This article originally appeared in Farm Implement News, May 15,
1930. It was sent to us by Dwight Rhodes, R #2, Clifton, Kansas
66937.
Not so long ago, the following prophecy appeared in these pages:
‘One thing is sure; progress in general purpose tractor design
will come with the development of diverse but successful types,
rather than assuming that the overall design of the first machine
is the only design that can prove successful.’
One man can couple the tractor to the take-off operated
tool.
This statement was made with full appreciation of the remarkable
job that Bert Benjamin did when the Farmall was developed.
Now comes considerable fulfillment of this prophecy in the form
of the Massey-Harris general purpose tractor. It is the first
really engineered four-wheel drive job that the writer has ever
seen.
The designers of this tractor had the following requirements in
mind: It should be able to operate satisfactorily on any soil or
slope where a four or six horse team can work.
It should be adaptable not only to specialized tractor tools but
also to the horse tools that the farmer already possesses.
It should be light enough to be worked on plowed fields, the
soil of which may not be helped by packing, but have enough
traction to meet every demand of two-plow service.
Offhand, one might remark that these requirements make a rather
large order. But look at the Massey-Harris solution of the
problem.
They made the general purpose machine a four-wheel drive. Yet
they kept the advantages of three-point suspension without even the
restrictive effect of springs between the oscillating axle and the
frame. The rear axle can rotate around the longitudinal center line
of the tractor, and wherever the lugs of either wheel are
‘touching bottom,’ they are yanking away at dirt.
For quick response to steering, it was felt that the front
wheels, notwithstanding they also are drivers, should pivot just
like any standard steering wheels, and they do. The driving torque
goes through universals on the principle of those on a Cord front
drive.
Then to get all the theoretical advantages possible in
four-wheel drive construction, it was necessary to change radically
the normal ratio of weight on front and rear wheels. With rear
wheel drive machines, the static weight on the rear wheels will be
approximately 60 percent of the total, with 40 percent in front.
This static balance changes the minute the tractor begins pulling
so that weight in effect is transferred from the front wheels to
the rear. This is particularly noticeable in the case of a light
tractor pulling its maximum load, for so little weight may be left
on the front wheels that it may be difficult to keep the front end
going straight, except straight up.
With the Massey-Harris general purpose, the statement is made
that every ounce of its weight ‘is balanced over its four
wheels when a normal load is pulled.’ From this it can be
assumed that with the tractor idle, the greater proportion of
weight is in front, but when pulling, the torque reaction of the
lugs against the ground transfers enough weight to the rear end to
produce almost equal weight and lug grip to each of the four wheels
when they are pulling their maximum. This, it might be remarked, is
the only way to get the utmost possible advantage out of
four-wheel-drive design.
All this translates itself into positive traction, usable not
only when surfaces are good and when the lugs can bite, but also in
powdery peat and mucilaginous mud. And in row-crop farming, there
are plenty of peat beds to be plowed and fitted and plenty of low
spots that it is unhandy to swing around when the rest of the field
is in perfect condition for cultivation and the weeds and grass are
growing between the rows.
In adapting the general purpose to every variety of horse or
tractor tools, the designers approached the problem from two
angles.
First they worked out very easy controls, so arranged that
extensions to pulled equipment could be easily and quickly made and
when so made, the outfit would be just as responsive as a
well-trained team of mules, if not more so.
The other factor is ease and quickness of coupling the tractor
to a drawn machine. Sometimes when such a hitch is to be made, the
hired man is mending fence at the end of a 160-rod field. To call
him back to help couple the tractor means no fence fixed. But with
this Massey-Harris, one man can stand back of the tractor, lift the
drawbar of the implement, and with the other hand on the clutch
lever, edge the tractor back by inches so that hitching consists of
dropping in the pin when the holes mesh. One man can even connect a
tool with power take-off connection. Hitching the general purpose
to a regular two-row cultivator would be much quicker than getting
out three or four horses and hitching up.
How the Massey-Harris designers combined a strong two-plow
tractor engine, a frame, and a transmission train to four wheels,
and still keep the weight down to 3810 lbs. (which is what the
general purpose weighs) is something they probably will have to
explain when their friends in other companies get them in a corner
at the next A.S.A.E. convention.
The engine is a four-cylinder 4×4?’, L-head, governed at
1200 r.p.m., developing a maximum of around 25 HP, according to the
company. Our guess would be 26 to 26? HP if test conditions are
favorable and the engine happens to be a high tester. There’s
always some variation between engines of identical design. At the
drawbar, the general purpose ought to develop 17? HP, but she might
run up even as high as 20 if track conditions are favorable.
The transmission provides three speeds forward: 2.2, 3.2 and 4
mph, with reverse 2?. Two brakes are provided, one for each front
wheel mounted on the differential shaft. These will act as stall
preventers if one wheel should land in a mud hole with a soup
bottom. Clearance between axles and ground is 30 inches, wheelbase
51 inches, and tread 76 inches. The inside turning radius without
brakes is 6? ft., with brakes 3 ft., sort of pirouetting on the
inner hind wheel.
The belt pulley, which is detachable, has a 12-inch diameter and
6? inch face and turns 800 r.p.m. The power take-off is 545 r.p.m.,
and ends in a standard 13/8 spline
connection, with 11/8 spline furnished on
special order.
The extension controls to the seat of the drawn implement are
furnished as extra equipment, as are electric lights with generator
and battery, and electric starter.
The most appealing thing about this Massey-Harris general
purpose is not its beauty and cleanness of design, but its
reflection of the forward-looking mental attitude of the men who
set their O.K. on its production, and those men must be Thomas
Bradshaw at Toronto and Grover Weyland at Racine. It takes nerve to
depart from the blazed path of easy progress and to strike a new
trail even though one is confident that it will lead to a great
goal beyond.
This Massey-Harris G.P. offers proof that in the farm equipment
trade, competent designers dare do what they think is best, and
having done that best, find their work appreciated by management.
No industry will stand still, let alone retrograde, with that
viewpoint.