Mad About Science: Arrows

By Brenden Bobby
Reader Columnist

One major technological development shifted humans from being fragile and awkward middling gatherers into apex predators that would go on to dominate the food chain across the entire Earth, for better or worse.

Arrows are a simple enough design, essentially a shrunken throwing spear that’s launched from a bow, but the value of this simple design cannot be overstated. A throwing spear was large and required an accurate throw, with a range of about five to 10 meters — this put hunters in danger of being attacked by larger predators or trampled by huge herbivores. Neolithic bows had a range of around 50 meters, allowing hunters to get the jump on their prey and retreat if things went sideways.

Medieval arrows and arrowheads. Courtesy photo.

A bow is useless without an arrow. We have evidence of arrows being fletched at least 67,000 years ago. The earliest arrows were fashioned with a bone tip, which was far from ideal when trying to create an accurate projectile. Breaking up large mammal bones was dangerous for neolithic humans — crushing implements lacked handles and many fingers were likely crushed, lacerated and infected, which carried the lethal potential in an age far predating antibiotics. Bone shards were rarely identical and far from aerodynamic, which meant the accuracy and range of early arrows was critically lacking.

Over time, arrowsmiths and fletchers shifted away from using bone and instead crafted arrowheads from flint, chert and obsidian through a process called knapping. This process was done by flaking away bits of a stone with another stone to create sharp edges and points, a process that was equally dangerous — if not even more so — than crushing bone with a rock. However, the result was critical for the advancement of human civilization.

Flint arrowheads increased the accuracy and range of neolithic bows, greatly increasing the success of a hunt and reducing the risk involved. This allowed humans to more reliably hunt larger prey and suffer fewer losses in the process. These kinds of arrows were so vital to early humans that they remained in use for tens of thousands of years.

It’s believed that the first metal arrowheads appeared sometime between 3500 and 2000 BCE. Initially made of bronze, metallurgy completely redefined archery. Archery in organized warfare presented such an advantage that it influenced the design of all other weapons and armor of the time. 

Bronze arrows were more easily replicable than their stone predecessors, which led to more uniformity in design, which meant increased accuracy for the soldiers launching them. Greater accuracy and range meant that armies on the receiving end of an arrow storm needed adequate armor to ensure their soldiers could get close enough to land strikes and break ranks of archers — this became especially important when sieging cities.

The force and range of an arrow is multiplied by elevation, so shooting down at someone from the top of a wall achieves two goals: it delivers a punishing strike and attacks an enemy while they’re occupied with climbing, leaving them relatively defenseless.

Bronze was great for its time, but it’s a soft metal and is easily deformed. Bronze arrows, once fired, were effectively useless until the heads were melted back down and reforged. The development of metallurgical processes that could refine iron into steel would again revolutionize arrow technology. Iron, and especially steel, are very durable metals, as we use them for a huge variety of tasks even to this day. Iron is also a plentiful resource, and while it’s more difficult to work with than bronze, it’s also much harder to deform with force in combat.

Despite the difficulties in working with iron during classical times, it is a very malleable metal that allowed for it to take on myriad shapes and forms, fulfilling countless functions. This was especially true of arrows.

Arrow technology had a renaissance in the medieval era. Arrows began to take on specialty functions to fulfill different tasks. Bodkin arrows employed a fine needle point at the end of a shaft designed to slip between the links of mail and pierce a target’s vital organs. Bodkin arrows are so effective that a medieval English longbow firing a bodkin from 50 meters can pierce many modern body armors. 

Broadhead arrows were developed to counter rank-and-file forces that were often armored in little more than gambesons (padded jackets) and everyday clothing. These were designed initially to hunt elk, as the large and sweeping heads would tear into flesh and cause immense hemorrhaging and a swift death — a trait that was not lost on lords and generals of their time.

A variation of broadheads were developed with larger heads to be launched at much closer range with the intention of killing cavalry horses mid-charge. Archers in the field are traditionally countered by fast-moving armored cavalry, while the broadhead may have helped level the playing field.

Another type of arrow was also developed during this period, which appeared as a forked head similar to the letter “Y.” There is much speculation about what this arrow was used for, with some claiming that it was designed to cripple charging cavalry horses, and others claiming it was effective at shredding sails of ships at sea to immobilize the vessel.

Arrowheads today are nightmarish things if you find yourself on the receiving end of one. Many are made of aluminum, which makes them very lightweight and easy to sharpen into a razor edge. Paired with the draw of a compound bow, these things are designed to effortlessly glide through flesh and cause massive bleeding. Fortunately, these are reserved exclusively for hunting.

Many other variations of arrowheads have been developed for use in hunting as well, including wire-headed arrows designed to widen upon flight and provide a larger area for hunting birds, and spring-lined arrowheads designed to catch in the brush and be easily recovered.

There are also rubber-tipped arrowheads used exclusively for target practice, as well as a variation on the bodkin arrow used in many archery competitions around the world.

Stay curious, 7B.