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should be larger than the lower of the pull force capability of the drill rig or the total strengths of the pipe to be installed, but not excessively greater. 3) Breakaway Link — In general, the recorded pulling forces as indicated at the drill rig will exceed the tensions experienced by the pipe or conduit throughout most of the pullback process. It is recommended that individual breakaway links be provided between the main swivel and the grip at the pipe, to ensure that the pipelines are installed within allowable load levels. Broken links will require removal of the pipe from the entry end. If a breakaway swivel is used as the breakaway link, and not specifically designed for direct exposure with soil, this item should be cleaned well after each application. The use of such a breakaway swivel does not eliminate the need for the main swivel described earlier. 4) Handling the Pipe — Extreme care must be exercised when handling the pipe to ensure that it is not subject to excessively sharp bends which may cause a kink or other damage to the pipe. Particular areas of concern typically include the pipe entry and exit points. It is important to minimize bending of the pipe as it enters the bore hole, and to ensure low friction on the portion of the pipe outside the hole. This may be accomplished by the use of appropriate lifting equipment and roller stands to reduce friction. Due to the potentially high tensile load at the pipe exit, it is especially important to avoid sharp bends at this point. G. As -Built Drawings and Information A record of the actual as -built bore path, including plan and profile views and vertical and horizontal deviations, indicating the relation to the planned path, must be submitted to the Engineer. Any information obtained during the initial bore regarding soil characteristics, etc. should be added. The experiences gained during the initial bore may be used to provide guidance for the backreaming operating, as well as for subsequent operations in the project area. Additional information should also be included, such as steering or correction commands, drilling fluid usage, and the type of drill head being used. Regarding the reaming and pullback operations, the pipe insertion velocity, duration, type and size of reamers (cutters or compactors), final bore hole size, drilling fluid usage, and required pullback forces should be recorded. H. Connection to Upstream and Downstream Piping Where the directional bored pipe is joined to bell and spigot, mechanical, or other types of unrestrained joints, the forces caused by shortening of the polyethylene pipe when under pressure must be counteracted per AWWA Technical Bulletin No. 8. The joint between the polyethylene pipe and any push type connection shall be mechanically restrained as well as the appropriate number of upstream and downstream joints as indicated on the Drawings. I. Completion and Cleanup 1) Pipe Cut -Off and Cleanup — The pipe shall be allowed to achieve mechanical and thermal equilibrium with its surroundings prior to cutting at either end. Premature cutting of the pipe may allow the ends to shrink back into the hole. The pipe may be cut after it has been verified that there has been insignificant movement at the pipe entry end and negligible residual tensile load at the drill rig end. If the bore ends are 02400 - 9 02400 — Directional Bore Crossings