Ed Malzahn, president and chairman of Charles Machine Works, maker of Ditch Witch products, has taken over duties as chief executive of the Perry, Okla.-based company.

Malzahn replaced former chief executive David Woods, who worked there 23 years and resigned in January to pursue other business opportunities. Malzahn is the grandson of Charles Machine Works pioneer Carl Malzahn, who started the business in 1902 as a blacksmith shop. Carl Malzahn's sons, Charlie and Gus, later took over and began repairing oil-field equipment.

Ed Malzahn is widely credited as primary developer of the modern trencher and founder of Ditch Witch products.