Hello NGDF -

It has been a pretty busy Spring for work on the C&S 1008 bobber caboose. At about the end of 2014, we realized after more inspection that the historic frame would not be practical to rebuild for an operating reconstruction. You may have seen in a prior thread in November 2015 how the nearly-complete historic frame was sent to the DSP&P Hist. Society in Como, for preservation and eventual public display. This update shows the construction of the new frame.

There were what seemed like hundreds of mortices and holes to locate and drill in the large sills, and a number of these show in the picture. In this step, the center sill is shown aligned and clamped with the two draw beams below, to complete the through holes that secure the beams together. The center sills are solid Doug Fir, 5 x 7, and the draw beams are 5 x 7 laminated white oak. Ten long 3/4" square-head bolts go through each center sill vertically.


Trial assembly of the frame continued, stacking the sills and spacer blocks outward from the center sills.The complete main frame fitted together very well. Some adjustments were needed to mortices and tenons, but nothing severe.


Next step was to mount the end beams onto the assembled frame. It seemed the best way to do this is to mark the mortices by transferring the existing tenon locations directly onto the beams. The two end beams are the only "historic" wood parts of the frame. We located large, salvaged 19th century "barn wood" at a company in Blackfoot, Idaho. These were good condition solid white oak, but there were still plenty of checks and termite holes to fill with Abatron (the white material). Following the time-test procedure, these mortices were started as a row of fostener bit holes and then hand-chileled square.


Here is the assembled wood frame, including the end beams. Yes, we know the entire caboose can't be rebuilt under the patio roof at Richard's house. But it sure made a more comfortable place to drill all those holes, and chisel all those mortices! We'll be moving it to the uncovered assembly location to start attaching the big hardware, such as the pedestals, air line, brakes, etc.


The frame is held together by 8 horizontal 1/2" tension rods that pass through from side to side. Richard had fabricated these a while ago. This shows two of the rods, and several of the holes that secure center sill and draw beam together. The square head bolts are sunk into square holes, following the original method. This allows the nuts to be tightened from below, even after the bolt heads are buried under the caboose floor.


More assembly photos in the next post.

Bob of AZ