Hi guys. Got another question.
I want to carve a creek onto my 2" foamboard, and adding some colverts. On a average, how wide should the
creek banks be at a 30 degree angle, and how far from the tracks should I put the colverts?
For those of you who helped with my weathering of the tracks question (floquil pens), thanks so
much. They came out great!
I wish I could figure out how to download pics here!
The best thing you can do is find a prototype to use as a reference. Doing so will give you a much more realistic look.
First post is right, get a few pictures of something near you or from the area you are modeling, for reference. Actually it is impossible to be wrong. I have seen some stream/river banks that slope very gently into the water. Other places it is nearly a vertical wall and they may not be that far apart on the same stream. If it is close to the tracks or a road, you might concider some sort of retaining wall along the edge of the stream.
As for the culvert depth, deeper is better, at least a couple of feet, but there are some places I have seen them only a foot or so below the ties.
Good luck,
All you need to do is upload your pictures to a photo hosting site like Photobucket (free) and then copy the URL link they provide and click on the icon with the little tree in toolbar in the message window, then paste the URL there and click on “insert”.
As Jay noted got to www.photobucket.com and start a free account.
Follow the instructions. If you have questions along the way just ask and we’ll get you posting your pics in no time 
All the advice given, regarding finding a prototype photo to work towards, is great. However, I just “winged it” on my N-Trak module, and had some slopes that ended up more like 40 to 45 degrees. Partly, this is deliberate, selective compression to fit things into the small vignette. But I think it turned out looking rather good - see below.
I basically carved by setting my knife tip at the stream banks, then letting the angle I held the knife set the angle. Also, I use expanding foam (“Great Stuff”) rather than pink or blue foam boards - which is softer and thus easier to carve with an old steak knife. Wherever I could achieve a shallower slope I did so, but the embankment for the road in particular is rather steep - however, as this is at the back of the scene, its steepness is not apparent.
The prototype slope toward the ditch would begin something on the order of 8.5 feet from track center Slopes of loose material would be something like 1 unit vertical to 3 units horizontal or greater. For modeling purposes you could perhaps “get away” with a 1-to-2 slope.
Mark
I would suggest that you buy a commercial culvert abutment with angled side walls, and cut the depth according to the height of the culvert. One can always saw off or add to the culvert. to make it fit. The stream is often wider than the culvert arch. Bob Hahn
“However, I just “winged it” on my N-Trak module, and had some slopes that ended up more like 40 to 45 degrees”
I think it’s “wung it”. I liked the realiam of the rocks and creek.
Eric
I can’t take too much credit for the realism of the rocks… because they are real rocks! I have a small collection of stones that I gather from time to time, trying to find those with interesting detail and a “scale” appearance. I set them into my finish plaster mix so they are kinda like icebergs, half buried. I don’t use hydrocal, but rather a papier-mache + joint compound mixture, which can be troweled on thick and worked for a nice long time. I color the plaster to match the rocks as close as possible, so there are some parts where it is carved/sculpted plaster rather than real rocks. But most of the exposed rock surfaces are the handiwork of nature’s God.
To anyone seeking to model a river or creek realistically, I have but two words: Lance. Mindheim.
July 2003 MR shows how he created the photo that appeared earlier , a photo that ranks as one of the most breathtakingly realistic model photos I have ever seen.
Dave Nelson
That’s a cool photo Mark, where is it?
John
A few miles south of the Grand Canyon along the Grand Canyon Railway. View is from the platform of the parlor/observation car. The RR has a “little bridge” (includes culverts, I’ll bet) on the average of one a mile.
Mark
Actually, that’s very prototypical. During construction, the contractor basically dumps the fill and lets it go where gravity puts it. Sometimes the slope is stabilized with rock or geotexture, often not.
Some civil/soils engineer prove me wrong, but my observation has been the 1:1 slopes of loose material are usually unstable and won’t remain at that slope for very long. Observe the angle of the abutments on this bridge on a railroad fill crossing the street. The angle there is more like 1 unit vertical for 2 to 3 horizontal units (1:2 to 1:3) slope. (Although this is the Santa Fe, the egg-shaped pedestrian tunnel looks like it was directly taken from an SP book of drawings for a culvert.)
Mark
I consulted an early-twentieth railway engineering college textbook which contained sample specifications for foremation of the roadway. For embankments, the slope for earth was specified to be one unit vertucal to 1.5 unit horizontal, and for rock to be a ratio of one-to-one to one-to-1.5. Of course, these materials were required to be created in layers and be well-compacted. Loose fill material wouldn’t do with those slopes.
Mark