FOREWORD Procedure in rotary drilling has largely been developed by the drillers. whose experience has been passed on to other members of the crew who@ in their turn@ become drillers. Engineers and geologists have done much to develop better equipment and methods for improving production after the well has been brought in@ but very little information on correct practices for the members of rotary-drilling crews has been recorded. All too frequently drillers have expected members of their crews to learn their work by the trial-and-error method. This has resulted in serious and costly injuries. This manual is an attempt to provide@ for members of rotary-drilling crews@ information which will make it possible for them to avoid many costly mistakes which have contributed to the all-too frequent injuries attendant upon rotary drilling. This manual was prepared by the Committee on Accident Prevention in Production@ and has been approved by the General Committee of the Division of Production.