# The Bollman Bridge For “G Scale”



## irondan (Jan 7, 2008)

The Bollman bridge will be our new project this is a very interesting bridge in Maryland. We are going to be making the G scale version of the this Bridge; below you can read a bit about it. Then I will add pictures of the process of making the replica.
The Bollman Truss Railroad Bridge at Savage, Maryland is the sole surviving example of a revolutionary design in the history of American bridge engineering. The 160 foot double-span truss bridge is one of the oldest standing iron railroad bridges in the United States. It was the first successful all-metal bridge design to be adopted and consistently used on a railroad. The type was named for its inventor, Wendel Bollman, a self-educated Baltimore engineer.


















The bridge was built for an unknown location on the main line of the Baltimore and Ohio Railroad in 1852, and was moved to its present location, spanning the Little Patuxent River on the spur to the Savage Mill, in 1887. The bridge remained in service until the mill closed in 1947; switching crews used additional cars in order to avoid crossing the bridge with locomotives, and thus there was never a need for a more substantial structure.
The Bollman Bridge is a two-span through-truss, resting on granite abutments at each end and a granite pier in the middle of the river. The truss structure is a mixture of wrought and cast iron. The truss configuration is the design patented by Bollman as the “Bollman suspension truss” in 1852. Each span is 79.5 feet long, 25.5 feet wide and about 21 feet tall. The Bollman truss suspends the deck from a network of tension members, while the top chord resists compressive forces. The system is therefore referred to as a suspension truss.
















The truss includes decorative elements, such as Doric styled vertical members. The cast iron end towers, which bear transfer the weight of the structure to the abutments and pier, are also detailed. A decorative and protective metal enclosure at the top of the towers was lost to vandalism, but was replaced during the restoration work. Metal strips at each portal read “W. BOLLMAN, PATENTEE”, “BALTIMORE, MD.”, “BUILT BY B&O R.R. CO.”, “1869″ AND “RENEWED 1866″. Replicas of the original strips were installed during the restoration.
The bridge was brightly painted, using red oxide for the towers and the heavier compression members and an ivory color for the lighter tension members.




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The first thing we did when we started the construction of our bridge was to replicate the decorative elements: The Doric vertical members and the metal strips for the portals.




























To make the metal strips, the front plates were drawn and then cut on a computerized plasma cutting table, then flat bar was attached around the plate to complete the front strip. 





























Once those two custom components of the bridge were made, we could move on to making each side of the bridge.












































After we had two sides for the bridge we started to connect them. 




















































The Finished G scale version is 11 feet - 4 inches long, 13" tall and 14-1/2" ID - 18" OD., wide enough for double track.




































































The bridge will get powder coated and after it is installed it will be painted as the original, red with white accents. This should be a nice bridge to look at and to run trains.


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## Big65Dude (Jan 2, 2008)

Absolutely fantastic work! Well done!


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## Larry Green (Jan 2, 2008)

This project is a work of art. Please let us see the painted bridge in place. 

Larry


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## altterrain (Jan 2, 2008)

What a beautiful project. I have been up there to see the real thing. 

Maryland is filled with all kinds of neat bridges like this retired lattice steel one near Cockeysville, Md. 



















-Brian


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## altterrain (Jan 2, 2008)

Ran across pics of the Bollman bridge here - http://www.historicbridges.org/mary...photos.htm 

-Brian


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## jimtyp (Jan 2, 2008)

Great work Dan! Absolutely astonishing! 

Brian, that is a gorgeous bridge! Someday if I get a CNC mill to create the lattice work ....


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## Mike O (Jan 2, 2008)

That's really a work of art Dan. I've seen that bridge and your work capturs detail graceful lines perfectly. The Bollman Truss was also used to cross the Potomac river at Harper"s Ferry. 

Mike


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## coyote97 (Apr 5, 2009)

Yes, i lift my hat!

Frank


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## Al McEvoy (Jan 3, 2008)

Beautiful bridge Dan! A real tribute to Wendel Bollman, who for a short period was the Baltimore & Ohio RR's official bridge designer. A Bollman Truss was used to span the Patapsco River just north of Ilchester Tunnel on the Old Main Line into Ellicotts Mills (now Ellicott City). Good photo can be seen at http://www.trainweb.org/oldmainline/omld1.htm about two-thirds of the way down this page. The excellent 19th century photo can be clicked on to see full size.


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## John J (Dec 29, 2007)

This isnt for that Ohio Dude?....We are going to have to chaned his name from Chillie Charlie to Crazzy Charlie. 
That is a great looking bridge. I like all the fancy decorative work on it. I like that big white one that Brian posted. YOu gona try that one too/


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## Stan Cedarleaf (Jan 2, 2008)

Dan, that's just awesome. What a great addition to "someone's" layout. It's a *DAN*- dy...


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## bottino (Feb 7, 2008)

Fantastic work again Dan. Liike Altterrain I lived very near that bridge, but unlike him, I am sorry to say, I have not seen it. My daughter lives near there now, so I will make the effort to see it myself. Are you revealing where it will end up?
Paul


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## Nicholas Savatgy (Dec 17, 2008)

Dan is the man........See you at e.c.l.s.t.s.


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## xo18thfa (Jan 2, 2008)

Very beautiful work. The decorative iron work is fabulous. When it comes back from powder coat, it will be like a Christmas present all over again.

Bob


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## smcgill (Jan 2, 2008)

Holy Cr*p Batman Dan's done it again!!


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## aceinspp (Jan 2, 2008)

Very nice indeed Dan. Glade to see you increased the height to accommodate the stack pack cars. Hopefully there will not be to many rivit counters going for the originality. Later RJD


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## SE18 (Feb 21, 2008)

This is pretty astounding. Looks like a fun project!


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## xo18thfa (Jan 2, 2008)

Ive reviewed this post at least a dozen times. It gets better each time.

What's the bridge they just demolished across Lake Champlain in New York? That would be a beauty too, at least the center span.


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## irondan (Jan 7, 2008)

Hello Guys 

Thank you for your all your comments, they mean a lot to us specially coming from people like you that really know your train stuff.

I want to thank Glenn Shadduck for trusting us to build his dream bridge. We also want to make a special mention to Johnny one of our custom fabricators, who did a great job of putting the bridge together. 

Everyone at the shop and people stopping by were very excited about seeing this project come together. 

By the way the bridge is back from getting powder coated … enjoy:










































Lately we have been working on some very interesting projects, there is a couple of them coming up that we would like to share with you. 

Stay tuned we’ll be back on this same bat-forum.


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## irondan (Jan 7, 2008)

Yes, we saw that on AOL and I was just thinking the same... It was a nice bridge.


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## xo18thfa (Jan 2, 2008)

Really nice work. That powder coat is gorgeous. Pardon me for putting on my long haired, dope smoking, hippy artist hat for a minute, but you really have to "feel" the final product in the raw material. If the zen is not in the bar stock, the project ain't gonna happen. You guys really let it out. Great show. Looking forward to the next.

Bob


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## Richard Weatherby (Jan 3, 2008)

Absolutely beautiful!!! It is truly a work of art. I can appreciate the work as I have also built this bridge in HO. I have the drawings somewhere. It is a historic structure which has been documented as one of the civil engineering wonders of the world. The truss rods actually split in two to allow the others to pass through. A combination of cast iron and wrought iron. An engineering masterpiece.


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## up9018 (Jan 4, 2008)

Beautiful work Dan!!! Starting to make me wonder if a big fancy steel bridge would look out of place on a logging line......hhmmmm


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## Dean Whipple (Jan 2, 2008)

WOW.....that is a piece of art....WOW.....


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## chaingun (Jan 4, 2008)

Dan, Great job as usual. I will say it again… 
Sir, you ARE a steely eyed railroad man! 
Best, Ted 
Ted Johnson 
GYT&S RR 
(Grit Your Teeth & Spit RR) 
Bouse, AZ


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## lathroum (Jan 2, 2008)

Can you do one half as long? 
I live in MD... not too far from that bridge... 
But I run indoor and the scale one is too big... 

lmk 

Thanks 

Philip


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## Nicholas Savatgy (Dec 17, 2008)

Posted By lathroum on 01 Jan 2010 08:25 AM 
Can you do one half as long? 
I live in MD... not too far from that bridge... 
But I run indoor and the scale one is too big... 

lmk 

Thanks 

Philip 

Dan builds to any size you want!!!!!!!


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## Glenn S (Jan 4, 2010)

The bridge will be on display in my layout (The Lincoln Pinnacle) on Tuesday, August 3rd, 2010 as part of the 26th National Garden Railway Convention.
As you can see, I only had Eaglewings build the superstructure. This is because I use a 12 foot section of aluminum ladder to span my water feature. The base of each side of the model is an angle iron which will allow me to bolt the bridge to the ladder rails. Neil has some drawings of the substructure detail of the bridge, and I'll bet he's just waiting for someone to order a complete replica, The Width and height dimensions I ordered were what I needed for a double track setup and, of course, clearance for G equipment. However, the proportions look very close to the prototype. I found an old stereoptican slide showing the Bollman at Harper's Ferry, then a little surfing found the surving bridge at Savage. I imediately removed the covered bridge that occupied the ladder, and vowed to spend the winter building a Bollman. But in October I was in the Pomona train show promoting the convention and Neil and the Eaglewings booth were directly across from me. So here we are. I may not have the granite piers replicated in time for the convention, but I'll have the best bridge on tour regardless.

Glenn Shadduck
President, Puget Sound Garden Railway Society.


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## Richard Weatherby (Jan 3, 2008)

For those interested in drawings and photos of the real bridge. Here is the site.

Historic drawings


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## Dave F (Jan 2, 2008)

Well, no big suprise here, as usual for you guys.. absoutley amazing job there... that's just breathtaking.


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## Steve Stockham (Jan 2, 2008)

True, we have come to expect some really nice stuff from the people here on MLS but every once in a while a piece comes along that deserves "special" attention and this is indeed one of them! _Superb!!_


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## irondan (Jan 7, 2008)

Can you do one half as long? 
I live in MD... not too far from that bridge... 
But I run indoor and the scale one is too big... 

lmk 

Thanks 

Philip 

Hi Philip, 

Just give me a call a we can figure something out. (602)276-8101


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## Ray Dunakin (Jan 6, 2008)

What a beautiful bridge, both the original and the model! Superb work!


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## andyb (Apr 19, 2008)

Posted By irondan on 30 Dec 2009 04:27 PM 
... 











I had a double-take when I saw this - first thought was that the vehicle was being use to test the bridge!


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## Torby (Jan 2, 2008)

So did I. "Wow, Iron Dan REALLY builds these things."


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