Access hatch opening

You may find my following web pages with "pretty" pictures helpful.  I prefer to use my access bridges as switches where possible.

Runner and Guest Access Bridges

Access Bridges used as Switches

Bridges Wired to Control Track Power with Relays for Engine Protection
https://slsprr.net/features/wiringIntermbrgRly.htm

See Access Bridges used as Switches where Swing Bridge on South End is shown.
The white, black, and purple wires on the left are secured under the bridge.  They slide
into fascia holes when bridge is opened.

IF you're going to hinge the track, the center line of the pivot pin on the hinge needs to be above the top of the rail. The first "up" motion with this geometry, the ends of the track moves apart. Otherwise, you'll need an additional gap so the track doesn't hit.

Wire power to the rails and it doesn't matter if there's a gap at each end. Safety interlocks (relays) are prudent, but not required. The risk is when (not if) your engine takes the big dive off the edge because you forgot and left the bridge "up".

For your curved bridge, scribe a line parallel to the edge of your benchwork and cut, 

I had two of them.  Here are pictures of one of them that was on a curve.  Notice the receiving notch to positively locate the closure every time.

Dennis

Thank You All !  Hope to figure this out, big challenge to tackle. The wiring (track power) after cut is made will be interesting to say the least for me.  I will check out the web pages.

The most important thing to do when you are spanning an aisle with plywood is to get it all lined up in place and supported, then screw a board to it that is longer than the span and screwed down on both sides and in the middle so the span cannot move while you are installing the hinges and the track.

Dennis

All good advice above.  One other thing I did was take an Atlas rail joiner and solder some "wings" to it.  I manually slide the rail joiner open and closed when I want the bridge open or closed.  This ensures the rails line up perfectly.  I painted them red for my visual reference, not for any real railroading reasons.

Have Fun!

Ron

P.S.  You might want to edit your title from Access Hatch to Lift Bridge.  I think of an access hatch as hole in the middle of a layout, that you must crawl under and pop up through.  You might get some additional participation with really good lift bridge ideas.

If I sit on the stool and the bridge is raised, I roll under clear.

Dennis posted:

The most important thing to do when you are spanning an aisle with plywood is to get it all lined up in place and supported, then screw a board to it that is longer than the span and screwed down on both sides and in the middle so the span cannot move while you are installing the hinges and the track.

Dennis

Dennis,

Was wondering what tool you used to cut the track on a nice clean angle like that.

My current method for cutting Gargraves track is a Dremel with extension and a cutting wheel. I mark each rail to cut, then do my best to keep the wheel square to the rail for a clean cut. 

I'm looking for a better method of making clean square, or angle cuts. I'm usually left with ragged edges that I clean up with a small file (very time consuming)...

Thanx...