Helix Designer

Plan a helix: enter the radius, how much it climbs each full loop, and how many loops, and see the grade it creates, how much track and height that adds up to, and whether each level has room to clear.

The “real grade a train feels” adds the curve penalty (about 32 ÷ radius percent in HO) to the geometric grade, because a continuous curve drags like extra grade. Check whether your engine can pull the train up that grade with the Grade Pull calculator, or read the physics in the glossary.