First sold in 1958, The David Brown 950 Implematic was the tractor manufacturer’s flagship model until 1961. It was a brief run, but it would be remembered as one of the best tractors David Brown ever made. David Brown was the tractor brand of choice on our family farm until the company was subsumed by J.I. Case in the 1980s.
Whilst rummaging through some old family papers, I discovered a catalogue for add-ons, or ‘accessories’, that were available for the David Brown 950 from the dealer. Some of which are equipped on our David Brown 950, which is an exhibit in the St Winnow Barton Farm Museum. I’ve seen a lot of 950s equipped with some of the weight and ballast accessories, but I haven’t seen many of the others.
The catalogue provides descriptions and illustrations for twenty David Brown manufactured add-on modifications. As the catalogue’s foreword states;
“It is acknowledged that the DAVID BROWN 950 tractor has the most comprehensive specification offered by any manufacturer. Occasionally however, additional equipment is required to further increase the versatility of the tractor, thereby adding to it’s earning power.”
I’ve included the illustrations from the catalogue below. The overarching categories are my own, not David Brown’s.
David Brown 950 weight and ballast accessories
Front wheel ballast weights
With the emergence of four-wheel drive came heaver front-ends, adding weight and ballast to the front of the tractor. However, back when everything was two-wheel drive and light at the front, it was common for heavy rear-mounted implements to cause a lot of lift.
From the catalogue:
Front wheel ballast weights are required to maintain positive steering when your tractor is operating with a heavy implement attached to the rear linkage. Weighing 95lb each, they are available in standard sets of two and if required two weights can be fitted to each front wheel.
Rear wheel ballast weights
Pre-four-wheel drive, lack of traction could be a huge hinderance. Adding weight to the rear wheels was intended to improve this.
From the catalogue:
In operations entailing heavy drawbar loads such as muck spreading which often has to be done in wet, heavy-soil conditions, maximum tractor wheel adhesion is a vital requirement to the tractor driver. Rear wheel ballast weights are an invaluable asset in these conditions and will substantially reduce any tendency of drivewheel slip.
Front frame extension ballast – Chassis ballast weights
Whilst more weight could be added to the front wheels, this was another option for adding weight to the front.
From the catalogue:
This set of permanent chassis ballast weights totalling 120lb. is specially designed to rest in the frame front extension well forward of the engine.
13″ x 28″ rear wheel rim and centre
Less-so for traction, fatter rear wheels spread the tractors weight, leaving reduced wheel marks on soft, tilled land.
From the catalogue:
Improved performance with reduced soil packing is a feature of the wider (13 in. x 28 in.) tyre which can be fitted as an alternative to the standard 11 in. x 32 in. rear tyres.
David Brown 950 engine management accessories
Downswept exhaust system
Whilst suitable for the road, a downswept exhaust is not ideal on the farm. Other vintage tractors in the farm museum have a similar exhaust, and it doesn’t take much to get them clogged.
From the catalogue:
A downswept exhaust system is available complete with silencer and fixing brackets for both the diesel and the gasoline/kerosene versions of the David Brown 950 tractor. This item is particularly useful where considerable road work is involved, and where a quieter exhaust is required.
Radiator blind
Quite a common addition to vintage tractors, but being fabric, they often perish over the years.
From the catalogue:
To maintain the exceptional fuel and maintenance economy of your David Brown 950 tractor it us most essential that the power unit should operate at its most efficient working temperature. In areas which have prolonged low seasonal temperatures this can prove difficult without some mechanical aid and can cause increased fuel consumption, oiled-up plugs, excessive bore wear, and sump oil dilution.
Air cleaner extension pipe
Apparently this kept the air intake up out of dust clouds and so on, however I can’t imagine this making too staggering a difference.
From the catalogue:
Dusty conditions and certain types of crop spraying can seriously interfere with the normal functioning of the air cleaner, necessitating frequent changes of oil in the bowl. Failure to do this when working in such conditions must inevitably cause damage to the internal working parts of the engine. The air cleaner extension pipe raises the pre-cleaner and facilitates the intake of clean air from above the dust clouds.
Foot operated engine control
Hand throttles are essential for tractor driving, but it can be staggering to think foot throttles didn’t exist for so long. Even later David Browns like the 995 had foot throttles as standard, but they left a lot to be desired. Yes foot throttles are essential for road work, but they can be a lot of help in the field too.
From the catalogue:
If your tractor is frequently required for road haulage a foot-operated throttle control will provide easier control necessary to meet the variable road conditions. This foot unit inter-couples with the hand throttle control linkage so that either can be used independently.
David Brown 950 operator oriented accessories
P.T.O. and belt pulley guards
Isn’t it hard to imagine a time when tractors could leave the factory without this sort of thing. I suppose there was no plastic cover on the PTO shaft either and if it got hay wrapped around it, there was no need to stop the drive to remove it?
From the catalogue:
The agricultural power take off regulations 1957, stipulates that all tractors must be fitted with a suitable PTO guard as part of their standard equipment. This guard which must comply with British standards specification must always be in position when the PTO is in use.
Tractormeters
I had to drive my Zetor Crystal without a working rev counter for much of last summer. Once I fitted one I saw just how far off the correct revs I’d been working. I wonder if tractor work was such a guessing game with the David Brown 950.
From the catalogue:
Tractoremeters are available for all David Brown 950 gasoline/kerosene and diesel tractors. the meter indicates engine, P.T.O. and belt pulley RPM, also road speed in each individual gear graded in MPH (or KPH). In addition engine running time in hours based on an average RPM is also recorded.
Power-operated steering
Probably the most advanced add-on on this list as the dealer was required to fit it. Early loader tractors were seriously hard work to manoeuvre around the yard. It would be fascinating to drive a 950 fitted with this modification.
From the catalogue:
If your David Brown 950 carries a front loader, earth-moving equipment or a heavy front mounted implement, power-operated steering will reduce driver fatigue to a minimum. This unit consists of a self-contained belt-driven hydraulic pump mounted forward of the engine, coupled to a double-acting hydraulic ram mounted on the frame and acting directly on the steering lever. This unit can be readily fitted to your existing David Brown 950 by your dealer.
Rear number plate light
Another modest modification that I thought was fitted as standard, perhaps this was only on later David Brown models.
From the catalogue:
A necessary piece of equipment for the road user. Complete with lead, clip and bracket the number plate light unit attaches to the rear of the bucket seat by means of screws.
Horn, mirror and license holder
Not quite twin beacons, but it’s a start.
From the catalogue:
Here are three accessories which are especially useful where the tractor is used on the main highways. Fixed to the near-side tank support-plate the horn is complete with horn push, leads and fixing screws. The mirror with backplate and screws for fixing to the near off-side portion of the tractor bonnet. The licence holder can also be fixed to the near side of the tractor bonnet.
David Brown 950 linkage and drawbar modifications
Pick-up hitch
Easily taken for granted, the pick-up hitch has not always been a fixture on tractors. I enjoyed seeing the original solution for preventing trailers from lifting out of the hook.
From the catalogue:
This time-saving, quick-action, power-operated hitch greatly simplifies hitching operations. When the hydraulic lift is lowered the jaw of the hook opens and the tractor can be hitched up to the trailer or implement without manual effort. Raising the lift automatically closes the hook and by engaging the locking bolt prevents unhitching wile towing is in process.
T.C.U. trailer drawbar
A uniquely David Brown solution, the traction control unit (T.C.U.) transfers weight from the implement to the tractors rear wheels by sending a adjustable pressure to the lift cylinder. Don’t ask me how it really works, but apparently it does. This feature was ultimately subsumed by four-wheel drive.
From the catalogue:
This special drawbar and linkage designed to enable the David Brown farm yard manure spreader and Pettit trailer when fitted with T.C.U. attachment to take advantage of the well-known David Brown traction control unit system.
Linkage drawbar
We’ve all seen vintage tractors equipped with this type of drawbar. Fortunately these are obsolete now that pick-up hitches are so prevalent.
From the catalogue:
This simple quick-hitch drawbar is secured to the ends of the lower links by pins and is intended primarily for light work.
Stabilizer bars
We take stabilizers for granted these days. Whenever I pop an implement on the back of an older tractor, I wince every time the load swings wildly from side to side. Up the stabilizers!
From the catalogue:
Designed to eliminate undesirable side-movement of the implement. These stabilizer bars can be fitted to make the linkage which normally floats laterally, rigid.
David Brown 950 hydraulic modifications
External three-way hydraulic valve
From the catalogue:
This valve provides for a forward and rearward operational take off in addition to the in-built power lift. The flow of oil from the pump is diverted from the in-built hydraulic cylinder and is taken directly into the valve body. By selection of one of the hand wheels any one of these three services can be operated independently. The valve is complete with the rearward take-off pipe and a quick release “exactor” self-sealing coupling. Operation of auxiliary equipment brought into action by these means is controlled by the hand-control lever mounted to the R.H. mudguard.
External isolating one-way valve
From the catalogue:
This one-way valve isolates the in-built power lift-cylinder and diverts the fluid to an external take-off point. It is available with one rearward connection pipe and a quick release “exactor” self-sealing coupling or alternatively with a forward connecting pipe with the coupling optional. The auxiliary equipment operating through this valve is controlled by the power lift hand-control lever mounted to the R.H. mudguard.