It had been decided to again experiment with a steam locomotive at Wylam Colliery (Newcastle) so the proprietor, Christopher Blackett, contacted Richard Trevithick but he decline to supply a locomotive as he was to busy.
Blackett then instructed William Hedley the superintendent of Wylam Colliery, to construct one. The idea of using a rack and pinion system was looked at, but to convert the 5 miles, then laid as a plate-way, from Wylam Colliery to the coal staithes on the Tyne, to a rack-rail system would have cost £8,000.
Hedley set out by experiment in 1813 to find out once-and-for-all if sufficient adhesion was available using a smooth wheel on a smooth rail. To do this he constructed a carriage operated by four men, two each side standing on stages suspended from the frame of the carriage. Each man turned a handle, which was connected by a cross shaft to the one on the handle on the other side. A gear was set on this cross shaft which engaged with a gear set on the wheel axle and so turned the wheels and moved the carriage along the plate-way. To make sure that the power was delivered evenly to all wheels at the same time, another gear was placed centrally to engage with the ones on the handle cross-shafts, so coupling the wheels.
He loaded this carriage with known weights ranging from two to six tons then attached more and more loaded coal wagons until the wheels of this man powered carriage slipped round. This experiment proved conclusively that just the friction available from the driving wheels of a locomotive was sufficient to haul a viable train of loaded wagons.
After these successful trials the carriage was converted to an experimental locomotive by mounting a cast iron boiler, with a single straight flue, this was fitted with only one cylinder connected to a flywheel. Was this based on or used parts from the locomotive supplied by Trevithick? This was not a complete success and in Hedleys own words It went badly, the obvious defect being want of steam.
It was probably this machine that was seen by George Stephenson and after inspecting it declared he could make a better one himself! |