What was the range of an ancient javelin?

[manomano]

Others considerations

I wrote about arrows not for only  for the loss of the energy on the distance but
primary to estimate the loss in distance  to lauch a similar object with a double weight with the same strenght ( 150 lbs)and the contrary.
Note: the 1,9 oz arrow have a diameter of 10 mm, the 3,3 oz of 12,7
Others results by Pratt,Stretton,Stanley,Walker are very similar.

Why?
Because the olimpic jav is 800 gr , our battle jav is 400-500 gr
To built a reasonable replica  take a broomstick and mount on it a rod of iron 1 cm diameter 40 cm long:
500 gr total weight , 150 cm long
a better balance weapon  that  using  a more short and large point.
Instinctively  you hold it just behind  the point, you hold an uniform bar at the middle.

History of Jav in modern olimpic games.
Modern jav are hallow and made in Al  and or glass fiber and follow rigid rules in making and
have much more than  some help from aerodynamic lift
To decresed the range the centre of gravity was moved foward of only 4 cm
giving a loss of performance of 1/5   (100:80)
But in the first years the javs were solid and much similar to the ancient one.
In 1912 the record is 62 m in 1906 53 m  ( 24 m/s , 22  m/s ) but the average was only 32 m  ( 18 m/s)
with a balanced object built to fly not to kill.
So, these last values must be used in comparison.
But remember with a run-up.

Returning to the arrows:
A 150 lbs bow lauch a  60 gr arrow at  320 ys  ( Strickland and Hardy)
A 100 lbs bow lauch the same arrow at  230 ys (Pratt also  24- 300 , 40 - 255)  (Stretton 50- 250 , 100 225 )

1 lbs = 4,448 N

At what distance a man with a force in the arm of 400 N  can launch a unbalanced 400 gr jav?
It' not the double of olimpic jav but less.
But the distance for a pila is not the half but more.

In my opinion:
An exceptional trained man  at 70 m , the average  trained man at  43 m , an ordinary draft soldier probably  less.
This give us for a jav a average  K of 80 J , so the historical effect can be understood.
At  very long range also a modest protetion given by a coat can be sufficient to avoid wounds.

[Erpingham]

1 lbs = 4,448 N

In the UK we would write this as 4.448 N, for those confused.

As to range, we have experimental data (its where this all started).  I'd rather we started from there than speculation based on 100 year old javelin records, adjusted on a guesstimate basis.

To get a launch energy of 80 J with a 450g javelin would give a launch speed of around 19 m/s, I think.  While I can understand the reasoning that trained athletes were more efficient and therefore ancient throwers would not attain the same launch speed, is this an appropriate scale reduction?

[manomano]

For , . sorry

I dont' make any reduction for an eventually unbalanced weapon, too many variables:
the iron  head is long and narrow as I think is better or short and large?
No reduction for air resistance but I reported it for jav are:   drag coefficient  1,2  aerodynamic index 5,53
I calculate a 400 gr weight because it's is  just the half of 800 gr and I think a reasonable weapon , so vel is 20,6 m/s for average shot  and over 26 m/s for the best shot.
The bow was discovered because is much better than a man's arm.
The difference between  the best and average shot  for  ancient warrior is the same as for  athletes  in 1906-30 period,
The olimpic ranges are increased  for ancient jav because weapon is more light.
I used confirmed reports for the average range  when olimpic jav was solid.