Looking back over the year, it is quite something to think that in April, Samson was no more than a set of frame plates awaiting assembly, a pile of patterns and a set of developing drawings.  It has now reached the end of the year and it would be fair to say that progress on its construction has been nothing less than startling, and far more rapid than we anticipated.  There isn’t really a pause in the job to hold a year review in, so here is a summary of what has been happening over the last week, with the promise of much more to report in the new year…

Below: The latest focus has been on setting up the crankshaft pedestals, marking and drilling the bolt holes in the boiler and carrying out the final alignments of all things rotary and waggly in this area.  The greatest expense on the project to date has come with the festive decorations, applied to the chimney, and (discreetly!) the reverser!

Below: Samson claims his first sacrifice, as Matt is digested down to his knees!  As the apprentice, he was ‘volunteered’ for the task of tightening the temporary nuts retaining the crankshaft pedestals, at the same time learning just how small in diameter the boiler shell is!

Below: David has spent a few days in the machine shop producing the stub axle for the intermediate second shaft.  This consists of a journal, which has an interface into the casting, with a central shaft and washer that clamps the assembly together.  This is seen here – the shaft and left hand collar being hidden between the boiler barrel and the casting, the nut and collar/washers being on the outside of the assembly.

Below: The whole assembly, with the outer stub being evident as the large lump of metal here.  This forms a stub (left) that presses into the casting, and a journal (to the right) on which the second shaft gear runs.  The right hand collar retains this in place against the central collar.  The rear collar (far left) is prevented from rotating by a spigot, seen in the photo further up this post.  You will notice that the journal is offset – it is fact eccentric to the centreline and thus enables the gear to be adjusted upon final assembly, before locking in place.  This ensures that both up and downwards deflections can be accommodated, but also any wear and later discrepancy can be compensated for. Consider also that the engine unit is mounted on the boiler, which is subject to expansion when hot, but has a physical interaction through the gear train to the frames and driving wheels – in themselves not solidly connected.  All of this has had to be considered and the gears, and more importantly their teeth, must also reflect this.

Below: The stub axle of the second shaft pressed in place but without the centre bolt fitted (this needed the casting removing from the boiler to fit from the rear.  the bright surface is the journal for the second shaft gear wheel.

David plans to focus on the eccentrics, eccentric straps and keyways on the crankshaft over Christmas (homework!).  Meanwhile, the wheel centres are in Staffordshire where they are to be machined, tyred, fitted to axles and have the crankpins added.  The pattern for the axleboxes is made and hopefully these, and the flywheel, will be cast in the new year.