Patent ID: 8487205

Claim:
A method for performing a burn-off operation, in preparation for a flash butt weld operation to join a first rail segment to a second rail segment, where the first rail segment has a first rail end face and the second rail segment has a second rail end face, the first rail end face facing the second rail end face and being nonparallel with respect thereto, the method for performing the burn-off operation comprising: applying a closing force to at least one of the first rail segment and the second rail segment such that the first rail end face and the second rail end face come into contact and causing an electrical current to flow between the first rail end face and the second rail end face, the electrical current flow being sufficient to cause a burn off of material at one or more points of contact between the first rail end face and the second rail end face; testing, on a repeated basis, for a burn-off operation termination condition by: obtaining a new value for a characteristic of the electrical current flow between the first rail segment and the second rail segment, first comparing the new value for the characteristic of the electrical current flow to a previously obtained value for the characteristic, and second comparing the new value for the characteristic of the electrical current flow to a predetermined threshold for terminating the burn-off operation; continuing, based on the testing, the applying the closing force and causing the electrical current to flow only if: the first comparing the new value for the characteristic to the previously obtained value for the characteristic indicates that a value of the sample for the characteristic of the electrical current flow is changing monotonically from sample to sample, and the second comparing the value of the sample for the characteristic to the predetermined threshold indicates that the value of the sample has not reached or passed a predetermined threshold; and otherwise, based on the testing, terminating the burn-off operation.