stevenfitch:119447 wrote:Sorry no, that was the current plan using a diamond crossing, the idea is to alter that totally to include a helix etc. the only constraints are.
Maximum two sets of points (the green points count as one set).
The size of the area.
The entry and exit are at top right.
I have come up with the below
The YELLOW is the ramp up
The BLUE is the ramp down
All of the GREY is at the higher (10") level
(* need to take into consideration the height of track and supporting structures as well as rolling stock height from rail head).
I thought I must be misunderstanding!
So the basic gradient calculation is the same, give or take, and you need a minimum of 30ft run to get max 1:30 gradient. That means on your latest proposal you need a minimum of 30ft from the point at which the blue coloured line starts, from the grey line on the RHS, to the beginning of the blue RH curve on the LHS of the inner loop.
Only you know if the length of those two straights plus the circumference of the curve, will give you that 30ft minimum. The same thing applies to the yellow line of course but since that is the outside, if it works for the blue line the yellow is probably OK as well. However don't forget that the first( upper) section of the yellow line can't actually be part of the gradient because it needs the full clearance where it passes under the grey lines to the left of the grey spur.
Its your railway and you can do what you like, of course, but to me it looks as though you are building in massive complications just for the sake of it.
