A.a fairlead block B.a swivel pin for the topping lift block C.a triangular steel plate with a hole at each corner D.the lower block of a multiple part topping lift
A.prevent barge movement in a lock B.secure two barges end-to-end C.secure barges to the towboat D.secure barges side-by-side
A.taut and leading forward B.slack C.leading out perpendicular to the centerline D.leading under the hull