Wednesday, January 14, 2009
A-Furnace Construction Underway
Furnace A is meant to be a scratchbuilt replica of Bethlehem Steel A-Furnace. Where possible I am trying to recreate the prototype exactly. This wouldn't be possible without the plans of this furnace drawn by Mike Rabbit. I am using the set that shows this furnace after a rebuild in the mid-1950's. The original furnace was constructed in the 1920's. The 1950s updates appear to have been mostly related to the gas cleaning systems, but I believe that the top works were redone, as well as some reconfiguring of the stoves. I chose to model this blast furnace for a number of reasons:
- I've always been a big fan of Bethlehem Steel
- The furnace is small so it will fit under my low basement ceiling
- The furnace used the older 3-pass stoves till it ceased operating - they are more interesting for me to model.
- There are a fair number of historical and present day photos of this facility
In fact, it is the only Bethlehem furnace that you can partially photograph in detail without needing permission to go on the former plant property. Despite
all this information, there are still elements of this structure that I don't have
any pictures of. Also, the plans don't include water piping, electrical conduits, steam lines,...etc. The photo above shows the raw material for the blast furnace body sitting on the floor, Mike Rabbit's plans at the ready for measuring, and the piles of shavings that results from turning these blocks of wood on the lathe.
The block was roughly 5.5"x5.5"x14.5" It was made using five 5/4x6 boards glued and clamped with yellow wood glue. I glued up blocks for A and B furnace at once, separating the stacks with wax paper. I allow the whole bundle to dry for two days and then I run the blocks through a table saw to remove the edges and give the block 8-sides. I do this to save some time turning, but also because even with the edges removed I'm at the limit of my lathe's capacity. Until the block is turned into a perfect circle the off-center block will cause the lathe to wobble and jump - the more mass and the larger the diameter, the worse the wobble. To control this to some extent I start turning at 500 rpms, until I get the block round, and then move up to 800 rpms, and then eventually 1200 rpms. In the picture above you can see the partially turned furnace body - I was working left to right, so the right side is just rounded, but not shaped yet.