Tracklayers (1942-1963)

As we have seen earlier, the first endeavour of David Brown into the crawler market was hardly what could have been called a roaring success as the VTK1 Air Ministry Tracklayer was really an abysmal failure. But David Browns had already invested a not insubstantial amount of time and money into the crawler production. Fortunately, one of the RAF track-layers had been loaned some months earlier to the Royal Engineers for work on sea defences in East Anglia. They were delighted with what they had seen, as it showed that at least one British manufacturer had the potential to make a crawler tractor and this would help them get round the strict embargo on buying equipment for military purposes from what were still neutral countries at the time. True, American-made crawlers were being purchased, but technically it was illegal to use these for any sort of offensive or defensive works.

VAK3 Tracklayer Prototype

Thus, in 1942, was born the David Brown DB4 a 38.5 hp crawler which was fitted with a Dorman Ricardo diesel engine and a 5-speed box. These were first successfully employed in the North African campaign, where the DB4 could traverse ground in which a wheeled machine would become bogged down. Fifty or so DB4 crawlers were used at Normandy immediately after the Allied beach-head was established there in June 1944, and their success in this exercise led to the Government requisitioning three more large batches in 1944, and five batches in 1945. We are not quite sure how many DB4 s were made altogether, but a figure of 110 is shown in some records as being the total number made before production ended on Wednesday 12th January 1949.

Undoubtedly, the DB4 track-layer was seen as being useful for civilian purposes too. The rigours of war had shown it could take any amount of abuse, and compared itself well against many of the American dozers, scrapers and crawlers that were flowing into Britain or which were sold as war surplus by the Americans after 1945. These ex-WD DB4s subsequently found employment in airfield work, forestry, road-making, and all-manner of reconstruction work projects in France, Holland and Belgium. Fitting these tractors with bull-dozers, angle-dozers, scrapers and so on, radically speeded up so many operations in this post-war period of reconstruction, so that the crawler tractor was seen as being a revolutionary new force in both agriculture and civil engineering.

Beginning in 1948 a series of tracklayers, which included the TAK3 (track-layer agricultural kerosene) and TAD3 (track-layer agricultural diesel) and ITD3 (industrial track-layer diesel), began to make their appearance. Straight away they began making inroads into areas which had been formerly dominated by American manufacturers, but perhaps their greatest accolade was to beat the Yanks on their own home ground, for they were widely employed in the construction of the new Alaskan Highway. The success of the company’s crawlers both industrial and agricultural gave rise for even greater efforts on behalf of the marketing department and as we discuss elsewhere, they came up with the ‘master’ concept for the ‘master’ concept for naming the various model types. So, in 1950, the crawlers became known as the Trackmaster, a designation which first appeared to the public at the Harrogate Convention that April. Two years later, the TAD6 and ITD6 tracklayer came out with a six-cylinder diesel engine which produced a mean 50 horse power; it was offered with a choice of two track widths for either agricultural or industrial use.

The following year it became known as the 50TD, as part of a new company designation scheme. This was a tractor that would stay in production until 1963 and see a total of 1,667 models being built. It was the company’s first attempt with a 6-cylinder diesel engine, and as such it was to set a number of challenges for the firm’s engineers, but it also gained many commendations and good reviews from outside sources. In 1953, with the introduction of the 30C and 30D wheeled tractors, the 30 series Tracklayers were introduced (these being the 30T, 30TD and 30ITD) and TAD6/ITD6 renamed as the 50TD/50ITD. Yet, despite their immediate success and total sales of 3,078 in the 30 series crawlers it was a fickle market and highly specialised as the demand for major improvements went marching on. Even so, it was evident that even the bigger tracklayers were being sold into heavy industrial applications which they were simply not suited for and the Service Department was facing a large number of requests for replacement clutches. The decision was therefore taken to examine the 50’s clutch and gearbox to see where the problem lay, and as a result the Mk.II 50TD appeared in March 1957 with a larger diameter clutch, new running gear and a substantially strengthened set of side-plates which were fabricated from 1” thick sheet steel.

A similar problem with ‘clutch reliability’ showed that the 30hp models were not up to the jobs that many contractors were expecting of them, and a proposal was made to up-rate them to a 40hp version and the first of these appeared early in 1960. However, due to the serious problems with the 900 series wheeled tractors that the company began to experience after they were introduced, a decision was taken not to immediately produce a crawler version but to defer production and see where things went.

The strive for increased power, however, was a major consideration for David Brown personally, and one day he announced that he felt that the company should have a 100hp crawler. In due course the order was passed down to Herbert Ashfield to implement, who writes, ‘In the 1950’s we were producing light agricultural crawler tractors at Browns, but sadly these had a fairly narrow market. The trouble seemed to be that the dealers (and the sales department for that matter), kept overselling them into the industrial market where the equipment required 40 horse power against the 30 horse power machines which we had available.

Now we had attached to our sales office a new market research department which looked into the matter and recommended that, if we were to have any future in the crawler market, we, should produce machines up to 100 horse power crawler capable of a top speed of 15 mph. We simply did not have the resources to tackle the top end of the market, but I set about producing a prototype and decided to go for a really big machine to Show everybody just what they had let themselves in for. After choosing a Leyland engine, we decided on a fabricated frame as being easier to construct than castings. When we came to the tracks, the quickest solution seemed to be to have a double sprocket and have four links instead of two, enabling us to use DB existing parts. The steering would be clutch and brake.

Having eventually completed the first machine, top management came and inspected it in the experimental fitting shop as the weather was bad. In the confines of the small shop, alongside 25 horse power agricultural tractors, it looked huge and its proportions frightened them to death; little wonder it became known to all concerned as Goliath! If mass production was to follow, it was declared that new machine and fitting shops would be required with bigger machine tools and heavier lifting equipment.

At this stage David Brown had now to be brought back into the picture. However, with a background of battle tank transmissions up to 700 horse power and marine transmissions for the navy running to several thousands of horse power, a mere hundred horse power crawler tractor looked very ordinary to him. He decided to view the beast on the Crosland Moor airfield, but in the vastness of the Pennine moors Goliath did not look half as big as it had in the fitting shop. David Brown looked at it with tacit approval and even smiled when Goliath rattled passed at speed. At this the boss flew back to London without comment and as Goliath took up a lot of space in the works, I decided to leave it on the moor. Meanwhile the production department went into the cost of the extra machinery and fitting shops required, if this crawler were to go into manufacture.

These results confirmed my original contention that we just did not have the resources and even if we had, they could be more profitably applied to agricultural wheeled tractors. When the smoke cleared away, the inevitable decision had been reached and poor Goliath had no future so it spent its days being used as a dynamometer up at the airfield where it was eventually scrapped.’ Various experimental tracklayers followed the 30, 40 and 50 series, including the DB5 of which 11 were built. The 990T offered the promise of a modern tracklayer for continuing production well into the 1960s, but this was not to be as Herbert Ashfield continues: ‘As we entered the 1960s the tracklayers were becoming a really big problem for us, because at this point in time we were producing far too many models and variations for the quantity we were selling; in fact we were producing less and less, and more and more if you know what I mean.

Our original agricultural Tracklayer had been designed for New Zealand, because that is where the demand was. In fact it was a very wide tractor which had a 64 inch track I think, I can’t remember precisely now, but it was very wide and you couldn’t turn it over. It was well appreciated in New Zealand, because it was very steep and hilly and the thing would slide sideways before it would turn over. It also sold well into farming areas where they had heavy clay which was obviously a good market. The big problem with our crawler was the fact that it was only a thirty horse-power Tracklayer; all the equipment dozers etc. which we had, were designed for the DB4 which was over forty horse power. Things were getting worse and worse, and people were saying that our crawlers were no good, but it was simply down to the fact that the dealers and users were asking too much of them. On one occasion I had to go to the United States to sort out this type of problem. because they were putting very large dozers on to relatively small tracklayers.

When they tried to lift them, the dozer blades just stayed on the ground and the tracklayer’s nose came up. It was quite a problem out there, because people were always overloading these machines, asking them to do work they just weren’t designed for. We had a lot of trouble with some of the dealers, particularly those who were fairly small outfits; many were ready to make a sale at any cost, so they’d fit anything to them. We should have really designed our own dozers from the start although, in fact, we did ultimately do just that, but until we did we had a lot of problems in this regard. The 50TD six cylinder crawler was less of a problem, and it sold very well in South America so we asked our dealers out there why this particular tracklayer sold so well; in reply they said “well, its big and red and noisy!” It was obvious by the ‘sixties that the demand for wheeled tractors was insatiable and we were making a profit on these, but we were making a loss on the tracked versions. Indeed these were a very difficult thing to produce, because our customers wanted industrial versions, wide versions, narrow versions etc., in fact you name it they wanted it.

Ultimately, when Jack Thomson became Managing Director, we had a major inquest on the whole lot of our models. We were clearly over-extending our resources in so many ways and something had to give if were to make an efficient organisation, so we went out of Tracklayers and concentrated entirely on wheeled tractors.’ Tom Lazenby recalls a similar series of events, saying; ‘There were two things that really happened in the crawler market; first of all we were casting our net a bit too far with the crawlers, because we’d originally gone into this to try and meet a demand from Australia and New Zealand, where there was a great need for crawler tractors on steep terrain or in countryside where the roads might be hundreds or thousands of miles apart. We could supply that market, and similarly the areas of Britain where they had really hard clay-type soils, a light crawler was just right for these conditions, but we couldn’t get to touch the big makers like Caterpillar. If we’d stayed at our area of speciality, just supplying a tracked version of our wheeled tractors we would have been alright, but it was entry to the industrial market which made things most difficult. Having failed to recognise our limitations, we made our second mistake and went on to try and compete with the big firms, our industrial division (at Feltham) were selling our machines into applications where they were simply too light and [as mentioned above] overloading them with equipment which they were never designed to carry.’ So in 1963, almost to the 21st birthday of the commencement of the DB4, the company went out of crawler production altogether.

For some it was just a natural part of the process of progression and concentration on the firm’s strong points, but one wonders how the 990T or possibly a 1010T might have performed had they been fully developed and put into service with a complimentary range of associated equipment. At one stage, after the new assembly line opened at Meltham Mills, I was asked to do a costing exercise for the updating of the old assembly line for the production of special industrial wheeled and crawler tractors. The capital costs were not high, but they came at a time when the company were facing a very uncertain future just after a crippling strike by our draughtsmen. As far as I know the industrial assembly line plans died as a consequence, and within a very short time we were sold to the American multi-national Case.













VAD6 50D


900 Series


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950 Series


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880 Series


990 Series