I think that what Guest means are the lines where Huddie talks about the way workers stand when cutting poles for the track i.e.

Now this's the Rock Island line. These boys is cuttin' with pole-axes The man cut righthanded he stan off to the side of the other man - th' man cuttin lef'haded he stan' f to the other side. Now the boys'll sing about the Rock Islan' Line that's a mighty good road to ride. An in that road the man gonna talk to the depot agent when he's comin out the cut with the Rock Island line freight train. Comin back from New Orleans this way. That man blows his whistle down there diffrent than the way the man blow his whistles here...