Shasta State Historic Park, CA 

Keystone Driller / Shasta Steam Tractor


Historic Core DrillerThe Shasta Steam Tractor is a four wheeled vehicle on un-sprung axles fitted with steel wheels. The tractor is self-propelled and powered by a single piston connected to a vertically oriented riveted steel boiler with integral firebox and stack. It is believed that the tractor had originally been constructed as a steam powered core driller used in the mining of ore and coal. The machine was built by Robert M. Downie of Butler County, Pennsylvania, owner of the Keystone Driller Company. The Keystone Driller #3 was designed for the petroleum industry in northwest Pennsylvania but soon became important prospecting machines for coal, zinc, lead, and gold and was used the world over. This portable drilling rig was designed with a double beam superstructure and folding A-frame mast, which would be raised to accommodate the drilling line and spudding sheave (a type of drilling apparatus). The steam tractor, as now configured, appears to have been a salvage or adaptive re-use of the frame and power source of the Keystone Driller for agricultural purposes. Keystone Driller Company literature describes this model as having been “improved” with the diagonal cleats added to the rear wheels; this information suggests that the Shasta Steam Tractor was a 1906 or later model.



Before Treatment: Shasta Core DrillerThe wooden frame rails have been badly damaged by weathering over years of unprotected display, causing the wood to split and become weakened by fungal decay. Bolts protruding through the wood have also allowed moisture to penetrate the interior of the beams, rotting the surrounding areas. As a result, the diagonal tensioning rod bolts have pulled through the deteriorated wood causing the weakened timbers to collapse under the weight of the boiler and front axle. The boiler has tilted to the rear and rests directly upon the soil. As the tractor collapsed, the steering shaft and diagonal iron tensioning rods were badly deformed. The wooden floor boards, which appear to be mid twentieth century replacements, are also badly rotted and have been fractured during the tractor's collapse. The undercarriage components have been pressed into the soil and continue to deteriorate at an accelerated rate. The iron components retain less than 20% of the vehicles original and / or in-service paint. Most, if not all of the metal components have been painted several times during the period of historic use. Exposed metal surfaces are corroded and moderately pitted overall. Areas of active iron corrosion are evident on the large drive wheels, and in areas where organic debris has collected, thus holding moisture in contact with the iron. The rear drive wheels are worn and abraded from use; however, they remain structurally sound. Many of the original components are missing, and accession files indicate that the drive gear and shaft are lost. In addition, numerous pipes, steam fittings, and gauges are detached and missing.



During Treatment: Shaping Reproduction TimberThe Shasta steam tractor (Keystone Driller) was photographed, examined, and all wooden components were measured and working drawings prepared prior to beginning conservation and disassembly of the driller. All wooden elements were locally milled and shipped to the B.R. Howard & Associates, Inc. conservation facility where they rough shaped before being shipped to Shasta, CA . The replacement timbers were finished on site; comparing remnants of the deteriorated timbers with the working drawings and measurements. Each timber was sawn and drilled to match each contour and bolt location found on the originals. Areas of active corrosion and scaling found on the iron components, fittings, and hardware were mechanically cleaned and/or chemically stabilized. All metal components were then given a protective lacquer coating using a reversible synthetic resin prior to re-assembly. The replicated mid cross member and the original piston support cross member were then bolted into position on the underside of the left and right frame rails. The front axle braces were secured to the mid cross member before the boiler was lifted into position using a boom crane supplied and operated by Redding Crane Service, under the supervision of employees of B.R. Howard & Associates, Inc. The straightened and repaired diagonal iron support braces which ran from brackets, bolted to the boiler, down to the upper side of the frame rails were then reattached to the boiler and bolted to the wooden frame rails. The steering column and worn gear were disassembled; the iron column was straightened. The steering mechanism was reassembled and reattached to the boiler and the worn gear was bolted to the proper left frame rails using original brackets and hardware. Adjustable jack stands were fabricated and installed under the boiler, piston, and fly wheel to help support the areas of greatest weight, thereby reducing the stress exerted upon the wooden frame rails.


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