Maybe I missed it somewhere, but on the outside of the left rail in the track centered in the picture is what looks to be some type of rail brace controlled by an Armstrong lever.  There are a series of what look to be supports with a thin bar between them and the rail.  I've never seen anything like this in years of looking at track and I'm still not sure if I've described it right or can see it clearly enough to describe it.  Any informed thoughts on this detail?

John Larkin