LOL. Mate it's still hitting the low 20s (that's degrees C) here which is why they call it God's country I suppose . Any day that isn't raining is good for a topless drive Thanks for the kind words Geeky and Bob. Plywood has been ordered and will be here Tuesday. Woohoo Last (?) revision below which widens out the top inner loop as big as it will go (14.5") without a major re-think. Also used a curved turnout up in the north east sector to smooth that out. Hiding most of the west side trackage has made it appear less busy too. Thanks for those suggestions VB............it was only a 4 Panadol modification
Ahah, there's always a downside isn't there? Hiding the lower track means there is less run for the gradient which now comes out at about 3.2%!!! Back to plan "A" I think.
starting and finishing there would get you ~2% 2inches in 8ft gets you 2% do you need 2.5? [ June 05, 2005, 07:56 AM: Message edited by: virtual-bird ]
I agree...just because the tracks are hidden, doesnt mean they cant be on a grade.... Aussies say "Mate", scot's say "Aye". I think its those scoundrel englishmen who combine the 2 and dont quite get it right, as usual
I want the grade as gentle as possible and lower than 2% if possible. According to the length of the tracks from XTrkCad along the north side it has to climb 2.25"in 78" = 2.88%. I've done yet another version which gave me 14.5" radius on the inner upper loop but had to drop the most southern track (engine service). I've relocated that area to the south east for the time being but can fudge an extra 2" or 3" later with a southerly extension of the layout when my wife's not looking Anyhow, this latest version gives me 2.25" in 115" = 1.95%
Well actually the hidden tracks on version 2 can't be on a grade because then there would be insufficient clearance between lower and upper levels. The grade must also be complete by the point where the tracks cross over at the east side.
Well actually the hidden tracks on version 2 can't be on a grade because then there would be insufficient clearance between lower and upper levels. The grade must also be complete by the point where the tracks cross over at the east side. </font>[/QUOTE]Helix
I wont hijack the thread, but just like to say thanks John for all his help sending me the Xtrkcad file to play with.... I have my layout drawn on the board!!!! I'll go back to my thread now
John, hows about 'dipping' the low tracks at, say, 1%.. Dont need to go far...say, 30" of grade ach way, and your down 2/3 of an inch or so. Lets you ease up on the climbing track grade a bit.
Yes that's a very good idea Disisme. Oddly enough I was awoken from my sleep in the middle of the night (probably about the time you posted) and this very thought came to mind. Ooooohhhh - twilight zone stuff this I'm working on it as we speak. Plywood sheets should be arriving in an hour or so. Let the cutting and cussing begin
I have that problem with my buddy in Dallas... We say the same thing at the same time, all the time...its freaky, and scary.
Two sheets of 12mm (1/2") ply just arrived. VB, latest version emailed to you. Final(?) version of plan (V4) is done and shown below without the hidden track. Minimum exposed radius is now 15". Western upper loop is 15.7" with easements Gradients have been re-calculated (see picture below) thanks to message from Disisme and max is 2%. Numbers = inches elevation. Eastern lower loop dip and rise is less than 1% Still need a slight gradient thru the station to make clearance at the west end of the upper loop but I doubt it will be very visible - I won't wear glasses when looking at that area. Western upper loop industry tracks will be level of course - no reverse hump yards for me. I now need lunch and box of Panadol. John
ach...some 2.8-3 in there man.... I'm wondering why you dont just leave the elevated track up there.... seems to me your track goes up, down, then up again (though your grades all show as positives, I assume it HAS to come down again somewhere)...Hold on...are those percentages, or inches? If you're at 2" (as indicated by your big red '2"' sign), you already have abundant clearance over the low track without the descent.
Firstly guys, I did say numbers = inches on the spot elevations plan. The green dots are all zero elevation. I've thought this through as best I can. Follow my thought process and see if I'm erring: 1. The table top material is .5" (12mm) thick. Therefore, to get 2" clearance the between lower surface and underneath of the upper layer, the top elevation would have to be 2.5" when the lower elevation is 0". (2.5 - 0.5= 2.0). 2. The critical points are the north east corner and the north west corners where the tracks cross over. The controlling one of these is the north east and is the cause of the steepest grade. I plan to cheat a bit by routing the top layer and using 0.25" ply to bridge over the tracks in that area. Thus, I only need to make the elevation 2.25" to keep my 2" clearance. 2. I can decrease the grade for the far north tracks by lowering the lower tracks where they cross and/or increasing the starting elevation of the northern tracks at the tunnel exit on the north west. I've chosen to do both. 3. I can't lower the low tracks by much more than 0.25" or it will look too obvious AND it has to climb up again to the starting elevation by the yard/staging track area. I want 1% absolute maximum there if possible. 4. Because the starting elevation for the northern tracks is now .75" at the tunnel exit, the whole upper station loop area has to rise a bit. I won't use .25" ply in that area for fear of losing structural integrity in the upper loop. 5. Ultimately, this gives me a max 2% grade on the north climbing tracks up to that 2.6 spot elevation and around 1% or less everywhere else. 6. Having said all that, I could cheat a bit more by making the physical clearance 1.825" given that I won't be running any of the more modern high rolling stock but.......................... Does this clear things up a bit? [ June 07, 2005, 01:56 AM: Message edited by: JBT ]
Looking at your image there... from .75 to the 2inch marker, only takes 5-6ft? thats more than 2% (I hate maths)... or am I reading it wrong? isnt it 2% takes 8ft to go 2inch? Are you going to use a router to hack the 'lowered' section?
Yes, a 2 inch rise in 100 inches (8 feet 4 inches) is exactly 2% and yes my run is 65 inches, but remember, the elevation at the .75 point to the west is .75 inch. Therefore the maths is: 2.0 - 0.75 = 1.25 inches rise required. 1.25 divide by 65 x 100 = 1.92% or rounded up = 2% I'll lower the "lowered section" by doing the cookie cutter thing. It's only taken me most of the afternoon to figure where to cut
