Don't ask me how it's done, but the snails are moving at sensible speeds. Using the bottom one as a reference, the others are moving at 2x,3x,4x and 5x faster than it.

The lowest common multiple of these is 60, so once every 60 crossings of the lowest snail, all the snails will be in a perfect staight line.

I tink it it's a variant on marquee, but don't quote me...

Bunnahabhain.

PS, this post will not exist until tomorrow.