BRITISH SUBSIDY TYPE MOTORS
Early Subsidy Schemes--Amount of Subsidy--Standardisation of
Driving Control--Important Mechanical Features--Provision for
Working in Convoy--The “Chain-Drive” Controversy--The Present
Position.
In view of the peculiarly advantageous circumstances detailed in the
previous chapter, the British subsidy scheme is from the pecuniary
point of view less imposing, and from the practical point of view far
more comprehensive than any other scheme yet attempted elsewhere. The
British War Department favours in general the use of vehicles intended
to carry in active service useful loads of about three tons, but as the
machines also have to take four men and a considerable quantity of kit
and stores, they correspond to ordinary industrial vehicles of four
tons capacity. There is a parallel, but much smaller, requirement, for
30-cwt. vehicles corresponding to the ordinary commercial two tonner
and capable of higher speeds than are desirable with heavier machines.
These lighter cars are intended for use behind mobile and fast-moving
troops, while the heavier type are for the service of the infantry,
and for the carriage of ammunition supplies. In each case, the total
amount of subsidy paid is from £110 to £120. A portion of this takes
the form of a cash payment when the vehicle is accepted, while the
remainder is an annual payment spread over a period of three years,
and is conditional on periodical inspection revealing the satisfactory
condition of the machine subsidised.
The agreement also provides that in the event of the War Department
desiring to commandeer the vehicle in time of war, a very liberal price
shall be paid to the owner, this price being of course dependent to
some extent on the age of the machine. The correct amount is arrived
at by deducting from the first cost of the car a certain regular
percentage intended to represent the depreciation in value during every
half year of normal service. After this deduction has been made, the
resulting figure is increased by an agreed percentage of itself, the
final result being that the price paid for any car under about two
years old is very near, if not quite equal, to the original first cost.
The first move made in the direction of a subsidy scheme in Great
Britain dates back to 1908. At that time it was believed that light
steam tractors best filled military requirements, and a number of these
were registered, the nominal payment of £2 per annum being made to
their owners. The industrial petrol vehicle was at this time passing
out of its period of probation, and it was not long before the military
authorities came to the conclusion that it represented a more useful
type, in view of the nature of the particular emergencies against which
they were chiefly called upon to guard. The ordinary steam-propelled
vehicle was open to certain objections, the principle of which is the
fact that its carrying capacity of fuel and water is limited, and the
latter must necessarily be replenished at fairly frequent intervals.
This is no great drawback in commercial work, but might be a very
serious matter indeed in times of war, when men and horses have a prior
claim on a possibly limited water supply.
In 1911 a scheme of subsidy for transport and supply motors was
authorised, and in view of the fact that no such scheme could be
matured until it had been in force for several years, a provisional
scheme was temporarily adopted, under which total sums ranging from
£38 to £52 were paid to owners of vehicles generally of about three
tons capacity. The present subsidy scheme was finally put into force
in 1912 after the War Office experts had conferred on many occasions
with representatives of the leading manufacturing interests. The
main objects of the scheme are plainly stated in the War Office
specification as follows:
(1) To make the manipulation and control of all vehicles the same:
and
(2) To minimise the number of spare parts which must be carried
in the field, having regard to the number of different makes of
vehicles of which the transport columns of the army would be
composed.
As to the first of these two stipulations, one would think that there
could hardly be two opinions, though in point of fact it has been
argued in some quarters that no standardisation of driving control is
in any way essential. Such a view one imagines can only be held by
those who are personally so fortunate as to have that mechanical knack
which allows a man to take charge of any car, however different it
may be from those to which he has been previously accustomed, and to
drive it with perfect safety and efficiency even at night-time and over
unknown and bad roads. We cannot assume that every transport driver
possesses this instinct, and we must therefore agree that the object
aimed at by the War Department is one which deserves every support. It
is, in fact, worth while to go into a little detail on this point, in
order to show what care has been taken to make everything as easy as
possible for the driver.
First, as regards the hand control. The steering wheel must provide for
76° of movement of the front wheels of the car; that is to say, 38° of
lock from the normal position on either side. In reaching the maximum
lock, two complete turns of the steering wheel must be made. Thus, a
driver who is used to getting a certain effect by turning his wheel
through a certain distance, will find if he is put on to a subsidy car
of another make that the same effect is still produced by the same
amount of movement. This, of course, helps to make him immediately a
safe driver in traffic or at sharp corners. The four-speed change-speed
gear is operated by means of a lever in a gate. This gate must be
formed of two slots and two selectors, the reverse being a continuation
of the first speed slot. The hand-brake lever must be arranged to push
on, and must be well away from the change-speed lever and to the
right of it. Furthermore, the brake lever must be 6 inches longer,
and must have a plain cylindrical handle, whereas the change-speed
lever is finished off with a circular knob. Thus, any confusion
between these two levers in sudden emergency, or in the dark, is
completely prevented. The throttle and ignition levers must be placed
underneath and to the right of the steering wheel, their movement being
independent of any movement of the steering column. Increased engine
speed must in each case be produced by moving the levers forward. The
total movement must be 90°, and the handles must be at right angles
to the main axis of the vehicle when in the centre of their travel.
This, again, means that a driver who is accustomed to producing a
given effect upon his engine by a given movement of the ignition or
throttle is in no way confused by being put on to a different car. The
only point in which any variation in driving control is permitted is
in regard to the accelerator pedal, the presence of which is optional.
However, if a foot accelerator is provided, it must be so combined
with the hand throttle that on releasing the accelerator, the throttle
valve returns to the position set by the hand lever. The clutch- and
foot-brake pedals are marked C. and B. respectively, and the clutch
pedal must be on the left, the brake pedal on the right, the travel
in each case being about 3-1/2 inches. From these details it will
be seen how carefully every item in the driving control has been
considered, with a view to facilitating the work of drivers who may
have to be moved frequently from one machine to another. As to whether
the arrangement adopted is a good one, we have strong evidence of a
favourable character in the statement of Mr. J. E. Thornycroft, to the
effect that his firm has adopted the War Office system of control as a
standard for all their vehicles whether of subsidy model or not.
At a rather later date it may be well worth while to consider whether
experience has not demonstrated the possibility of combining with
a full subsidy scheme a modified scheme insisting only on vehicles
of the right load capacity, and the adoption of all details of the
standard control. In this way, if the true subsidy model continues to
be somewhat unpopular amongst commercial users, a very fairly adequate
reserve will be brought into being without any considerable trouble.
Turning now to the second of the two main points which the War
Department have attempted to cover, we find the fulfilment of the
scheme beset with much greater difficulties. Every attempt to
secure standardisation in the parts of vehicles of different makes
must necessarily entail expenditure by the manufacturers, both in
getting out new designs and also in arranging for economical workshop
processes. Such expenditure is only justified commercially if the sale
of the resulting products is sufficient to secure profitable trading.
Some allowance, of course, must be made for the added prestige accruing
to a firm licensed to build for the War Office, but this is in itself
insufficient encouragement. Consequently, every stipulation made with a
view to standardisation must be covered by subsidy grants, sufficient
to cover both manufacturer and user in respect of any additional cost
or disadvantages in operation. The War Department has recognised the
impossibility of asking for complete standardisation, and so killing
the individuality of different types of vehicle. The tendency of any
such process would be to throttle normal competition, and to prevent
progress. Consequently, standardisation can only be attempted in
certain respects where it appears for one reason or another to be
highly desirable. For example, radiators are notably liable to damage,
and consequently the connections of the radiator to the machine are
standardised to allow of ready replacement of this essential as a
whole. The radiators are mounted on trunnions, the bearings of which
are in halves, and the positions and dimensions of inlet and outlet
connections are definitely fixed. As an additional safeguard, a stout
cord in the form of a bar or tube has to be placed across the front
of the radiator. The engines are not standardised except in certain
details, as, for example, the method of fastening on and driving
the magnetos, which are arranged with a view to rapid removal and
replacement whole. No high degree of standardisation is possible
without incurring great expense and other disadvantages so far as
concerns the design of the clutch and the change-speed gear, though the
ratios of the latter are determined for reasons which will be explained
later.
As regards final drive, some degree of standardisation is possible so
far as the axle arms and bushes are concerned. The bearings of the
front wheels are standardised so as to make the wheels interchangeable,
and the diameters of both the front and rear wheels are fixed. Makers
and users are left with a fairly free hand as regards the type of
body to be fitted to a subsidy machine, but in general this must be a
lorry body with detachable sides and ends at least two feet high, and
carrying a frame to take a complete overhead cover. Use is also found
for a certain number of box vans.
Many provisions are made in the subsidy scheme with a special view
to making the vehicles suitable for working in convoy. In the first
place, it is stipulated that all engines shall be fitted with governors
which shall automatically control their speed to 1,000 revolutions
per minute. This prevents drivers from racing their engines and
over-speeding their cars when running light, and also determines a
definite top speed, which should be almost exactly equal for all
subsidy machines, as it were. Coupled with this, are the provisions as
regards change-speed gear. The engine governor having limited the speed
of the 3-ton type to 16 miles per hour, and the speed of the 30-cwt.
type to 20 miles per hour, the next step is to secure that, when road
conditions require the use of lower gears, the whole of the vehicles
in the convoy will need to change gear practically at the same point,
and when on lower gears will run practically at the same speeds. With
this object in view, it is stipulated that the ratio between top and
bottom gear shall be about five to one, giving bottom speeds of about
three and four miles per hour respectively for the two classes. This
provision, taken in conjunction with the stipulated engine dimensions,
should secure that every vehicle is capable of tackling a gradient of
one in six on normal road surface whether fully loaded or empty. It
will be seen that the point kept in view has been the desirability of
arranging everything so that drivers of a large number of machines
working in convoy--that is to say, running along the same road at short
intervals behind one another--shall not have any difficulty in keeping
their proper distance, and so in preventing any risk of collisions.
For similar reasons the fitting of a ground sprag is made compulsory.
The object of the sprag is to prevent a vehicle from running backward
if, for example, the driver misses his gear on a steep gradient. The
fitting is not necessary on ordinary commercial machines, since the
brakes will almost certainly hold the car before it has run more than
a few yards, but in the case of one vehicle in a long convoy, those
few yards may mean a collision with the following car, and a hopeless
muddle causing serious delay. In view of the possibility of some one
car failing, every chassis has to be fitted with towing hooks at
the ends of the side members of the frame fore and aft, so that each
machine can, if required, either be towed or tow another, and any “lame
duck” will not obstruct the whole convoy, but can be dragged along to
some point where it can be towed out of the way, and the rest can be
allowed to proceed.
Other points in the scheme have in view particularly the fact that
the machines must be required to operate on very bad and possibly
on very hilly roads, and may even be needed to make detours across
country when roads are destroyed or entirely blocked. The chief points
in this connection are the provision of high ground clearance, which
must in no case be less than 12 inches, the stipulation as to size
of wheels, which are rather larger than usually found on commercial
vehicles, and various stipulations ensuring adequate protection of
the mechanism from mud and dust. Generally speaking, these provisions
constitute one of the principal difficulties in making the scheme
successful, principally for the reason that large wheels imply
a rather high loading platform, and this is objected to by many
commercial concerns on the ground that it makes loading and unloading
more difficult. On the other hand, larger wheels are better for the
roads, and consequently it is within the bounds of possibility that
trading concerns will presently be compelled by law to put up with
their disadvantages. From the point of view of motor users in the
Colonies, high ground clearance and large wheels are very valuable and
even essential features. Consequently, the subsidy scheme works in well
with many Colonial requirements, and manufacturers whose machines are
accepted by the War Department probably depend for success of the type
to no little extent upon the likelihood of orders from abroad.
[Illustration: _“The Autocar” photograph._
SAURER MOTOR FIELD KITCHEN.]
In the interests of the proper guarding of the mechanism from mud and
dust, the experts of the War Department have considered it necessary to
stipulate that all cars must be driven on the live-axle system either
through bevel or worm gear. In the first instance, only the former was
accepted, but more recently the worm drive, as exemplified by the
products of its pioneers, Messrs. Dennis Bros., has met with approval.
The point to be noted is that the chain drive--which, in the opinion
of many manufacturers and also of many users both at home and abroad
is unequalled for heavy work--is definitely debarred. Considerable
antagonism to the scheme as a whole was thus created, and one is forced
to the conclusion that the reasons for refusing the chain drive were
not solely connected with the question of protecting from mud, but were
possibly more concerned with the fact that, while a chain drive is
probably quite as economical in maintenance as any live-axle drive, it
requires rather more frequent adjustments and attention, and possibly
small renewals.
In commercial practice, this consideration carries little or no weight,
but on active service a breakdown is none the less serious because it
is caused merely by a breakage to one link in a chain and not by the
entire dislocation of the whole transmission gear. One gathers that, at
the present moment, chain-driven machines are in fact being used in
the service of the British Army, and in the interests of the success
of the scheme in the future, the hope may be expressed that practical
experience will show that any fears as to unreliability of this type
of transmission from the military standpoint will prove entirely
groundless.
When the great war broke out, the position was briefly as follows.
The subsidy scheme had not been in force for a sufficient length of
time to secure through its means the complete fleet required. The War
Department itself owned upwards of one hundred lorries of subsidy
type, and a limited number were to be found in civilian service. Among
these, the Leyland, which was the first type accepted for subsidy,
was probably the most prominent. It has been necessary, therefore, to
depend not only on a supply of machines of subsidy type, but in the
first instance on the requisitioning of other cars of suitable load
capacity, and more lately on the steady purchase of new vehicles of
types which, if not according exactly to the subsidy requirement,
approximate to it sufficiently to secure reasonable facilities for the
easy repair and maintenance of the machines of the transport and supply
columns, both of our existing Expeditionary Force, and also of the new
armies now in course of formation.