It has been a few weeks since we last looked in on progress on Samson, but this doesn’t mean that there hasn’t been a great deal of progress to report! Rather the distractions of everything else going on in and around the department. So, here are some images to bring readers up to date with what we have been up to…
Below: A highlight in the construction has been the offering of the cylinder block to the boiler barrel. Dave had made such good progress with the slidebars and connecting rod that the whole assembly has now been trial fitted and adjusted, aligned, trialed again and finally committed to metal in the form of drilling the holes to mount the cylinder block on the shell – no going back now! Here is a general view of Samson showing this progress.
Below: A close up of the crosshead and slidebars. An additional bracket is to be fitted here, which awaits machining. This supports the ends of the bars as well as the lifting links for the valve gear. The brass lubricator provides oil for the little-end where this is pinned to the piston rod via the crosshead.
Below: From the other side we see the cylinder block in position and one drain cock in position.
Below: Moving to the opposite side we can see the expansion link in place as well as a good view of the slidebar lubricating pot. The wooden wedge is acting in the role of motion bracket, which as referred to above, awaits machining and fitting.
Below: A close up of the crosshead, piston-rod, gland and cylinder end cover assembly.
Below: Note the crosshead slippers – the bronze items that form the actual moving surface between the slidebars.
Below: A view of the piston and end of the piston rod – lessons learned on Coffee Pot have been employed here. The piston itself is formed of three pieces, into which the piston rings are sandwiched rather than sprung.
Below: Back on Samson and we can see a displacement lubricator in temporary position, which will supply oil to the valve chest and whence the cylinder itself. Upon completion an engraved brass plate will fit within the valve chest cover seen here, making due note of the builder and location…
Below: Another general view of the engine unit atop Samson’s boiler.
Below: We have known for some time that there is a remarkable similarity between Samson’s proposed boiler design and the Heywood 15 inch gauge locomotives, particularly the Katie/Ella/Ursula engines. As the former remains (though as frames only), the middle is proposed as a replica and the latter is a completed and operation replica, we have been able to study the design in detail. At least two replica Katies also exist, with a third boiler for the original also being designed – seen here. James Waterfield, who built and owns Ursula, very kindly gave Graham Morris and myself the opportunity to study the new boiler for the original Katie at Station Road Steam near Lincoln. He was also able to provide drawings, of both the Heywood originals and the replica boilers, as well as a wealth of experience in operating this boiler and some of its foibles.
Below: A view taken inside the firebox – essentially a steel tube with tubeplate at the end. We will have a flanged tubeplate, butt-welded to the furnace tube, which we also hope to have flared rather than fitted to the backhead by an angle ring – much more in keeping with the contemporary design of Samson.
Below: Katie’s front tubeplate. Again we will have this flanged rather than welded. A hand-hole will replace the main steam pipe outlet seen at the top here, as Samson’s steam is jacketed around the cylinder and via the regulator and steam chest.
Below: Katie’s backhead. Samson will be very similar, though the regulator gland will be replaced by a steam manifold.
Below: The Heywood firehole door ring also supports the firebars and is cast to clear the rivets for the furnace tube too – we will copy this as it seems to be a usable and tidy feature and we are not entirely sure what would have been fitted to Samson anyway!
We were very grateful to James and his colleagues for their assistance and advice regarding the marine type boilers fitted to the Heywood engine and Graham is now producing the drawings that will be submitted for approval with a notified body (RSA) for approval before we order the tubeplates and furnace tube.