Pictures By Alan

The rail was made for material handling. Which apparently means it's designed to move around parts in a factory, for assembling cars or whatever. It's made by Knight Industries. This one appears to be a RSD5300 Series steel rail. It's suitable for 500 pounds and has a 5:1 safety factor, so in theory it's good up to 2500. Even that assumes the rail is anchored to the ceiling at nine foot increments. Here, it is anchored to the ceiling much more often, so is presumably even stronger.