I’ve clearly not been doing enough blogging recently, whereas quite a lot has been happening- although these two facts may not be entirely unconnected. More to come in future posts, but one thing I must update is the progress on Blyth. Dave Humphreys has sent us a very image-heavy email detailing the recent progress, including the machined brake cylinder parts shown in an earlier post.
This is the bronze liner for the brake cylinder, ready to be shrunk into the outer housing. This process uses the expansive properties of the metal- either the outer shell will be heated to cause it to expand, or the inner liner will be cooled to create the opposite effect- creating clearance to fit the liner into the outer shell. When both regain the same temperature, the expansion (or contraction, depending on the method used) will hold the two immovably together. It’s the same method used to shrink steel tyres onto railway wheels.
The above is the steel shell, machined to receive the liner above. The end cap for the cylinder is seen in the lathe, in the process of machining. How nice it must be to have all the equipment on hand!
From brake cylinders to locomotive cylinders- the end covers for the cylinders have also been cast and machined- shown here is one of the rearmost covers. The centre bore of the end cap will take a bronze gland to make a steam-tight joint around the piston rod. The two sockets above and below this accept the slide bars, which guide the piston crosshead, just as in the picture of Scaldwell’s crosshead that I included in the previous Blyth post.
The slide bars have also been manufactured, and are pictured still shrouded in their packaging. They will remain this way until fitting, to avoid damage.
Pictured below are the two front cylinder covers, plus the spring hanger bolts for the leading Adams truck. I know from experience these covers contain much more material than you might at first think, and weigh a commensurate amount.
And last, but by no means least, the brake shoes have been cast as well, all of which means we are coming very close to a rolling basis for Blyth.
An image hungry post, but it brings us up to date vis-á-vis Blyth. Much more, as I say, has been going on at Blyth Road, but that will have to wait, as the Rev. Awdry used to say, for Another Story.