This tank model is based on D&RG engineering drawings of September 1900 with variations as we have noted on various photos, drawings, etc. The tanks on both the D&RG and the Rio Grande Southern R.R. varied in many     details from these standard plans though and, indeed, the variations were numerous from tank to tank. The support posts were not all spaced as per the 1900 drawings and the bases for the posts of several tanks were not the     concrete pads shown here. Some tanks had the frost box in the centre, others at the front. Earlier tanks had strap     iron hoops to tighten the staves, later tanks used iron rods, and some tanks had a few rod hoops fitted between the strap hoops. Some tanks had a round roof, others an octagonal roof, and the roofing material could be cedar      shingles or sheet elaterite. The Chama tank even had track and waterspouts on both sides of the tank.