When I started phase two of my track plan there were a few spots where I knew I would need bridges. Working in the transition era I felt that a metal trestle span would be more appropriate then a wood trestle. Not having the skill to weld I decided to use aluminum. I purchased some 1/16" x 1/2" angles, 1/16" x 1 1/2" flat stock, some 1/16" x 1/2" flat stock to be ripped to 1/4", and rivets.After determining the height I needed, I drew my trestle form on a piece of plywood, including a 1 1/2" extension for securing the bridge sides to the trestles.
This is a finished trestle ontop of my patern. Once the trestles were made I cut some of the 1 1/2" flat stock into spacers.The spacers were measured out as 3/4" plus 1 13/16" plus 3/4". Carefully bend these at the 1st mark then measure from out side face of the fold to the next line to insure that the mark is at 1 11/16" and bend. This will set the two bridge sides at 1 15/16" to run under the track rails. These were riveted every 4" on one piece of 8’ flat stock stopping 8" from the end and keeping the top and bottom edges even and square. NOTE: I wanted to keep my trestles spaced at 2’ so when I layed out for the spacers I marked off through 24" then set a trestle in place and marked outside the trestle, then measured off another 24" and again placed a trestle. When the trestles were marked I also measured the space and marked center for a spacer.
My jig After the first side was done I placed it and the second side in a jig I made for 20’ diameter curves. I then riveted the second side to the spacers checking as I went to keep them just shy of 4" spacing. When I got to the trestles, I placed them between the sides and butted the spacers up to the extenstions to insure a good fit. You can rivet the trestles inplace at this time or when you finish the sides. At this point I test fitted the sides in my area and cut the two sides to fit. Finish putting in the last two spacers.
The completed bridge showing the spacers in place On how to mount the bridge I decided I wanted concrete footings. These are 2" square by 4" high blocks with mounting bolts I made from 2" brass screws I bent to help them hold.I also needed to cut feet for the angle uprights. These were from the 1/2" pieces I had leftover. I cut them to fit tight against the angle of the bracing and made them 1" long these were drilled with a 3/16" bit and riveted to the bottom of the angle stock.
the footings
The bolts With all pieces made I painted and lettered my bridge prior to installation. Forms were made for abutments and concrete was poured. Once the abutments set up I attached the footers to the trestle bents and prepped the area to pour the bases to hold the footers in place.
Showing anchor bolt in place
The base is poured and the abutment is in place
How the whole thing turned out. Now I ready to start track. If I left anything out just ask Dave
