Your post piqued my interest (having spent many happy hours at the Jersey Shore near there), so I did a little digging around.
Barnegat was a terminus on the Jersey Central where it connected with the Tuckerton Railroad which at one point ran a line out to Long Beach Island.
A google map search shows that there is a rails to trail west of Route 9 so that is probably your yard. Going to the TrailLink website ( https://www.traillink.com/trai...rnegat-branch-trail/  and looking at photos, there is apparently the footprint of a turntable at Lat: 39.75844 Long: -74.22207 ( type 39.75844, -74.22207 into Google maps. This is near Rosehill Road. I expect the yard was somewhere in here.
If you go back and discover anything, let me know.