Phantom Curve ...Hoodoos!

Lex A. Parker, MMR, CRC

    

Phantom Curve stretches from milepost 312.20 to 312.50 on the Cumbres and Toltec Scenic Railroad, originally known as the Denver & Rio Grande Western.  This scenic wonder is just north of the border between Colorado and New Mexico and just west of Mud Tunnel.  The pedestal rocks and tall pinnacles, also known as "hoodoos,” are formed from breccias of the Conejos Formation.  Breccia is a rock formation of broken angular chunks of rock cemented in a matrix of fine sand and sediment resulting from a volcanic eruption.  This material tends to be susceptible to erosion and weathering and because of its source, has many shades of colour from grey to red.  A pinnacle typically evolves when protected by a harder material or cap rock that remains intact above it while the exposed material below is slowly eroded and washed away.  An excellent photograph of the curve showing the tracks winding through the pinnacles is on page 19 in the publication Ticket To Toltec, by Doris B. Osterwald.  During a photo runby on a rail fan trip, I took numerous photographs of the site for future reference.  Two of them are above.

Forms

I was extremely fascinated by these formations when I saw them during a train ride I took on my way to the last Narrow Gauge Convention held in Durango.  I was looking for a unique scenic idea for one corner of my Denver & Rio Grande Western layout and decided this was it.  I wondered how I could do it.  Rock moulds would definitely not work.  I had not seen these formations modeled before.  After much thought, I began by planning the locations for the pinnacles.  I had used corrugated cardboard profiles successfully for the last few years to form the general base and support for my scenery and rock walls.  I thought this would be the best method for what would turn out to be very heavy scenery.  I cut out a general outline to the height required for each spire and attached it to the base of the layout framework.  I cut out a similar profile next for each spire, cut it vertically in half and glued half to both sides of each form, creating an 'X' in cross section.  Some of these would flow together and some would carry on down below the layout framing for a sloped embankment.  Spires located in front as well as behind the tracks added visual dimension.  I glued one inch strips of cardboard horizontally around these forms at about 4" on centre to hold news paper balls that were stuffed inside.  I occasionally sprayed the papers with water to stop their tendency to spring out of shape.

Shell

When I was completely satisfied with the contours, having done some modifications as I went along, I prepared to hold the entire lot together with plaster.  This, more than any other form of scenery building, is as close to sculpturing as you'll get.  I used Hydrocal because it dries quickly and is extremely hard and strong when cured.  I tore up 4" to 6" squares of brown paper grocery bags and dipped them into the soupy mix of Hydrocal covering both sides.  Then I laid them onto the framework starting from the bottom and working up.  By doing this, I established a strong base to support the weight of the plaster and paper mix.  If I had started from the top, the supporting structure could sag and may have collapsed under the weight.  The horizontal strips of cardboard soon became useful  because I could  wrap about one inch of the top of the paper squares over for support.  Otherwise, I found that some of them would begin to slide off and down the sides as I began a vertical ascent of application.  When I had covered the scenery with the mix, I prepared a little more Hydrocal and smeared handfuls over the entire surface to smooth it out and to make sure I had coated everything.  When this base was dry, it was extremely  strong.  At any time after this I could pull out the stuffed newsprint.