The Carolina Sandhills Lines in HO Scale

[davefoxx]

. . . and we're back!  There's not been a lot of progress on the Seaboard Central 3.0 lately.  I have painted myself into a corner, and will have to make a major revision.  When I originally built the branch on the hill, I anticipated a single track crossing.  Now, that I converted the SBD roundy-round to double track, I don't have enough clearance, because the overhead bridge will require more substantial structure, i.e., deeper plate girders.  So, I hemmed and hawed and finally came up with a solution.  The existing grade is approximately 3%.  If I go to 4%, that will provide sufficient clearance, and, since the trains on the branch are only 3-4 cars long, the grade is not a concern.  These HO locomotives are heavy.

So, after experimenting and successfully using Woodland Scenics foam incline sections on Aly's layout, I bought some 4% incline from MBK, which is supposed to be delivered today.  I may get into ripping out the existing hill this weekend and starting over on the branch.  Of course, this means ripping out the only powered turnout on the entire layout.    Once I sort this out, I can design and build the necessary trestle to clear the SBD line and add a small (and much needed) staging yard.

In the meantime, I've been playing with odd projects like this.  Since I model 1983-86, an EOT device seemed like something to have fun with.  So, I bought one at a train show and transplanted the guts over to an Atlas truck (so the trucks would match).  This necessitating a lot of filing, cutting, and removal of material from the truck to allow the electronics to be transplanted.  But, success!  I really like it, and the flash rate seems realistic.  I have DCC, so, with 12-14 volts on the rails at all times, the lighting effect is reliable.  I glued the FRED to a Sergent Engineering coupler and tucked the wires up underneath to represent the air hose.  By the way, the coupler is still fully functioning even with the FRED attached.



DFF

[DKS]

What does the area around the bridge look like? There may be some alternatives to tearing out that whole branch and relaying it...

[davefoxx]

What does the area around the bridge look like? There may be some alternatives to tearing out that whole branch and relaying it...

I'll get a picture when I get home from the office this afternoon.  I think that I only have about 3" of overhead (I miscalculated that one!) and really should have closer to 4" to allow for the bridge and roadbed.

DFF

[davefoxx]

What does the area around the bridge look like? There may be some alternatives to tearing out that whole branch and relaying it...

Here we go.  The overall scene for perspective:



And, the close-up, showing the lack of overhead.  Since both tracks are on a curve and they don't cross at a ninety degree angle, the plate girders over the lower tracks need to be longer and, hence, taller.  I probably don't need to add a full 1:1 inch to the height, but I do want to clear excess height cars, such as that ICG high cube boxcar in the background.  Besides, if I'm fortunate to find HO scale Twinstack Sealand intermodal cars (like I had in N scale), I will want the ability to run double stack trains.



The Woodland Scenics 4% foam incline pieces were on the doorstep when I got home this afternoon.  I think I'm committed to redoing the hill.

DFF

[Scottl]

Good to see you back @davefoxx .  Looks great, but that first shot sure looks familiar somehow... 

[davefoxx]

Good to see you back @davefoxx .  Looks great, but that first shot sure looks familiar somehow... 

Heh, heh.  Seriously, I was proud of how that scene was coming together and would like to recreate it in HO.  Someday: Kudzu Jesus.

DFF

[DKS]

Well, I imagine you'll follow your instincts, and it will all come out just fine. But just for the sake of argument, I'd be tempted to do one of a number of things that's done in the real world.

One is to build a super-shallow deck bridge for the branchline; I have reference photos of one that's made of nothing but steel H-beams butted together across the width of the track--the bridge is maybe 16-18 inches deep from the bottom of the ties down.

Another alternative is a concrete "culvert" bridge--looks more like a short tunnel. It would successfully disguise the fact that it's a little on the thin side right under the branchline track.

Either that, or I'd do something like this:

http://davidksmith.com/modeling/video-7.htm

I'd remove a portion of the double-track curve, instead of the whole branchline, and excavate some of the foam to create a nice smooth dip under the bridge.

But hey, that's just strange me.
 

[davefoxx]

Well, I imagine you'll follow your instincts, and it will all come out just fine. But just for the sake of argument, I'd be tempted to do one of a number of things that's done in the real world.

One is to build a super-shallow deck bridge for the branchline; I have reference photos of one that's made of nothing but steel H-beams butted together across the width of the track--the bridge is maybe 16-18 inches deep from the bottom of the ties down.

Another alternative is a concrete "culvert" bridge--looks more like a short tunnel. It would successfully disguise the fact that it's a little on the thin side right under the branchline track.

Either that, or I'd do something like this:

http://davidksmith.com/modeling/video-7.htm

I'd remove a portion of the double-track curve, instead of the whole branchline, and excavate some of the foam to create a nice smooth dip under the bridge.

But hey, that's just strange me.

Your video:  Haha!  I've never seen a dump truck driver drop it into first gear so quick!

I thought about the height of the girders over the track, but I'm afraid that the distance will require more than simple I-beams.  I have a great picture of an ACL bridge over a two-lane highway that was constructed that way.  But, I figure that the distance that I need to clear is two to three times the distance of a road-width clearance.  I'm okay with this bridge being a light loading, but I'm afraid that if I go too far, it just won't look right.

The culvert is an option, but I don't think that it's apropos for the area that I'm modeling.  A simple wood or steel trestle is more in keeping with the rural North Carolina setting I'm attempting to achieve.

I actually thought about lowering the SBD main, but that would require careful alignment while plowing out the 2" sheet of foam under that track.  But, the truth is that I'm lazy.  I don't feel like ripping out that track.  The branchline will be much less work for me, and, if it takes a while to complete, I can still JFRT on the SBD loop.

Thanks,
DFF

[Point353]

Would this type of bridge work for your application?



Place the abutments as close as possible to the track - and don't forget the "close clearance" warning signs.

[davefoxx]

It would if the track on top was straight.  Since it’s an 18” or 20” radius, I can’t do a through plate girder bridge.

DFF

[pdx1955]

Given the curve on the branch and the need to cross over two tracks, can you get a long enough of a straight span to fit even with a deck girder/beam bridge? If not, you'll need to find room for a pier - which looks like a really tight fit to me unless you move one the mainline tracks to create room between them. 

[davefoxx]

I don’t know, Peter, but I believe that I have enough flexibility with the track through there that I could increase the radius over the plate girder portion, if necessary.  As usual, I’ll find out the hard way.  There’s definitely no room for a center pier.

DFF

[davefoxx]

Well, deconstruction has begun.  Here's before (2" foam cookie-cutter construction):





And now, with deconstruction almost complete (I have to finish cleaning the glue residue and foam bits out of the far end of the trench, the 2" foam roadbed blocks are being glued back in without risers:



Three pieces reinstalled and three to go:


The best part is that I still have my track center for when I begin gluing down the Woodland Scenics' inclines over the 2" foam.

DFF

[Point353]

It would if the track on top was straight.  Since it’s an 18” or 20” radius, I can’t do a through plate girder bridge.

[davefoxx]

Food for though, especially if I can increase the track radius through that part of the bridge.  The rest will be a wooden trestle, so I have flexibility on the curvature.

DFF