RAILWAY LOCOMOTIVES WITHOUT COUPLED WHEELS OR HEAVY DRIVING WHEELS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Henry Daniels at the Office
of the Commissioners of Patents on the 12th May 1879.
"
WILLIAM HENRY DANIELS, of 43, Windsor Road, Holloway, in the County of
Middlesex. RAILWAY LOCOMOTIVES WITHOUT COUPLED WHEELS OR HEAVY
DRIVING WHEELS."
Mr. John Wolfe Barry in his work on "Railway Appliances" says, pp. 30/32,—
The general requirements of permanent way are, that all its parts must be strong
enough to bear without damage the heaviest loads which are to come on the
line. The severest strains.to which the line can be subjected are determined by the
heaviest loads carried on any particular pair of wheels. In the case of lines worked
by locomotives the heaviest loads are on the driving-wheels of the engine, as,
unfortunately for the maintenance and renewal of the permanent way, the only
way by which up to this time the power of the locomotive has been applied to the
traction of trains is through the adhesion due to the insistent weight of the driving
wheels on the rails.
The weight on the driving-wheels of large engines, such as drag the Great
Northern express trains, is as much as 15 or 16 tons on a pair of wheels, or 8 tons
on each wheel when the engine is travelling steadily; and this may be much
increased when the engine is lurching.
This great weight is most damaging to the permanent way, and efforts are
made on most railways to get rid of the concentration of weight without giving up
any of the tractive force due to the weight by distributing the weight required for
adhesion over two, three, or four pairs of driving wheels coupled together. The
system of coupling engine wheels has, however, many disadvantages, and it is a
moot point whether it is less damaging to the permanent way than heavier con-
centrated loads carried on a pair of uncoupled wheels. A coupled engine does not
travel so easily as an engine with one pair of driving wheels, and the slightest
inequality in the diameter of the wheels coupled together produces a detrimental
action on both the wheels and the rails. Smali inequalities of the road produce
much more friction with coupled wheels than with single wheel engines, and thus
what is gained by a reduction of concentrated weight is more or less neutralized by
accompanying disadvantages.
It is much to be wished that some means may be found of applying the
tractive force of the locomotive through all or through most of the wheels of the

page_text: vehicles forming a train. If this could be satisfactorily accomplished, instead of
the permanent way being exposed to strains from driving wheels supporting from
10 to 16 tons on a pair of wheels, it would have to bear little more than the
strains due to the weights of the heaviest loaded trucks or carriages, which rarely
have more than from 3 to 8 tons on a pair of wheels. It would be difficult to
estimate the saving which such a revolution might effect in railway working
expenses (page 227).
A few words are necessary with regard to the weights which are carried on the
wheels of locomotives, as this matter is one which has a most important bearing on
the form and material adopted for many parts of railway appliances. The fact that
the tractive force of locomotives is almost invariably exerted through the adhesion
between the driving-wheels and the rails due to the weight of the engine, has been
already alluded to above (page 31), and the consequent concentration of weight on
one pair of driving wheels, or, as an alternative, the coupling of two or more pairs
of heavily loaded wheels has been there referred to, as a difficulty in working
railways which at present seems irremediable.
In the present form of locomotive the whole weight of the locomotive, whether
it be in motion or not, rests at all times entirely upon the rails, so that no part of
the weight of the locomotive ever acts directly to draw the train.
In the proposed new form of locomotive, the locomotive rests with its whole
weight upon the rails only, so long as it is not in motion with a train attached to
it. When drawing a train, as soon as the locomotive begins to move part of its
weight, instead of continuing to rest upon the rails, id est, upon the wheels of the
locomotive, ceases to be supported by them, and is made to assist in drawing the
train by acting directly upon the carriages attached to the locoomtive.
In order to accomplish this, it is necessary to make the locomotive not, as at
present, in one single body, but in two perfectly distinct parts connected with, but
wholly independent of each other, so that only the weight of one part shall always
be resting upon the rails, i.e., upon the wheels of the locomotive, while the weight
of both parts will only rest upon them when the locomotive is not drawing a
train.
For this purpose it is necessary to make the part, whose weight is to assist in
drawing the train, be supported on wheels or rollers resting on an independent
platform, which, in its turn, is to be suspended by strong chains (or wire ropes)
attached to the ends of the locomotive. These chains again pass over rollers or
pulleys at the ends of the locomotive, so as to allow the chains to be drawn
backwards or forwards without difficulty.
The ends of these chains are attached to cross-bars at the ends of the locomotive,
and the train of carriages instead of, as at present, being hooked on to the body of
the locomotive itself is attached to one of these crossbars.
In this manner, when the locomotive begins to move with a train instead of, as
at present, instantly and immediately beginning to draw the carriages of the train
after it, it first begins to drag the platform from under the independent part of
itself, which is loose. And as the locomotive drags the platform horizontally
forward it raises up the weight of the loose part resting on the platform. But
since only one end of the platform is attached to the locomotive itself, the other
end being hooked on to the train, in exact measure as the weight on the platform
is lifted by the forward motion of the locomotive off the locomotive itself, it is
made to rest upon the end attached to the train, which it then tends to draw
forward, and continues to do so as long as it remains supported by only one end of
the locomotive, i.e., as long as the latter continues to be moving in advance of the
train.
By this means far more of the weight of the locomotive acts in drawing the
train than when the whole weight of the locomotive rests entirely upon the rails,
since part of the weight of the locomotive is made to act directly in drawing the
train, being lifted off the locomotive itself, and made to rest upon the train.
In order not to have the weight of the loose part always resting upon the chains,

page_text: the platform may be made to rest upon a second set of wheels or rollers under-
neath it, attached to the frame of the locomotive.
The loose part supported on the platform may contain the supply of fuel, or of
water, or of both. It should be provided with springs to avoid jolting.
The platform and chains will require to be made of great strength, as they will
have both to support the weight resting upon them, and to draw the train.
"
Care to be taken in attaching the train of carriages, so as to avoid any tendency
on the part of the first carriage to "tip over in consequence of being over-
weighted at one end.
The difference between the form of locomotive now in use and the proposed new
form may be briefly summed up as follows:-
Instead of being made in one single body, the whole weight of which rests at all
times entirely upon the rails, the proposed form of locomotive consists of three
parts.
1. The frame of the locomotive containing the tractive power, the whole weight
of which always rests upon the rails.
2. The independent part which is loose and distinct from the frame, the weight
of which is to serve as motive power in drawing the train, and,
3. The platform with its attachments, only one end of which is to be supported
by the locomotive, and the other by the train.
The distinguishing characteristic of this Invention is that instead of letting the
weight which is to assist in drawing the train rest upon the rails, it is made to act
directly on the train by pressing upon the connection between the locomotive and
the train, like muscle on a tendon; whereas in the present form of locomotive, not
only does the whole weight of the locomotive itself always rest entirely on the
rails, but in addition the driving wheels are purposely made much more heavy
than they would otherwise require to be, simply in order to enable the locomotive
to draw the train.
At present the weights of the train and of the locomotive are opposed to each
other, both resting on the rails. In the proposed form of locomotive, the locomotive
will be able to act with far more energy to draw the train, for while the whole
weight of the train will continue to rest on the rails, part of the weight of the
locomotive, by being suspended between it and the train instead of resting on the
rails, will be held in the air, where of course it can act upon the train with
incomparably more power.