TITLE: Hafting tests on tanged blanks
AUTHORS: Nassim Zejly, Bonnie Wright, Fanny Olivier, Narciso Domingos Sabao

[DESCRIPTION]
By the end of the Middle Pleistocene and the beginning of the Late Pleistocene (around 150,000 - 130,000 years ago), the Middle Stone Age in North Africa witnessed the emergence of tang technology. This innovation is characterized as a technical solution that facilitates hafting. Moreover, this technical behavior was consistently represented as point technology. This notion leads to the assumption that the tang was used for hafting in an axial orientation, with the tang being inserted into another material like wood or bone. However, what about the rest of the artifacts? What if the tang was not inserted but used for fixation instead?

In our experimental work, we explored alternative hafting methods where the tang was not inserted but used for fixation. These methods involved testing two hafting systems: the juxtaposition of the tanged artifacts onto wooden sticks, and the insertion of one edge adjacent to the tang. The choice of hafting systems was motivated by the thickness distribution of the produced convergent artifacts.

After hafting, we tested the functionality of these artifacts through three main activities: throwing the spear points, using the spears for penetration, and conducting butchering activities. The first two activities were tested on a simulation of animal carcasses using a mixture of gelatin and pig bones (two scapulae and two radius ulnae), while the butchering activities were conducted on fresh pig limbs.

[STEPS]
SECTION: 1) Animal resin preparation : here is the followed recipe
1. Purify the water by boiling it, then let it cool down.
SECTION: 2) Gelatine tests : 4 different test were made to find out which is best for the fake carcass
4. 1st test
450ml of water for 50g of gelatine : success.
 

 

SECTION: 4) Knapping
13. Production of (convergent) blanks : 11 in total.
 







SECTION: 5) Hafting
18. Additional step for the hafting of knives.
SECTION: 6) Spear use
20. Cutting : only one active part used on one raw material (pig limbs).

The cutting was done on pig’s trotters. There were two users, doing a skinning action.
We cut 7 times all around the leg and every 2 cm, then removed the strips of skin by cutting into the fat. We decided to carry out this action to observe at which level of the paw the marks on the bone are most visible.

Participant 1, who instead moved the knife back and forth, achieved a time of 28.15 minutes for the 7 rounds and 28.28 minutes for removing the strips of skin. Which makes a complete time of 56.43 minutes.

Participant 2, who cut with a rather sharp gesture, achieved a time of 19 minutes for the 7 rounds and 21.38 minutes to remove the strips of skin. Which makes a total time of 40.38 minutes.
SECTION: 8) Washing
27. Lithics : 30 minutes in hot water, then dry with a paper towl.
 

SECTION: 6) Spear use
22. Piercing : static activity : no run-up. The target is at the experimentator's feet.
Don't hesitate to register individual information (height, weight, hands dimensions...)
Every use was filmed and a picture of the spear was captured after every use.
Every impact was located on the gelatine and marked, especially of a bone was touched. 
 


 

SECTION: 6) Spear use
23. Throwing : Settle with a fix distance for all of the users.
Don't hesitate to register individual information (height, weight, hands dimensions...)
Every use was filmed and a picture of the spear was captured after every use.
Every impact was located on the gelatine and marked, especially of a bone was touched.
 

 
 

 

SECTION: 6) Spear use
19. Take a picture of everything (for the before / after use comparison).
SECTION: 1) Animal resin preparation : here is the followed recipe
2. Put twice as much water than resin, then let it sit for 24 hours.
SECTION: 3) Gelatine preparation
8. We opted for 5L of water for 730g of gelatine.
SECTION: 3) Gelatine preparation
10. We wedged the sitting gelatine so that it covered the scapulae.
 


SECTION: 3) Gelatine preparation
9. Bones disposal inside of the future block of gelatine.
 

SECTION: 1) Animal resin preparation : here is the followed recipe
3. The next morning, heat the mixture using a bain marie, without going over 60°.
 


SECTION: 2) Gelatine tests : 4 different test were made to find out which is best for the fake carcass
5. 2nd test :
350ml of water for 50g of gelatine : success.
 

SECTION: 2) Gelatine tests : 4 different test were made to find out which is best for the fake carcass
6. 3rd test :
400ml of water for 50g of gelatine : success.
SECTION: 2) Gelatine tests : 4 different test were made to find out which is best for the fake carcass
7. 4rth test :
450ml of distilled water for 50g of gelatine : success.
SECTION: 3) Gelatine preparation
11. Let it sit for 24 hours, the temperature must stay rather cool, then remove from the mould.
 

 

SECTION: 4) Knapping
14. Creation of a database to register the information :  https://docs.google.com/spreadsheets/d/1HfSV_gF87GJr9aV6UalQ8rctDjXmvuSQWcvl-Sfw4Mk/edit#gid=0
SECTION: 4) Knapping
12. 
 

 

 

SECTION: 4) Knapping
15. Pictures and basic structural drawings of the blanks.
 


SECTION: 5) Hafting
16. Lateral hafting (8)
Material required :
- tanged blank
- standardised wooden stick
- animal resin
- vegetal fibre
SECTION: 5) Hafting
16.1. Saw the wooden stick in order to split it widely enough to insert the tanged blank as desired.
 

SECTION: 5) Hafting
16.2. Insert the tanged blank in the splitted stick by pressing the tang towards the bottom end of the stick and inserting one of the lateral parts of the blank inside the wood.
 

SECTION: 5) Hafting
16.3. Maintain the position and cover the whole with animal resin (on top and inside of the wood + around the tool). Covering it by spinning above the pot full of animal resin might be easier.
SECTION: 5) Hafting
16.4. Fix the point by using the vegetal fibre. Secure it by covering as much as you can, but let the active part of the spear show.

 

SECTION: 5) Hafting
17. Axial Axhafting (6)
Material required :
- tanged blank
- standardised wooden stick
- animal resin
- vegetal fibre
SECTION: 5) Hafting
17.1. Saw the wooden stick in order to split it widely enough to insert the tanged blank as desired.
SECTION: 5) Hafting
17.2. Reduce the thickness of the stick on the end part and put the tang of the blank on top of the stick. If you use this method, your hafting device must be solid.
SECTION: 5) Hafting
17.3. Maintain the position and cover the whole with animal resin (on top and inside of the wood + around the tool). Covering it by spinning above the pot full of animal resin might be easier.
SECTION: 5) Hafting
17.4. Fix the point by using the vegetal fibre. Secure it by covering as much as you can, but let the active part of the spear show.
SECTION: 5) Hafting
18.1. Saw your wooden stick to the desired length before hafting the knife.
 

SECTION: 5) Hafting
16.6. Let the spear dry.
 

 

SECTION: 5) Hafting
17.5. Let the spear dry.
 

 

SECTION: 7) Unhafting
24. Cut the vegetal fibre with a knife and carefully extract every blank.
 

SECTION: 7) Unhafting
25. Label every blank.
 

SECTION: 7) Unhafting
26. Extract the potential splinters stuck in the gelatine.
SECTION: 8) Washing
28. Bones : extract from gelatine, then put in boiling water.
 

 

 

SECTION: 6) Spear use
21. Make an aditionnal database for used tools : https://docs.google.com/spreadsheets/d/1HfSV_gF87GJr9aV6UalQ8rctDjXmvuSQWcvl-Sfw4Mk/edit#gid=462676800 (sheet 2)
SECTION: 9) Analysis
29. Bone analysis.
SECTION: 5) Hafting
16.5. Add an extra layer of animal resin on top of the vegetal fibre.
 

SECTION: 9) Analysis
30. Lithics analysis.
SECTION: 9) Analysis
29.1. Take scaled pictures of the boiled bones.

 

SECTION: 9) Analysis
29.2. Identify the traces on the bones and to which use they correspond to.
 

SECTION: 9) Analysis
30.1. Check the documentation for every use and register how many takes the participants succeeded in, for each use, each hafting system.
 

 

 
Employ statistical tests by using the R package, to assess whether there were significant differences in success rates between orientations ("Hori" and "Verti"). Two common statistical tests, namely the two-sample t-test and the Wilcoxon rank-sum test, were used to compare success proportions for each participant individually and when their data were combined.

 


 


 

 

 

 


SECTION: 9) Analysis
30.2. Use a dinolite to observe the traces of impact on the different types of hafting / activities.
Describe the traces and locate them on every blank.