Des Plaines River Crossing Part I

I have begun construction of the Des Plaines River crossing located in Maywood, IL which is just east of the Proviso Yard.  The bridges used for this crossing are a series of steel girder spans supported by four very long cement piers.  The four piers are much longer than needed to support the steel girder spans.  I'm guessing they were built this way for possible future expansion, but I am not certain.  Below are a couple of pictures of the prototype.

   Since there are no commercially available piers that match the prototype, I decide to mold my own piers with a scratch built styrene mold and poured plaster.  I came up with the dimensions of the piers using measurements from google maps.  I also used measurement from the actual location on the layout as I needed the height of the piers to match the existing track alignment.  Styrene sheets were cut and then glued together for the mold.   The mold does not have a top or bottom which allowed me to slide the hardened piers out without breaking the mold.

   I used liquid cement to join the joints of the mold.  After giving the liquid cement 30 minutes to dry, I mixed up some plaster to the consistency of a chocolate shake and poured it into the mold.  The plaster I used was "Smooth It" from Woodland Scenics.  I think just about any plaster would do fine.  I choose this product only because it was what I had on hand.  It worked quite well with the resulting pier being heavy and dense.  The wet plaster was too much for the thin styrene walls of the mold.  So, I used a couple of weights to keep the walls of the mold straight.  After about 10 minutes, the plaster was firm enough for me to use a small piece of styrene to clear off the top of the plaster.  After a few hours, the plaster was hard enough to remove from the mold.  The plaster was completely hard and dry overnight.

   Here are the four piers placed where they will located for the crossing.  I'll post more as I continue with the project.