The shocking premise that a precursor to the modern chainsaw was used in childbirth is historically accurate. Before it became the powerful tool used for felling trees, the concept of the continuous chain cutter began in the medical field. This invention was not an act of barbarity but a desperate attempt by 18th-century surgeons to solve a deadly problem in obstetrics. Understanding the tool requires grasping the perilous circumstances that made such an invention a necessity.
The Surgical Necessity of the 18th Century
Childbirth in the late 18th and early 19th centuries presented extreme dangers, particularly obstructed labor, known as dystocia. This complication often occurred because the infant was too large to pass through a pelvis that was narrowed or deformed, frequently due to conditions like rickets. When the baby became stuck, time was a severe factor, and the physician’s options were few and grim.
The Cesarean section, which involves surgically removing the infant through the abdomen, carried an almost guaranteed maternal mortality rate. Without effective anesthesia or an understanding of antisepsis, the mother often died from shock, hemorrhage, or widespread infection. Therefore, a C-section was avoided until the mother was deceased or near death, making it a procedure to save the baby but not the mother.
The only other recourse to save the mother was a craniotomy, which involved destroying the fetus’s skull for extraction, sacrificing the child to save the mother. Faced with two near-certain deaths, physicians sought an intermediate solution that could widen the birth canal quickly enough to save both. This medical desperation led directly to the development of a tool designed to cut bone with speed and precision.
The Original Tool and Its Function
The device that would eventually lend its core concept to the chainsaw was developed by Scottish physicians John Aitken and James Jeffray between 1780 and 1785. The tool was designed to facilitate symphysiotomy, a procedure requiring the separation of the pubic symphysis—the joint connecting the two halves of the pelvis. The goal was not to dismember the pelvis but to widen the birth canal by a small, sufficient margin, generally about two to two-and-a-half centimeters.
The original medical implement was a small, hand-powered device, bearing no resemblance to the gas-powered saw of today. It featured a fine, flexible chain with serrated cutting teeth wrapped around an oval guide blade. The chain was driven by a hand-crank, allowing the surgeon to cut through the tough cartilage and sometimes the bone of the pelvic joint with a continuous, smooth motion.
This design represented a significant improvement over the traditional method of using a rigid surgical knife or a standard bone saw. The continuous motion of the chain saw was faster and caused less trauma to the surrounding soft tissues, minimizing the risk of infection and shock for the patient. Although the procedure remained dangerous and was often performed without anesthesia, the tool provided a controlled way to perform the necessary surgical dissection.
From Medical Implement to Mechanized Forestry
The mechanical principle introduced by Aitken and Jeffray—a continuous loop of cutting elements—proved highly effective for dividing dense material like bone. Over time, the surgical tool was refined and adapted for general orthopedic surgery, most notably by German physician Bernhard Heine, who invented a similar device called the osteotome in 1830. This tool was used for excising diseased bone and performing amputations, further establishing the chain-cutter concept as a surgical standard.
The original surgical symphysiotomy procedure and its specialized tools began to fall out of widespread use in the late 19th and early 20th centuries. Advances in antiseptic techniques and the introduction of effective anesthesia dramatically reduced the maternal mortality rate of the Cesarean section, making the C-section the safer and preferred option for obstructed labor. The medical chain saw was largely superseded by simpler instruments like the Gigli twisted wire saw for bone cutting.
Meanwhile, the concept of the endless chain cutter was applied to a different industry: logging. The mechanical advantage of the continuous cutting chain was scaled up to create industrial-sized tools for cutting wood. In 1905, Samuel J. Bens filed a patent for an “endless-chain saw” intended for felling the massive redwood timber of the Pacific coast. This was the conceptual leap from a delicate, hand-cranked surgical tool to the large, motorized logging equipment that evolved into the portable, gas-powered chainsaw recognized today.