HOW POWERFUL WERE THE MEDIEVAL LONGBOWS?
Unfortunately, virtually no bowstaves from the medieval period have survived. So how do we know how powerful the bows would have been? Some evidence can be obtained from the arrows, which have survived. Because the 'archer's paradox' demands that a particular bow needs an arrow of suitable spine (stiffness) then by measuring the properties of a medieval arrow we can estimate the strength of the bow for which it was designed. When these calculations were done, the answers were almost unbelievable. They suggested that the force needed to draw a medieval longbow could have been in the range 110 to 180 pounds (500 to 800 Newtons). Although these figures are astonishing, they have been confirmed by calculations based on the bows found in the wreck of Henry VIII's ship Mary Rose, which sank in 1545. It seems likely that in 1415, when archery was at its peak in England as a technique of warfare, bows would have been no less powerful than in 1545, when archery was already beginning to lose ground to firearms
Reproduced from Physics Review January 1995 by kind permission of the author and publisher and republished in InSight, the Stortford Archery Club Newsletter, Issues 5 & 6, Summer and Autumn 1995