In my last blog entry - was it really two weeks ago - I mentioned I had started to give some thought to the roof girders which support the two inner pitches of the roundhouse roof.
The three pitched roundhouse roof has four supports - the outer walls form two - the other two are 4' high latticed girders each supported by four cast iron octagonal columns, situated under the two troughs of the roof .
I obtained these columns from Colin Seymour - Alan Gibson - as left over stock from the EM Bath Green Park project that Alan was involved with - they are cast in whitemetal.
Having now obtained sufficient stocks of brass and nickel silver section - courtesy of Eileens & Metalsmith Ltd - I decided today to make a start.
Here is my scale drawing of one of the 46' lattice girders, six of which are required for the two girders together with four shorter ones each 18'6" long.
The top and bottom of each lattice girder is formed from pieces of 'T' section - 5mm x 3mm - obtained from Metalsmiths. This special section is milled and includes a 0.5mm channel down the centre which I have used to insert and solder lengths of 2mm x 0.5mm nickel silver strip - Eileens.
The 4 verticals were cut first and soldered into the bottom 'T' followed by twelve diagonals from the same material.
Finally a piece of 5mm x 0.5mm nickel silver has been soldered at each end to form the vertical 'T' section.
The next job is to cut the twelve pieces of 2.5 x 1.5mm 'T' section brass to form the outer diagonals at the two ends [ they are 7.5" wide] and 2mm x 1.5mm 'T' section for the twelve inner diagonals [ 6" wide ] and solder them in place. To complete each girder a rivetted overlay - top and bottom will need to be formed and added.