Trencher: Impingement on Buried Objects
Abstract There is a resemblance between the digging chain of a trencher and the folklore chain saw. The safety of trenchers requires that the similarities and differences between these two machines be understood so that appropriate warning signs can be formulated. There is a notion that the trencher can be suddenly thrust rearward in the direction of the digging chain in the manner associated with the chain saw. There is also a notion that the kickback characteristic of the chain saw is also characteristic of a trencher digging chain. This paper shows that these rearward thrust and kickback notions for the trencher are false. On the other hand, contact with moving teeth is hazardous on either machine.