Daryl's amazing railroad tattoo (San Francisco)

Train tracks, switches and tunnels cover his entire body, front and back, from head to toes (litterally), in a perfectly symetrical and seamless pattern. He designed the tattoo and said it took 200 hours of work to realise the work.

Daryl spent many years of his life "freight train hopping", which involves countless days of walking long miles along desert tracks.

The structure formed when two rails are crossing is called a frog (in french, it's called "coeur de croisement").

There are two technical errors in this part of the tattoo. Can you find them without looking at the Notes on the photo?

Check my other photos of Daryl's railroad tattoo.