A Swing Bridge instead of a Duck Under

[ngauger]

The cut should begin about 1 - 1/2 inches from the end of the 1 x 6 at a 60 degree angle. Notice the side of my bridge (top) ends at the cut. You are beginning to cut that triangle you saw earlier & through the 1 X 6 NO Further - as evidenced by the cut mark in the layout

Just mark it with the saw blade for now.

When you have a "good mark" in the 1 x 6 - lift it above the layout - just lift the end of the bridge enough to clear the layout & open it. Now saw the end off. you can use any powered saw now.. I used the jig saw.

When you cut off that triangle... Pick it up, close the bridge again & lay that triangle in the empty space. MAKE SURE everything fits tight!! And again - check the levels and easements at this end of the bridge. ~~~~ Everything look good????? ...... Your ok then.

Open the bridge again & put the triangle down on the bridge so you wont lose it

Now - the throw bolt... Mount the throw bolt by closing it & swing the lock over as above.... The top of the bar should be "just below the height of the layout" The object here is to lock the bridge straight - but not interfere with the track on the bridge. Here's that pic again for reference:
   
When you have it mounted - open the bolt (it should drop down) -- close the bridge tightly again - Press down on the bridge and Hit the bolt with a hammer, from underneath, to make a mark on the bottom of the bridge.

Drill a 1/8 hole straight up through the 1 x 6 at the center of the mark. drill as straight (vertical) as you can.

When you have done that - drill a vertical hole down through the 1 X 6 (using the small hole as a guide) the Exact diameter of the bolt bar.
Here's a view of the finished hole and a detail view of the "Paint paddle" I used for a shim.:
   
Now, close the bridge (again) & push the bolt up through the hole & lock it - Everything should be nice & tight - no movement.. What's that?? it moves a bit???

Pick up that triangle and pull on the bridge (it wont open because of the bolt) - put the triangle back in the open area & push it against the bridge... Now the bridge should stay tight. I can shake my layout by "shaking" the bridge.

Pre-drill a hole in the triangle & through the support block & screw it into place. BE CAREFUL NOT TO SPLIT THE BLOCK!!!!!

Now when you close the bridge against that triangle, the hole should line up with the bolt & you can push the bolt through the bridge bottom & lock it tightly.