IDRick What is the best way to stabilize the long freestanding end so track aligns with the lift-up?
Use shear paneling to stabilize the long freestanding section. You can use 1/4" plywood or OSB (or even drywall) panels glued to the sides of the freestanding structure to obtain an incredibly strong and rigid structure. I used 1/4" drywall backdrops that double as shear panels on 13 foot long peninsula that is double cantilevered off of a central backbone 2" by 3" frame. With the addition of the drywall shear panels, one can get up off the floor by grabbing the fascia of the lower deck and pulling themself up without budging the peninsula.
Hornblower
Alignment is crucial. I built my liftout using a good set of hinges, and placed blocks at the receiving end to ensure it falls at the right place. It's been stable for the last three years... The black dot in the middle is an on-off switch, that shuts all the system down to prevent accidents.
Simon
20181004_073416 on Flickr
20181004_073403 on Flickr
You can't but it could be made to be more stable when bridge is in place, just make sure you have a robust interface.
I used mating, 1/4" aluminum plates with a pair of dowel pins pressed into one plate and clearance holes (only a few thousandths clearance) on the other.
DB_2 by Edmund, on Flickr
When the "bridge" is in place the dowel pins align everything perfectly and a threaded hand wheel snugs everything up on the center stud. I have two locking set screws threaded in the plate which allow vertical adjustment at the rail head.
DB_1 by Edmund, on Flickr
You may have to make occasional adjustments to your 22 foot island but maybe you could set the legs into those hard-rubber furniture cups or something similar to minimize movement.
Hope that helps, Ed
I'm considering a lift up section and wonder how to stabilize the layout. Three sides of the layout will be along the walls while the fourth is 22 ft long (2 ft wide or less) and in the center of the room. What is the best way to stabilize the long freestanding end so track aligns with the lift-up? I don't have permission to lag bolt the layout end to the concrete floor.