Plastruct bridge kit

Your photo brings back memories of my assembly of this very strong bridge a couple of decades ago.

What lengths are you building?  What color will they be?  Will you add rivet detail?  How will it be mounted on the layout?

As for a specific prototype, I know of none.  But it appears to be a Pratt truss type per this lengthy discussion of the truss bridge:

https://en.wikipedia.org/wiki/...s_bridge#Pratt_truss

If you can, take photos and post a serial thread showing how you built them.  There are often questions about the availability of such bridges so you would be making a valuable contribution to the accumulated experience preserved here.

Good luck.

I would be interested in following a build thread on this bridge. I have one still in the box. I am holding off building it until the spot for which it is intended is ready. Hopefully, second half of this year.

John

Ok, I'll see what I can do.  I could not find any bridges built with H beams like this , so (and I am not putting the manufacturer down because I think the bridge kit is a great value) ,,I guess it's a sorta free lance bridge.  It is going to be installed in a club and at a distance from any viewers that would make most anything with diagonal black things look like a credible bridge.   Also I didn't want this to turn into the Sistine Chapel or the Winchester mystery house year long project

So after a good deal of research, i decided to build pretty much as the instruction sheets suggest.  With one major exception--it will fit around existing road bed without cutting track --That may sound crude, but when you see how I'm doing it , no one could tell--and it keeps me from blocking the mainline and having to do a lot of work in a not so easy location .

I will put rivets on the scab plates .  Am making them smaller because they looked too big to me.  Speaking of rivets, I have used a lot of methods, and find that just making them individually on a press works best . It does not take that long once you get going.   The sewing machine schemes seem like such a great idea, but trying to implement that idea, well, ain't so easy..I think Jerry White  (he was a great guy)  got it down, but I tried converting an old trundle Singer and spent way more time with my new hobby of sewing machine conversion than it would take to do 20 models  ,and it still was not that good and not easily adjustable for spacing.

So I went to pull out my NWSL sensi press that I bought to keep from having to set up my drill press...I used it last year, and for the life of me, I can't find it--OK, so I take a medication to walk, and it does trash short term memory...But how in heck do you loose a press? ? ?  Lordy day.  So I just accepted my fate and ordered a larger press from Micromark --and it has a punch set too ,,when I find the sensi press, I can say I needed the larger one for hole punching --now you see I've got this all figured out , but it hasn't come yet --no matter, the plates can go on last .

Pretty sure I lent it to a friend --he was building an old Ambroid kit , and I said 'toss those wooden bolsters & fab some from plastic or brass strip & put some rivets on the top ...Looks muuucho better & you can feed the train air through easier..... 

I also would like to follow this build. Can these kits be adapted to a double track with 4.5 C/L spacing?

There will be two spans, one at 24 inches and one at 22 ".  they will go next and to the rear of a couple of Atlas bridges, one of which I just put in last month.

The first step was deciding how many panels.  you want an even number or you will have an 'X' in the middle instead of a 'V' (Not that that is the end of the world..I have seen prototypes that way)   I drew the sides out a couple of different ways, and found four panels looked right.

in one pic, I have set the plates on ..they still seem large, but That is because most  bridges are not built  like this--even though I did find one that was close although it was  a brand new welded bridge. I will link it if I can find it again.

Hi Rick--I think you could adapt it to any number of tracks ..you might have to order more beams, but that's easy.

JJ, thanks for the additional photos and information.  These are the best threads IMO.

SUGGESTION:  When you add new photos and information, edit the thread's title with the date of the update.  Doing so makes it much easier to follow your progress.

Thanks, again for the additional photos and info.

Hi Carl-- I appreciate any suggestions--I guess I am a little thick--wouldn't editing the title make a new thread?  or maybe not , but how should I do that ?  Just put the date after the title ? 

anyhoo, i found the bridge --It appears very close to what can be made with this kit, but am not sure if in the photo , the new bridge has square beams instead of H section --no matter ..maintain course and speed says I !  https://www.enr.com/articles/4...er-i-235-replacement

Editing won't make a new thread or bump it.

J J Davies posted:

Hi Carl-- I appreciate any suggestions--I guess I am a little thick--wouldn't editing the title make a new thread?  or maybe not , but how should I do that ?  Just put the date after the title ? 

anyhoo, i found the bridge --It appears very close to what can be made with this kit, but am not sure if in the photo , the new bridge has square beams instead of H section --no matter ..maintain course and speed says I !  https://www.enr.com/articles/4...er-i-235-replacement

JJ, to edit the title, go to your original post that started the thread and click the gear icon.  You'll see the edit function in the drop down menu.  Editing will do nothing but edit the title.

Thanks for the photo of the bridge.

For those that followed the link , it shows this picture.   And it would seem that the leaning columns  on the ends are made up to be a square section rather than 'H' .  I think the upper and lower long beams are the same .  No matter. I chose to "lighten" the structure a bit so that it looks more at home to the classic era.   also I made a remark about a welded bridge. This is obviously not that one.  

Pic 1 is holding the little pieces using some Starrett parallel clamps --getting them to stay put in the right attitude is kinda a trick, but the CA works amazingly well on this ABS & a little kicker and it's off to the races. Holding the entire sub assemblies square  is important of course  m and you can see I have taped a square down on the plans I drew. .  The last oic are the little cross members going from the sides to the main beams under neath.  these have to be notched to fitinto the main I beam and I did that on a little proxan chop saw .  You are going to want to do those in pairs , that is, cut a piece twice the length and notch both ends and then cut in half --it's a lot easier handling and controlling these when they re bigger.    

More of the cutting and placing of the top cross beams  The blade is a metal cutting type, and you must get the conversion washer so you can run regular 1/2 bore blades--this gives you a lot more selection.  Choose a blade with the most teeth that you can afford--As a general rule  More teeth equals less grab, and on these little pieces , grab is a major concern . also, when I installed this blade , it had a run out --sort of like out of round--to the tune of about 30 thousanths--YIKES --that can happen with the conversion washer, as it begins to rely on the centering of the blade screw instead of the arbor --so watch out for that and put a block near (or your dial indicator)  the cutting edge of the blade and rotate by hand to check. if it's not perfect,  you should be able to make a pencil mark and loosen the screw and shift it. It's kind of important and it happens all the time. so give it a check. 

Assembling the sides.  Anybody that does not have 1-2-3 blocks should get some.  Starrett blocks cost a fortune but you can get Chinese ones off Ebay for about 5 bucks each , I think , anyhooo , they are great for model building. They even have some holes that are threaded 5/16-18, so you can make jigs.   The 2nd pic shows measuring the sub assembly with blocks and adjustable parallels  The parallels are fantastic for setting this sort of thing up as they can slide to different dimensions and then can support weight or hold against clamps -ther'e on ebay all the time.       

Holding it together square for gluing . The blocks are precision square , but it goes with out saying that if your subassemblies are out of whack , this is where the **** begins.  Looks like I got pretty close as it all fell together as it should   1st pic is measuring with inside caliper and then transferring to chop saw. This saw does not have a lock down , so a scrap placed in the guard mechanics does that trick .  am still waiting for my press to rivet the plates before attaching  

It"ill make a believable bridge .  the center girders are wide so as to hide the existing roadbed ply wood. at the distance of this installation , nobody could tell . I am relying on those girders to "fish around " the long ties that I will be placing down. if it won't wiggle past, I only used a small drop of CA on one of the girders,  so I can break loose it and re-glue after setting it into position. If there is any interest I will post the installation. last pic is bridge inverted. 

I built  one of these for a friend. For rivets I used Archer Decals. I bought the bridge kit for around $50 and used 2 pkgs of rivet decals for about $36. It looked really good and all I used was a straight edge.

Dick

Interesting reveal--I thought you were building a bridge; but, got a faux bridge instead.  That's a lot of work to conceal plywood.

Mine went together using a Zona razor saw, miter box, and steel rule with appropriate Plastruct adhesive; albeit, 25 years ago.

Excellent value for what the kit provides, and very easy assembly requiring nominal skills.

Bridge pics from installation over I235 or Broadway extension in Oklahoma City.  These two spans replaced old existing girder type for the Santa Fe line, took place on 1-27-2018.  This is a great thread, I have the same Plastruct bridge needing assembly.  Also, the design firm, Benham Constructors, is the firm I retired from in 2014, after working for them since 1999.

Jesse

Hi Dick -- Yes. I originally planned on using the archer rivets . Bought a couple of packs and still may,  but the layout of the diagonals meant a lot of cutting ..we'll see. 

Jesse-- those are great pictures ! ! !   Those sides  must be 40 or 50 feet high !   And the pic of the big jack stands is a classic.   That bridge probably is the closest to the plastruct kit , but still your pis appear to show that the beams around the perimeter are boxed in --that would make sense .  maybe you could sway your old firm to letting copy parts of the plans.  

 A couple more pics --the last is a cheap drill press that I "accurized"  I was so frustrated by the slop in the quill when I bought it , that I took a chance of ruining it , and took it apart and cut the face all the way through _ then drilled and tapped four 1/4 -20 screws---two that compress and two that hold the sawn gap apart . that way I could adjust the clearance of the quill, and essentially reduced it to zero, it was very successful.   It is capable of drilling with great precision, and also I have set it up for punching and rivet embossing. The only reason I have a Dumore precision drill also is that the Dumore is small.    

Jesse-  also. speaking of bridge replacements--google   Salmon bay draw bridge ...It's behemoth that the GN built back in 1912 & needs replacing that BNSF will start next year.  They said it was because the trunion pins were squeaking,  but I don't know, I was under that bridge twenty years ago , and it was returning to the earth from whence it came then , let alone now !   but I don't imagine  BNSF would announce that  "we are replacing a 200 million dollar bridge for the **** of it " ..or better yet,,,," Yeeeah, we are kind of replacing that bridge , uh, because it , like , might fall down any day now....But we have comprehensive new safety regulations in place assuring that anyone in a train traveling over the old bridge is advised to wear a safety belt, and to show our utmost concern , we have issued all engine crews inflatable rafts  . Although the rafts were too expensive for brakeman, so they have been instructed where they can buy used inner tubes .""  

JJ Davies…    Thanks for the comments.  Yes, the "jack stands" on both ends of the second span are hydraulic for lifting the bridge.  That gives the clearance for positioning the Goldhofer  multi-axle units under the span for transport to the install location. Do not know the weight of each span, but the heaviest lift I was ever involved in, when heavy rigging supervisor back in '80s and '90s, was a 500 ton chemical reactor in a Rohm & Haas plant, Deer Park, Texas.  Had to used a 750 ton capacity Krupp with super lift package for lifting and placing Goldhofer under to move out, then relocate new one for the Krupp and set in place.  Anthony Crane did the heavy lift for us on that and other turnarounds in the plant.  Interesting and challenging work, miss it and being iron worker in earlier days... sometimes.....LOL!!!  Then, being in management later has problems of it's own...… dealing with people...…..

Jesse   TCA  12-68275

Jesse---- Yeah, the jack stands were awesum!    I was invited by the Ironworkers on one job out to a bar...after a few hours, I asked what the occasion was..."What? , no , man, we do this every night".   Those guys were fun.

Yep, nothing like a good cold one at the local "ice house" after a long day to unwind sore muscles.  Not counting the good fun it could turn into as the evening wore on and friends dropped in.

Jesse

Those jack stand look like me setting the car jack stands I have in my garage next to an Atlas O scale truss bridge.  WOW!

Cold  ONE?  One ? ha ha hha 

Train club finally opened back up to some degree and I installed the bridges yesterday.   They will do for what they are and the location , but I think I would have done things differently if it was possible to see these up close.  Namely ,  I think modeling standards have risen to a point beyond just practicing  "free lance" jabs at prototypical practice.    I guess we can blame the internet partially for this .  as real pictures and information is so readily available.  All that said, I'm not sure how exactly I would do over ,  maybe cutting apart an Atlas bridge  or laser cutting parts like I have seen some greater mortals do.   Like I said , this will be fine for the less than up-front-visible place it is .

Forgot to mention I decided on plastic sheet gussets.  There was a lot of rivets , so I made a gang riveter --a machined block that held 8 pins that I fitted to a press.  it was very successful ,  and by doing 8 at a time, reduced the 1,000 + rivet job to under two hours .

J.J.,

Impressive in itself in the pictures you had taken to document your build progress.

Even more impressive in those showing it installed.

Keep up the good work.

M.H.M.