# Wooden Arch Bridge -- Progress Updates.



## xo18thfa (Jan 2, 2008)

A couple of weeks ago I posted some photos of the start of a wooden arch bridge as part of a portable steam layout I plan to build. Work resumed after a short break and the arch truss phase is done and so work will soon start on the abutments. Here is the current status as of 28 Nov. 



















The idea came from a “Google” book search for wooden arch bridges. Two very nice ideas came up so I combined features from both. I believe these are French streetcar bridges. Here are the ideas I got from a “Google” book search

http://1stclass.mylargescale.com/xo...ea%201.JPG

http://1stclass.mylargescale.com/xo...ea%202.JPG

This file is the original download from Google and shows some more detail.

http://1stclass.mylargescale.com/xo...Bridge.jpg

What follows now are the details of the construction.

Best place to start is with the most difficult parts, the arch assemblies. Here is what the base arches look like when they are done.










I am not exactly sure the names of the various parts, so I made up my own. For reference purposes, here are the names of the parts:










The upper and lower arches are glued up bent wood laminations. The laminates are pine, 1/8” x 3/4" in section. There are 6 laminates on the lower arch and 5 on the upper. A rather elaborate jig ensures that glued up arches and consistent and tight. The jig starts out as a series of MDF rectangular blocks screwed down in their approximate locations on a plywood or particleboard backer. Here is the rough jig:










The inside row of blocks will form the lower arch. The middle row forms the upper arch. The outside row of blocks are for clamping during glue up. It is important to number key the blocks to the backer board. The blocks will come off the backer board a few times during the glue up process. The blocks have to go back into their original positions or the jig will not line up correctly.

Right now, the jig is not ready to use. The block are still square and not in any kind of accurate location. The next step is to “set” the jig with the proper radius. Cutting the correct radius is easy to do with a router attached to a trammel arm and turned like a compass.

Here is the router set up to cut the radius. Note the trammel arm has 4 pegs holes. One for each radius to cut:










Swing the router like a compass to shave off the MDF blocks to the proper radius.










Don’t try to take the whole cut at once. It is best to take 3 passes, lowering the router a bit each time. Here is the jig with all the radius cuts.










With the arch jig done, stop for a break. Next time we’ll start gluing up the arches.


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## jimtyp (Jan 2, 2008)

WOW! I wondered how you got those arches to look so good.


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## Mr Ron (Sep 23, 2009)

That is quite impressive. I suspect you are also a woodworker. With those jigs, you could make a few bridges for sale. I can appreciate all the work you are putting into your project. When I'm building my models, I use a lot of jigs as I have a lot of duplicate parts to produce.


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## up9018 (Jan 4, 2008)

Very nice looking bridge Bob, keep the updates coming, can't wait to see how it looks when you are done. 

Chris


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## Torby (Jan 2, 2008)

Astounding!


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## Madman (Jan 5, 2008)

Incredible workmanship!!!


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## tom h (Jan 2, 2008)

The talent here on MLS never ceases to amaze me, great job! cant wait till its done.

Tom h


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## Grimm (Oct 5, 2009)

Awesome!! It is looking too cool for words. 

Jason


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## smcgill (Jan 2, 2008)

Way to go Norm!!


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## SE18 (Feb 21, 2008)

that's a terrific idea with the router and trammel and pegs for radii; nice craftsmanship too!


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## Ted_Roy (Jan 2, 2008)

Beautiful work! Outstanding craftsmanship. I cannot wait to see it finished. Keep up the in-progress pictures though, it is an inspiration to us all. 

Ted.


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## Richard Weatherby (Jan 3, 2008)

My kind of bridge!!!! I hope that I can borrow that design? A beautiful piece of work.


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## Doddy (Jan 23, 2008)

As soon as I saw the build quality in the first picture posted, I thought Huh! this is going to be interesting.

The laminated strips reminded me of the technique used to build replica WurliTzer Stoprails for Theatre Organs. To see those methods used to make what is looking to be a great bridge is very welcome.


Great work - subscribed !


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## John J (Dec 29, 2007)

The detail of the cross braces and the angle blocks is what impressed me. 

Are the tracks going to go on top of the arch bridge or between the arches?


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## Steve Stockham (Jan 2, 2008)

_ Very_ impressive! I an really enjoying seeing the incredible workmanship displayed here on MLS!


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## Cap'nBill (Dec 27, 2008)

"Part of a portable steam"...., give us an idea of the concept so we can dream along with the build. What incredible patience to take on such a build! Just the jig is a marvel in workmanship. Bill


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## xo18thfa (Jan 2, 2008)

Thanks to all for the kind words and positive feedback. Possibly this weekend I can start on the abutments, but for now I can post work to date.

Ron: I use jigs a lot too. Most of the are just slapped together from scrap on the floor for a single purpose. But some end up very complicated and take days to make. There are so many in the shop now I forget what they are for.

SE18: Commercially made trammels are available, but it is just as easy to make them. Then they are the exact size you need. This one got extended 18" from its original size at the last minute.


Richard: If you want to copy the plan it is OK with me. I figure once something is on the Internet, it belongs to everyone.

John: The rails go on top. This is a deck type bridge. Most of our local club member's layouts are standard gauge. Us narrow gaugers can't operate on them. I don't want a narrow gauger or a 7/8" scale showing up and not being able to run.


Bill: The portable I have in mind generally follows this from Mr Duval in France:

http://1stclass.mylargescale.com/xo...e_indB.pdf

The only differences are to use dimensions to fit standard lumber and plywood. And make the corners in mitered section so the are a little broader. The bridge abutments will have an adapter panel of some type to match the modules. I suppose a regular 48" section can substitute for the bridge as well, if needed. Phase I of the layout will be a rectangle oval with a double main line and some short sidings on the straights. Phase II is an attached yard.


Thanks again to everyone. Next part soonest.

Bob


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## xo18thfa (Jan 2, 2008)

Once again, many thanks to all for kind words and stopping by for a look-see. 

Now it is time to use the jig to glue up the arches. The arch laminates get a bead of glue, a quick line up, a little bend by hand and dropped into the jig. It is a good idea to lay down some pieces of wax paper on the jig ahead of time. Otherwise the arch will stick to the jig (did that once). The laminates get clamped securely in the jig using the outer form blocks and wedges. Here is an arch in the jig:










Here is a close up of the wedges that clamp the arch against the jig:










Clamp the laminates into the jig starting at the center and working outwards. Lay down the laminates by hand and thumb press a wedge into place. The end wedges may need a little tap with a hammer to get the laminates laid down. Have a damp sponge ready to clean off glue squeeze out.

Here is the first arch glue up out of the jig.










Glue up the remaining arches the same way. Unfortunately, glue will squeeze out on the bottom side of the arch and there is no way to clean it off while it is still wet. Those sides will face to the center of the bridge, where nobody can see them.

To my very pleasant surprise, there was almost no spring back in the arches when they came out of the jig. More importantly they all came nearly identical.

Screw down the center row of form blocks and start on the upper arches:










Glue up the upper arches same as the lower.










Next time will get on the parts between the arches.

Thanks and take care, Bob


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## lownote (Jan 3, 2008)

This is very interesting to watch--thank you. 

I remember years ago talking to a guitar maker, who told me that a lot of his work was making jigs and fixtures, and that a lot of what he talked about with other luthiers was...jigs and fixtures. He said he still did a lot of things free hand, but nothng beats a well designed and well planned jig


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## xo18thfa (Jan 2, 2008)

Lownote: There was a show on TV “How it’s Made” I think, they were making violins. Jigs that would not quit, dozens of them.

Now it is time to do all the parts that go between the arches. I used maple for these parts. Maple cuts and drills much cleaner than pine, with no tear out. And since these arches are under considerable compression by the tie rods, maple will not compress or deform as softer pine.

Start with the angle blocks. At first I thought the upper and lower angle blocks would be the same. But after doing the math, I found out they are very different. The lower angle blocks have an angle of 21 degrees and the uppers are 27. To make the blocks, cut a strip of maple with the table saw blade tipped to the correct angle. Cut both sides. Use feather boards to ensure the strip stays tight in place:










Crosscut the strip to form individual angle blocks. 

All the cross braces, angle blocks and arch spreaders between the arches are pinned together with 1/8” wooden dowel pins. This involves drilling hundreds of holes accurately and consistently. Trying to layout all these holes with a ruler, one-by-one, is impossible. The use of drilling jigs on the drill press is the way to go. Correctly set jigs will locate holes quickly and perfectly every time. Here is an example of a drilling jig used in the drill press vice for the angle blocks










Little jigs like this assemble in no time from scrap lying on the shop floor. Make sure that the jig is accurately located and that it’s clamped down tight. Notice that the drill bit is choked up short in the chuck. This prevents “wandering”. Use a sharp drill bit and run the drill press fairly fast. In no time, all the angle blocks are drilled perfectly.










Glue the lower angle blocks to the lower arch. Only the lower angle blocks get glued. Everything else goes in dry and is compressed together with the tie rods. Trying to measure the location of the angle blocks is difficult and slow. Instead use a gauge block to accurately space them out. 










Next make up the arch spreaders. I don’t have any pictures of the arch spreaders, but they are done the same way as the angle blocks.

Now it is time to do a preliminary fit up of the arches with the angle blocks and spreaders only. Use the lamination jig to help with this step. Line up the arch spreaders and upper angle blocks as best you can by eye. Then clamp the upper arch in place.



















When the preliminary fit up looks good, measure each of the 28 positions for the cross braces. Take the average of the measures and use that number for the length of the cross braces. When I did the math, the cross braces should have been 2.908”. In reality, they came out to 2.903”.

Make the cross braces from 1/4" square maple. Drill a hole in the end of the cross brace to accept the 1/8” dowels. I found it easier to assemble the arch using a slight larger drill than 1/8” for the cross braces. Use a #29 (.136”) drill. This drilling jig for the cross braces has a more vertical orientation then the jig used on the angle blocks. But the idea is the same.










Still have a lot of work to do before assembling the arches. Next time is intermediate stringers and a lot of metal work.

Thanks and take care, Bob


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## Totalwrecker (Feb 26, 2009)

Wow! 
It's a pleasure to watch you work... 

John


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## peter bunce (Dec 29, 2007)

Hi, 

Nice work, I knew there was a huge amount of work involved ion these wooden bridges but not as much as you have found out.

Here in the UK there was a number of these bridges some of which were viaducts. there was one at Ouseburn, near Newcastle on Tyne that had five arches, and a local one at Broadbottom had three arches: here is a photo of that from the web. 











Increasing traffic meant that replacement was needed and they were replaced with iron or steel spans after a short time, with rot of the wood no doubt playing a part in our wet maritime climate. Broadbottom and its very close cousin at Dinting were replaced by iron girder spans on the original pillars. Later still extra pillars were needed which destroyed the symmetry of Dinting viaduct. Both are still in use. 

Thank you for the photos they are very interesting, I'll bet you are glad that you do not need to build 5 arches though!


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## Matt Vogt (Jan 2, 2008)

Fantastic work as always, Bob!

That's a shame that the spacers came out 5/1000's short. Since you probably want to just start over, email me for my address so I can get rid of your prototype...









Seriously, though, I have always wanted to build a similar bridge, and while I'm sure it won't be up to these standards, this will help immensely! 



Take care,
Matt

PS - Love the stripwood sawmill you helped me with!


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## xo18thfa (Jan 2, 2008)

Thanks John.

Peter: That an interesting photo. Thanks for posting. That span look like one of the options in the book I found. I thought these were just light rail, but it looks like they wre main line too. 

Matt: Well, it was a tough decision and a gamble to deviate from the plan so much. Actually I am just trying to show off. Thanks.




Looks like some "honey-do's" this weekend, but maybe get started on the abutments.

Bob


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## xo18thfa (Jan 2, 2008)

Before assembling the arches, build up the intermediate stringers with the packing blocks. The stringers and blocks are 1/2" x 3/4" pine. With the arches still in preliminary fit up, layout and measure the stringers and packing blocks. The angles look complicated, but in reality there are only 3 angles. The intermediate stringers are mitered to for a 25 degree angle. The packing blocks are either 5 or 10 degrees. The miters on the intermediate stingers are glued with a 1/4" oak dowel pin. Drill the stringer end for the dowel pins by tilting the drill press table and using a fence.










Glue the stringers together with a little fence jig to ensure consistency:










Glue on the packing blocks and the intermediate stringers are ready to install.










Now it is time to make the tie rods and tie plates. The tie rods are 4 x 40 TPI stainless steel threaded rod. McMaster-Carr has threaded rod in 6-foot lengths. Measure the required lengths and cut. I found it easier to cut the threaded rod with an abrasive wheel on a Dremel tool, rather than using a hack saw. Put a nut on one end of each rod using Loctite #242. Home Depot has Loctite #242. The nuts are the “small pattern” type from McMaster Carr. They give a better appearance than regular size. 

The tie plates are 1/8” x 3/8” steel. Cut to length and clean the ends up on a grinder. The same kind of wooden jigs work fine for drilling steel. They don’t last as long, but they work. It is a good idea to “spot drill” the tie plates with a centering drill before drilling thru. It prevents the drill from sliding around on the steel surface. Drill the tie plates to match the threaded rod.










It is finally time to assemble the arches. I originally thought of using the lamination jig a to aid in assembly. It proved too cumbersome, so I just juggled all the pieces and assembled them on my lap.

Start assembly by plugging in the arch spreaders and cross braces into the lower angle block










Coax the upper angle block into the cross braces.










Thumb press the upper angle block onto the arch spreader. It’s coming together.










Place an upper arch and an intermediate stringer assembly in place. Line everything up and lightly clamp together.










Now install the tie rods and plates. Start with middle and work outwards alternating sides. Once they are all in, retighten. The ties in the middle will probably be loose.

Finally the arch assemblies are done. The hard part is over.



















Next time we will get on the truss work above the arches

Thanks and take care, Bob


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## harvey (Dec 30, 2008)

Beautiful work, so nice to see some wood construction. This is a great demonstration on the use of jigs and boy do they make life easy as well as making all the parts the same. They are well worth the effort and the results speak for themselves. Just a great job and a delight to look at. 
Thanks for sharing this with us.


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## Steve Stockham (Jan 2, 2008)

Most impressive indeed! I feel like I've just attended a masterclass on woodworking!


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## xo18thfa (Jan 2, 2008)

Steve and Harvey: Thanks for the kind words. Had a chance to work on it this weekend and got a good start on abutments. It’s really looking like a bridge now. 

The truss assembly above the arches is next. Up to this point, work has been “mass production”. All duplicate parts are cut at once to the same size. Assembly is just like doing an old fashion tinker toy set. But along the way several little errors crept into the work. Even tho the arches look identical, they are not. From now on it is best to cut and fit remaining parts individually.

To build the upper truss work, get out a long straight edge and measuring tools. Measure each vertical individually for height and horizontal distance from center.










The verticals on the upper truss use 1/4" oak dowel pins in each joint. Drilling 1/4" along the top of the arches was difficult. To make it easier I fashioned a jig to hold the arch steady on the drill press table.










Next, drill the upper stringer to accept the verticals. Layout each individually based on measurements taken earlier. Set up a fence on the drill press to ensure each hole is in the middle of the stringer.










Each vertical requires a 1/4" hole to accept a dowel pin. Tilt the drill press table to 90 degrees and set up a fence. Clamp a block at the bottom to support the vertical. Once set up you can drill a million holes perfectly centered every time










When all the parts are cut and drilled, it’s matter of assembly like a tinker toy set. Most of the verticals went in with a light tap of the hand. Some were stubborn and need a little more coaxing with a clamp.










Before moving on, a note about dowel pins. Wood dowel pins make for easy and strong joints in model building. Before using a dowel, measure the diameter. Some of these pins come as much as 1/32” off, plus or minus. Measure and use the correct drill.

Every once in a while an “oh crap” happens. In the above photo there is a short clamp sticking upward. One of the shortest verticals split apart during assembly. So I just laid in the glue thick and put on a clamp. It seems to hold. That happened twice. Another “oh crap” happened when of the short verticals got too long after gluing in. All of the careful measuring and still screwed it up. To fix it, I just re-sawed the joint with a thin kerf “ryoba” saw, poked in some glue and clamped it down. The thickness of the saw blade was just enough. That happened twice too.










These trusses are very strong. So from now on there is no real need for fancy joinery. The remaining pieces go in with glue and 23 gauge pins. The diagonals go in next. Measure, cut, glue in and stake with a 23 gauge pin nailer. Many of them ended up identical, so they get cut as a group and adjusted as needed.










The cross braces are just glued and pinned.










The arched trusses are finally done. They look sharp. There are four trusses, two in the middle and two on the outside. It is time for a beauty contest to see which trusses go on the outside for the public to see.



















With the trusses all done, it is time to start on phase II, the abutments.


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## coyote97 (Apr 5, 2009)

THATS A HIT!


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## sbaxters4 (Jan 2, 2008)

Posted By coyote97 on 14 Dec 2009 03:24 PM 
THATS A HIT! More like a HOME RUN!!!! In my book that is.... LOOKS GREAT!


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## Richard Weatherby (Jan 3, 2008)

I am glad that you did not show us the final product first, because each step makes it more remarkable than the previous. This is a true masterpiece. I just love how wood can perform just like iron & steel.


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## placitassteam (Jan 2, 2008)

Fantastic wood work. That takes a lot of patience to cut all the little pieces. I never though of using dowels, all my bridges are pinned and glued. I have noticed that I have to tighten the truss rods every once in a while.


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## xo18thfa (Jan 2, 2008)

Many thanks for the kind comments to those who stopped by for a look.

It is time to get started on “Phase II”, the abutments. The abutments are just wood boxes that secure the truss ends and decking. Trim embellishments and a paint finish will give it a nice carved stone look. First thing to do is use an adjustable bevel to capture and then measure the angles on the truss ends. 










They should be fairly close to the same. If not, check the top stringer. It may be a bit long and could use a trim. Average the angle of the eight truss ends and use that figure to start on the abutments.

Do the abutment sides first. The angle is based on the measurement from the trusses. Do the truss side in two pieces and laminate together










The rest of the roughed out abutment boxes are just a “glue and screw” job










Go ahead and drop in a truss to see what it looks like.










The trusses get attached to the abutments by screws into the arches and upper stringer. Trying to screw into the soft pine is not a good idea. Instead, drill into the arches and stringers and glue it a short length of oak dowel. The oak will give a more durable bite for the screws.










Next add some blocks for the trusses to rest upon. These eventually become part of the “stone” look of the abutments. Add a strip across the top. The upper stringers rest under these. They ensure the trusses are consistent in height. Carefully measure and drill for screws.










Turn the abutments upside down and drop the trusses onto the ledge. Use an awl to punch the location of the screw holes into the oak dowels on the truss ends. 










The punched mark never lands in the center of the arch ends. But that’s OK, as long as it hits the oak. It is important to number key the trusses to the abutment so they go back into the same spot. Drill a pilot hole into the punch mark. Use a somewhat large pilot drill. Only the screw threads need to bite the wood, not the shank. 

Assemble the trusses into the abutments. The upper stringer rests against the ledge, but will not reach the abutment box. Add a “stone” block behind it and tighten the screw. Now it’s looking like a bridge.










A significant disaster occurred during assembly. Twice I missed to pilot hole on the upper stringers when driving in the screws and went into solid wood. I got about a half turn and split the stringer about two inches. If that happens, disassemble and take out the cracked truss. Drive a screw into the split and open it up. Open up the crack, but try not to make it longer, it’s already bad enough. Jam a glue bottle into the crack and pump in glue. Push the glue deep in with a pin. Withdraw the screw and clamp the split. Re-drill the pilot hole a bit bigger, just in case it has an idea to split again. 

When I took the above photo, one of the middle trusses was still split. The next time it comes apart is for final painting of the abutments. The split gets fixed then.


Now comes the moment of truth. Measure the diagonals of the abutment corners. If they are equal, the bridge is square. This one turned out fine, so leave it at that.


Next time we will start the deck and work on abutments trim.

Thanks and take care, Bob


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## Gary Armitstead (Jan 2, 2008)

Bob,

Absolutely beautiful craftsmanship!


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## Trainwreckfilms (Aug 19, 2009)

Could i pay you for the plans for an 8ft span? lol no but seriously i am interested....


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## Trainwreckfilms (Aug 19, 2009)

BTW BEAUTIFUL!!!!


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## xo18thfa (Jan 2, 2008)

Colin: The plans for this bridge came from a Google Books search for wooden arch bridges. I found one image that shows two types. I did not get the name of the book, just downloaded the image.

This is the original download

http://1stclass.mylargescale.com/xo...Bridge.jpg

From this came two half images.

http://1stclass.mylargescale.com/xo...ea%201.JPG

http://1stclass.mylargescale.com/xo...ea%202.JPG

These images got "blown up" on Microsoft Power Point to half size, printed out in sections and taped together. That's all the plan. I use bits and pieces of each and make up some of it along the way.


In fact, I have another bridge to do for my steam layout and this is all I have for an idea so far:

http://1stclass.mylargescale.com/xo...ge%201.JPG

Thanks, Bob


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## Madman (Jan 5, 2008)

You would have no problem finding a job in a cabinet shop


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## aceinspp (Jan 2, 2008)

I do not think there are words to describe your talent. Oh well how about looks cool. Later RJD


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## xo18thfa (Jan 2, 2008)

Last week after the abutments and trusses went together I measured the diagonals of the bridge to see if it was square.










Last week it was squared, this week is was not. Some how it decided to shift around and was out of square enough to need some fixing. Most of the time only way to fix an out of square situation is with a little brute force. Stand the bridge upright with the long corner on the floor. Get over top and give it a squeeze.










My son Andy has the touch. He got it back in square. Real engineer types call this “crush to fit”.

It’s time to lay the sub-deck members. Clamp a straight edge lengthwise on the abutments. This serves as a stop so the sub-deck members line up. 










Use two little spacer blocks to ensure the members get spaced correctly. Work from each end and meet in the middle. With the sub-deck in it looks more like a bridge.










Next I added some blocks on the corners to serve as ends for the hand railing. If I did a better job of planning, I would have included these in the construction of the abutment boxes.










Now it is time to turn these not-so-good looking abutment boxes into something that looks like stone. A variety of trim pieces and brick embellishments, covered by paint, will make that happen. 

Disassemble the trusses and start adding some trim work. Take the extra time and effort to miter all the trim work to cover any end grain. Wood end grain takes paint differently than with the grain. It is better to hide the end grain inside a mitered joint than risk seeing it thru the paint.










That’s it for now. Next time we will start adding the brick work and get the abutments ready for paint.


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## Bills (Feb 20, 2008)

Bob, 
is this going outside? Fantastic project, thanks for taking us through the process! 
Bill


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## CapeCodSteam (Jan 2, 2008)

Did your shop taker over a kitchen? If so. I'm envious


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## Jerry Barnes (Jan 2, 2008)

Wow, that is something else!


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## jimtyp (Jan 2, 2008)

Bob, if someone had said this was possible a month ago I'd have said, no way! But there it is, absolutely gorgeous!


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## xo18thfa (Jan 2, 2008)

Thanks guys. I greatly appreciate the support.

Bill: No, this is part of a portable layout (yet to be built). It will live mainly indoors. For outdoors it would have been cedar, teak or cypress. More nails and screws, less glue.


Kent: That's a spare reefer in the shop. The shop is partitioned off from the garage. 

There is still a lot of experimenting to do. Painting the abutments is a test for today. Lots of changes along the way too. Things get cut off and re-done. Lot's damage repair also. Thankfully there is an overkill of screws, nails and glue that if something breaks there is still plenty holding it together.

Thanks again, Bob


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## xo18thfa (Jan 2, 2008)

It’s time to start adding the brick work to the abutments. Bricks are small blocks of wood glued to the abutment bases. Eventually the finished abutments get a few coats of primer and then a top coat of a textured paint with a “stone” look.

The bricks start out as long strips of clean, tight grained wood. To give an appearance of a mortar joint, set up a router table with a 45 degree chamfer bit. Run the strips thru lengthwise just taking off a little chamfer. Use feather boards to ensure the stock stays tight against the fence and on the table. Feather boards also keep your fingers away from the bit. 










To make individual bricks, set up a stop on the miter fence and slice them off one at a time.










The ends of the brick also need a little chamfer to simulate a mortar joint. There is no fast, production way to do this. Just buff them lightly on a disk sander, one at a time. It takes a while to do this step.

The first bricks to go on are the corners. The corners require a little extra work in that they are mitered from 2 pieces. 










Apply the corner bricks starting at the top and working down. Mitering the corners gives it a nice “wrap-a-round” look.










Once the corners are on, start applying the field bricks. Start on both sides and work towards the middle. Any short bricks or odd cuts should be in the middle and not on the ends. 










The chamfered blocks give a very nice texture.










I am not sure if real masons would lay bricks diagonally, but it looks nice.










Next time we will finish up the brickwork. The other day I did a successful paint test with the textured paint. It turned out fine. The textured paint should look good on the abutments.


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## Grimm (Oct 5, 2009)

I'm very amazed at your work, lots and lots of fine detail work. This bridge will most definitely be an heirloom piece. 

Jaosn


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## xo18thfa (Jan 2, 2008)

Continued work on the abutment brick work. Applying the field bricks on the first abutment did not work as well as I hoped. I started by aligning the bricks along the top edge, working from the sides to the middle and top to bottom. 










When I got it all filled in I noticed that the mortars were not quite straight. I was not very noticeable, but needed to get fixed on the second abutment. To get better alignment of the bricks, draw parallel lines every few rows. This is similar to a real mason pulling a leveling string.










Lay a row of bricks along each line, then fill in between the rows.










This method worked much better. The brick rows are straight from top to bottom.










Draw parallel lines where ever field bricks go in. The bricks will always line up. Also start laying bricks from the side and work to the middle. Fill in the middles, edges and where ever else with bricks cut to fit. Abutments are finally done.










Set the trusses in and have a look.










Really looking good. The stone paint should make these look super nice. 










Next time we will get started on the railings.

Thanks and take care, Bob


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## Grimm (Oct 5, 2009)

Wow!! That's impressive. 

Jason


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## xo18thfa (Jan 2, 2008)

Thanks Jason, very much appreciate that.
The railings are the last major assemblies before “going final”. 
Here is what the railings look like finished:








I had a difficult time staying with the original dimensions I worked out. Form some reason the railings had a mind of there own, so instead of sticking to the plan, I just tried to make everything consistent. Thankfully they turned out fine.

Start with cross members. The cross members go together with a lap joint. Lap joints are strong and greatly help putting the cross members together. Cut the cross member stock extra long. Set the miter gauge on the table saw to the proper angle. Set up a stop block and cut the lap joint in each cross piece.








The miter gauge set up makes every cross piece identical








Lap joints usually line up themselves, but it is a good idea to use a jig to glue up the cross members. The crosses need to be consistent in angle.








Cut several extra cross pieces and glue them up. The extras come in handy, to cover any mistakes later. Gluing in the jig got all the cross pieces identical.








Now it is time to cut the cross pieces to form corners. Make up a little holding jig like this. Make it oversize for now.








Set the table saw fence to make end cuts first. The first pass of the jig thru the saw will cut it to length as well.








With the first pass done, turn the cross piece and cut the other side.








With this same setting cut both ends on all cross pieces. When that’s done, turn the jig 90 degrees to cut the top and bottom of each cross pieces. Just as before set the table saw fence, make the first pass thru and then cut the remaining cross pieces. 








The results of the effort are perfectly identical cross pieces with clean 90-degree corners.







http://1stclass.mylargescale.com/xo18thfa/Arch Bridge/Railing 9.JPG[/img
The hard parts of the railings are done. Next time we will finish the handrails.


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## audi84 (Jan 13, 2008)

Looks super, Bob, but when do you sleep ?? 

audi84


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## Totalwrecker (Feb 26, 2009)

Forget the texture paint, seal it with clear and let your work speak for itself! 
That is an awesome bit of Craftsmanship and art! 
Bravo!

John


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## kormsen (Oct 27, 2009)

i think this bridge should be put in the masterclass section.


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## sbaxters4 (Jan 2, 2008)

Absoulutly Incredible!!! No words even come close to how fantastic this project it turning out! When you started I was thinking that I would try to do something like this for a bridge I need but as this has gone on I must come to terms with my inability to even attmep something of this level.....  First I don't have the space, I also do have the tools and I really don't have the patience or the fine detail craftmanship to even come close! Thanks for sharing!


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## Mr Ron (Sep 23, 2009)

Hi Bob, All I can say is; a beautiful job. Too bad all that brickwork is hidden by the bridge structure. I'm curious as to why you didn't make the bricks in long strips instead of individual bricks. That's what I would have done.


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## xo18thfa (Jan 2, 2008)

Thanks fellas. Appreciate all the kind words.

Looking back now, leaving the bricks in strips would have been easier. And more consistent. That one will go in the after action report for next time.

The abutments are painted already. Did them in the textured stone paint from Home Depot. They turned out nice. 

The next command decision is the finish on the bridge itself. I am leaning towards a coat of spray-on Thompson's Waterseal on the whole thing. Stains or oils may be a problem. There are all kinds of glue blotches on the wood. I tried to keep it clean, but I know they are all over the place. Oil and stain may not penetrate well thru glue and leave a spot. Since this bridge is for a steam layout so there will be of water splatter around. Thompson’s is probablt the best way to go.

I test sprayed a piece of the texture paint and it works fine. Texture still looks great.

The bridge is almost finished. Only have to lay the track and it's done.

I have decided there is one rule on the layout: NO alcohol engines.


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## xo18thfa (Jan 2, 2008)

The cross pieces were the tedious and time consuming. With them done, the rest of the handrail constructions goes quickly. Start assembly of the cross pieces by cutting the posts that go between. Using a straight edge, glue the posts and cross pieces together.










This first assembly is to just hold the posts and cross pieces together. Next glue on the top and bottom rail caps.










The rail caps add a lot more strength because of more gluing surface. Add a little more reinforcement with a 23-gauge brad into each post.










For a little extra trim appearance ad a second, wider rail cap on the top and bottom edge.










The handrails need to rest on feet. In real life rainwater would collect on the bridge surface along the handrail and rot things out quickly. The feet provide drainage, plus they look good. The feet are glued in place and secured with a dowel pin made from a toothpick.










Glue the feet into pre drilled holes and the handrails are done. They get fitted to the bridge during final assembly.










The handrails turned out nice. They also ended up surprisingly strong. They certainly won’t take a hard bash, but should do all right. 










Just can’t resist seeing what the handrails look like on the bridge.










Very nice.










As of this afternoon, the bridge is actually finished. Got the track laid today and the railings on. All that's left is a coat of Thompson's and the rest of the construction series. Next time abutments get painted and trusses go together final. Also have to get the top deck and a little more trim work.


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## up9018 (Jan 4, 2008)

Wow, that is beautiful Bob! 

Chris


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## CapeCodSteam (Jan 2, 2008)

This keeps getting better and better


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## xo18thfa (Jan 2, 2008)

All the fabrication work is pretty much done. Time to get on with painting the abutments and final assembly. To paint the abutments I used Rust-o-leum brand “American Accents” stone textured spray paint from Home Depot. This particular color is called “bleached stone”. Here is how they turned out:










The camera does not get the color very well. Bad lighting in the shop probably. It’s a light cream color, “beige”, the women call it. It’s a good color










And a very quick look with the trusses dropped in.










The paint is easy to use, but there are some tricks I learned during the test. Priming is very important. Use an oil based white spray primer. Water based primers will raise the grain on the wood and leave a fuzzy texture. Brush on primers could leave brush steaks or fill in fine detail. Spray on three light coats of primer to avoid runs.

The texture paint sprays on thick and lumpy. At first you think all the detail is done, but as it dries, it lays down and the detail returns. Spray several light coats of the texture paint until you get the look you want. I ended up with three coats. Wait 15 to 30 minutes between coats. The texture paint takes a long time to dry. Leave it at least over night before handling. 

The texture paint comes in various colors. I used the lightest color. It works fine over the white primer, but if you ever use a darker color texture, paint the surface with topcoat paint first. This texture paint is primarily texture. It does not have a lot of color in it. Much of the final color comes from what is underneath.

Another thing is that texture paint does not fill gaps. I thought it would since it goes on so thick. In the end, it does not. Any gap in the woodwork over about 1/32” needs caulk or filling.

The bottom line is that the use of wooden block and trim covered with textured paint to simulate masonry worked better than I imagined. I will use the technique again. The next logical step is to weatherproof it somehow for full time outdoor use. 

With the paint work done, it’s time to assemble the trusses to the abutments for the last time. Screw the trusses back into the abutments. When all the screws are in, withdraw them one at a time, coat with glue and put them back in. Glue coated screws hold very strong. If you have a glue bottle with a long needle tip, squirt some deep into the hole, just to be sure.

Start applying the deck covering. Carefully mark the centerline of the bridge over its full length. Start laying the deck planking from this line and work outwards.










Put a small drop of glue on each cross beam. Pin the deck planks down with 23 gauge pins just enough to hold them in place. As you work outwards, measure to the edge with a ruler to ensure progress is uniform. If things get uneven, put in some very small gaps between the deck planks as needed so that the last plank goes in spot on.










When all the planks are in, very lightly draw pencil lines across the deck surface on centers of all the beams. Fill in with 23 gauge pins on each plank on each beam. Nothing looks nicer than long straight rows of evenly spaced nails.

Lastly, apply some trim work to cover the ends of the beams.










Looks like the deck of an aircraft carrier










That’s about enough work for now. Next time we will nail down some track and finish this project up.


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## denray (Jan 5, 2008)

Bob 
OUTSTANDING absolutely OUTSTANDING I am glad to hear this is not an outside bridge, with all those small pieces you have to think and rethink your cutting technique inorder to keep the fingers. I know a couple guys with short fingers due to small pieces. Great modeling 
Dennis


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## coyote97 (Apr 5, 2009)

thats really unbelievable.

Many people say its no art to rebuild an objekt in scale.

But this shows: IT IS!

Besides the need of much patience, you need a good eye to see how it is prototypical and how it can be done scaled. 
I dont know if with this project anything can be done better?!?!?!? 

Its real deep fun and admiration just to see the photos!

Frank


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## chuckger (Jan 2, 2008)

Hi Bob,

WOW, That's one **** of a bridge. A super, super job. Really enjoyed watching the build on this one. Thanks for sharing.

Chuckger


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## Dwight Ennis (Jan 2, 2008)

That's one helluva piece of work Bob, and one helluva piece of art!!







You are a master craftsman!


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## kormsen (Oct 27, 2009)

well,Dwight, you are a moderator. 
so i guess, you could make this bridge immortal by putting it into the "masterclass" area. 
it sure deserves it.


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## Tim Hytrek (Jan 2, 2008)

WOW Bob. That is AMAZING!


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## Richard Smith (Jan 2, 2008)

Bob, 

You have raised the art of woodworking and modeling to a new level. That is some of the finest wood modeling I've ever seen. Marvelous!!!


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## Dwight Ennis (Jan 2, 2008)

well,Dwight, you are a moderator. 
so i guess, you could make this bridge immortal by putting it into the "masterclass" area.Actually I can't. However, I will submit the idea.


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## xo18thfa (Jan 2, 2008)

Thank you very much for all the kind words. I really appreciate them very much. This one actually got finished this past Friday. It was very exciting to get the last parts on and finally see it all done. No more imagining.

Dennis: Keeping fingers out of the way is a big deal. There are two major ways you get hurt. First is during production cutting, you can get in a hurry and not pay attention. Second on a deliberate cut you check to make sure everything is lined up, but forget to inventory the location of fingers. You have to be careful.

Frank: For the plan I blew up the old ink drawing on a copier to half size, and measured off of that. Elevation drawings are easy to do, perspective drawings or photos are much more difficult. When the arched trusses got finished, the drawing was only a guide, hoping to get it close. 


Many thanks again. Next time, this one will be done.

Bob


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## xo18thfa (Jan 2, 2008)

All that’s left to do is lay down some rail and attach the handrails. There are probably 100 ways to hand lay rail and probably an easier way than I did it. First measure between the narrowest obstruction on the bridge. Half of that width is the distance between track centers. 

The rail is Code 250 from Llagas Creek. A friend gave me about a mile of it, so that’s what’s going in. The spikes are 20 gauge wire nails, half inch long. 

Cut the ties to the desired size. Set up a small angle stop jig on the drill press to drill one spike hole in each tie. Each hole ends up on the same spot on each tie










Glue and pin down each tie. Ensure they are in straight row and the drilled holes are on the same side. Start laying ties from the middle and work outwards.










Push in a spike in each hole drilled on the drill press. Forceps work better than fingers. Hand drivers work better than hammers.










Lay a rail tight up to the row of spikes. The row of spikes should be straight. If not, pull out the offenders and re-drive them. Drill a pilot hole tight against the rail foot and drive a spike in half way. If everything looks good, drive both spikes home.










Using a track gauge, secure the second rail in place. Drill pilot holes on both sides of the rail. Drive in both spikes.










Do both sides and it’s done.










Last thing to do is install the handrails. Glue them down on each foot and pin nail on both sides. Mostly likely you will have to fit some take-up blocks between the ends of the handrails and the end posts on the abutments.

With that, the bridge is done. It has yet to receive any kind of finish on the wood. I was thinking about using Thompson’s Waterseal, but a buddy of mine suggested using a siloxane based sealer. Siloxane is a concrete sealer and is more penetrative then Thompson’s. It turns out that the stone textured paint takes about a month to fully cure. So there is plenty of time to think it over and do a test.

In the meantime, here it is:




























I took the bridge over to Clark Lord’s for a photo-op with his Southern 4-4-0 “Schools” (Aster) and a Bullied coach (David Leech). That “Schools” looks right at home.

http://1stclass.mylargescale.com/xo...ne%204.JPG

http://1stclass.mylargescale.com/xo...ne%205.JPG

http://1stclass.mylargescale.com/xo...ne%206.JPG

Many thanks to everyone, both here on the board and in private for your support and advice thru the whole effort.

Thanks again, Bob


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## Torby (Jan 2, 2008)

Speechless.


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## Grimm (Oct 5, 2009)

Awesome job, looks great!! You should have gotten a picture with two engines on the bridge going in different directions. So, how much does it weigh? 

Jason


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