Saturday 10 June 2023

Engine Fitted To 4415!

Come on down and see for yourselves!  All of this frantic work on the body is of course to enable KS4415 to make a public appearance in Porthmadog during the Welsh Highland Railway 100 event on the 23rd-25th June. Who would have thought that the engine would be fitted before the event? Martin Greenland, Blackburne donkey engine restorer par excellence, that’s who.


A number of the completed components are going on to give a taste of the engineering as well as the appearance of the locomotive. No surprise that the MDB4 is still at Farndon Engineering. The above view shows the cab interior, partially fitted out with the petrol starting engine, starting gear box and radiator. There is a similar view in 15/- Change (which we can flog you out of the back of the cab if you have not already got one).
Now you can play ‘spot the difference’ and complain about the recess on the flywheel and the missing Diesel engine, the front hatch cover is removed in the old view,  no cab handrails in the new…

Ha! Cab handrails now planished (drawing 33362 refers). The one on the right is the replica, turned up by Rob Bishop and all of them have  been planished to within an inch of its life by Rob Collins. They are upside down in the photograph.

This view shows the handrails fitted, together with the cab back and driver seat (both original components).

We have had to let some new steel into the cab back, the majority (coloured red oxide) is original. The angle iron stay stiffens up the back sheet to ensure that overweight drivers do not buckle the sheet, another largely original component with a repair to the top. All of the other angle components are new.


To give the front elevation a bit more character the hatch handles have been recovered from the old hatch and fitted to the replacement.


So, looking more complete than it has done in many a year, 23rd-25th June will see this marvellous Diesel pioneer out and about. Come on over, see the beast, buy the merch!

Thursday 8 June 2023

Making a spectacle

Like a moth to a flame I’m drawn to the awful and predictable pun, even though the Kerr Stuart drawing refers to them as a windows. Going back in time to the 17 October 21 blog, the mechanics of the window catches were described when Bob Smith and Adam Livingston were busy making the patterns, the castings from which arrived back in time to make an appearance in the 16 February 22 entry. Norman Bond has subsequently produced the patterns for both the round and rectangular windows and the components for these have been cast too, arriving during the special Christmas of 2022 with the injectors, governor body and a box of new drills to make all those rivet holes.

Our machinist man for these little jobs, Dave Linton (who is also our little man for machining jobs) has put some considerable mental effort into working out how best to set up the various bits for machining. This is the clamp set-up used in the four jaw chuck of the lathe to turn the catches and hinges.


The hinge castings and bearings are seen here post machining. The castings with the slots are the lower hinges to the windows.


The slots allow the hinge to clamp onto the pins, to hold the window in the open position.  The full assembly is shown here, with the wing nuts also machined by Dave.


Who also made all of the other brass components required to fit the hinges to the cab sides. 


Like all blokes who have kept something in their shed for years, he was particularly pleased that the kitchen worktop offcut from 1999 made a wonderful mounting plate to support the round windows for machining.  It is seen here mounted on a rotary table, being used to machine  two castings to make them into a matching pair. 


The drilling in the lower picture came first but it is hard to envisage the ingenious rotary table set-up from the drilling view. Worth capturing the moment in case you want to try this at home.


With all four castings drilled and mounted on the board Dave then put the whole set in in one of the Dean Smith & Grace lathes at Boston Lodge to skim them.


The various components, with the exception of the catches to hold the windows shut, are seen here in a dry-run assembly on the loco. It is curious that the bosses are outside the cab, requiring a slot cutting in the cab front.


Mounting the windows in this way moves the centre of the hinge pins outwards, allowing the hinges to be almost flush with the cab sheet (as shown in the drawing below). 


Another minor detail that is so nice to get right, which can be seen in the photo below: