Bunkhouse rails?

I have a 33qb with couches on the lower part and bunks on the top. I was interested in knowing if anyone has seen rails I can use for my kids just in case...

I have a suggestion....can you use the side rails like they use on beds for little ones learning to sleep in a big bed? We bought one for our granddaughter (to use at our house) and they can be folded down out of the way. We bought it either at Target or Walmart.

we bought one made by safety 1st that folds up and is adjustable. We used it in the bottom bunk of our FunFinder 240X last year as a make shift crib and then moved it to a single bed in the house after. This year there is no issue as the youngest is old enough to use the double bunk of the NorthTrail 28BRS without a rail. Here's a link to the one we used successfully. It adjusts to any thickness of mattress too.

http://www.walmart.ca/en/ip/safety-1st-secure-topside-bedrail/106367