204

THE NEW ZEALAND GAZETTE.

conveyance of passengers at thirty miles per
hour. The cost of laying down the rails must
of course vary with circumstances and localities
In the plains of Australia and India it could
scarcely exceed one to two hundred pounds per
mile. Bridges are not included in the estimate,
but as the heaviest portion of the train does
not exceed ten cwt. per foot run, very light
bridges—which may be exported—will suffice.
The sides of ordinary roads may be taken
advantage of.

The weight of ten miles of line, one engine,
and twenty vehicles, including rails, sleepers,
and fastenings, will not exceed seven hundred
and eighty tons—equal to the transit in one
train of eight hundred passengers, or fifty tons
nett of goods, so that the freight may be cal-
culated.

The cost of this delivered in England will
be at the present time

DESCRIPTION OF IMPROVED RAILROAD,
SUITABLE FOR THE COLONIES, AND FOR
BRANCH LINES, OR FEEDERS TO MAIN
TRUNK RAILROADS.

It being very desirable that a system of
Railroad be introduced, suitable for the require-
ments of a moderate traffic conveyed at a low
rate of speed, and which may be constructed
at a low cost within the means of our Colonies,
and of rural districts in Europe, the following
description of improved Railroad is submitted,
as being found to fulfil the conditions desired,
and which has received the approval of many
eminent engineers and capitalists.

In Railroad construction, the weight of the
locomotive engine intended to be used, and the
speed proposed to be maintained, governs the
strength and cost of structure.

The engines in use upon most European
and American Railroads weigh from twenty-six
to thirty-six tons, exclusive of the weight of
the tender; and the running speed ranges
from twenty-five to fifty miles an hour, with
gross loads of from eighty to three hundred
tons.

These weights and speeds involve the adop-
tion of a permanent way (rails, sleepers, &c.,)
of great weight and solidity; the rails weigh-
ing 65lbs. to 100lbs. per yard, and necessitating
the construction of bridges and substructure of
a correspondingly massive and expensive char-
acter.

It needs no argument to prove that a Rail-
road so constructed, and suitable for carrying
the enormous traffic existing between the large
European and American cities, is more than is
demanded by the requirements of an ordinary
traffic and a thin population, such as is generally
to be found in our Colonies, and in our agri-
cultural districts at home.

It is found that, for the conveyance of a
traffic beyond the capacity of ordinary macad-
amised roads, at a speed not exceeding twenty
miles an hour, a locomotive engine, weighing
not more than eight tons, running upon light
rails, is sufficient.

Engines of this kind have, of late years, been
patented by various inventors, such as Bloydell,
Bray, Taylor, and others, whose traction
engines are constructed for running on ordinary
macadamised roads, and have been adopted by
several ship-builders and others, and by Govern-
ment for use in the national dockyards, and for
service in India.

A locomotive engine, somewhat similar in
principle to these, weighing eight tons, on four
coupled wheels, with a gauge of 3 feet to 3
feet 6 inches, and capable of passing round
curves of four to five chains radius, will draw,
upon a level Railroad, a gross load of 160 tons,
at a speed of fifteen to twenty miles an hour;
a gross load of sixty-five tons up an incline of
one foot in one hundred; of thirty-five tons up
an incline of one foot in forty; and of twenty
tons up an incline of one foot in twenty.

The weight of engine being reduced to about
one-fourth that of ordinary locomotives, the
weight and strength of bridges and permanent
way can be reduced proportionably; so that,
instead of having a rail weighing 65lbs. to
100lbs. to the yard, one of 30lbs. to the lineal
yard is ample.

The width between the rails (or gauge) being
only 3 feet to 3 feet 6 inches, curves of four to
five chains radius being admissible, and gradi-
ents so steep as one foot in twenty employed,
the natural surface of the ground can be the
more readily followed; and heavy earth-works
and viaducts being avoided, the formation of
the road-bed, bridging, and all the work under-
neath the ballast usually denominated "the
substructure," will be of an inexpensive char-
acter.

The road-bed, at formation level, need not
be more than sixteen feet wide, including three
feet on either side the ballasting for side drains.

For the light engines and trains used on
these lines, the heaviest portions of which do
not exceed 10 cwt. per foot run, wire suspension
bridges, at a very low cost, such as those used
in America, will answer every purpose; these
are very durable, and are made up to spans of
one thousand feet or more.

The permanent way, occupying a width of
only six feet, may be laid down along the sides
of common roads, and the traffic worked by
horses, where it is not sufficient to necessitate
the use of locomotive engine power. The rail
used is five inches in depth, and weighs 30lbs.
per yard; it is fished at the joints, and secured
between longitudinal timbers of hard wood,
which give great vertical and horizontal stiff-
ness; it is trenailed down to cross sleepers,
placed at intervals of nine feet.

The locomotive engine, used as before
described, is adapted for speeds of fifteen to
twenty miles an hour, and carries fuel and
water for that distance.

The engine, being about one-fourth the
weight of ordinary locomotives, will not crush
the rails, which are something over one-third
the ordinary weight, while the bearing surface
of the timber sleepers upon the ballast is little
less than the ordinary area.