By Dan Beard
Working Plans for the Construction of Safety Double-Runner.
The Double-Runner, or Bob Sled, as it is frequently called, possesses many advantages over the long sleds
formerly used west of the Allegheny Mountains. The old-fashioned sleds were
steered by the boy in front kicking with his heels on the frozen snow, or the
boy at the stern by dragging one foot behind as a rudder. This answers very well
for a sled of the dimensions of the "Get- There," but when the sled is
seven, eight, or ten feet long, and loaded underneath with pig iron to give it
weight, the boy in front who steers has a difficult and exceedingly dangerous
task, especially if the hill is steep and icy; and it is next to impossible to
steer such a craft from the stern by dragging one foot behind.
The double-runner is much lighter and very much easier to steer on account of
the front sled being arranged so that it can be moved independently of the rear sled, for a turn to the right or
the left causes the "bob " to take the direction indicated by the
front runners; but double-runners steered with a wheel, lever, or yoke in front
are very dangerous, as the steersman, in case of an accident, is thrown against
the steering apparatus, usually with serious results.
The safety double-runner does away with this danger by having a bridle with
which it is steered. It also does away with the danger of collision by having an
automatic brake that will stop it, in times of danger, within the distance of
its own length. These are qualities which will be appreciated by all who
"slide down hill," as we called it when I was a lad, or who are fond
of coasting, as our school-readers called it then, and as everyone calls it now.
How to Build a Safety Double-Runner.
Make four good runners after the manner described for the
"Get-There," but make these runners not over six inches high, thirty
inches on the top edge, and with more rake to the bow and stern (Fig. 422). Next
make eight braces, each fourteen inches long, one inch thick, and two and one
half inches broad, and mortise the ends as shown by the dotted lines in Fig.
At a point three inches from the rear top end of the runner, measure off on
the top edge three inches, then two and one half inches, and mark the points.
Eight inches in front of the last point make another mark and measure two and
one half inches again, and mark it. Now set the runner upon its bottom edge and
fit your braces on the two-and-one-half -inches marks, and with a pencil trace
upon the top edge of the runner the outlines of the mortise.
Saw out the lines so that the braces will fit neatly in the notches, as shown
in Fig. 424. The braces should be of good ash wood, free from knots, and must be
fastened to the runners with good long screws, the holes for the latter being
carefully bored with a gimlet. For a top-board cut out a piece of board one inch
thick, fourteen inches wide, and thirteen inches from front to rear.
Fasten the top-board securely to the runners over the braces with screws
(Fig. 425). Find the center of the top-board by ruling a line from each corner,
as shown by the dotted line in the top view, Fig. 425. The center of the
top-board and the spot in which to bore a hole for the
is placed where the diagonal lines cross each other. The king-pin is of iron,
with a rounded head and with threads on the other end to hold a nut in place.
Fig. 428 shows the pin and the nut proportional to the size of the sled, the
diagram, Fig, 429, shows an enlarged view of the king-pin.
is the long board that forms the top for the double-runner. Each sled has a
top-board of its own, but the board that joins the two sleds and upon which the
passengers sit we will call a reach-board. This should be free from knots, of
strong elastic wood, sixteen inches wide, an inch thick, and as long as you may
desire the "bob" to be. In the one we are describing it is eight feet
It is evident that if we fasten the reach-board to the top of the two sleds
with nails it will be as difficult to steer as the big sleds we spoke of at the
beginning of this description; and if we fasten it directly to the top of the
first sled by the king-pin the friction in turning will be too great To obviate
this, make, of oak, a bench-block, fourteen inches long by four inches wide by
one inch thick, and, finding the center by the intersection of the two diagonal
lines, as you did with the top-board, make a hole for the king-pin (Fig. 426).
Place the bench on top of the sled exactly in the center of the top-board and
see that the two king-pin holes fit exactly one above the other, and that the
ends of the bench are even and flush with the sides of the sled. Then securely
fasten it in place with good long screws or bolts.
Make a second block, now, of
good oak, about nine inches long by three inches broad by two and one-half
inches thick, bore a hole for the king-pin through the center of it and trim it
down to the form shown by Fig. 427. This is the reach-board block, and must be
securely fastened to the reach-board by bolts. Fig. 432 shows the elevation,
that is, side view of king-pin, bench, and block all in place. Fig. 434 shows a
top view. Of course the reach-board, from this point of view, will hide all
underneath it, but in this case we must pretend that the X rays have been turned
on and the dotted lines show the skeleton underneath. Now for
The Back Sled,
which, of course, it is supposed, was put together at the same time as the
front one, and is an exact duplicate of it.
We need for the back sled a
bench-block fourteen inches long, four inches wide, and three inches thick.
Lengthwise through the center, from end to end, bore a hole for the stern-pin
(Fig. 430). After this is done make two side- blocks, one inch thick and a
little broader than the bench- block (Fig. 431). Bolt the bench-block to the
rear of the back sled and fit the reach-board on for trial. Mark the spot where
the side-blocks are to go and bolt them securely in place.
On the rear sled, in
the side view, the bench- and side-blocks are shown in place. The dotted lines
show the bench-block behind the side-blocks. The stern-pin is similar to the
king-pin but runs crosswise in place of perpendicularly. It is also fastened
with a nut and washer at one end, while the rounded head holds it at the other
end. If the rear sled is allowed to have too much freedom it will wrench itself
loose at the first obstacle it strikes. To prevent this attach a small chain or
strong cord to each runner and to the bottom side of the reach-board, as may be
seen by a glance at the elevation and plan of back sled (Fig. 432). The cord is
shown by dotted lines on the plan or top view (Fig. 434)
The Automatic Brake.
From a hasty glance at the plan and elevation this may appear to be rather
intricate and difficult to understand; but with the exercise of a little
patience you will see that it is very simple. There is a block against which a
pin is kept by a spiral spring. A peg through the pin near the after end keeps
the spring in place, and a staple, screw eye, or ring, behind the peg protects
it and supports the brake-pin. A similar ring supports the forward end of the
pin and keeps the spring confined between the two. There is a small indentation
in the block to receive the end of the pin (Fig. 433).
Any boy can see that a chain looped over the end of the pin, after the manner
of the one shown in the two views (Figs. 432 and 434), will drop to the ground
when the pin is pulled forward, and when it falls to the ground it will be
directly in front of the rear runners. The latter cannot go far with a bunch of
chain under each runner, and the whole thing will stop even when the headway is
something extraordinary. To loosen the brake the boy in front simply puts his
foot against the end of an iron rod that has one end bent over to receive the
foot. A push on this pulls the picture wire cord that runs from it to the end of
To bring the brake within reach of the steersman's foot two of
those brass bell-cranks that all bell-hangers use when they have to turn a
corner with their bell-wire, are necessary. These cranks are fastened at their
middle to the bottom of the reach-board, while the wire picture-cord connects
them with the brake-pin and the bolt at the side of the reach-board. The bolt is
made exactly on the principles of a bolt for a door, but one end of this bolt
has a hole through it to hold the wire, and the other end is bent into a crook
as a rest for the foot.
A footrest for the bow man is made of ash, and extends at least ten inches
upon each side of the reach-board, to the bottom of which it is securely
fastened. In each end of this foot-rest there is a pulley-wheel, as shown by the
dotted lines. Across the top of the front runners a brace is securely fastened
to which the bridle is attached. The bridle runs through the blocks or pulleys
at the end of the footrest. With the bridle in his hands and the automatic brake
ready for instant operation, the steersman may coast down what are considered
dangerous hills, and feel that there is no great peril.
Should an obstacle, such
as a wagon, a horse-car, trolley, or steam-car, suddenly appear, one push of his
foot drops a loop of chain in front of the rear runners and his safety
double-runner will stop almost within its own length. If too sudden a stop
unseats the steersman, he simply slides off, for there is no dangerous wheel,
yoke, or helm in front for him to be thrown against. It is not to be supposed
that the reader is to make all the iron-work for the safety double-runner. This
the blacksmith can do, and if the expense is greater than one boy feels disposed
to stand, remember that this sled is built to accommodate a number of boys, and
a club can be formed which will make the expense very light.
should have large links, but not necessarily very heavy ones. It must be
fastened with a ring-bolt at each end to the bottom of the reach-board. The
runners of the sleds should be shod with half-round irons, and everything made
with the idea of strength in view. Use bolts in place of screws wherever it is
practicable. The sled will not be found expensive, and if well built, it will
last long enough to be used by two or three generations of boys. Load your
double-runner with a crowd of jolly fellows and start down the hill. May you
enjoy the ride with that keen pleasure which only youth and health can feel. The
longest hill has its foot, and the faster you coast the sooner it will be