Tuesday, April 7, 2015

Building a California tankhouse

In early California, many farms and even homes in small towns had their own well. To obtain the convenience of indoor plumbing, an elevated water tank was built to provide water pressure in the house. Many of these structures naturally had open framing below the tank, but over the years it was common to enclose the support structure, and even the tank itself. The result was a distinctive structure, readily recognized once one knows what it is; they are named “tankhouses.”
     These structures were built in California from the 1860s to the 1930s. Eventually the development of centralized and town domestic water systems made them obsolete, though a fair number remain standing today. The photo below is from the Wikipedia entry on “tankhouses,” and was photographed in Sonoma County. (The entry is at: http://en.wikipedia.org/wiki/Tankhouse .) This one still has its windmill to pump water into the tank, rarely seen today.

The presence of windows is fairly common but not universal, often added when the support structure area was put to some other use. We take weekend trips to nearby Mendocino, California from time to time, and there are many different versions of these tankhouses throughout town.
     Because these are distinctive California structures, I wanted to build one somewhere on my layout, and decided that it would be appropriate as the water supply for my stock pen. The nice thing for modelbuilding is that there is no visible framing, so it can be made entirely of siding, adding only corner trim boards.
     I had some leftover scribed basswood from a laser kit, and the board size seemed all right for one of these structures. The space I have for it has a base about 10 scale feet square. For the first story, I cut trapezoidal pieces 10 feet wide at the bottom, 7.5 feet wide at the top, and 11.5 feet high. These were airbrushed the SP depot color, Colonial Yellow, using Tru-Color paint no. 153.
     I assembled these in my usual procedure, using a square piece inside the corners to give  more gluing surface. Note that although the side pieces are trapezoids, the horizontal cross-section of this part of the building is square at each level. This means that square corner pieces work perfectly. I used Evergreen styrene strip, 1/8-inch square, for these corners, and clamped each pair of sides in turn with reversed clothes pins, as you see here; the horizontal-positioned pins in this photo hold the styrene to one of the sides, the other pin holds the other side. This worked quite well.

     When all four sides were assembled, it looked like the photo below. Although the four sides are of identically dimensions, the final building is not square, because two of the sides overlap the other two. The slightly rectangular building that results is not inaccurate; I have seen a number of these structures whose base was not square.

Trim boards will be applied to the four corners to conceal edges.
     At this point the upper story can be added, merely a small house-shape, usually with a protruding floor of heavy planks (which support the bottom of the water tank). I will show the completed structure in a future post.
Tony Thompson


  1. Tony, Great choice of structures! They sure are vanishing fast around here... Are you aware of the HABS drawings of the Krohn family's water tank in San Martin, CA? They have a half dozen photos and 3 scale drawings here: http://tinyurl.com/mkpafsm. Good source for details! - Eric

  2. Great link, Eric, thanks! I did not know about the HABS choice of one of these structures. Everyone note, the Library of Congress photos and drawings can be downloaded by anyone. Note that the Krohn structure, like the one in Sonoma County shown in the post above, has a one-and-a-half to two-story base, which is a common style, but many of the ones I have examined close-up in Mendocino have roughly single-story bases. That is the style of the model I am building.
    Tony Thompson

  3. My home town of Los Altos, CA has several, including a refurbished 1915 example at its History House museum. I built a model of one about 40 years ago as a teenager, not long after I started reading local resident Bob Brown's Narrow Gauge Gazette. The model is long gone, but now I shall have to have another.