The Hurd & Simpson Locomotive
Above: The Hurd & Simpson locomotive project: 1874
The basic idea behind this design was to take the smoke from the boiler and recycle it through the fire again: "..'the products of combustion from the fire receptacle are returned to the same by means of an injector activated by compressed air... also in devaporising escape or exhaust steam..." which seems to indicate that the inventors thought that continuously recycling the exhaust gases would make them innocuous enough to be released into a confined space like a mine; I am less optimistic. It also appears they planned to condense the exhaust steam.
Here is the naming of parts for image above:
The fire is stoked automatically by the rotary feed barrel under the coal hopper; there is some sort of power-operated shovel feeding the fuel into the fire but it is not visible in the image. Therefore the fire could only be fed when the engine was moving, and it would be fed whether necessary or not; this seems to indicate a lack of knowledge of locomotive operation on the part of Messrs Hurd and Simpson. A similiar problem results from driving the boiler feedpump from the rocking lever; this approach was abandoned very early in the development of locomotives.
After this the description of operation becomes incoherent, referring to "...the steam combined with the highly heated and expanded gases escaping through the valve k to the cylinders, or back again into the boiler when the engine is not working." which seems to indicate that the compressed exhaust gases were to be injected into the boiler rather than the firebox, making it an Aero-steam power power plant.
The Hurd & Simpson locomotive was a cab-forward design , the driver looking to the right of the picture. He had no access to the fire. All this recompression of exhaust gases must have been very efficient indeed, because there is no chimney visible at all. Possibly the silliest feature is the huge coal-hopper perched above the locomotive. That would have much raised the centre of gravity, probably making the locomotive unstable, but worse still it is hardly suitable for a locomotive intended to work under ground in a limited headroom. The compressed-air locomotives for mine use showed how to keep a low profile.
The article in The Engineer stated that a locomotive built on these principles was "...nearly ready for trial." but I fear that was wishful thinking.
Hurd and Simpson were in business making coal-cutting and compressed-air machinery. Their company went into liquidation in 1876:
"...Proceedings for Liquidation by Arrangement or Composition with Creditors, instituted by Frederick Hurd, of Wood street, in Wakefield, in the county of York, Mining and Mechanical Engineer, formerly carrying on business with Edward Thornhill Simpson, of Walton, in the said county, Soap Manufacturer and Colliery Owner, as Mining Machinist, under the style or firm of Hurd and Simpson, and subsequently with Edward Simpson and Charles Henry Simpson, both of Wakefield aforesaid, Soap Manufacturers, as Mining Machinists, under the style or firm of Hurd and Simpsons, and Hurd and Simpsons' Patent Mining Machine Company, and sometimes under the style or firm of Frederick Hurd and Company."
Image and info from The Engineer, for 21 Aug 1874, p153. The index describes it as a Patent Locomotive Engine, but no patent number is given in the article.
Thanks to Tom Bates for bringing this design to my attention.
A CRIME UNCOVERED!!
When I first saw the drawing above, I thought the rocking lever at the back was a bit reminescent of the Belpaire & Stevart lever locomotive; I did not pursue this thought. My friend Bernd was more alert and spotted that the the Hurd drawing is to a large extent a rip-off of the Belpaire & Stewart drawing. Just as a sample:
I could go on, but I think this demonstrates beyond doubt that Hurd and Simpson were not only wholly incompetent locomotive designers, but also lazy plagiarists.
History is judging them harshly.