The construction of my elabroate railway stopped for a few months after we descovered that the room was not long enough to allow for a gentle enough gradient to get the trains up onto the top level of the layout. To solve this I have proposed a Helix, but after doing all the maths, my ratio dosn't seem quite right.

Using Pi and a ruler I worked out that one complete circle of 2nd radius equates to 106 inches of track. Is this correct?

The train has to climb about 8-9 inches and I would like to use a gradient of 1:50, as I have heard this is a fairly safe gradient to use. Is that correct?

If I am climbing 8 inches at a 1:50 gradient that is 400 inches of track required. Is *that* correct?

Using all those numbers I worked out that my helix would need 3.7 complete circles to rise 8 inches. Correct?

Im not good at maths, and before I go ahead and start cutting stuff up, I just wanted to check that all of the numbering is correct. Is 1:50 a safe gradient?

Thanks for any help,

Pete.