Frozen Thursday

[KentuckySouthern]

A big frozen, wind whipped 18⁰with 18 on the wind gage as well. Snow is off and on blowing around like mad out across the State Hwy East of me, traffic looks slower than usual. I looked outside aftr originally posting this, it looks like an additional 2-3" of Mother Natures Bounty

Spent time on making a jig for a trestle as came up in yesterday's visit.



It took me a couple hours. No complex math involved so it went well. Plans are from a Campbell Timber Trestle kit #751, I have two kits so plenty of materials if I continue.

Staying home today. The Doll just made cornbread so I'm feasting!

Be well, stay warm. Single digits below zero w/ double digit negative chills the next 48 hrs here Scares us old folks.

KS

[Jerry]

Morning everyone

Karl your off to a great start on that trestle.

Hopefully I'll see time at the bench today.

Everyone have a wonderful day!! 

Jerry

[deemery]

Karl, on your trestle, it's interesting that the inner legs have 'batter' (slope off vertical.)  I've seen it both ways, where only the outer pair of legs have batter and the rest are vertical, and where they all have batter.  The last couple of trestle projects I did, I got lazy and did vertical inner posts.  

Off to PT in a bit, then I have to come back, change, and go to the store.  I hear that milk, bread and toilet paper are selling out in the Mid-Atlantic states in anticipation of the weekend storm. I used to wonder what people did with that stuff, but then I decided I didn't really need to know what they did the privacy of their own homes.  (But they should also buy water jugs, something I need to replenish.  The expired distilled water jugs get used for mixing plaster & Sculptamold on the layout...)

dave

[jbvb]

Good morning Karl, Jerry, Dave and later arrivals.  The lower Merrimack Valley is up to 40F with pale sun through thin clouds. My wife has set to work on her next styrene scratchbuild: 114 State St. in Newburyport, home of American Legion Post 150 in my layout's era (later, they talked themselves into a big cinderblock hall off US 1, but lost it to insufficient profit due to skimming followed by playing games with the taxes).

I appear to have found all the extant pictures of my bridge project, so I'll continue styrene fabrication after lunch.

[Jim Donovan]

Afraid I am the party popper, windows are open, 73 outside and sunny in Central Florida. I am sure it won't last but I plan to enjoy the day. I was a to finish the design and print areal hard part of the bridge project. Pretty cool when it actually comes out right!

Have a great day.

Jim



I made this from a FSM kit a few years ago for local museum. Thought I'd share the picture.

[KentuckySouthern]

Dave said: "Karl, on your trestle, it's interesting that the inner legs have 'batter' (slope off vertical.)  I've seen it both ways, where only the outer pair of legs have batter and the rest are vertical, and where they all have batter.  The last couple of trestle projects I did, I got lazy and did vertical inner posts." 

I've looked at so many different schematics, plans and prints of so many variations of wooden bridge making with timbers, posts, piles and various shapes, verticals, angles, numbers, sizes, distances that are so boggling as to drive one to distraction.  There are at least 4 different variations within the Campbell plans that I can decipher, that I can't quite figure which little group of little sticks with a solid wrap of a once rubber band is and where it could go, or not. 

Currently I am sorting out the various pieces/parts of the two Campbell trestle kits it's   Add in any thought of road curvature and the hair starts to fall out.  I do apologize for any sense of smugness on my earlier post.  This will work out.  I just need to probably quit over thinking it. 

I DO have one additional concern, the area I wish to put the trestle is a wide curve, excess of 36" but the timber trestle plans make zero reference to any curve, while the #303 and $304 kits using round dowel verticals includes and assumes curved use.  Anyone ever built the timber bridge for a curve? 

I sure do understand your mention of simplification, Dave.  From what I've seen, nothing is off the table as far as "correct" configuration.

KS

Nice model Jim.  Very nice.

[deemery]

Karl, my trestle/truss combination was curved.  Here's how I did it.


I started by cutting out the piece of spline where the bridge would go. If you don't have equivalent sub-roadbed, curve a piece of flextrack to the correct radius/shape, then lay paper over that and trace the curve with a pice of colored chalk.  Then flip that paper over, and trace the BOTTOM of the rail pattern.  That gives you a properly curved assembly jig, as viewed from beneath the bridge.

Then I decided/allocated the trestle bents along the curve.  You can use the centerline, or one of the two track lines. But you want to be able to draw lines perpendicular to the point-of-curvature for each bent.  My bents are on 15' spacing.  Draw the centerlines for each bent on the template.  Now use those to cut your stringers, from bent centerline to centerline.  The ends of the stringers will be angled (except at the two bridge end abutments.)  I did 2 stringers under each rail, and did some test sanding to make sure the joint looked good.  Here I did little splice pieces (prototypical) where the top of the trestle bents would go.


I used the track/stringer assembly to measure the trestle bent heights.  I laid down footers, then used the assembly in position to measure the height of the bents.


Now once you have the bents built, use the template that shows the -bottom- of the curve and double-stick tape, tape the stringers on the template.  Then glue each bent to the stringers aligning with the centerline of the bent location centerline.  The net result is a bridge constructed along the right curve, with the bents sticking up in the air. 


If you're using hand-laid track, you should probably lay down the ties on the inverted template, then glue the stringers to the ties. 

dave