One reason I prefer larger than 17-18" radius, comes from watching the prototype. To me, watching a train coming around a sweeping curve is a real treat. Would be a favorite place for photos. So I want to recreate this in N scale. Boxcab E50
For the record, I use 19 inch radius curves in visible areas of the Wilmington and New York, with one unavoidable "cheat", and 11 inch radii in hidden sections and staging. It was the best I could do given the area. Since it's 1963 on the pike, 50 foot cars are about as long as things get, with the exception of a Doodlebug and RDC. But as a general and somewhat off topic comment, taking into account Gregg's (thirdrail) note with respect to the prototype, it seems that the minimum radius of the vast majority of N Scale layouts is in fact a huge compromise versus the prototype... perhaps something to recall the next time the "urge to bash" appears?
Model railroads are by nature a compromise. You just have to decide how much compromise you can live with. For example, I think the minimum radius for a real EMD F7 translated into just under an 18" radius curve in N scale. I rarely (in fact never) have seen N scale (or HO) steam locomotives that hiss and pop steam.
As long as we're picking nits... It's "H0" not "HO" And H0 is 1/87.1, not 1/87... So 17" radius in N scale would be 31.23" radius in H0. =P
Ok or is it 0k? So or/0r is it s0? Let me guess you are saying we should be saying that it is H zero not H Oh. I mean I can have a picker-nick and keep up with the best of them. 0h dear wh0 br0ught the ants? Mark, d0n't y0u like a wide b0died w0man with 17 inch curves? Did s0me0ne say we are having just t00 much fun? I thought that was the whole idea! G0t to love this H0bby!
Someone needs to tell the graphic artist at Athearn that curved letters should be about 3% larger than the rest of the letters. Doesn't that 'O' look ridiculous next to an H that is the same height? Someone needs to make these nit-picking threads more often. They're fun!
I used to live in La Grange, IL, two blocks from the 3-track BN "racetrack" AND two blocks from the 3-track IHB, which crossed under the BN near Ogden Avenue (this was sort of like being an N-scale person living on an NTRAK module). There are two interchange tracks between the two lines. I measured the radius of one of them at 500 feet, which works out to 37.5 inches in N scale. This is just about the smallest radius we could expect to find on something approaching a prototype mainline. I remember regularly seeing 89' TTX cars snaking around this curve ... very slowly (the overhang looked just like what we see on our model railroads!)... So, my take on all this is that "broad" as defined by Armstrong is anything but. This reminds me of my first job on a survey crew with the old CB&Q in 1968 (before the BN merger). We used degree of curvature to lay out curves. A curve of large radius, as for a railway, cannot usually be laid out by using the radius directly. It is much easier, and more practical to lay out a curve with a transit and a 100-ft engineer's tape. Here is how it is done: The degree of curvature is customarily defined in the United States as the central angle D subtended by a chord of 100 feet. The reason for the choice of the chord rather than the actual length of circumference is that the chord can be measured easily and directly simply by stretching the tape between its ends. A railway is laid out in lengths called stations of one tape length, or 100 feet. This continues through curves, so that the length is always the length of a series of straight lines that can be directly measured. The difference between this length, and the actual length following the curves, is inconsequential, while the use of the polygonal length simplifies the calculations and measurements greatly. A 1° curve has a radius of 5729.65 feet (or about 35 feet in your basement). Curves of 1° or 2° are found on high-speed lines. A 6° curve, about the sharpest that would be generally found on a main line, has a radius of 955.37 feet (or about 72" in N scale). On early American railroads, some curves were as sharp as 400 ft radius, or 14.4°. Street railways have even sharper curves. The sharpest curve that can be negotiated by normal diesel locomotives is not less than 250 ft radius, or 23°.
Robert: Good explanation of tangents, etc. Here is a tutorial from a railway website. I would add that this description is indeed a curve and not a tangent radius. For modeling, that makes the space required even larger. I once modeled a true tangent on a nine inch radius curve and it was very effective in allowing even 80 foot cars to enter the curve. It did not, however, help them negotiate the nine inch radius after they were in it!
His standards are based on what models can negotiate, not on scaling down reality. Remember that, to many people at least, real-life railroad curves appear sharper than they actually are. It's a common optical illusion. I'm one of those people who sees absolutely no need for huge radius (like 30" in N). It's like compression of distances between towns.
