I've not worked it out to be honest, but very steep. It's really a one way circuit, but, some of the lesser brands of loco like HLW and Bachmann will pull trains up it. My USA Trains NW2 has no traction tyres and it will pull 3 coaches up. Nothing LGB or Piko I have will even pull their own weight up, and they have tyres. In fact, as a general rule, anything without traction tyres seems to have better traction than something with tyres. I know it's steep, but not just there, LGB and Piko are so so poor at gripping. The wheels are too shiny.That looks a pretty cruel grade, what is it?