Building the Canyon Diablo Bridge


dang, I wished I had known.
Anyway, my first attempt at making a Silicon mold.
Suspended the bridge footer upside down in a Tuperware bowl then mixed the two ingredients together. Started to pour the somewhat thick goop into the Tuperware bowl and then the wood footer began to float up outa the bowl. Dang, I had to mix a bit more of the silicon to fill the Tuperware bowl all the way up then pour it while trying to hold the footer in place so it wouldn't plop outa the bowl. OK, got the silicon all scraped outa the mixing bowl, now how to keep the footer down in the silicon for 6 hours while it cures. I found a 10lb barbell plate and put that over the Tuperware bowl to hold the footer down. Hmmmm, the footer isn't pushed all the way down into the silicon. Out to the garage to find a large thick fender washer to put under the barbell plate. OK, getting this silicon all over me and the table top tryin to do this. OK, got em stacked correctly under the plate. Hmmm, is it centered in the Tuperware bowl? I better mark the center of the footer so I can see it through the hole in the barbell plate. Found a Sharpie, lifted the barbell plate and the washer slides off into the silicon but I grab it in time. Try to mark the center of the footer but the Sharpie doesn't want to mark the surface of the wood footer because I had sprayed the releasing agent on it. Keep scrubbing the surface with the Sharpie and it starts appearing on the wood. OK, stack the washer back on it then the barbell plate. Center the barbell plate over the Tuperware bowl, check through the hole for the washer and the Sharpie mark. Got it. OK, go watch the Army - Navy game while the silicon sets up.

Mold.jpg
 
Last edited:
OK, the mold took. Took a little tugging to get the block of wood out. Didn't have to cut it up.
I sanded down another block of wood to go in the center so the production pieces wouldn't crack and suspended that in the mold then poured the Woodland Scenics plaster.
Now, just have to wait till tomorrow morning for it to setup.

1215191209.jpg
 
SAY -- That looks like you got a good mold?
I had to laugh about the "dance" you did getting the pattern in place.
That was funny!
 
D&J RailRoad said:
I am starting this thread as I suspect there will be a lot of activity in the construction I am undertaking.
I have a section of my empire that was designed to have a bridge installed. At the time of construction, I didn't have any idea of what kind of bridge I was going to put there. The following video shows this gap.


The gap is a little over 500 scale feet or actually about 82".
As I have looked at quite a few designs, I have ruled out the truss type bridge because of the expanse of the canyon. I wanted something more substantial than viaduct type bridge. I happened upon the Canyon Diablo bridge one day and knew that was what I wanted to build.


I have found just about every picture and video on line about the bridge and have read about the history of the area from numerous perspectives. I've seen the N scale version of it that was built by an NMRA member but can't reach him for any details of his measurements or construction technique.
I am venturing out on my own to make estimates based on the available pictures and videos.
At first look, you would just assume this is all I beams, but look closer. You will see that all the beams are rectangular stock. Some completely closed like the main arch is and some with oblong holes or square plating riveted along the open sides.

So far, I have estimated the main arch beam to be a scale 1/2" tall and 3/8" wide. I can only figure this by comparing the arch beam to a locomotive that is passing over the bridge with pictures like this one.

View attachment 31434

The only choice of material 1/2" X 3/8" to build this bridge will have to be solid brass stock for the main arch. There is no source for hollow rectangular brass stock in the estimated dimension. Plastruc tubing is to flimsy and there is no such thing as solid plastic stock in the required dimension. I don't trust wood enough for this, plus it just wouldn't have the appearance of steel beams. There is aluminum stock but it will be difficult to weld. I'm not going to try glue on this nor will I use out of scale pins.

I bought a sample section of brass square tubing then painted it a flat black to compare to the picture above. It just didn't have the same look so I think I'll scrap the brass idea.
Click to expand...
Very cool, i counted 35 cars.....
 
Alright! Looking good!
Have you thought about making a few dozen more? You already have the mold ...
Maybe you should do a "poll" and check the demand? (snicker-snicker)
 
Actually I did think of that. I have a set of modules that I take to the train shows that our club participates in. The set is 20' long, 4 five foot models.
Another member wants to buy them from me so I can start building a new set. I'm doodling with the idea of another Diablo Canyon bridge. This would be another set of modules long enough to provide the support for the bridge as well as being transportable in a pickup truck.


0413181821.jpg
 
Finished painting the bridge grime black. Lots of little nooks and crannies.
The third footer is in the mold setting up now. Just one more to go.
I'm fiddling with the bearing shoe that sets on the concrete footers and has the pin going through it into the bottom of the legs of the bridge. I'll have to make 8 of those out of heavy plastic.

3.jpg

1576543873413.png
 
You must log in or register to reply here.



Back
Top