The success of the sucker-rod system for pumping oil wells is due, primarily, to the pumping oil wells is due, primarily, to the simplicity of the surface, as well as the subsurface equipment. In the early life of the industry the wells were shallow and could be adequately pumped with beam-type surface equipment. As wells were drilled to greater depths and larger volumes had to be pumped, consideration was given to other types of surface equipment to actuate the sucker-rod system. Some of the advantages of long-stroke pumping are (1) fewer stress reversing cycles pumping are (1) fewer stress reversing cycles resulting in longer sucker-rod life, (2) more net plunger travel as related to polished rod travel, (3) longer subsurface pump life due to reduced number of pumping cycles and increased area of wearing surfaces in the pump, (4) less tubing and sucker-rod coupling wear in crooked or slant holes and (5) less frequent servicing of subsurface equipment. The long-stroke pumping unit covered by this paper has the following advantages in addition to those listed above: (1) increased production due to uniform polished rod velocity production due to uniform polished rod velocity (this is highly important in pumping viscous liquids), (2) less reducer torque due to short torque arm and (3) more horsepower developed by a given reducer due to higher rotating speed of the drum shaft. There may be some question as to what constitutes long-stroke pumping of an oil well. Twenty years ago a beam-type n unit with a 100-in. stroke was considered to have a "long stroke". As the requirement for pumping more liquid from greater depths developed, beam-type units were made larger and with longer strokes to satisfy this demand. There is now one beam-type pumping unit available with a maximum stroke length of 300 in. It is difficult to say what the limit will be on length of stroke for a beam unit. It will probably be determined by the degree of success of some other type unit, such as the one to be discussed. A number of long-stroke pumping units have been built with varying degrees of success. They were generally limited by mechanical design problems or adverse effects on other components problems or adverse effects on other components in the pumping system. Influenced by the old adage, "If at first you don't succeed, try, try again", another design* of a long-stroke pumping unit was conceived and the advantages of long-stroke pumping have been achieved to a very high degree. pumping have been achieved to a very high degree. The key to the success of this unit is a contoured drum for spooling wire rope assemblies to actuate the sucker-rod string and suspend the counterbalance. Fig. 1 shows an installation of the long-stroke pumping unit. The stroke length is 34 ft and the polished rod-load capacity is 35,000 lb. Two geared speed reducers have been built with ratings of 310,000- and 420,000-in. lb peak torque capacity. Maximum recommended input hp to these reducers is 75 and 100, respectively.