This review is from O Gauge Railroading,  February 2003. Reprinted with permission of Myron J. Biggar Group. 

ATLAS O PRATT TRUSS BRIDGE

by Barry Lewis

O scale Pratt Truss bridge kit; single of double 2-rail or 3-rail track; ABS plastic and Styrene construction; internal steel support beams; length: 40-1/4”; width 5-1/2”; height: 9-1/2”. 3-rail version supplied with rail joiners for Atlas O, tubular or GarGraves track; price: $114.95 single track, $149.95 double track, $49.95 bridge add-on kit (converts single track to double track). Manufactured in China by Atlas O LLC, 378 Florence Ave., Hillside, NJ 07205; website www.atlasO.com.

I love bridges; they’re so dramatic. In the operating bridge world, I’d say the drama queens are Lionel’s bascule bridge and lift bridge. And then there’s the Hellgate bridge original and reproductions: high, wide, and handsome in a league of their own – until now. As my teenage son would say in admiration, this new Atlas bridge is nasty. It’s really just your typical metal railroad bridge. But in full O scale with complete prototype detail, its size and the overall effect are magnificent.

KIT PROTOTYPE

The Pratt Truss bridge is the archetypal metal railroad bridge found almost anywhere in North America. The first Pratt Truss was built in 1844, and this type of bridge was commonly constructed on rail lines at least into the middle of the last century. Many Pratt bridges continue in service, with railroads choosing to repair rather than replace older structures. The prototype for the Atlas O model was built on the Missouri Pacific Railroad and is still in use – the MP, however, has since been merged into the Union Pacific.

Judging by prototype photos and drawings, it seems virtually no structural part has been omitted from the model. Rivet detail is everywhere, and the ties on the bridge deck have simulated wood grain. At 27’ high and 18’ wide, internal dimensions exceed the minimum bridge clearances set by the American Railway Engineering Association. One could easily run an overhead catenary or trolley wire through this structure.

ASSEMBLY

As Atlas’ instructions note, the hard work has already been done for you. The two bridge sides are pre-assembled. The floor is a single assembly strengthened by two internal thin metal plates ¾” wide and by the 40” long nickel silver bridge rails. This bridge should support any of today’s heavy diecast engines.

The instructions are well done, and assembly is enjoyable and easy. I put our sample together in about an hour and a half while watching TV, but I would disagree with Atlas’ claim that “The kit is designed for simple snap assembly; however you may desire to use glue for a more permanent assembly.” The sides and floor do indeed go together with simple screws and pegs, but the detail pieces that really finish the bridge off and complete the lacy detailed look must be glued on. The top and bottom “X” braces will fall off if not glued.

In addition, although the three middle truss supports on our sample did snap in, the truss supports on each end (the top trusses of the bridge “portal,” if you will) needed to be glued. So, although Atlas makes an add-on kit to convert a single-track kit to double track, I suspect it might be difficult to later disassemble and convert a decently built single-track bridge.

A couple of assembly notes are needed. Be careful with the thinner plastic trusses. I mistakenly applied too much pressure (squeezing the bridge sides together) and cracked on of the end portal trusses while installing it. Also, step one of the instructions directs you to remove a screw from the metal tab at the end of each bridge side. On our sample, those screws had already been removed and were in a sealed bag of small parts. Not realizing they were in the bag, I mistakenly removed the other screw in the tab, which holds it to the bridge and also holds some of the side structure together. You may need to use this second screw in step three to adjust the tab when fitting the floor and sides together. All this makes sense if you have the kit in front of you.

            Paint:  At the least, I’d use a dulling spray to kill the shine of some of the plastic parts. But the fine detail of this model is hard to see on a jet black finish; so painting it grimy black or engine black a few shades more gray than the plastic will bring out the rivets and other small details. Prototype bridges were most commonly painted black, but other colors would also be prototypical. Western bridges were often painted silver, particularly on the Union Pacific and Western Pacific.

I’d paint all the pieces before assembly with an airbrush or spray can, covering the gluing surfaces with masking tape. Then I’d touch up the glue joints again after assembly.

            Assembly pegs:  The model has 14 plastic pegs that hold the bridge sides to the floor. They’re about the only element on the model that is not prototypical, sticking through the “knee braces” that attach the floor to the side trusses. I’d glue the pegs in, then slice off the heads and tail, and smooth the surface with modeling putty. Alternatively, I’d substitute short pieces of Styrene or metal rod for the pegs.

            Bridge shoes:  A prototype bridge sits on metal bridge shoes (also called feet or pedestals) at each corner rather than resting directly on its supporting piers. I’d add this detail because the rest of the model is so well done, and because I like the effect of the air space between the bridge and the piers filled only by those small feet. On a real bridge, the shoes at one end are fastened rigidly to the bridge and piers, and the shoes at the other end have rollers to allow the bridge to expand and contract with temperature changes. John Keil of Keil-Line Products in Wonder Lake, IL, makes two types of bridge shoes for about $7.00 a pair plus shipping. John says his metal shoes will easily support the weight of the Atlas bridge and a heavy locomotive. He can be contacted by e-mail at Oscaler@aol.com or by fax at 815-728-0595.

            Piers:  A bridge this grand deserves to sit on a fine pair of concrete or masonry piers. The few O scale piers currently available are too narrow for this bridge, but Jim Elster of Scenic Express (see his ad in this issue of OGR) is working on a set of masonry piers for the Atlas bridges. The style will match Jim’s current Pennsylvania RR stone block series of tunnel portals and retaining walls.

            Another thought:  If you really want a moving bridge, it probably wouldn’t be too difficult to convert this Atlas bridge into a center-pivot swing bridge. The structure might not be totally prototypical, but the effect would be convincing and impressive.

Having run out of superlatives, it’s time to wrap up this review. In closing, I think it’s safe to say that once again Atlas O has boldly gone where no one has gone before and given us a reasonably-priced plastic model that rivals the detail once only available in brass.