David Roberts: Tractor Pioneer Extraordinary

Hornsby tractor

This Hornsby tractor was built in 1896. It featured a 20 HP oil engine of Akroyd design.

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Hurley, Berkshire England SL6 5LL

The following article, which is reprinted from Guard magazine, was sent to us after a friend sent Russell Jones a copy of the September/October 1984 issue of IMA. That issue contained a letter and picture from George E. Hoffman, 9312-173A Street, Surrey, B.C., Canada V3S 5X7, asking for identification of the crawler he had to restore. This article provides background information on that machine.

The Englishman David Roberts is perhaps one of the least known pioneers of the crawler tractor.

As the Chief Engineer, and later as the Managing Director of the company Richard Hornsby & Sons Ltd., of Grantham, Line, his design concepts promised world leadership at the turn of the century.

The machines he designed and built were at least a decade ahead of any other development being worked on in the world at that time.

The strength was his engineering capability and the weakness which frustrated the commercial development of his ideas was the weakness in sales and marketing.

This weakness resulted in the decline of Richard Hornsby as a company and the abandonment of their brilliant pioneering work on the crawler tractor. Perhaps the whole situation is best summed up by the press comment made sometime after the closure of the company.

'Unfortunately the firm's marketing was not always able to match up to the situation either. Advertising seems to have been a particularly weak point with Hornsbys. They neither advertised as frequently nor as effectively as their competitors. Unlike their engineering products, the Hornsby's advertisements tended to be unimaginative, and many good opportunities for promotion were missed.'

When one researches the progress and development of many British companies, one sees the same trend repeated again and again. The Roberts saga is especially disappointing as his designs and his prototype machines showed great promise, which if the need for marketing had been identified, they could have taken advantage of enormous markets which within five or six years were identified by American pioneers led by Benjamin Holt.

Whilst David Roberts gave up his work because he was incapable of developing markets, the Holt organisation moved ahead strongly and opened up sales opportunities in many parts of the world and was soon manufacturing crawler tractors on a volume basis.

The Roberts story starts in 1903 when the war office offered a prize of 1000 for a tractor which could haul a 25 ton load for a distance of 40 miles without stopping to take on extra fuel or water. This was a serious attempt to progress beyond the age of the steam traction engines whose range depended on plentiful supplies of fuel and water.

Messrs. Richard Hornsby & Sons Ltd of Grantham, Lincolnshire, welcomed this competition. They had had long experience with steam traction engines, and had built their first oil engined tractor in 1896. This was a 20 HP machine, powered by a horizontal single cylinder Hornsby Akroyd oil engine. Their entry for the competition was an 80 HP twin cylinder machine. One cylinder was horizontal, the other was inclined 30 degrees upwards. The tractors had 4 speeds and weighed 12 tons.

From several entrants, the Hornsby tractor was the only one to complete the course of 40 miles. A bonus of 10 per mile had been promised for every mile in excess of 40. The Hornsby travelled a total distance of 58 miles before running out of fuel thus earning a bonus of 180 in addition to the 1000 First Prize.

Hornsbys were seeking much bigger prizes. Their Chief Engineer, David Roberts, had an ambition to mechanise the Army's military units. He was secretly working on his chain track invention which would enable tractors to travel with certainty and safety over loose sand, soft ground, river courses, bogs and uneven ground. Such surfaces were often impassable for traction engines fitted with wheels. In 1904 Roberts took out his British Patent No. 16,345 which claimed: 'My invention relates to Improvements in Traction Engines, Road Locomotives and Motor Vehicles, or Vehicles to be drawn thereby.

'It is well known that traction engines or other heavy road vehicles as now constructed are limited in their use by reason of their wheels sinking to too great an extent when travelling over soft or sandy ground and over surfaces of considerable irregularity.

'Now this invention has for its object to obviate this defect and to this end the locomotive or other vehicle is mounted upon a pair of front and a pair of rear wheels provided or formed with peripheral sprocket teeth; these wheels are mounted upon front and rear shafts respectively and either or both pairs may be driven through the ordinary spur gearing when the vehicle is a self-propelled vehicle.

The 1896 machine from Hornsby was redesigned in 1905 and equipped with full tracks. The engine was the same single cylinder used in the wheeled unit.

'Two pitched chains of links and pins with cross bars or blocks of metal or wood to make contact with the ground are passed around the front and rear sprocket wheels, one on each side of the vehicle and form a track. The weight of the vehicle body (and engine) is taken by side brackets provided with curved pathways or bearing surfaces resting on rollers which, in turn, are supported on the chains, or on rollers of large diameter revolving on fixed pins. With this arrangement when the vehicle is running the body is, so to say, rolled forward on the chains. Steering may be accomplished by varying the speed of the driving sprocket wheels on either side of the vehicle. Dated this 23rd day of July, 1904'.

Four further patents were taken out by Roberts in the following years:

No. 23,736 of 17th November 1905 claimed: 'Improvements in or connected with Road Locomotives and Vehicles.'

No. 7,289 of 26th March 1906 claimed: 'Improvements in Variable Speed Driving Gear.'

No. 19,574 of 31st August 1907 claimed: 'Improvements in or connected with the steering of Road Locomotives and Vehicles.'

No. 16,436 of 14th July 1909 claimed: 'Improvements in and connected with the Driving Axles of Chain Track Tractors and Locomotives.'

In 1905 one of the 1896 type single cylinder oil tractors was fitted with the Roberts chain track. This machine was rated at 20 HP and weighed 17 tons. Trials at Grantham in July 1905 and February 1906 were observed by War Office staff.

Encouraged by the success of the first chain track tractor, the 1903 prize-winner was fitted with chain tracks in August 1906. Private trials of this machine were carried out in July 1907. It was on this occasion that the British 'Tommies' coined the name Caterpillar to describe the fantastic machine. These trials, again, were very successful and it was decided that royalty would have the pleasure of inspecting the new invention. In May 1908 trials at Aldershot were attended by King Edward VII and the Prince of Wales (later King George V). David Roberts had the honour of being presented to the royal observers at the trials. This must have been his proudest moment. It seemed his ambition was about to be realised. At his suggestion dummy wooden guns were fixed to trailers which were also fitted with chain tracks. The Army were indeed interested. Glowing reports were produced by the Army Mechanical Transport Committee. With the basic idea proved, Roberts decided to experiment with faster machines, to see what speeds could be attained.

A further development was the steam powered crawler built for the Yukon. This machine has recently been located near Vancouver, Canada,

The Hornsby machine met with little commercial success whilst Holt of America moved ahead with expanding worldwide sales. The track design of Hornsby was sold to Holt and the English company gave up their development work,

In August 1906 Hornsbys had purchased a 40 HP petrol-engined Rochet-Schneider car. This was fitted with chain tracks in 1907 and was thoroughly tested at Grantham before being taken to Aldershot for Army Trials in November 1907. This lightweight machine, weighing only 4 tons, achieved speeds of 15 mph, over rough ground. Hornsbys commissioned a movie film of this model, to be shown in London and provincial cinemas as part of an advertising campaign to sell the chain-track idea for a variety of uses. The film was included on the bill of the Empire Theatre in Leicester Square, London, in the summer of 1908. Other attractions on the same bill were: 'The Belle of the Ball' featuring Adeline Genee, a world famous Danish dancer, and 'Dialect Recitations' by a gentleman. Even so, the star item was, without doubt, the Hornsby film, which incidentally is reputed to be the first film ever made for commercial purposes.

So far each of the tractors built was designed for operation over rough, hilly or boggy land. David Roberts' fertile mind turned next to a vehicle suitable for desert warfare. This had to be a light tractor capable of operating at high speeds on sand. In 1908 a 75 HP Mercedes car was purchased. It was powered by a 6-cylinder petrol engine. In contrast with the Rochet-Schneider, the Mercedes was fitted with wooden wheels to carry the chain tracks. Trials were held on the beach at Skegness during 1908 and 1909 when speeds of 25 mph were attained! Such speeds were not achieved by any other tracked vehicle until the Second World War!

All the work at Grantham was not restricted to chain tractors. Wheeled Tractors were constantly being improved. The War Office purchased three 50 HP four-cylinder oil engined tractors in 1909 and conducted extensive road trials. This purchase was quickly followed by an order for similar machines fitted with chain tracks. Four tractors were purchased. The first Hornsby No. 35082, was a 60 HP six-cylinder oil engined machine, delivered to the War Office on 5th May 1910. The other three machines were all fourcylinder 50 HP oil engined tractors. They were delivered on 16th July (two machines) and 26th July 1910. No. 35082 was driven by road all the way from Grantham to Aldershot. This machine was converted to petrol fuel in 1911, raising the HP to 105. It is the only one of the War Office machines to survive, and is preserved in the Royal Armoured Corps Tank Museum at Bovington, Dorset.

Hornsby's main effort was aimed at mechanisation of the Army Artillery units although they expected to find a large market amongst civilians wherever a machine was required to operate in difficult terrain.

Although Hornsby's designs were, in the writer's opinion, brilliantly ahead of the world, the facts are they only sold one machine in their history for civilian use.

This contrasts with the brilliant success of Holt and Best and a number of other manufacturers, who within a year or so of the Hornsby developments, had thousands of machines at work.

The only crawler tractor that Hornsby sold commercially, was to work on hauling coal in the Yukon. This was an 80 HP, 25 ton machine. Due to operational conditions, the machine was not a great success. What is interesting, is that this tractor still exists in Vancouver, Canada, and currently work is afoot to restore it to working condition.

So apart from this isolated machine, Hornsby's campaign to replace wheels with chain tracks (by now commonly called 'Caterpillar' tracks) was having little success. Despite the various tractors that had been sold to the War Office, a similar fate was in store for military applications of the revolutionary idea. The following extracts from Army reports are indicative of their attitude:

'It is impossible in a column with other troops, its noise and smell are abominable and very few horses will pass it. The wooden blocks forming its feet are nearly worn away, and it is unable to carry sufficient fuel for itself for any time, and its machinery appears to be unreliable. The team of eight horses in my opinion is far superior under every condition.' Thus spoke a Horse-Artillery senior officer!

The War Office Mechanical Transport Committee replied as follows:

'If mechanical transport is sandwiched in between horse-drawn vehicles in a column or route it will always show to a disadvantage, because it is slower up the hills and retards the column, but on the level or downhill it will be impeded by them.

'Increased horse-power of the engine will also tend to remedy slowness on bad roads, but it should be borne in mind that the Committee never contemplated that the tractor should work in columns of horse-drawn vehicles, as in principle mechanical transport does not fit in with horse transport,.. .the present machine is more noisy than desirable or necessary, but it should be remembered that the design is experimental. So far as fuel capacity is concerned, the tractor can carry sufficient fuel to take it 100 miles.'

The tractor in question was returned to Hornsby's factory where the engine was converted from paraffin to petrol. Many other improvements were made to the machine and it was driven by road back to Aldershot where it completed further successful trials with the Heavy Brigade. Even so, it remained an experimental vehicle as far as the artillery officers were concerned.

By the end of 1913 Hornsby's had become thoroughly disillusioned. Thus, early in 1914 they sold the patent rights of the chain-track invention to the Holt Manufacturing Co. of New York for the sum of 4000. Holts had been working on chain track designs for a number of years. They had preferred to concentrate on a combination of tracks and a wheel for steering.

Within a year the War Office were placing orders for hundreds of chain track tractors to the Holt design! Rustons built 442 of these machines at Lincoln under license from Holts. They were four-cylinder 60 HP petrol engined machines, powered by Baker-Perkins engines produced at Peterborough. They were fitted with a two-speed gearbox. Steering was controlled by the front-mounted wheel, assisted by separate brakes and clutches acting on the chain tracks. A number of these Ruston built tractors were shipped to Russia.

No evidence can be found of any further Hornsby interest in chain (Caterpillar) tracks.

The David Roberts story commenced in 1895 when he joined the firm of Hornsby as their Chief Engineer. Clearly the records show that his engineering ideas were years ahead of the world. One ponders on the questions, where would the company be today if their marketing skills and awareness had been as strong as their engineering vision.