The Haining s/c ploughing engine that he designed at the same time has a fork of 7/8" radius with 3/8" straight bits passed the radius centre on both sides. So open at the bottom.

How I made the part for my engine.

Edited By MichaelR on 23/01/2021 19:04:27

I silver soldered the parts together, it could be done from one piece.

MichaelR

Richard,

I have sent you a message with some modification notes.

Best regards

Paul

Richard,

The email address failed, so did the PM, so I am sending this drawing through the forum, it seems the only route I can get it to you.

This drawing is the John Haining design for the firehole door, for some reason it appeared in only a later series.

Haining designed the door ring arrangement to avoid putting screws directly into the copper backhead. As your boiler is steel, you might choose to attach the ring directly, though with steel screws, you may never get them out, and with bronze screws there is a risk of electrolytic corrosion inside. I made mine as shown, except I used a thin copper liner, not a steel one, with tabs bent up inside to retain it. This is fine.

Make the latch big enough for stubby fingers, when hot, you will be flipping the door open and closed frequently. It has to close securely, if it swings open you will lose the fire.

Regards

Paul