Solid Built as a one piece cast design, just like its cousin of the self-guarded variety, the solid manganese steel frog is meant for heavy traffic areas but at moderate to low speeds. Which is why placing a frog like this on a turnout off of a passing siding is an ideal situation for this type of frog design. Just by the look of it, you can easily tell that this frog sees action on only one route over it. Photo taken from a grade crossing.
