In 1898 David Brown began to manufacture machine cut gears and in 1902 they moved to the current site in Huddersfield at Park Works. David Brown died in 1903 and his sons Frank and Percy succeeded him and began to produce self-contained worm gear units complete with bearings and shafts.
1913 saw the company's first overseas venture when Timken-David Brown was established in the USA to manufacture worm gear units. World War 1 saw the number of employees at Park Works increase from 200 to 1000 as the company began to manufacture main propulsion units for warships, gun training and elevating mechanisms and trench mortar bombs. By 1921 the company was the largest worm gear manufacturer in the world.
Worm gears are a compact means of achieveing high gear ratios between input (worm) and output (cog) , and have the advantage that they are self braking (meaning that the output shaft cannot drive the input shaft.) This makes them ideal for heavy duty control applications, such as jacking or lifting, but this comes at a cost. The worm gear has a greater area of contact with the driven cog then other gear systems. The contact pressure is also greater then in individual units of multi gear systems achieving the same overall gear ratio. The result is the generation of heat, which can damage vital components. This is a problem for designers of machinery who need gearboxes to run continuously with a variable load when space is restricted, such as conveyors in mines. David Brown solved the problem with the development of the Radicon worm gear in 1933. The name Radicon refers to the dissipation of heat by Radiation, Conduction and Convection. These gearboxes can safely work at up to 100C and can be adpated to work at even higher temperatures. They had produced 1 million of these units by 1968, and in 2012 a huge range of Radicon gearboxes are still being made with variants suitable for most industries all over the world.
In 1935 David Brown patented the Merritt-Brown controlled differential steering for tank transmissions. Previously most tracked vehicles had been steered by stopping the track, on the side to which the driver wished to move, by using a system of clutches and brakes. However, while this worked well on flat ground, the direction of steering became unpredictable on slopes, The problem was that as soon as one track was declutched the vehicle would tend to run downhill on that side. The problem was worse when heavy trailers were being towed or the brakes were worn. (Going up hill there was a risk of severe oversteer, while going down hill the vehicles would turn in the opposite direction to the drivers intentions. Later clutch and brake systems were improved to overcome these problems and were claimed to save energy compared to the differential system) However the brake controlled diferential is a much more satisfying solution as engine braking is maintained to both tracks whatever the state of the steering controls. Tracked vehicles became safe to use on slopes, and full advantage could be made of their natural stability and high ground contact area.
The first David Brown/Ferguson tractor was produced in 1936. During The Second World War the aero division produced over 500,000 gears and the gearbox division over 10,000 tank transmissions. David Brown acquired Aston Martin in 1947 and Lagonda the following year. In 1959 Aston Martin won the world sports car championship which included Le Mans and the third successive win at the Nürburgring.
In 1972 Aston Martin-Lagonda was sold to Company Developments Ltd which was later owned by the Ford Motor Company. The David Brown tractor interests were sold to Tenneco International (Inc.), becoming affiliates of J.I. Case, also in 1972.
David Brown is now part of an international group involved in producing power transmissions for Mining, Power Generation, Renewables, Oil & Gas, Rail, Metals, Defence, and other key Industries including: - rubber, sugar processing, cement, materials handling, port equipment and cranes, marine test rigs, water treatment and water transportation, pharmaceuticals and chemicals, pulp and paper, and specialised heavy automotive. Modern David Brown gear boxes are produced to suit all applications from 1hp up to the giant transmissions used in Naval Destroyers and Liquid Natural Gas Tanker Ships
Most David Brown Tractors were built at Meltham.
Few, if any , tractor manufacturers can equal the David Brown record of pioneering achievement in tractor manufacture and development. Major examples are:
David Brown Tractors were also awarded the Queens Award to Industry for Export four times, and the Queens Award to Inustry for Technological Achievement, as well as a host of awards from major Agricultural Societies
The VAD12 stands for "vehicle Agricultural Diesel 12 Bhp" After the Second World War, David Brown wished to persuade farmers who were still using horses to try tractors, and decided to produce a light tractor for this purpose. They studied two tractors which seemed suitable, namely the Massey Harris Pony and the Allis Chalmers Model G. After considering these two tractors they decided to use the Allis layout, with the engine at the back, but retained the possibilty (from both tractors) of mid mounting implements. Rather then using the Allis's D-Shaped frame, they produced a skeleton frame, with a single beam connecting the back and front axles. This would improve the drivers view of the implements and, and also making attaching and removing implements easier.
The main criticism of the Allis Chalmers was that its small petrol engine produced little torque, and stalled under the heavy loads required for ploughing. Initially David Brown fitted the prototype with a 4 cylinder Ford engine, but found that the heavy weight extending behind the back axle unbalanced the tractor causing it to rear up. They then tried buying in some two cylinder diesels, whose centre of gravity would be much closer to the back axle while still producing adequate torque. Unfortunately the vibration of these engines so close to the drivers seat proved to be unacceptable, and so they set about designing their own engine. The resulting 2 cylinder air cooled diesel engine, with a heavy flywheel to maintain torque and a dummy piston to reduce vibration, proved to be very reliable, economical and well up to the job of ploughing. The engine produces 12BHP at the rated PTO speed of 1500rpm, and 14.1BHP at the maximium speed of 1800rpm
Sports car enthusiasts may be interested to know that the clutch used on the David Brown 2D is the same type as the Borg and Beck used on the 125HP Aston Martin DB2. Although you don't quite get the James Bond experience when using it, it is a very smooth and controlable clutch that performs very well on a light tractor. The clutch drives a 4 speed (plus reverse) David Brown gear box giving speeds of 1.64 mi/hr, 2.77mi/hr, 3.83mi/hr, and 7.68mi/hr at rated engine speed of 1500rpm rising to a maximum of 9.25mi/hr at 1800 rpm.
The next problem faced by the designers was the implement lift. The Allis had used a mechanical linkage powered by the driver, but with 12HP to use and ambitions to plough, it was thought that some sort of assistance was desirable. At first they tried spring assistance, but this proved to be rather too exciting for the test drivers, and a search began for hydraulic systems. However all the systems found that were suitable for just 12 HP were found to leak, and this was thought to pose a risk of crop spoilage. In the end they settled on the pneumatic system that was used on all the production tractors.
The pneumatic system can, in theory, lift almost three quarters of the weight of the tractor, but as it lifts in the middle of the tractor the machine is always in balance and no ballast weights are required. This meant that in spite of its meagre 12HP this little tractor could operate many implements that were designed for much more powerful conventional tractors. Not only is the basic layout efficient but David Brown were able to save weight by using the central chassis member as the pneumatic resevoir. Not only that, but a Schrader valve allows the tractor to power a whole range of machinery in the field, that would normally be restricted to the workshop. And, what's more the DB2D is also fitted with a standard PTO shaft. The PTO is driven from the output of the gear box, and so only "ground speed" is available, though at rated engine speed of 1500rpm PTO speed is 642rpm, with the tractor in second gear
The tractor was introduced at the 1956 Smithfield Show to great acclaim by the industry and particularly the academics. Claude Culpin, of the National Institute of Agricultural Engineering, and author of the, much reprinted, agricultural machinery "bible" of the 1960s and 1970s called it "the first succesful Systems Tractor", by which he meant a tractor that was designed to allow implements to be attached at various points, not just at the rear. Just think of the systems tractors that have been built since! The list might include Unimogs, MB tracs, Deutz and Fendt tool carriers, the American Fox Rivers unitary harvest tractors, Dowler Giants, and even JCB Fastracs. And what about the miriad of self propelled sprayers and spreaders, many of which have a simple base vehicle to which many diferent bodies can be attached? The point being that David Brown, through the little 2D showed engineers that there was more then one way to design a tractor.
At the time of its launch, there was a European tractor with a similar layout. This was the Lanz Alldog which had a single cylinder water cooled 12HP engine and hydraulic lift. It also had a rectangular frame. The cooling water, the hydraulic lonkage and the square frame all added to the weight of the machine, which was described as underpowered, and it was withdrawn from manufacture within two years of the introduction of the 2D. However, as we will see its production run of just over 2000 units wasn't at all bad, and found success mainly as a light on/off road transport vehicle, as it could both carry a load and tow a trailer.
Allis Chalmers were forced to improve their product, and the many variants of the Diesel model G vastly outsold their British and European competition.The Massey Harris Pony did not survive the merger with Ferguson, but had already sold perhaps 20,000 machines.
Meanwhile David Brown failed to impress the horse farmers, who believed that their horse drawn implements would be pushed by the 2D, as they would be mounted in front of the driving wheels. (Although many farmers kept their horses for excellent reasons, others appeared to be incapable of understanding that implements were actually being pulled from the front axle of the DB 2D.) However, market gardners loved the 2Ds. The implement linkage could be split so that a left handed plough could be used while going in one direction and a right handed plough in the other. This left nice level seed beds, without the need to mark out lands, and the short wheel base of the tractor and mid mounted ploughs meant that the headlands were very narrow, and could be left as access paths. This was before the era of reliable herbicides and so weed control was done by hand, or was a two man job using a cumbersome tractor mounted steerage hoe. Steerage hoeing was always very stressful as the tractor driver would be driving in straight lines and minimum speed, while the hoe operator felt that his sharp hoes were roaring past delicate and valuable crop plants at 100 mi/hr. Operating the hoe was also physically exhausting. So while the hoe operator was going frantic the driver was going to sleep, and when the tractor veered off course a shout from the hoe operator would result in a course correction that would initially plough out a yard of crop plants. Some good friends of mine refused to speak to each other for a fortnight after an afternoon with a steerage hoe! The 2D layout meant that steerage hoeing could be done by one man, without any of this stress. Not only was the driver fully occupied, but any steering corrections took the hoe in the right direction!
On two ocasions I have been told, by very prosperous looking gentlemen, about the affect 2Ds had on their lives. In both cases the story went along the following lines, " During the war the whole family had struggled to make a living from tiny market gardens, but things changed when Dad bought a 2D. The uncles and aunts went and got proper jobs in the cities, the children stayed on at school and eventually went to University. Dad ran the Market Garden on his own, until he bought more land and started employing staff. We owe our fortune to the 2D" With fans like that the 2D soon dominated the market for horticultural tractors. Hundreds were sold in the London area, in Evesham, the Fens and also in Holland. A lot also went to Africa. However, after a year or two this specialist market became saturated, and David Brown had to spend time desiging special versions for almost every sale. They designed a special long wheelbase one with a low carrying frame for a fruit grower to drive under apple trees so that the fruit could be picked straight into boxes. There were a variety of industrial versions, but perhaps the strangest of all was a Naval version with a very short wheelbase and which carried about a ton of extra weight. These were used to manouvre aeroplanes on the deck of aircraft carriers.
After about 5 years the decision was made to suspend production, after just 2008 tractors had been built, and that after designing a new engine specifically for the tractor! However the 2D was in no way a failure. As Claude Culpin had predicted the 2D was a very important design. It was also very well built, and many were still working 30 years later. In fact survivors are are still in demand for steerage hoe work on organic farms. The 2D was one of those small machines that you felt would never let you down, and a 2D driver I spoke to who would drive 6 miles to and from big East Anglian vegetable fields. said that the only thing it lacked was a cab! In spite of endless prompting I could not get get a criticism out of him. Needless to say such reliable and well designed machines influenced the planning of the farms and gardens they worked on, and when the tractors eventually died people would build their own replacements.
One such was Evenproducts from Evesham who have a large market garden to demonstrate their horticultural irrigation systems. Their replacement for the 2D (built in the 1980s) demonstrated the innovative attitude diplayed by the David Brown engineers. The Evenproducts 2D replacement has the same external dimensions, and similar power. But it has a square frame similar to the Lanz Alldog, except that its is made of light alloy. The lift is different too, being electrically powered and designed so that it can be bolted onto a variety of mounting points around the main frame. I have also heard of people replacing David Browns with heavily adapted tool carriers made by Bean a decade earlier. But my impression is that the 2D was the tractor everybody wanted.
During the DB2D production run David Brown built many implements for the tractor, including ploughs, mowers and other powered machinery. They even built handheld pneumatic hegetrimmers driven from the tractors compressor via the shcrader valve. It could handle most hoes and light secondary clultivators up to 10 ft. I have seen machines with spring tyne cultivators. The set up I used most often was a tool bar with 4 Webb cell wheel sugar beet seeder units, and a Horstine Farmery chemical applicator mounted above the main chassis member
The Glyn-Coch DB 2D started work at Wisbech in Cambridgeshire in 1959. By the early 1970’s it had found its way to Rothamsted Experimental Station where it was used by a team studying the biology and control of eelworm. Eelworm, (also known as nematodes or aschelminths), are microscopic roundworms, and the species they were interested in were those that live on the stems and roots of crop plants. At that time eelworm were very serious pests and, for example, an infestation in a potato field would mean that the crop could not be grown in that field again for at least 8 years. For a potato farmer who had invested in a chitting house, potato planting and growing machinery, a harvester, and a warehouse, this was a very serious problem indeed. But eelworm affect most agricultural crops, and not much was known about them, at that time. Many farmers coped by bringing in contractors to sterlise the soil, typically with methyl bromide. This was quite drastic action, destroying much of the soil fauna and flora.
The Rothamsted team (lead by Dr Alan Whitehead) would visit farms as soon as possible after they heard of an infestation and would take soil and crop samples back to the laboratory. In the lab they would search the samples for eelworm, and then set up cultures of the species that seemed likely to be doing the damage. This was not an easy task as there many species of eelworm, and most of them do not damage crops. Having obtained cultures of candidate species they would then find a suitable site for a field experiment.
Generally a farmer, or the Rothamsted farm staff would plough and carry out the intial cultivation of the site, and then the David Brown 2D would be used to inject methyl bromide soil sterilant into deeply rotovated soil. THis would be covered with polythene to seal in the sterilant and left for it to work. When the soil was ready small plots in the sterilisd area would be innoculated with the eelworm culture and the crop planted using the David Brown 2D. During the growing season the plots would be monitored. and at harvest assessments would be made of the damage made by each of the test species of eelworm. These experiments were repeated annually for three years to ensure that the results were not biassed by unusal weather.
Once the team knew which the important species were they could test chemicals in the lab against sub samples of the eelworm cultures. The aim would be to fiind chemicals which were reasonably safe to use, and would only kill the pest eelworms. When chemicals were found that approached this ideal they then used them in field experiments similar to those described above, except that now, there was no need to sterilise the soil first.
The next stage was to carry out trials to optimize the time of application and the ammount of chemical used, balancing affectiveness and environmental safety. They also looked for chemicals that could specifically attack the pest species, leaving the more benign eelworm species unharmed. Part of this process was to look at chemical placement, as the pest species of eelworm can only move about a centimetre during a growing season. For wide row crops, such as potatoes and larger root vegetables etc it was not necesssary to treat all the soil. Leaving untreated soil between the rows would leave a natural population of pest species to maintain the diseases they suffered from These diseases would be available to attack the natural population of pests in the following year, so that less chemical needed to be used.
Dr Whitehead's team started designing improved chemical placement tools, and when it came to testing the tools the DB2D really came into its own. The engineer on the team, David Tite was also the driver, and from the driving seat he could watch the soil flowing round his latest protoype and see where the granules were going. This enabled the team to rapidly improve the prototypes until they got to a state where they thought that commercial development was possible. They asked a local ebgineer, Horstine Farmery to take on the project, and shortly afterwards his company was taken over by the very large multinational chemical company Union Carbide, who adopted the Rothamsted Fantail Applicator as their worldwide tool of choice for applying their soil applied nematicides.
The DB2D also had another advantage for the test team, and that was its relatively small size and light weight. Almost every county in the UK has a different eelworm fauna, and this meant that the field experiments had to be repeated all over Wales, Scotland and England. I seem to remember that the little tractor even got to Northern Ireland some times! The DB2D is the ideal size to tow behind a Landrover, and most of the equipment needed for a trial could be packed on the trailer, under the implement lift. So if you think that you have already seen this tractor visiting a farm near your home, then you probably have!
When Union Carbide adopted the fantail applicator, the powers that be decided that the team had done all the work that was needed on the control of eelworm, and started to wind the project up. Each time a member of the team was promoted there was no funding to replace them, and eventually they ran out of tractor drivers. Meanwhile, I had been managing another field team, and Dr Whitehead ask if I could lend him a driver. By that time, the DB2D was looking rather old fashioned and my colleagues didn't want anything to do with it. However I remembered it as a very interesting tractor when I was a student and volunteered to do the job myself. So for about three years I would spend one or two happy days drilling plots for this remarkable team. Alan Whitehead was known as quite a fussy scientist (which no doubt contributed to his success) so it is just as well that I had total faith in the tractor, and could concentrate on doing what was required.
At his stage Alan was working on biological control of eelworm, and having covered most of the major crops, potatoes, sugar beet, oats, beans and many others, was now working on forage legumes such as clover and lucerne. He had made cultures of the crop's main eelworm species, and used them to culture the bacteria that attacked them. When I was working with them the team were inoculating the plots with cultures of bacterial spores instead of chemicals. The advantage of using bacteria is that some species of bacteria have a single host, that is to say that they only attack the one species of nematode. This is really the ultimate form of pest control. However biological control is very dependant on weather and other environmental factors. It is no good applying a biological control if an amaoeba you had not noticed comes along and eats it all up, or if rain washes it away before it has had time to work. Developing biological control takes a lot of research, which British Tax Payers (you and I ) are not prepared to fund, and they need much more scientific input in individual farmers fields to put into practice, then consumers are prepared to pay for. But thanks to the work of people like Alan Whitehead, David Tite and their colleagues we have basic information on which others can build, when the public once learn to value their food supply.
Three years after my last outing with the DB2D I was hard at work in the lab when I heard a lot of crashing and banging in a nearby shed. Looking out of the window, I saw people throwing scrap metal on top a familiar red shape, which was still just visible. I would like to say that I flew into action, but those who know me would agree that I never fly, but to cut a long story short, I soon found myself having to buy a trailer to take the tractor home, and then had the problem of working out what on earth to do with it!
As I have said, this is a tractor that inspires confidence, but that is not to say that it is not a querky little tractor. Although it has most of the controls of other tractors of its time, their layout is quite unusual, the view from the drivers seat is quite diferent, and, as I write this, it occurrs to me that this tractor feels remarkably stable.
When I demonstrate the tractor, I explain how much one has to love tractors in order to start a DB2D. It has an electric starter, and a manual decompressor. However the controls for these are out of my reach from the driver's seat, and on opposite sides of the engine. So I have to put the gearbox in neutral, set the manual governor control to a mid setting, get off the tractor and walk to the rear where I use my left hand to operate the decompressor, and bending over the bonnet find the starter button by looking through the hole on the bonnet through which the air intake passes and reach round the outside of the bonnet for the button with my right hand. (Imagine hugging the tractor.) Once the engine starts turning I drop the decompressor and and as soon as the engine fires release the starter button. In case the tractor is still in gear the designers kindly put the emergency stop button at the back of the tractor, over the trailer hitch.
Returning to the drivers seat the dual brakes (and conventional parking ratchet) are in the conventional position on the right, the clutch pedal is also conventionally on the left. The gear lever is outside your left knee and the governor control lever extends forward from the engine, terminating by your left elbow. The compressor (which can get quite hot) and the PTO shaft are between your feet. The only instrument, the ammeter is in the small of your back!
So far so good. You've started the engine, and you are about to drive off, and then you notice how small the brake pedals are. They are OK for my size 10 sandals, but you wouldn't want to go to work in sandals with that hot compressor and PTO shaft so close, and wellies make the use of the dual brakes a bit fof a precision job. (Perhaps they were designed to be operated with the heel of your boot?) Great when you have had time to get used to them, but don't think that you are going to be able to counter wheel slip (there is no dif lock) by using the brakes on your first day out. It's a good job that the design means that wheel slip is not a common problem!
I like the clutch - even before I was told about its Aston Martin pedigree - I've never had a problem with it, but after a day manouvering around small plots, I begin to notice that the ridge on the end of the pedal has begun to creat a bruise on the ball of my foot. The gear box is, like all others of its era, a simple crash box without a suggestion of synchro, but is easy to use, but for one drawback. I started driving a DB880, with what I regard as a gear box that is right way up, at least it is the same way up as older DBs, DB 990, DB 1200, Fergy T20 series, the MF35, MF135, Fordson Dextas and Majors, contemporary Internationals and Deeres, but on the DB2D the gear box has been rotated forwards by 90 degrees. This is not normally a problem, as there are only 4 forward and 1 reverse gears to remember, but in times of stress, such as my first (and only) excursion into the show ring I lost all but bottom and second, and got repeatedly lapped by International Titans, road rollers and JAP engined Howard Dragons! Strangely I could find all 5 gears when it came to loading up at the end of the day and they have been there ever since!
Steering is light and direct even with a heavy implement load, and you get good, but not dangerous feedback. Our tractor understeers badly (when manouvering without an implement ) because the front axle has been reassembled back to front to allow more space for experimental machinery. (This makes it impossible to set the toe-in correctly.) But as this reflects such an important part of the tractor's working life I am reluctant to return it to its factory layout.
In order to mount implements the tractor must be driven to them so that they can be manually pulled underneath the frame. The linkage must the be lowered by means of the levers on top of frame in front of the steering wheel. The levers can be reached by leaning forward from the driving seat and stretching forward. With a heavy implement load it is often easier to stand operate the lift.) A latch operated by your thumb locks or releases the levers, which are directly attached to the pneumatic rams and lift cables which transmit the force from the rams to the implement. A movement of about 1/2 an inch at the top of the levers is enough to activate a pneumatic valve that allows the rams to assist you to move the linkage in the appropriate direction. Implements have to be clamped onto the linkage, an operation requiring the use of spanners, rather then the lynch pins that we are used to these days.
Attaching the implement can be quite a struggle compared to more modern machinery, but when a heavy load is attached you can enjoy a gentle lulaby of hisses, on your way to work, as the bouncing tractor causes the linkage to swing against the pneumatic valves. Come to think about it I should have remembered to tell you about the sound of the engine, but then it is a two cylinder air cooled diesel. It is not as noisy as some, but you can forget your MP3 player.
The tractor is really at home in the field. In most conditions it simply does the job. At working speeds on cultivated soil the hissing from the control valves becomes a rare and useful event, reminding you to lift the linkage a bit more if you are turning on the headland, or drawing attention to a change in seedbed quality.
At present the tractor can be viewed by prior appointment at Glyn-Coch Craft Centre, where it is usually shown as bare tractor without implements. The tractor can be demonstrated with a selection of the tools used on experiments. Machinery enthusiasts will note the plate gear attached to the central PTO which was used to provide a range of speeds to spray pumps and granule applicators. We have a variety of potato equipment, Webb seeder units and Horstine Farmery granule applicators. We also have a couple of early "lash up" chemical placement tools.
Last, but not least is our 180 year old Taskers field roller, which is still doing the job it was designed for.
"They don't make them like that any more! "
We have: -
Mugs with pictures of lesser tractors (for the same price): -
1959 David Brown tool frame tractor with aircooled 2 cyl Diesel and pneumatic implement lift
Spent 30 years working on field experiments all over the UK for Rothamsted Experimental Sation. Significant work on eelworm control including prototype chemical applicator testing and biological control tests.
The first successful "Systems Tractor" with variants for industry and aeroplane tug on RN Aircraft Carriers.