Thetford

Thetford Town

The Home of the Burrell

Here are some details which may be of interest to those contemplating building a Burrell and wishing to know a little more about their history.

St. Nicholas Foundry in Thetford is situated in-between St Nicholas Lane and Minstergate Street and is the home of the Burrell. This was not the original home as a foundry existed on the corner of Tanner Street and King Street prior to St Nicholas Foundry existing but it was at St Nicholas Foundry that all the best known works of the Burrell family were created for over 125 years. Whilst it was Charles Burrell (1817 - 1906) who is accredited with the success of the business, it was started (as we now know it) by three Burrell brothers much earlier in 1803 at the St Nicholas lane site. The three brothers were Joseph, James and William and they based the business on the Shop and Foundry of James originally existing on the corner of Tanner Street and run by Joseph. Charles Burrell is the son of James. James took control of the brothers business when Joseph died in 1831. A few years later (1837) James too passed away and left the business to Charles at the tender age of 20. Under Charles the business became known as Charles Burrell, Engineers and Agricultural Machinists and was to be seen at all the Agricultural shows in the region showing farm implement's. However it was not until 1846 that Charles produced his first steam powered engine which was a Portable Engine		Charles Burrell

The first steam engine was produced about 1846. This was similar to the one shown (right) which is the follow on design exhibited at the Great Exhibition of 1851 in Hyde Park, London The most notable difference between the one shown and the original is its fire box. The original was much higher with a domed top and the cylinder sat in front rather than on the top. The flywheel was on the left hand side rather than as shown. The motive power was the good old horse ......

These engines were made in sizes of 5, 6, 7 and 8 Nominal Horse Power and apparently were sold for about £180 pounds or so.

The use of steam in the UK to power motivation started about 1892. However before that time another engineer called James Boydell had taken out a patent on a design of "endless railway wheel" in 1846. This wheel was claimed to prevent land being cut up by the passage of cart wheels but it was also claimed that it could be used on the land to prevent the wheel sinking in ... or "saving the draught" as it was put "thus doing away with the difficulty of working locomotives engines for ploughing".		The Boydell endless rail wheel

Although Boydell had a stand at the Great Exhibition exhibiting his endless railway wheel and Burrell were also exhibiting, it was not until the Royal Agricultural Society Exhibition of 1855 in Carlisle that Charles Burrell and Boydell met and concluded a licence deal allowing Burrell to fit the Boydell wheel to his self propelled engines.

Burrell was not the first with such a wheel ...Garrett of Leiston exhibited such a wheel on their engine in 1856 at the Chelmsford Royal Agricultural Society Exhibition. Burrell completed his first such fitted engine in late 1856 with it appearing in his 1857 catalogue for the first time.


The 1856 Burrell -Boydell Engine

The engine illustrated had twin cylinders, one either side and two speed gearing and was capable of pulling six plough shears. A number of these engines were built to various specifications

By 1859 no less than six versions of the engines had been designed and built. Many of the later versions were to find overseas customers, mainly Empire countries such as India and the Crimea but Egypt and Brazil feature too.

The last of the Burrell-Boydell designs was in 1862 and was catalogued at a price of £750.

The next design phase took Burrell into the chain driven engine starting in the early 1860's and which was to last until the 1880's although Burrell started to build fully geared engines in 1880 with the introduction of decent steels for gears rather than the earlier cast type.

The chain driven era

The chain driven design of 1863 consisted of the cylinder on top of the firebox with the crank carried on brackets across the boiler having a geared intermediate shaft also across the boiler, This carried the chain pinion driving a rear wheel. The steering was still in front of the engine with a fireman located at the back on a manstand which also carried the coal. There were no brakes fitted! About 1869 improved designs emerged and a fast and slow speed sliding pinion were introduced. These were mounted at either end of the crankshaft and each drove a chain pinion, one to each hind wheel. The clutch for these pinions was operated by the steersman from the front. A third variety of chain drive improvements occurred in the early 1870's which solved the problem of chain stretch. The inclusion of the simple jockey pulley enabled adjustment to be made as wear progressed. Additional a handbrake was introduced, and the hind axles sprung. The final improvement was the addition of the winding drum. Two engines of note built at the end of the chain drive design. One was a 14 ton engine with double chain drive but incorporating a differential gear to help turning. The other was four shaft chain driven engine with fully elliptical rear axle springing. The chain drive system lasted until 1880 when Burrell adopted the fully geared engine. It is interesting to note that in 1872 the requirement for engines travelling was still for a man with a red flag to precede it by 60 yards and for the maximum speed to be 2 miles per hour.		Type DL Double Chain driven Engine

The geared traction engine era

The first geared engine appeared from the Thetford Works in 1872. It had two speed gearing and an unsprung hind wheel axle. There were four shafts with the sliding gears on the second shaft. No differential gearing on the hind wheels was fitted. As can be seen from the picture it was fitted with a belly tank, but only four were built to this design. Later models had improvements but none of note until 1875 when differential gearing was added to the third shaft and a water tank was added under the footplate. This engine is reported as being the first to be owned by a travelling showman, Savages of Kings Lynn.		1872 First Geared Traction Engine

Burrell owed much to Aveling's designs about this time. It was Aveling who first placed the crankshaft over the firebox securing advantage to the driver by making the flywheel easily accessible. Likewise it was he who pioneered hydraulic riveting. Burrell adopted many of the ideas but slowly and his adaptation of the designs had deficiencies. Although improvements were made the years between 1871 to 1876 were difficult for Burrell as they had competition making better engines. In 1876 Burrell introduced new designs of 6 and 8 NHP engines and their position improved somewhat. Unfortunately for them, and others, the effects of the Great Agricultural Depression commenced and this was to last until 1884. The engines produced in 1875 were nevertheless the first of the three shaft designs. They had two speeds and differential gearing. These early engines were not considered a success. Later designs introduced in 1876 of a heavier nature were successful and set the company on a path which was to later earn them the reputation of being the Rolls Royce of traction engine builders.
		Combined differential and Winding Gear Drum Burrell Patent
Burrell introduced a combined differential and winding gear drum which was patented in 1887 This became a sought after design with a number of Burrell's competitors taking out licences and paying royalties. Another important patented design of Burrell was the arrangement of gear selection levers. This design ensured that it was impossible to select two gears at the same time. The forerunner of many a mechanical interlock. It is now a familiar part of traction engines.		Gear selection levers Burrell Patent
In the middle of the Great Agricultural Depression Burrell introduced what was to become the famous T6 engine. Twenty one were built over 5 years. The design with variations was to be produced until 1920.

The introduction of rear wheel springing occurred in 1888. The problems with sprung wheels was the difficult task of keeping the gear teeth on the drives in proper mesh.

		Diagrammatic view of the Burrell patent rear wheel springing.

The Burrell solution to this was his patent 2316. This had the drive pinions firmly engaged to a spur wheel on an intermediate shaft running in an enclosed tube. The other end of this shaft had a spur wheel engaged to the final drive gear. The secret was in the universal joint fitted to the end of the intermediate shaft. This allowed the left hand end of the shaft to rise and fall with the main drive gear on the sprung axle whilst the right hand end of the shaft remained in a fixed position with its spur wheel running on a bearing on the outer of the intermediate shaft tube.

Interestingly the use of hornplates were only introduced as a standard in 1892. This meant that engines were constructed narrower
		To be continued