How powerful was a lance strike

[Imperial Dave]

https://www.medievalists.net/2025/04/medieval-lance-strike/

Over to you...

[Erpingham]

An interesting comparison is this

https://www.academia.edu/33789994/AN_EXPERIMENTAL_INVESTIGATION_OF_LATE_MEDIEVAL_COMBAT_WITH_THE_COUCHED_LANCE

Note the considerable difference in impact energy calculations.

I think one error in this new paper is to calculate that all the possible energy from the knight/horse combo is transfered to the target whereas a lot is retained as the combo continues to move (unlike a Honda Civic hitting a wall). The target is also not rigid - if you do it right the parts of the target separate out and the knight part flies through the air and crashes to the ground. The destruction of the lance also absorbs energy.

Incidentally, the abstract of the paper at Physics Special Topics states

"A knight wielding a lance riding upon a destrier warhorse at full gallop delivers a blow with the energy of a typical hand gun round (.45ACP) at 541J and the equivalent momentum transfer of being struck by a 1kg bag of sugar thrown out of the cockpit of an F1 car doing it's top speed of around 230mph (104Nm). "

These figures aren't in the paper, nor is the Honda Civic.  Note the impact is compared to a 541J handgun round, which is rather less than 53kJ. This really needs one of our engineers and mathematicians to look at it.

[RichT]

I know these sort of quantifications are all the rage but I do wonder what their value is. For one thing it seems there are too many variables and unknowns to make any force calculation (or strength calculation or penetration calculation or whatever it is) really meaningful. But even if some widely agreed number was arrived at, so what? We know a lance strike could knock a man off a horse (because, jousting). We also know lots of other outcomes were available (like lance breaking, or missing, or hitting a limb and bouncing off). What new knowledge or understanding is gained by arriving at some number for force of impact (in circumstances x, given variables y)?

[skb777]

I'm not sure I can take something serious that begins with 'Physics Students Do the Math'

I don't know the first thing about Medieval warfare did they really fight by charging headfirst at each other with lances or is this just a romance/joust thing?

[Erpingham]

did they really fight by charging headfirst at each other with lances or is this just a romance/joust thing?

No, in a joust you ran parallel with each other. Head on collisions did occur but it was accidental. In the 15th century, as a health and safety measure, they put a barrier running down the tiltyard to keep the riders from colliding. There is a nice image of this form of joust in the Medievalist article.

[skb777]

did they really fight by charging headfirst at each other with lances or is this just a romance/joust thing?

No, in a joust you ran parallel with each other. Head on collisions did occur but it was accidental. In the 15th century, as a health and safety measure, they put a barrier running down the tiltyard to keep the riders from colliding. There is a nice image of this form of joust in the Medievalist article.

Ok headfirst probably wasn't the best term to use

[Erpingham]

Ok headfirst probably wasn't the best term to use

Apologies for being literal but if the question was meant "did individual combatants charge at each other from opposite directions with lances?" the answer is yes 

[Cantabrigian]

I think that the main conclusion I'd draw from the description of this paper is that 3rd year undergraduates studying physics at Leicester aren't that good at maths...

[Ian61]

In other words - You can calculate the force an elephant exerts through a stiletto heel but this misses the point that they dance on their toes.  

[Imperial Dave]

 

[Erpingham]

I think that the main conclusion I'd draw from the description of this paper is that 3rd year undergraduates studying physics at Leicester aren't that good at maths...

While admiting this journal is generally quite light weight, if not whimsical, I do get the impression these guys should avoid a job involving mathematical modelling of real world events in future.

Further consideration of the simple issues here suggests they make the mistake of transfering all the KE of the participants through the lance in one hundredth of a second. Normally both riders will maintain a good proportion of their KE (they keep going - either as entire combos or bits of combos)  Even if they collide, the energy tranfer will take rather longer than a hundredth of a second. I think I'll stick with the experimental version.