... visit us at Barrowmore so we're overdue making the return visit. Regards, Richard posted: 18 Nov 2007 04:07 from: Martin Wynne Richard Oldfield wrote: We've always assumed the gradients required to get to a new level are such that we wont be going for a bi-level solution. As you say it would also require an amount of skilled carpentry that might be better invested in more boards on one level. It's an intriguing thought, though. Hi Richard, Here you go -- idea no. 2 mostyn_hi_level.png The inner green ramp is the slightly shorter of the two. From the toe of the turnout at A to requiring a clearance at B is 6080mm. Deduct say 250mm for half of the vertical curve at A and you have an effective ramp length of 5830mm. If you design the bridge at B for minimal construction depth (say a U-channel fabricated in copper laminate with the rails soldered directly to the deck) I think you could get away with say 65mm lift at B. That gives you a gradient of ...