PARTS COMPOSING THE UNDER-CARRIAGE.—FRAMING THEM
TOGETHER.—WROUGHT-IRON PERCHES.—BRAKES.
We have now to consider the construction of the lower framework, or
_carriage_.
The following is a list of the chief parts of a _coach_, as generally
known:—
Wheels.
Axles.
Springs.
Beds, or cross framing timbers, which are technically
termed the fore axle bed, the hind axle bed, fore
spring bed or transom, hind spring bed, and horn
bar.
Perch, or central longitudinal timber connecting the
axletrees.
Wings, which are spreading sides, hooped to the perch
and framed to the hind beds.
Nunters, or small framing pieces, which help to bind
the hind beds together.
Hooping-piece. A piece of timber scarped and hooped
to the fore end of the perch to secure it to the
Wheel plate, which is the circular iron beneath which
the fore carriage turns.
The fore carriage consists of the fore axle beds, into which are
framed the
Futchells (French, _fourchil_, a fork), which are the longitudinal
timbers supporting the
Splinter-bar and the
Pole, to which the horses are attached.
The hinder ends of the futchells support the
Sway-bar—a circular piece of timber working beneath
the wheel-plate.
A circular piece of timber of smaller size, supported on the fore
part of the futchells for a similar purpose, is called the
Felloe-piece (often made of iron).
On the splinter-bar are fixed the
Roller bolts, for fastening the traces.
On the pole is fixed the
Pole hook, to secure the harness.
The perch and beds are strengthened with iron plates, where
necessary, and the other ironwork consists of
Splinter-bar stays, to resist the action of the draught.
Formerly these were affixed to the ends of the
axles and called “wheel-irons.”
Tread-steps, for the coachman to mount by.
Footman’s step.
Spring-stays.
On the beds are placed
Blocks, to support the
=C= springs; to which are attached
Jacks, or small windlasses, and
Leathern suspension braces.
These parts fitted together would form what is generally known as a
coach, or a vehicle, the body of which is large, and suspended by
leathern braces from the ends of =C= springs. They enter into the
formation of all vehicles more or less, but for the other kinds some
part or parts are omitted, as in a brougham hung on elliptic springs,
the =C= springs, perch, leather braces, &c., would be omitted, and,
of course, elliptic springs and a pump-handle would be added. All the
woodwork is lightened as much as possible by the introduction of
beading, carving, chamfering, &c.
In starting the carriage part the workman first takes the perch and
planes a flat side to it, and then works it taper from front to
back. The top and bottom curves are then worked up, or at least some
portion of them, and then the front and hind spring beds are framed
on. A pair of spreading wings are then fitted to the sides of the
perch; these are simply circular iron stays, swelled and moulded to
take off their plainness. A pair is fitted at each end of the perch.
The hind axletree bed is then scarfed upon the top of the perch and
wings, and is connected with the hind spring bed by two small framing
pieces called nunters. At the front end of the perch a cross bed
called a horn-bar is scarfed on the perch, at the same distance from
the fore spring bed as the hind axle bed is from the hind spring bed,
viz. the length of the bearing of the spring, or about 15 inches.
The horn-bar is connected with the fore spring bed by the two spring
blocks, which are either framed into them or scarfed down on them,
and also by the hooping-piece, which is scarfed on the top of the
perch. The perch is then planed up to the curve it is to have when
finished, and it is then taken to the smith, who fits and rivets
on the side plates, which have ears at the ends for the purpose of
bolting them to the beds. The carver then does his work by beading
the perch and beds, having due regard to the finish of the parts,
rounds and curves all the ends. On the under side of the perch is
riveted an iron plate, and on this plate is an iron hook for hanging
the drag shoe and chain (if such be used). The hind framing is now
put together, all connections being by means of mortises and tenons
secured by screw-bolts. The wings used to be, and sometimes still
are, of wood, in which case they are hooped to the perch by iron
hoops, and are rebated to receive the perch plates. The hooping-piece
is then hooped in a similar way to the fore end of the perch, and
the transom firmly bolted. The carriage is then turned bottom
upwards, and the smith fits to the fore part the wheel plate or
turning iron, across which runs a broad plate the width and length of
the fore spring bed. A similar plate runs across the hind spring bed.
The hind axle is then fitted to the wings and perch, and let into
its bed at the ends, where screw clips secure it, the bolts passing
through the perch.
The carriage is then turned up into its old position; the wheel-plate
is cased on the top with carved wood, and a plate is riveted to the
side of the horn-bar. The springs are now fitted to their blocks and
bolted firmly down. Iron stays are bolted to the springs beneath the
beds to render them still firmer. The footman’s step, and the steps
for the coachman to mount to his box by, and other ironwork that may
be required in the shape of stays, &c., are then fixed in their place.
The under portion of the fore carriage is framed to the fore axletree
bed, which is a very stout piece of timber. Through this are framed
the two futchells which receive the pole. The upper part of the
axletree bed is covered with a strong plate to match the wheel-plate.
A circular piece of timber, called a sway-bar, is bolted behind the
axletree bed, and this is also plated beneath for security. In front
is a smaller piece of the same kind, and they both serve for the
circumference of the wheel to rest on. The splinter-bar is bolted on
to the fore end of the futchells and secured by branching stays, one
at either end connecting it with the axletree bed. As an additional
security, iron stays are fitted to the bottoms of the futchells
passing over the axle, which, in addition to bolts, is secured by
screw clips at the ends, the same as the hind one.
The carriage above described is one suspended only on =C= springs.
Sometimes elliptic springs are used in conjunction with =C= springs,
and the former are then termed under-springs. In the latter case,
of the double combination of springs, the constructional timbers
may be of a less size or scantling, owing to some of the strain and
concussion being removed. In this case the axles are clipped to the
under-springs; but the general mode of construction is the same.
In first-class work a wrought-iron perch is used instead of the
before described wooden one. This generally follows the contour of
the underside of the body, and is called a swan neck. It enables
the perch to be constructed of a much lighter appearance, and being
really light, and to a certain extent elastic, all the beds and
iron stays may be proportionately reduced in weight. The wheels and
axles also, having less to carry, may also be made lighter. The
system was introduced by Messrs. Hooper about 1846, and at first was
only applied to broughams and sociables, but it has gradually been
applied to the largest carriages, especially barouches and landaus.
These perches are supported on horizontal under-springs, and are not
now made so light as at first, for it is found that unless the hind
wheels follow steadily, not only is the carriage heavier behind the
horse, but the perch itself is frequently bent against very small
obstructions; a stronger and stiffer perch is therefore now used, and
it is found easier both to the horse and to the passengers.
When the body is suspended from =C= springs by leather braces, great
care should be used in the selection of the material for these
latter, and for this purpose the best and strongest leather is
required.
The use of brake retarders to the hind wheels has now for some
years superseded the old-fashioned drag shoes. It is evident that
the action on two wheels must be better than on one only. The brake
can be applied or removed without stopping the carriage, which
is necessary if a drag shoe be used. This is rather an important
consideration in undulating country, for it would be a great
inconvenience to have to get down and put on the drag shoe when
descending a hill, and when at the bottom to stop and get down
again to remove it, in order to proceed along level ground or up the
next hill, and so keep on like this all day. The lever brake was
the original form, as still seen on drags, &c., but in many parts
it is superseded by the foot or treadle brake, more especially in
Scotland. This kind of brake is also the one used by the London
Omnibus Company. The blocks which press upon the wheels have been
made of various substances—cast iron, wrought iron, brass, wood,
india-rubber, and leather. The wood is the best for the hold on the
iron tyre and absence of noise and smell, but it wears out fast.
India-rubber, especially for light carriages, seems to be the most
satisfactory.
We have given, generally, the operation of framing together the
under or carriage parts of the vehicle. But as some very important
considerations regulate the shape, construction, and formation of
most of these parts, they must be discussed separately. For this
purpose they will be considered under the following headings:—
Wheels.
Axles.
Springs.
Wheel-plates and fore-carriages.
Ironwork generally.