Thursday, November 2, 2017

Little John Creek Bridged!

The bridge at Little John Creek is supported by stone abutments with the scenery roughed in around the bridge.
At long last, Little John Creek has been bridged. Just south of Farmington,
this water course is crossed by the Copperopolis Road. Up until now, the crossing has just been a piece of 3/4" plywood. I had been planning to install a cast iron Phoenix-style bridge but hadn't quite figured out how to make the Phoenix columns.
     The prototype columns were constructed with four pieces of cast iron, each formed in a quarter circle. Flanges were then riveted together to form a hollow tube. I ended up by using a styrene tube with .020x.020 styrene strips glued around it. With the size of the tube and the distance from the viewer, you just don't see whether or not there are rivets. The rest of the bridge was constructed with other strips and shapes of styrene. To build something similar, see Jim Vail's article in the May/June 2001  Narrow Gauge and Short Line Gazette. I used Jim's article plus drawings for a similar bridge in the California State Railroad Museum.
     To facilitate track cleaning and eventual scenery, I decided to make the top part of the bridge separate from the track-bearing portion and removable. The trusses themselves were made using a jig to ensure that the two sides were alike. Chooch stone bridge abutments were used but had their height and width cut down to match the location and bridge. They were then colored with acrylic paint to match the colors of other stonework in the area where my railroad ran.
     The bottom part was eventually glued to styrene bridge shoes and to the abutments. The plywood temporary bridge was then cut out beneath the track and the roadbed and ties removed so all that was left were the rails. The rails were then coated with Barge cement on their undersides. Wooden wedges made from construction shims were coated with white glue and slide under the abutments gradually lifting them until the rails just touched the bridge ties. They were left to dry and then a small heated iron was used on the rails to melt and the glue and bond the rails to the ties.
The abutments are in place with the bottom part of the bridge lying in place beneath the rails.
Glue-coated wedges allowed the abutments to gradually be slipped beneath the rails. The excess parts of the strips were sawn off after the glue dried.
     Typical scenery forms made from cardboard strips overlaid by kraft paper forms the basis of the adjacent hillsides and riverbed. Eventually, plaster cloth will be added to form a hard shell.


  1. Lovely bridge - the first Phoenix type construction I have seen modeled. If you had a prototype with more than 4 ribs, in HO scale a potential material is the inner "rod" from the Gold'n'rod Rod and Tube cable material used by model airplane enthusiasts and those of us who use Blue Point turnout mechanisms. It is essentially a tube with flanges, six or seven I believe. Modeling a Phoenix Iron bridge is on my someday list, as they were once quite common and I model the late 1920s when they would have still been in use on short lines and other lightweight trackage. The N&W had some massive (length) Phoenix truss bridges but replaced them when tonnage got to be too great for the line. I imagine since the bridges were pin connected they may have been disassembled and sold off to other lines.

    1. Great idea! I've even got some of the Goldenrod laying around. I'll definitely keep it in mind for another bridge.