The 'Roall' Easton and Anderson Beam engine
This 65 HP Woolf Compound A frame Waterworks rotative beam pumping engine was built by Easton and Anderson at Erith in 1891 as one of a pair installed in the Roall pumping station of the Selby and Pontefract Water Company at Eggborough in Yorkshire.
The Cylinders are 14" bore x 36" stroke (HP) and 20" bore x 46" stroke (LP) The HP has an expansion slide valve* fitted which is operated by a very unusual linkage from the beam and the LP a simple slide valve . Watts parallel motion is fitted to guide the piston rods.
Working speed was 20 RPM of the 12' diameter 9 ton flywheel which is cast in two halves, however the pumping was achieved by an LP piston tail rod, the cylinders of both engines being cantilevered out over the well, the extended piston rod extended down the well to the pumps.
The engine has a throttle governor of as yet 'unspecified' parentage
A very plain and robust design this engine had a chequered history before arriving at Forncett, after nearly being donated to us it was 're routed' to Anglian Water with the intention of being rebuilt near Rutland water, it was dismantled by AW staff and stored in the pumping station at Empingham for some years until it was decided that it would not be rebuilt there and was once again offered to Forncett, it arrived as a pile of bits and as we had not dismantled it it was fortunate that some good photographs 'in situ' at Roall had been taken some years previously.
It was decided to install in the 'Dover Engine House' (the valvegear floor of which can be seen top right in the photo) so foundations were prepared, the roof removed and a very large crane was required to lift all the components over the other engine houses and into position, this being made marginally more interesting as the crane driver was out of sight of where the the installation was occurring !
During the exercise it was found that the substantial LP piston rod had acquired a serious bend during its trip to Forncett and this had to be straightened under a sizeable hydraulic press before completion of the rebuild.
* Update October 2001
Recent research into Easton and Amos by David Eaton, Chief Engineer and Webmaster of the Westonzoyland Engine Trust indicates that Charles Amos, one of the partners, introduced a form of expansion slide valve several years before the Meyer patent was sealed in 1865, the Westonzoyland engine, built in 1861 is fitted with this. It is unlikely that having their own design, the Erith firm would have paid a license fee to use the design of a competitor so it is probable that this engine also is fitted with a previously unrecognised Amos expansion slide valve - more information will be added as it becomes available.