|
|
||||||||||||
|
|
||||||||||||
|
|
||||||||||||
|
|
||||||||||||
|
|
||||||||||||
|
Part 1: 1802 1808 Trevithick Part 2: 1812 1813 Blenkinsop Part 4: 1814 1816 Stephenson (1) Part 5: 1817 1825 Stephenson (2)
|
1814 |
George Stephenson
|
||||||||||
|
||||||||||||
|
|
The locomotive was tried on the Killingworth Colliery Railway on 27th July 1814 where it was placed on a section of edge rail and ascended a slope of 1 in 450 pulling eight loaded wagons weighing around 30 tons at a speed of four miles an hour. The use of two cylinders gave a smooth motion, remedying the problems caused by using a single cylinder and flywheel. The locomotive went into service at the colliery and it was soon discovered that it did not need the grooved rims on the wheels to carry out its work. The drive through cranks and gears gave a lot of problems, especially when they became worn, causing jerkiness and a great deal of noise. This was the first locomotive to use smooth flanged wheels with an edge rail and showed that sufficient adhesion could be obtained using this method. Even though it gave less friction than using a flanged plate rail where contact was made with the side of the wheel as well as the rim. This locomotive was named My Lord after one of the partners, Lord Strathmore. It is possible that another geared locomotive was constructed later in the year, and possible named Blucher after the commander of the Prussian Army at the Battle of Waterloo. 16/5/03 |
|||||||||||
|
|
|
|||||||||||
1814 |
William Brunton
|
|||||||||||
|
|
|
|||||||||||
1815 |
George Stephenson / Ralph Dodds
|
|||||||||||
|
||||||||||||
|
|
The patent showed two methods of keeping the wheels at the same angle to each other. The first involved using cranked axles with rods connecting them. This was too advanced for the technology of the time as a cranked axle could not be made that would stand up to the constant jarring and forces applied to it in normal working conditions. The second way involved mounting a toothed wheel at the centre of each axle connected by an endless chain. A locomotive similar in design to the geared locomotives but incorporating direct drive was constructed at Killingworth and tried on 6th March 1815. It worked well and was set to work. 16/5/03 |
|||||||||||
|
|
|
|||||||||||
1815 |
William Chapman / John Buddle
|
|||||||||||
|
||||||||||||
|
|
This locomotive worked at Wallsend, at this time it was laid with wooden rails which caused problems, so in 1816 it was decided to try it at Washington but the wooden rails used here also caused binding problems so it was laid up. After the Wallsend railway had been relayed with Loshs patent iron rails the locomotive returned to Wallsend. The locomotive was rebuilt with a larger boiler and the cylinders were moved above the wheels so direct drive via crankpins on the wheels could be employed. The gears between the frames were retained as a means of coupling the wheels. This rebuilding, which increased the weight from 7.5 tons to 9 tons, could have taken place soon after the locomotive returned to Wallsend. It then seems to have worked for many years and contemporary reports imply that there may have been more than one Steam Elephant at work at Wallsend. After Robert Stephenson, Georges brother not his son, was dismissed from Hetton Colliery he was replaced by Joseph Smith as Company Engineer. Joseph Smith had been responsible for the re-building of the Chapman / Buddle engine at Heaton and also built Buddles Rainton locomotive. It seems likely that he bought a Wallsend locomotive to Hetton where it worked for ten years before it disappeared from history. While there it was probably named Fox. The existence of a Chapman / Buddle locomotive only came to light when a watercolour sketch came to light and was exhibited in 1965. An old lady who had a detailed oil painting based on this watercolour visited the exhibition. Later she gave this to a local school where it remained until retrieved by Beamish Museum in 1995. A piece of text written by Stephen Oliver in 1834 has also come to light The great coalfield of Newcastle appears likely to be exhausted within two hundred years. Shares in railway companies will then be at an awful discount and steam elephants will inevitably perish for want of food! A full-size, working replica of this locomotive has been constructed and can be seem at Beamish Open Air Museum. The staff using contemporary illustrations, the painting, and the original account book for the building of the engine, produced a set of engineering drawings and, in October 1999, started the task of building The Elephant. Much of the construction was done in the North of England, with the final construction and boiler testing taking place at Ross on Wye. 16/5/03 |
|||||||||||
|
|
||||||||||||
1816 |
William Chapman / John Buddle
|
|||||||||||
|
|
||||||||||||
1816 |
John Blenkinsop / Krigar
|
|||||||||||
|
|
||||||||||||
1816 |
George Stephenson / William Losh
|
|||||||||||
|
||||||||||||
|
|
The obvious way to make sure the weight of the locomotive was carried evenly between the wheels was to give it some form of suspension. This also had the advantage of ensuring that traction was available from all the driving wheels by making sure they were sitting correctly on the rails. Especially difficult to maintain if six wheels are used. Road vehicles had used springs for a long time but because on these early steam locomotives the drive came from above if the wheels were sprung it would bounce the locomotive. What was needed was a form of suspension that included a form of damper. |
|||||||||||
|
||||||||||||
|
|
The solution Stephenson and Losh came up with was to place a cylinder on each side of the boiler above each axle; this was connected to the boiler and frame by flanges. The top of each cylinder entered the water space of the boiler and was open at the top to allow the water to enter it. Inside the cylinder was a piston, packed to make it steam tight. A rod, passing through the frame, connected the piston to a bearing that rested on the axle. The axle was held in a guide to make sure it only moved vertically. This enabled the axle to take up any inequalities in the track, providing a relatively smooth running locomotive. Another change made at this time was the introduction of the eccentric, which had been invented by Nicholas Wood the Viewer at Killingworth Colliery; this was used to operate the valves. |
|||||||||||
|
||||||||||||
|
|
A number of locomotives were constructed incorporating these features and used the usual layout of two cylinders, nine inches in diameter and lined with sheet copper, inserted vertical in the top of the boiler. The pistons worked vertically onto cast iron cross beams which worked connecting rods driving direct onto the wheels. A valve operated by a handle controlled the amount of steam admitted to the cylinders and so regulated the speed. The steam was admitted alternatively to the top and bottom of the cylinders by sliding valves, which were driven by eccentrics attached to the axles. The exhaust steam was piped into the chimneys, which were turned upwards before they allowed the steam to exit. |
|||||||||||
|
||||||||||||
|
|
Nicholas Wood in A Practical Treatise on Rail-Roads published a description of the blast pipe in 1825 (an edited version is included below) long before the controversy of who invented the blast pipe. On the earlier locomotives the steam was exhausted to the atmosphere, this created little noise, but it was found difficult to produce enough steam to keep the locomotive working. Stephenson decided to divert the steam into the chimney through pipes with upturned ends. This increased the velocity of the air through the fire and caused it to burn hotter. The big drawback of this was the noise caused by the escaping steam, which was amplified by the chimney acting like a trumpet. When larger flues were fitted to the Killingworth locomotives it was found this level of blast was not required, which led to the locomotives using less coal. The use of a strong blast causes a lot of unburnt fuel to be sucked up the chimney. 16/5/03
|
|||||||||||
|
|
||||||||||||
|
|
|
|||||||||||