight of the standard wagons, according to
requirements; all bulky joiners’ and carpenters’ work is also done in
this shop.
The pattern and joiners’ shop contains a 5 in. Holtzappfel lathe; and a
small circular saw; 2 instantaneous-grip vices; saw tooth-setting
machine; and a variety of other special appliances, in addition to a full
set of joiners’ tools.
The saw-shed contains a 30 in. circular saw bench; a band saw; a small
general joiner; an 11 in. planing machine, and a small emery grinder.
The engine house contains an 8 horse-power Otto gas-engine, of which the
water circulation is effected by a small centrifugal pump.
The drawing office is fitted up with the usual appliances, and is in
telephonic communication with my house and two of the stations on the
railway.
The general stores comprise timber; foundry sand of various qualities;
five kinds of pig iron; copper, spelter, tin, &c.; bar, rod, and angle
iron; wrought-iron tubing up to 2 in.; bolts, rivets, nuts, and pins;
steam fittings of all kinds; every sort of requisite needed in the
construction of small railways and rolling stock, and also for meeting
house and farm requirements.
The pattern store contains patterns for all the locomotive, carriage,
wagon, signal, permanent way, and general experimental work; and for
drain grates, gutters, &c. which are supplied from Duffield for my other
estates.
The shops are lit by gas, and the 15 in. gauge line runs throughout. The
construction, both in wood and iron, is done as far as possible to
template, and every endeavour is made to turn out the very best work,
which is perhaps the more easily attained in that there are no profits to
be considered. At the same time it should be explained that the shops and
machinery are, throughout, though good and sufficient for their purpose,
in no way models of excellence. Their object is only to turn out the
chiefly experimental work required, and the gradual additions that have
been made during the twenty-five years of their existence have been done
as cheaply as was consistent with efficiency.
Outside the shops are a weigh-bridge for weighing rolling-stock and
loads, and a six-ton crane to tranship heavy goods from drays to the 15
in. railway.
Adjoining the workshops is the locomotive shed, with rails raised 30 in.
above the floor, so as to get more easily at the lower parts of these
small engines. It is arranged for two locomotives, and is fitted with an
air jet for raising steam, and with a water supply.
The carriage and wagon stock is, for the most part, housed in three sheds
at various stations on the main part of the railway, 80 ft. above the
workshops.
VIII.
SCIENTIFIC CONSIDERATIONS.
THE present section contains the result of experiments and experience on
points which, for the most part, are of interest only to those who study
the scientific side of railway work. I here take the opportunity of
placing on record various considerations, more or less connected with the
subject of narrow-gauge railways, of too technical a nature to be mixed
up with the descriptive pages. This explanation will account for the
somewhat disjointed nature of the statements which follow.
The fact that narrow gauge locomotives are usually required to surmount
much steeper gradients than are generally to be found on standard
railways, makes adhesion a question of the first importance. It is very
generally supposed that the co-efficient of adhesion between a wheel and
a rail is a constant fraction of the insistent weight, varying slightly
with the molecular structure of the metals in contact. There is, however,
reason to believe that it decreases considerably with an increase of
weight. In locomotives of the standard gauge, with from 12 to 18 tons per
driven axle, it is generally held that a co-efficient of adhesion of
one-sixth is all that can be counted on with certainty. From a number of
experiments on the Festiniog Railway, with the results of which the late
Mr. Spooner, who himself supported the theory, was good enough to supply
me, I found that the load there per driven axle was five tons, the
co-efficient averaging about one-fifth. Again, with my small engines that
have a load on each axle of from 1.2 to 1.6 tons, the calculated
co-efficient is two-ninths, in support of which I give the following
experiment, conducted in the presence of two gentlemen belonging to a
firm of locomotive builders, when it was under consideration to build for
military purposes some engines on the plan of the No. 2 described in
Section V.
I guaranteed that the locomotive referred to should take a load equal to
its own weight up a gradient of 1 in 10 a quarter of a mile long, which
then was, in parts, as steep as 1 in 9, with a short curve of
half-a-chain radius at the severest part. This was satisfactorily
accomplished. The day being dry, I was requested to ascertain what was
the maximum load that could be hauled. On reaching four tons, when the
start had to be made on a less gradient, the engine barely struggled up,
and this was evidently all it could do. When full up with coal and water
it weighed at that time 3 tons 6 cwt. During the experiment, however,
there were but 3 tons 2 cwt. on the three axles, all of which were
coupled. The boiler pressure was 145 lbs. exactly, and, the gross weight
of engine and train being 7 tons 2 cwt., the gravity resistance on the
gradient of 1 in 10 was equal to 14.2 cwt. The weight of 3 tons 2 cwt.
available for adhesion, reduced by a tenth part, which the gradient
converts into gravity resistance, was equal to 56 cwt. Thus, without
reckoning the curve friction of the whole train and the journal friction
of the wagons, both uncertain quantities, the proportion of developed
tractive power to load was as 1 to 3.9. This result confirms the
probability of the truth of the above assertion. Assuming its
correctness, which appears beyond doubt, what is the explanation of
increased proportionate adhesion with a decreased weight on the driven
axles? The reduced diameter of wheel in the smaller engines might seem
to offer a solution of the problem. Experience, however, goes to prove
that, if there is any difference, a larger wheel has, with equal
insistent weights, a better grip of the rail than a small one. I am of
opinion that the weight is directly responsible for the difference. A
wheel rests upon a rail on one point, or possibly on a transverse line of
which the length is equal to the width of the rail. With a small
insistent weight the molecules of the wheel and rail interlock without
injury, and adhesion, on the principle of an infinitesimal rack and
pinion, is the result. As the weight is increased on the fine bearing
area, the molecules become disturbed, and fail to offer so firm a
fulcrum. Ultimately they become displaced, and move as rollers between
the two surfaces, materially reducing the adhesion. If this theory be the
correct one, as is not improbable, the graduated reduction in the
adhesion would be accounted for.
That the rolling wheel and rail do actually interlock was demonstrated by
Sir Douglas Galton in his experiments on the retarding power of brakes,
when he pointed out that, on a wheel becoming skidded, the rack and
pinion motion was converted into a series of jumps of the wheel across
the microscopic teeth of the rack, with a consequent reduction in
adhesion proportionate to the sliding speed. In confirmation of this
statement I detailed, during the meeting of the British Association at
Sheffield, an experiment I made by reversing a locomotive so as to skid
the wheels, and ultimately to cause them to revolve in a contrary
direction, while descending an incline. With skidded wheels the descent
was at a certain speed with backward revolution of the wheels the speed
increased rapidly, the effect of the reversal being to cause the wheel to
slip over the rail at a speed greater than that at which the engine was
moving, thus showing that Sir Douglas Galton’s theory of the adhesion
diminishing in proportion to the extent of departure from the
interlocking or rolling motion of the wheel on the rail remained
consistent even beyond sliding contact, and disposing of the old theory
that the loss of adhesion with a skidded wheel was due to the creation of
a polished point of contact on the wheel.
Another somewhat curious point in connection with adhesion is the slip of
the driving wheels, which is naturally in the direction of causing a
greater number of revolutions of the wheels than would be due to the
length of rail travelled over. Occasionally, however, I have, in
experimenting, noticed that fewer revolutions are made than would suffice
to travel the distance as measured on a centre line between the rails.
That is, the wheels slipped forward instead of back. This freak is
probably due to the outer wheel on a curve slipping forward when, owing
to considerable superelevation and a low speed, the inner wheel is the
more heavily weighted, the distance then travelled being the reduced
length of the inner rail.
I now proceed to explain the basis of calculation of the net loads hauled
on various gradients, as appended to particulars of each locomotive
described in Section V. The resistance on the level consists of journal
friction, tire friction, and locomotive internal friction. Tire friction
is practically nil, except on curves and in strong side winds. Journal
friction I find, in the case of my small rolling stock, to be covered by
an allowance of 10 lbs. per ton. Owing to the numerous curves another 10
lbs. per ton must be added to cover tire friction. A tractive power of 20
lbs. per ton proves quite sufficient to keep the train in motion on the
level. It is not, however, enough to start the train on a curve, nor to
overcome the inertia due to journal friction when, as on an incline,
there is no slack between the wagons, and the whole train must be started
at once. After considerable experience I find it necessary to add a
further 20 lbs. per ton to the required tractive power. A total of 40
lbs. per ton is thus allowed as a good working equivalent of the
frictional resistance of the train.
The friction of the locomotive is a much more complicated question. There
seems very little information available on this point. It has been said,
in the case of full sized engines, to absorb thirty per cent. of the
tractive power, but this is a vague estimate, out of all reason
excessive, unless it be intended to include gravity resistance on a steep
incline. It is desirable to consider the nature of the various causes of
resistance to motion separately. Viewed as a carriage only, the journal
and tire friction of the locomotive may be taken at the same amount per
ton of its weight as in the case of the trains, namely, 40 lbs. The
additional resistance due to friction of the moving parts of the
mechanism cannot be calculated as a constant. If the engine is developing
but a small portion of its power, the amount will be small; when loaded
to its full capacity there will be a large increase of internal
resistance, varying, however, in proportion to the accuracy with which it
is put together, and the stiffness of the framing.
Such experiments as I have made show clearly that, when exerting
approximately its full power, the total frictional resistance of the
engine does not exceed 100 lbs. per ton, and when running light is much
less, but in what proportion less I have as yet failed to ascertain
satisfactorily. Of this 100 lbs. per ton, from 20 to 40 lbs. is due to
journal and tire friction, leaving from 60 lbs. to 80 lbs. per ton as the
deduction for internal friction.
I thus conclude that an allowance of 40 lbs. per ton for train
resistance, and 100 lbs. per ton for engine resistance, is a basis for
calculating the tractive power required on the level that is sufficient
under all possible narrow-gauge conditions. In the case of gradients
there must, of course, be added the gravity resistance of the engine and
train, which is, on a gradient of 1 in 100, one-100th of the gross
weight; on a gradient of 1 in 50, one-50th, and so on.
In calculating the tractive power of the engine, the effective pressure
in the cylinders may be reckoned at fully nine-tenths of the boiler
pressure, on account of the low piston speed.
The above particulars are not to be taken as representative of what can
be got out of a narrow-gauge engine in a few isolated experiments only,
but of what is well within the compass of daily work.
IX.
REMARKS ON NARROW GAUGE RAILWAYS.
UP to this point I have merely detailed the particulars of the
construction of my experimental railway and of the line at Eaton, giving
at the same time the reasons that have led me to adopt certain methods
and designs. I now propose, in conclusion, to offer a few remarks upon
the application, in this country and abroad, of small railways of 2 ft.
gauge and under to do work at present done by means of horses and carts.
The cases in which such lines can be profitably applied may be classed
under two heads; the one, where, in a country possessing ports or a
system of railways, large establishments, private, public, or industrial,
might be connected therewith by a narrow gauge line so as to reduce the
cost of transport below that which has to be paid for haulage by animal
power on roads; the other, when no roads worthy of the name are
available, and the choice is a light railway or nothing. The chief
condition of success in both cases is a sufficient traffic between two or
more definite points. Military railways, however, must be regarded from a
somewhat different standpoint, as the object here is to supply a movable
centre as expeditiously as possible with the vast commissariat
requirements of an army rather than to study economy. It is not my
intention to enter into the pros and cons of small railways for war
purposes. Suffice it to say that some countries are ahead of us in the
matter, which is one that has, in England, been allowed to drop rather
into the background.
Returning to the consideration of cases where a fairly large traffic has
to be delivered to a port or railway system, the first question that
arises is that of transhipment. Material of any kind can be as
effectively delivered on ship-board by narrow gauge railway wagons as by
horses and carts, if not better. In reckoning up the cost of transhipment
from small wagons on to a railway system—no great matter with proper
appliances—it must not be lost sight of that, even if a branch of
standard gauge were constructed to many establishments, the large wagons
cannot, as a rule, be got up to the point where the material lies, and a
preliminary transference in barrows or carts is necessary. With the
little wagons it is usually possible to get right up to the place and to
load direct, in which case there is clearly no additional expense
incurred. It is, further, often forgotten that there is on the standard
railways endless transhipment for the sake of economical transport, in no
way connected with a break of gauge.
Again, a small line can be carried round curves, up gradients, and
through confined premises, where a wider line would be inadmissible. In
many places the unsightliness of the standard gauge would be objected to,
nor can such a line be made very light if it has to carry, as it must,
the 7 or 8 tons per axle of a full sized coal wagon (see Appendix A).
The narrow gauge has also the advantage in first cost, and by bringing
the small wagons on to a level with the floors of the large ones, or, in
the case of minerals, by erecting a simple shoot, the transhipment
difficulty may be reduced to a minimum.
It is not well to have gradients steeper than 1 in 40 where avoidable, as
difficulty will be experienced in slippery weather; but it is quite
possible with suitable engines to work inclines of moderate length, as
steep as 1 in 12. The diminution of the power of the locomotive on
gradients is also a matter for consideration, the importance of which
will be clear when it is stated that if an engine will haul, as it
should, in addition to itself, ten times its own weight on the level, it
will haul, speaking roughly, only four times its weight up 1 in 50, twice
its weight up 1 in 25, and once its weight up 1 in 12. More work can be
done if adhesion does not fail, but the above is an approximate working
average.
The speed on small lines is not generally a matter of much moment, owing
to their usually moderate length. A locomotive that is sufficiently
powerful to start a given load, will without difficulty get it along at
from 8 to 10 miles an hour. It has occurred to me that a very fair
approximation to the reasonable running speed of which any gauge is
capable is to be found in estimating that the speed of passenger trains
is equal to as many miles per hour as the gauge is inches wide, and, for
goods trains, to half that amount.
The permanent way should be made a thoroughly sound job, as it will then
cost but little for repairs. Particulars of what is recommended will be
found in Sections III. and IV. I am no advocate of portable railways,
which may be well enough for hand trains, or even for horse traction, but
a locomotive requires a solid and clean road if it is to work to
advantage.
It is often possible to carry a narrow gauge railway by the roadside or,
as at Eaton, over pasture lands without the necessity of fencing the line
in. Fences can be crossed as described in Sections III. and IV., so long
as arable land is avoided. Where the route is not wholly the property of
the projector of the railway, the requisite way-leave may frequently be
leased by paying an annual acknowledgment of from 3d. to 6d. per yard
run.
It now remains to show what traffic is required in order that a line of
this description may repay the outlay upon it. This may best be effected
by drawing a comparison between the cost of locomotive traction on rails
and horse traction on roads. The cost of loading and unloading will not
be included, as these are the same in both cases. (See also Section IV.)
Taking the minimum distance apart of two points, between which haulage
may be supposed to be required, as one mile, the smallest and cheapest
gauge as 15 in., and allowing 2,000 yds. to the mile so as to include the
necessary sidings, the cost of the line will be as follows:—
2,000 yds. of 16 lbs. steel rails, cast-iron sleepers, £650
ballast, and laying
Fence bridges, field crossings, fencing, and other £200
structural works; but exclusive of river bridges, tunnels,
or other costly requirements
Earthwork, if an approximately surface line ... say £250
One 4½ in. cylinder four-wheeled locomotive £400
12 wagons to hold 1 cube yd., at £12 each £144
Extras ... say £156
Cost of 1 mile of line, equipped complete £1,800
If laid with pitch pine sleepers a reduction of about £100 per mile would
be effected, the cost of renewal being correspondingly increased.
The engine would be capable of hauling a gross load, exclusive of its own
weight, of 12 tons up a gradient of 1 in 50, which may be taken as a fair
ruling gradient for a surface line. This would be equal to an average
paying load of about 8 tons; so that, supposing the engine to make one
trip per hour, about 60 tons would be moved per day; although, with a
double set of wagons and men, 100 tons would easily be handled.
If the engine worked two days a week, or say 100 days per annum, it would
have hauled 6,000 tons one mile in the year. A less load hauled on the
return journeys need not be taken into account, as this would make no
difference in the comparison, such work being practically done without
extra cost in both cases.