Some Bridge Scenes

The backdrop makes several of the under-construction scenes look more presentable.

Greasewood trestle was inspired by several prototype WP structures.  It combines Micro Engineering girder bridges with towers/bents scratchbuilt from Central Valley parts to closely approximate WP style bridges.  The concrete footings and abutments were scratched from styrene sheet, again following photographs.  Both will be buried to varying degrees in the finished scenery.

Elsewhere along the line are some smaller bridges like this deck girder (note that it has the same type of abutments as the trestle - this angle shows their hollow construction):

Finally there's this through truss:

The abutments here are also styrene sheet, this time based on a WP truss bridge across the Humboldt River in Palisade Canyon, Nevada.  The left abutment has wings to hold back the fill, while the right one does not.

Wonderful Job!

Congratulations on the milestone.  So did you make a gold spike to place where you installed the last piece of track for the mainline?!

It looks like you built the bridges in place immediately, rather than do as many do, install subroadbed and cut & replace it later when the bridge is installed.  Is that the case?  That is what I prefer doing myself, and I'm curious to know how many others do it that way.


Ken L.

Re: Ken

Thanks for the kind words.

"So did you make a gold spike to place where you installed the last piece of track for the mainline?"

No, since there are no spikes anywhere near the place.  I've considered painting a spike on the last piece of flextrack to mark the spot.  It's hidden inside a helix, but I'll at least know where it is.

"It looks like you built the bridges in place immediately, rather than do as many do, install subroadbed and cut & replace it later when the bridge is installed.  Is that the case?"

I build the roadbed first and cut it out later, but had the bridges mostly ready before the roadbed was finished so I didn't have to wait long to get them in.  For example the subroadbed around the larger trestle is spline, which was built in its entirety first.  I then finished the bridge, and used it to locate extra risers and other supports, finally cutting the roadbed after all those were installed.  I then added the cork and laid track leading up to the bridge.  The process for the others was similar; all the subroadbed goes in first, then the extra supports to maintain alignment, followed by cutting the subroadbed, then adding cork.

Very Nice!

Very nice, enjoyed the update this time.

Very cool.

Congrats on the milestone! 

Looking good, Rob!

Rob,

You're making great progress and it's looking good!  Thanks for sharing.

Rick

Thanks guys

I appreciate your checking on the progress.  More to come...

Nice Bridges

Very nice bridges, Rob. I especially like the Greasewood trestle- how about some more photos when you get a chance? The through truss is nicely done, too.

Tom Patterson

More Bridge Pics

Thanks Tom - by request, here's an additional selection of craptastic point 'n' shoot photos!

This shot shows a bit more of how the trestle interfaces with the spline roadbed.  Having a riser close to the abutments helps prevent the roadbed from trying to move out of alignment once the span is cut away.  Doing all this installation before adding the cork (or Homabed or whatever) keeps screws from introducing deformation into the cork.  The bridge track is from Micro Engineering, with code 83 running rails and code 70 guard rails.  It was painted black along with the rest of the bridge and then dry-brushed with acrylics to look like weathered wood.  I like how it came out.  Final weathering of the remainder of the trestle will wait until after scenery goes in.  The rails on either approach are not spiked yet, also in anticipation of removing the bridge during scenery construction.

Here's the opposite end of the trestle, looking at the abutment from a different angle.  As noted in an earlier post, the abutments are hollow.  Note the internal styrene reinforcements that help to hold the assembly square, and the notch in the spline to clear one such reinforcing piece (a continuation of the shelf where the bridge shoes sit).  You can also see some more detail of the tower.  While I built the tower to match typical WP practice, the basic assembly was inspired by the Steve Karas article that appeared many years ago in MR.

The span across the tower is a 30' girder bridge from Micro Engineering, while the remaining spans are 50' ME bridges.  The trestle was "curved" by cutting off the ends of the girders on the inside of the curve. The "shoes" atop the footings are stacks of styrene bits that approximate their counterparts on some WP trestles.  Other styrene pieces were used for gussets, including the triangular ones on both ends of the 30' span.

Now a closer look at the approach to the truss bridge.  This shows how the styrene abutment was designed to allow for the track to reach all the way to the bridge itself.  You can also see the wood ties that extend for a few inches beyond every one of these bridges to keep rail joints away from the bridges and allow for smoother track flow.  Pending weathering and scenery construction, the bridge ties are still sitting loose here, hence the minor misalignment that's visible.

Bridges

Thanks for the pics, Rob. When I saw the trestle photo I wondered if it was based upon the article that Steve Karas did many years ago. I used parts of his article for construction of one of the towers on my layout. That's a great looking trestle, and the dry brushing on the ties looks outstanding.

On your abutments, it appears that the ballast will go right up to the edge of the abutment. Not sure how the WP handled it on their abutments, but it would appear that the last regular tie before the bridge ties would have no ballast on one side (unless that thin strip of styrene at the very edge represents a thin wall of concrete that would hold the ballast back). I had the same problem on some my trestles as you can see in the photo below.

It always bothered me that the last regular tie sat on part of the concrete abutment with little ballast around it. So I checked a number of photos and found that the bridge ties are usually run onto the abutment and are held in place by the guard timbers. I am in the process of changing this on my trestles as you can see in the picture below.

Unfortunately, in some locations the abutment is too close to the rail so the last bridge tie is thinner than the others as in the photo below.

While it looks ok, I wish I planned ahead a little better on this. You may have already considered this in your design, especially if you copied the WP abutments. If not, perhaps this might save you some pain down the road after the scenery is installed.

Tom Patterson

Well done

Really nice work Rob!  Congratulations on your accomplishment.

Do you have a layout plan on-line somewhere?  I really enjoyed the glimpses that your pics allowed, and I'd like to see more.

It was great having you here to operate in May.  Stop back soon!

Abutments and Ties

Wow, Tom - you introduced a question into this discussion that I never thought to ask.  The WP photos I have don't necessarily do a very good job of showing the exact arrangement of ties at the abutments.  I have some better ones of UP bridges, which appear to show either 1) ballast extending all the way to the edge of the abutment, with the last bridge tie essentially flush with the face of the abutment and thus mostly retaining the ballast, and 2) the last tie at the abutment being long like a bridge tie but the same thickness as a regular one, and held in place by the guard timbers.  While it's a bit hard to see on my examples since everything's still sitting loose, I was intending on using option 1.  Now I'll have to do some more research and see if I should be doing things differently.  Good thing you brought this up now!

Re: Joe

Thanks for the compliments.  I don't have a good plan of this thing to share.  I build based on a scale pencil drawing, and make changes liberally based on how things look in 3-D, so the railroad as built doesn't always resemble the plan.  Before building, I laid out the benchwork outline with masking tape on the floor, and that was about the last time the paper plan got used.

I have some more in-progress photos in some earlier blog entries, but that's about it for the current layout.    Click on my user ID and you can get access to those if you're interested.  I REALLY want to get this project operational to validate the track as installed so I can get moving on scenery and therefore have something actually photogenic to share for a change.

I had a blast operating your IAIS and wouldn't mind coming back.  If your travels take you out my way you're welcome to stop in here as well.  Cheers!

Ballast/Bridge

Rob, these images are from the Thomas Sub of CSX, formerly Western Maryland. The location is 6 miles west of Kitzmiller MD where the line crosses the Potomac River from the WV side to the MD side. I took the photos because I will have this bridge modeled on my railroad. The pics show ballast/tie/abutment relationship. There are a ton more pics on my blog entry about the bridge.

Re: Alan

Thanks for the pics dude!  Your first photo above shows the look I thought I was aiming for, as does this one from your site which shows the same location from the side (click for the direct link to Alan's photo page):

Wish I had some better photos of how my prototype handled this, or if they varied depending on the bridge.  As Tom suggests, the prototype has multiple approaches beyond what I realized at first.

I started this blog post to talk about one thing, and am ending up learning about something else.  This kind of information will help make my layout better, and I hope it helps others too. 

Is that span resting right on the concrete?

Or is it because of the camera angle i can't see any "shoes" for it?

Ken L

Bridges

Not to high jack this thread, but those are some great bridge photos on your website, Alan. It appears the bridge rests on steel plates which are held in place by the odd braces at the bottom of the girders at each end and in the center of the span. I've seen a lot of bridges in my time, but I've never seen a set-up like this. The wide ties at the end of the span are also unusual. By the way, your blog is very impressive.

Tom Patterson

Abutments

After re-reading your post, Rob, I noticed that you plan to remove the bridges during scenery construction. I'm not sure when you plan to weather the abutments, but you may want to consider doing it before you rough-in and complete the scenery. You just need to be careful while installing the scenery, or cover the abutments with something. I followed this process on a number of abutments on my layout and was pleased with the results initially. But after seeing the photo below from Joe's King Creek bridge, I realized that the weathering was too light. I then went back and re-weathered eight abutments and two piers- with all the surrounding scenery complete. Even though I practiced before hand, it was nerve wracking to start applying paint over completed scenery. And while I'm please with how they turned out, luck played a large part in the end results.

By the way, the sweeping curves and turnouts in the first couple of photos really look great.

Tom Patterson

Weathering Sequence

Tom Patterson sez:

"After re-reading your post, Rob, I noticed that you plan to remove the bridges during scenery construction. I'm not sure when you plan to weather the abutments, but you may want to consider doing it before you rough-in and complete the scenery. You just need to be careful while installing the scenery, or cover the abutments with something."

My usual order on these things is to weather the bridge and abutments after the scenery shell is roughed in, just before the bridge gets permanently installed.  That way I can use the actual bridge components to test-fit into the scene as I work without fear of ruining the weathering job until the last possible moment.  Using styrene is a big help during this process since most scenery mess can be washed off readily.  I've also done some weathering after bridges have been installed, but as you indicate it's a bit tougher.

beautifull

excellent jobs

Alberto H Del Bianco  -- WP fan

Brazil

more informations

Dears Tom and Robert

I would like to know more about the layout

regards

Re: Alberto:

Thanks for the comments.  For more on the layout check my other blog entries https://forum.mrhmag.com/journals-was-blogs-891775.  You can find more on Tom's work by clicking on his profile as well, plus I think he has an article coming in the next MRH issue.