Steel chisels cutting wood and bone

[be unique]

TL;DR Summary

Hardness and structures of bone, wood and steel have interesting effects. Any observations are welcome.

Below 17 degrees bevel , a steel chisel cuts pine wood without tearing shreds but 25 degrees is the upper limit for hardwood. Bone is said to resemble wet pine-wood.


2mm thickness is the limit for steel cutting bone.

.". difficulties arise for the surgeon when using conventional chisels, due to the large chisel cross-section, namely in particular the risk of a premature and, in some cases, uncontrollable fracturing of the bone, excessive traumatism of the bone.. Since, by virtue of the guide, the chisel blade can be very thin, eg. 0.5 or 1.0 or 1.5 or 2 mm, there is only a small widening of the cutting gap by the chisel thickness. The risk of premature fracturing and jamming is thereby decreased. The traumatism of the bone is reduced."
https://patents.justia.com/patent/4586496https://siamagazin.com/this-man-turns-lignum-vitae-wood-into-an-extremely-sharp-knife/
Measuring the thickness of the blunt side and width ( using his fingers and nails to calibrate the mm. ruler) then the knife has a 20degree bevel . It is 3mm thick at 10mm back from edge. A sword is about 12degrees . It is 2mm thick at 10mm back , as is the patent surgical chisel. Both in angle and thickness the wooden knife is not suited for smooth chisel cutting into bone ( slicing cucumber is fine, no problems, I found). A 25degree chisel cuts hardwood and could be 2mm thick at 10 mm back but 2mm wood-blade is not good. Pine is about 10% steel strength and Lignum hardwood is around 15% steel ( so a .5mm thick chisel is possible).

Tests of sharp hardwood ( Janke 20k N, 1000kg m3) and steel on pine , pig-skull and Synbone forensic skull confirm this . Momentum was at 33mph/53kph by sports radar speed-gun. Wood can't chisel bone.

 

[anorlunda]

You ask no question. What it's your purpose for this thread?

Are you the author of that article? Do you have a personal interest in that patent?

 

[Baluncore]

A good read on the subject is “The Science and Engineering of Cutting”, by Tony Atkins. (The Mechanics and Processes of Separating, Scratching and Puncturing Biomaterials, Metals and Non-metals). 2009, Paperback ISBN: 9780750685313.

 

[be unique]

If the data given is valid , then my purpose is to question these:
The death of Kaakutja: a case of peri-mortem weapon trauma in an ...

https://www.cambridge.org/core/product/.../core-reader
Sep 15, 2016 - Experiments by Lewis (2008) using a range of sword types illustrate how ... closely resembles that produced by an African 'Samburu' sword. pp 1327,8

Kaakutja, Perhaps the First Known Boomerang Victim - The New York ...

https://www.nytimes.com/2016/10/18/science/first-boomerang-victim-australia.html
Oct 17, 2016 - The skeletal remains of Kaakutja, an aboriginal man who scientists think was killed by a boomerang about in the 13th century.

NYTimes has an image of the excised bone. Would you agree that wood is unable to give that smooth slice across the laminated cortical plate? Did a sword do that?

 

[anorlunda]

OK, that is much more clear. Thank you for your cooperation.

But it also suggests that the forum should be biology, not mechanical engineering. Forensic scientists study medicine to learn about bone fragments. Medical examiners in particular.

I'm going to move the thread to biology.

 

[berkeman]

". difficulties arise for the surgeon when using conventional chisels, due to the large chisel cross-section, namely in particular the risk of a premature and, in some cases, uncontrollable fracturing of the bone, excessive traumatism of the bone..

What are some typical orthopedic surgical procedures that use chisels? I've only done a little searching so far, so it does appear that they are used. What are they used for in which specific surgeries? Thanks.

https://www.sklarcorp.com/orthopedic/chisels/hibbs-chisel-8838.html

 

[be unique]

I've used a cleaver in butchery but don't do surgery. Willing to try , low fees.
That chisel is for "heavier bone" but is a massive 12mm , 1/2 inch thick. wow. Braun chisels tell me their chisels are 2mm thick. https://o.aolcdn.com/images/dims3/G...images/n-MARK-FRASER-INJURY-SKULL-628x314.jpg

An ice hockey puck is about a boomerang's weight , but probably faster
for Momentum. The trauma here is comminuted depressed fracture but not cutting the inner cortical plate . The length of the cut on a puck-circle shows the depth is about 4mm, 1/6 inch which is halfway through the skull. This is not a slice across the plate like the Kaakutja fracture.

 

[sysprog]

@berkeman: Laminectomies, facetectomies, and osteophytectomies are among the procedures for which osteotomic chisels are apt to be used.

 

[Baluncore]

A wooden boomerang that is designed to return is light-weight and has a rounded leading edge and sharp minimum-drag trailing edge like an airfoil. Most people who get a boomerang try first to throw it, spinning backwards.

Do not underestimate an Australian hunting boomerang. It is heavier and has a sharper leading edge at the tip. It is not expected to return. It is designed for range in a straight line, to fly through a flock of birds until it hits one. The wood species is selected to be bent and dense, then it is heated and shaped in a fire to make it harder.

I believe the injury to the skull pictured could have been done by a hunting boomerang. There are several contact geometries to consider. If the initial contact was with the tip of the forward traveling blade, the rotation and linear flight energy combined would be available to cut into the bone. A flake of bone was then broken out. Penetration may have been initially aided by the surface flesh that prevented deflection.

Scratch marks on the bone show it was mainly sharp-edge pressure and not the slicing action expected of a curved slashing blade.

 

[be unique]

There are many web examples of sword cuts by edge pressure.

https://render.fineartamerica.com/i...e-trauma-1903-science-source-canvas-print.jpg

Thickness is the problem . Blades in Australian Museum Sydney are 5-10mm thick at 10mm back from edge. The profile is bi-convex like bullet nose. Skull is about 8mm thick on frontal sides so the boomerang in Kaakutja skull has to be also in the outer cortical plate , not just within the trabeculae diploe. This gives the ice-hockey puck effect compared to 2mm sword. Bone also hardens under sudden shock ( partly due to liquid in the marrow) causing brittle random fractures.

Here is another angle showing the straight , clean cut.
https://www.google.com.au/search?q=...AUIDigB&biw=1024&bih=625#imgrc=uRsNLy3v0UdJnM:

 

[Baluncore]

This gives the ice-hockey puck effect compared to 2mm sword.

I live in Australia where we do not play ice hockey so I do not know the puck shape, mass or what you mean by the "ice-hockey puck effect".

You also need to specify what you mean by a 2mm sword. The wedge angle of a chisle decides if it will jam in a material or bounce out again. The critical angle is the ArcTan( coefficient of friction between material and blade). If the edge angle is too sharp it will jam in the cut which may chip the cutting edge of a thin blade.

 

[be unique]

Baluncore,
In post #7 you can see the ice hockey puck- effect in a skull , and 2mm meaning "thickness of sword". A puck , a rubber disc , is like a blunt object with 90 degree profile . The bi-convex boomerang tip, cutting obliquely along Kaakutja's cortical plate, is like a blunt instrument also. As my first post noted , the angle of a chisel is significant , below 17degrees for softwood. But in cortical bone there is the added effect of random cracking due to thickness above 2mm rather than edge angle.

A boomerang at 5-10mm thickness has twice to five times the front area of a 2mm thickness causing increased resistance. The momentum is placed on a wider section of bone causing deformation compared with severing a thin layer.
This resembles a rowing dinghy's bow- wave compared with a racing yacht , there is more disturbance.

 

[be unique]

When 5mm thick at 10mm back from edge , a boomerang has edge-angle of 30degrees and at 10mm thick it is 60 degrees ( plus the bi-convex curve).

 

[jim mcnamara]

It takes exceptional proof to prove an exceptional statement. That is what you are trying to do. So you need "multiple lines of evidence". You do not mention those at all. And you certainly could do a better job on the boomerang problem. IMO.

I think what you are attempting to do is to assert that current interpretation of some fossil evidence of trauma is wrong. Which is okay, go for it. Science works that way.

Consider:
Australian buloke is an extremely hard wood, with a Janka hardness higher than any other commercially available wood. It dulls tool steel. Note the cross grain level is moderate. This increases breaking resistance substantially. Hunting boomerangs are/were often fire treated to increase hardness. You need to show that the force required to sever the required bone thickness can never be generated by a hunting boomerang, forget medical chisels for a while. Buy some dog bones at the grocery and start testing on them with boomerangs made from local really hardwood species. Never underestimate so-called 'primitive' people and their technologies.

https://www.wood-database.com/australian-buloke/Other evidence:

But is there reasonably local evidence from local scientific excavations of iron refining sites or are there any extant iron/bronze/copper tool examples dated to the period in the general locale of the fossil find? Using only the fossil as evidence for something is a great first step. You need corroborating evidence to support your claim.

Local resources to check:
Is there evidence of some 'foreign invasion' of metal working peoples in the relevant time frame?
Sources of metal tools like trading. I.e., is there bog iron nearby? Copper ore nearby ? Nearby might be several hundred kilometers.

Neolithic peoples do not make metal weapons (by definition) and if they do they leave traces like smelting furnaces. So do metal working visitors.

You may be on to something interesting, but it needs lots of work.

 

[Baluncore]

A boomerang at 5-10mm thickness has twice to five times the front area of a 2mm thickness causing increased resistance. The momentum is placed on a wider section of bone causing deformation compared with severing a thin layer.

Your use of blade thickness is not rational. It is the cutting edge that penetrates to remove the material. A hunting boomerang is very hard and has a sharp cutting edge. I don't know where you have been getting your data on hunting boomerangs, but they weigh ten times the 170g of an ice hockey puck, and it takes a strong arm to throw one. Maybe the word boomerang is now more restricted to light weight toys that return. The injury to the skull shown was probably caused by a hunting stick (kylie), or a throwing stick. Both can be similar in shape to a returning boomerang, but they are much heavier, fly straight, and are lethal weapons.

 

[be unique]

Jim
"You need to show that the force required to sever the required bone thickness can never be generated by a hunting boomerang ". That's an odd thought . A brick can strike bone but doesn't generate force , the brick-thrower does that. In post#1 the Janke hardness is noted and mulga is similar to buloke. Tests were mentioned in #1. The issue is not medical chisels but the biological nature of cortical bone - it can be cut cleanly by 2mm thick but not by thicker instrument. Boomerangs are made of wood and have to be thicker than 2mm . This is the limit which prevents slicing and causes the ice-hockey style comminuted fractures.

My question remains , where is the evidence in the published articles for wood? Science can't change to fit presumed history.

 

[be unique]

Baluncore,

A heavy kylie is robust but my mulga boomerang weighs 520g , my machete is 580g and Indonesian keris swords are reportedly 300-600g. A kylie is lethal but sharp mulga blades can't fit between cortical plates. The final comment here is interesting:

https://www.abc.net.au/catalyst/stories/4211835.htm
Emeritus Professor Richard Wright AM
. . But whether it's done with a machete or whether it's done with a steel axe or stone axe, I don't know.

Dr Michael Westaway
When you look carefully at these sort of lesions, the striations are fairly diagnostic of an edged steel weapon. So it may actually be evidence for frontier violence. This is significant because we actually haven't seen anything like this in the archaeological record in Australia before.

Dr Michael Westaway
Looking at the experiments on bone that have been published in the United States and elsewhere, we can see that edged weapons, and swords in particular, create traumas very similar to what we're seeing in the man from Toorale.

NARRATION
Bizarrely, the skull wounds on Toorale Man appear similar to those on gladiators in Imperial Rome.

Dr Michael Westaway
It was curious because one of the healed traumas looks very similar to what is documented in an important case study looking at the remains of gladiators. And it looks like a healed trauma from a sword wound.
Dr Michael Westaway
That means that there are weapons being used by people in western New South Wales that are creating signatures that look like, you know, sword wounds.
Badger Bates ( Aboriginal elder)
Our old people back then did not have a blade like that. If that carbon date is 700 years old, there is something wrong somewhere.

 

[Baluncore]

A kylie is lethal but sharp mulga blades can't fit between cortical plates.

The cutting edge does not need to fit between the plates. A flake can be created by a square cornered tool at a discontinuity.

@ be unique.
Why do you insist on referring to the cutting edge angle by the blade thickness? Surely “rise over run” represents a wedge angle. Specification of “rise” without “run” is insufficient and certainly not helpful to understanding the cutting process.

I believe you have decided that it must be a metal blade, so you have conducted an opinion pole from the literature, and cherry picked the results. That is not scientific. One incomplete example is an anecdote, it does not constitute a proof. You must find the metal edged weapon that caused the injury, or you must find more examples.

 

[be unique]

Kaakutja shows the inner cortical plate with smooth surface. The blade must have been across the trabeculae, between the plates. If it was thicker than 2mm then it would cause random cracking, not smooth surface. That is why Braun make 2mm thick surgical chisels . Bone anatomy is not optional like MacDonald's customer burgers and this skull is normal.

Where do I say angle is thickness? In post#1 2nd para , thickness is explained.
Blade-angle is relevant to damage but thickness is more so. There are many web examples of blunt force trauma and of sword trauma in skulls. The ice-hockey one is similar ( lighter weight , faster speed) but thicker than sword . There is a difference between excised fractures and comminuted depressed fractures . Textbooks give standard anatomy and standard descriptions of bone behaviour.

Baluncore, do you use a wooden knife , wooden axe or wooden car-frame?
If not , why not?

 

[be unique]

Here are some comments on the response of bone to force:

A technique of percutaneous multidrilling osteotomy for limb lengthening and deformity correction.
Yasui N1, Nakase T, Kawabata H, Shibata T, Helland P, Ochi T.
The bone is drilled percutaneously, using a special drill guide, and osteotomy is accomplished by connecting the multiple drill holes with a small chisel. This technique can prevent undesirable bone cracks.

Orthopedic Hardware - UW Radiology - University of Washington

https://rad.washington.edu/about-us/academic-sections/.../orthopedic-hardware/

Washers are generally used in two situations. They are used to distribute the stresses under a screw head so as to prevent thin cortical bone from splitting.

WO2004089233A1 - Osteosynthesis plate for operative care of bone ...

https://google.com/patents/WO2004089233A1?cl=en

The bore diameter may be reduced relative to conventional holes . On the other hand there is the possibility, based on the location of a fracture to select one of the holes without the risk of a bone crack in the vicinity of the fracture.
---------------

This has graphics of surgery for removing a piece of cortical skull-bone for transplant. Note that the chisels must be thin and carefully moved in sequence to protect the plate from fracturing ( near the end of the page).
The inner plate is thinner so is more liable to be damaged by chiselling.
---------------

https://www2.aofoundation.org/wps/p...srg/93/04-Approaches/A70_Coronal-approach.jsp

The initial grooves are deepened to the level of the diploë.
The diploë must be visible, which is indicated by cancellous bone bleeding.
..
The outer cortex grafts are separated from the calvarium by sequential advancement of thin osteotomes through the diploic layer.

 

[Steelwolf]

Being a historical weapons and armor builder, with a LOT of experience not only in making swords, but in the use of them, as well as having had a father who was a cabinet maker as well as UDT SEAL, so I learned a lot about weapons use and materials etc.

The skull shown on the original paper and NYTimes article appear to be made strictly from the saber-like Wonna, a wooden throwing stick that was also essentially a battle axe if used in hand. Seeing pictures of the weapons possible involved I have to say that with the materials there in the area, where flint and obsidian are extremely rare, mostly being sedimentary type stone for large areas, wooden implements and the specific technology of treatment, fire and plant extracts to harden the material, and having handled some of these implements myself I will state that I find the wounds on the skull in question do not look like wounds that would have come from a metal sword.

They have more the appearance of fast, light impact without the 'carry through' that a dense metal blade would have had, especially in that area for a cut and the fact that there are no other 'cut' marks on any of the bones, especially lower arm defensive wounds. Their description of the 'wonna' a fighting boomerang, makes if fairly clear that was the likeliest weapon to make that wound. Splintering etc on a high-speed impact like that can remove chunks of bone fairly cleanly and even softer wooden implements, used at high speed, can do that kind of damage, high speed being either full man's throw or swing to kill. A hardened chunk of Australian Ironwood will do massive damage.

The reason we do not use wood for knives is their fibrous nature and no edge-holding ability, but the wood is tougher than many metals and not as brittle as most, and lighter so it can be moved at speed. With a weapon speed is more important for a cutting weapon than mass because of the E=M x V^2 with more energy coming from square of speed vs linear of increase of mass. A lighter fast weapon can do more damage than a heavier slow weapon.

Chisels are also for controlled cutting, usually shaving the bone in increments (I well know having had full 2 level fusion at C5-6-7 with multiple laminectomie, which is Why I am no longer making a living building swords.) And when cutting bone or wood with a chisel it is very different than a massive, high energy swing with a sharp club so as to make the comparison not at all comparable.

The hockey puck would do similar damage blasting out a chunk like that even with a 90 degree corner. Without the missing chunk of bone and seeing if it was cleanly split off or shattered would make the determining difference, as well as finding a metal sword in that geological strata and area, or proof of their existence. Without such I think we have to go to the Occam's Razor view of the Wonna being the most likely weapon to cause that damage as it was the indiginous weapon at the time, and the other injuries do not show any sort of edged weapon type marks, and if there was a fight with a sword involved, like that, it would be more evident on Other bones, such as the ribs, which appear to have more of a blunt force trauma to them. The arm injury I am ambivalent on as it could easily be a spalled piece from dull impact, and there is no evidence of edged cut on it even though it appears smooth and conchoidal.

Obviously the individual had survived heavy head wounds before, as there is the healed scars from previous injury to the head. But it looks like the wound to the right side of the skull likely taking out the eye is what killed this man. And it appears to be high speed, low mass impact due to the way the conchoidal edges of the thin side of the flake removed and the apparent crushing of the bone directly under the 'end' of the cut and the piece apparently shattered out of the wound.

But I see no reason to think that it would have been a metal weapon, although there is the distinct possibility of lost sailors having been cast ashore there in Australia, possibly with swords etc, well before Western Colonization. So while there is the slim Possibility of there being a metal sword there the likelihood of it is Low, so I am going to have to back the view that the wound was made by a hardened wood wonna at close range.

 

[be unique]

Hi Steelwolf,
>They have more the appearance of fast, light impact without the 'carry through' that a dense metal blade would have had, especially in that area for a cut and the fact that there are no other 'cut' marks on any of the bones, especially lower arm defensive wounds.

The article agrees with a light-weight weapon. Mulga boomerang , machete and Keris sword are around .5kg. If a wonna cuts a skull then it would make the same arm marks so the absence is how the fight happened.

>Splintering etc on a high-speed impact like that can remove chunks of bone fairly cleanly . A hardened chunk of Australian Ironwood will do massive damage.
Sounds OK on paper . Any evidence for that? 'Massive damage' is not slicing off a flat triangle flap of bone.

> A lighter fast weapon can do more damage than a heavier slow weapon.
Interesting.

>And when cutting bone or wood with a chisel it is very different than a massive, high energy swing with a sharp club so as to make the comparison not at all comparable.
A thick chisel causes cracks, a thin one doesn't . A blunt instrument causes random damage, a sword doesn't.

>The hockey puck would do similar damage blasting out a chunk like that even with a 90 degree corner.
Eh? Kaakutja has no chunk blasted out , it's a flat slice with straight edges.

"The wound to Kaakutja's face and the slice off the humeral head are consistent with a very sharp blade - I am prepared to stand corrected but I would have said that even a very hardwood could not be sharpened to this extent. I could believe the healed linear wound could be a linear depressed fracture which could in theory be produced by a thin sharp hardwood object but the strikes to the face and shoulder would have resulted in fractures and not the fine slices into bone seen here." ( Smith, Martin 2017).Bournemouth Uni ,UK.

"Now I see the full significance of your conclusion ! Martin Smith is a well-known expert so a good endorsement." ( Robertson 2016) Australian Forensics.

The author tested boomerang on pig-skull.
"I have received the following comment from the writer: " The aim of the experiments were to determine whether traditional Aboriginal weapons could have caused trauma similar to that of the Toorale skull. Unfortunately our methods did not produce trauma,.".
School of Archaeology and Anthropology.
ANU College of Arts and Social Sciences, Canberra. "

Neither did my test with sharp mulga boomerang on pig-skull and Synbone. Machete on Synbone gave similar results to Kaakutja , a triangle with straight edges. There had to be reason for the Bronze Age then Iron Age then Chinese steel exports. Here are the suspects:https://portal-images.azureedge.net...d-3220-4208-a5d0-a99100bd3f91.jpg?w=540&h=360
https://www.alamy.com/stock-photo-s...al-short-sword-samburu-national-98194992.html

https://s3.amazonaws.com/productimages.goantiques.gemr/55586714/578737120_fullsize.jpg

 

[Steelwolf]

I have Built wooden swords as well as steel ones and bronze, the wood would do exactly that kind of damage, especially the Aussie Ironwood varieties that are used. A pig skull has very different morphology and is NOT a good example of how Human skull would chip/cleave.

While there IS the (Note the exact wording) Possibility of there being a sword in the area, the Likelihood of there being one is extremely low. So, until YOU come up with actual PROOF that that was done by a metal weapon, I am going to continue to insist that that is a wood based impact wound on the skull, that it is chipped and conchoidally edged showing that it was split off from percussive force. That is not a 'sliced' piece, it is broken out of there. It is too bad the missing piece is not there as it would have told us a lot about how that wound was formed, but the wooden wonna appears to be the culprit.

You can post all the Links to stuff you want, I have done the actual work of Doing it. You have presented enough information, such as your talk concerning chisels, to show that you do not know the difference between a tool designed for careful carving of medical materials vs a crude and nasty, high tech as possible, treated wooden weapons As Are Know To Exist in the area at that time.

And yes, weapons have progressed, but a person with a rock can sneak up and kill the guy with all the high tech gear and high powered weaponry, and the stealth and simplicity of a rock is still used today, they do not jam, do not require maintaining.

You seem to be pushing a Theory that has no proof, and, as an expert on this particular subject, even though I do not have the nice little mentor or teacher tags, I ran my own business with the swordmaking for over a decade, and there were many years of playing with knives and using, trying various ones out when I was in the Military and overseas on Guam, PI, Diego Garcia, Perth and Darwin, and yes, I got to see and play with some indiginous weaponry, so I DO know of what I am talking about. Properly treated and hardened wood, when used by a skilled expert, will EASILY leave Cleaving type wounds like that. I could build a sword out of softer wood like Teak that would still take a chunk out of the skull just like that, and the hardened wood Wonna would do the trick quite easily.

As I pointed out before, unless there is a chip of metal left in the skull or the sword itself in the area, and a history, you are not going to be able to CREDIBLY show that this was anything other than a wooden weapon, very expertly used. Wooden Weapons WILL do that kind of damage easily. Most of the world does not get wood as hard as Australian Ironwoods, and yet very durable wooden items have been made and last the ages.

My worry here is that you are coming at this from a point of personal theory and trying to find proofs in the materials and other cutting implements. The real equivalent of this would not be a machete, but an axe, and that would have carried a great deal farther into the skull, so would a machete, although modern machete's are made from rolled steel, and do not have the distally tapered thickness from tang to tip as well as edge thickness and back of sword at the forte. In essence, modern machete is not at all similar to the older swords as it is very high tech alloys (even carbon steel, by comparison, is high tech) and thinner than the older swords. It is not a good stand-in for the era.

So you are trying to compare modern medical chisels to a wooden battle axe, and trying to find modern examples and instead of keeping an open mind, and going where the data leads, you seem to be on a This HAS to be a Metal Weapon Wound, and doing the 19th century thing of pushing the investigation ONLY in the direction of things that You Think are Pertinent because it SEEMS Similar to something else today.

You do the old Aboriginal peoples a great disservice if you are thinking a wooden sword is That inferior to a metal one when those throwing sticks and fighting boomerangs were deadly dangerous and serious.

Besides, you can get similar wounds using something like a thrown dinner plate or ashtray, again it is the speed of the impact giving the extra force vs the weight.

 

[Steelwolf]

Why I push the 'Properly made and expertly used' is because wooden weapons get used in a different manner than the metal ones; higher speed for one thing, and they knew the possibility of the weapon splitting or cracking, and would use that as a feature rather than a bug, so they would have a fine rounded edge that could, upon impact, split along the grain and leave a sharper edge than before, the fresh split edge being sharper, IF should it split is is allowed for.

The people took very good care of the weapons and maintained them. Our way of doing things is very different, they were similar to Olympic Athletes, compared to modern man, just for their day to day living, hunting and gathering bands. In some things the expertise has been lost, the ways of making war have not been practiced since the Aboriginal peoples have been conquered and nearly culturally assimilated before allowing them their land and practices back, and war is still forbidden, so there are points that have been lost as far as Man-fighting and weaponry and the skills needed for it.

 

[be unique]

Why do you say it's not sliced ? slice:"a thin, broad piece ". The entry , floor and exit walls are smooth , not "blasted chunk".
The issue is not about modern chisels but how bone reacts . A pigskull is about 1mm thicker than human frontal cortical and is used to replicate shock damage for legal evidence in trials. Synbone is designed to closely replicate human skull and has a thin rubber skin . All the tests by boomerang had the same result. My machete is 1.5mm thick, swords such as Indonesian keris are about 2mm . We can't expect an exact result but the difference between metal ( my garden spade) and boomerang is like chalk and cheese.

"Properly treated and hardened wood, when used by a skilled expert, will EASILY leave Cleaving type wounds like that." Hmmm? Where did you see it?

 

[be unique]

"It is not anticipated that a wooden chisel would meet the relevant requirements related to compliance with the essential principles and as such not be marketed promoted or supplied for use as a medical device.
Kind regards
Medical Devices Branch
Therapeutic Goods Administration
Department of Health
PO Box 100 Woden ACT 2606 Australia "

 

[be unique]

Centuries later this Indonesian knife was painted in North Australia. About 200 Indonesian loan-words exist there and there seem to be words in southern Australia from Old Java language , 800-1300 AD. The skull is dated 1200s.
https://www.google.com.au/search?q=...AUIDigB&biw=1009&bih=616#imgrc=hhGdUSr4VbhlAM:

 

[Steelwolf]

If I was there and able to show you the differences between types of attacks used with a metal sword, when you are trained for using such, and a wooden weapon, with the different training, and the types of wounds they make. You are using 'VERY' Modern stuff which just in it's composition of alloys is miles better than the older material, in order to have the same strength, for the era, it had to be a Lot Thicker than we have them today.

You say only the steel blade does the trick. May I suggest that is all you know the use of? That and Modern tools? Swords and Machetes are Similar, but not exactly the same, Machete is a specific tool that is made thin and wide to cut plants. It is only similar to sword in being a long cutting item. The Balance and Tuning, the positioning of the percussion and repercussion points in the blade had a lot to do with the dynamics and use. A machete is balanced closer to a hatchet, with the weight at the tip, rather than a balanced and tuned mass distribution able to be used for defense as well as attack, and not go breaking after the first couple of swings. A machete is not made for that, it is a cutting tool.

The ironwood throwing sticks, hardened in fire, actually come very close to metal strengths and is better than copper as far as hardness and bending goes, it was better than copper. The only benefit copper had was being able to take a very fine edge, which wood does not. But, at high speed, it does not NEED to be razor sharp to remove spalls of bone like that, and that IS what that was, a spalling event, just like the shoulder. Even steel spalls if you hit it hard enough, bone does so fairly easy, and that is how you are getting triangular chunks, as that is Not slicing.. it could Not possibly be slicing at the degree that the fracture shows, and be a shallow angle cut from the extreme left, it does not make sense as far as positioning of bodies and combat would have to be.

What does make sense is a heavy overhead attack aiming at the eye socket in an attempt to crush it, and the victim turned with the impact and thus being hit fairly straight on, the flake would have then cleaved to the left (the victim's right) and possibly sent said piece spinning into the dirt.

For it to be a slice it would have been cutting from left to right, which would Not have given that up-down crush to the eye socket and notch the bottom of the socket as well, it was more than just on the top of the eye socket, it went all the way thru the eye and into the cheekbone after glancing off the front of the brow. That is part of why I say it is not steel, as it would have carried further into the skull, and the direction for it to be a slice is off unless the attacker was left handed, and it Still would not have left that kind of wound.

And your sarcasm with the chisel is not actually appreciated, as you were trying to use the fine edged keen tool to conflate with a brutal battlefield weapon and very different wound types even if it HAD been a steel sword, the marks made would look totally different. It shows that you have little if any real tool use training nor likely the actual weapons use training, let alone any sort of training or experience in the making and use of wooden tools, implements and weapons.

It DOES sound like you have money to be able to spend on the testing materials, but if you are not using REAL wooden implements made by the person trained in it and Used by their maker...it is a very different thing, they do not just go and buy their throwing sticks from the local walk in mart. But why are you throwing that kind of money at this?

I do have to wonder WHY you are doing this? Are you trying to disprove the theory that it had to have been a Native Weapon? If so, why? Supposed lack of tech? There is a lot more to a real, properly made too of wood, the grain type, the type of wood, what it is treated with, how it was seasoned, fire and sand hardening, are all facets of it, and they were EXPERT at it, especially 600 years ago, before Colonization destroyed their cultures. Look at Utzi in the Swiss Alps, his backpack, weapons and tools were copper are, but there were several different types of wood used just in the making of the pack, wood that would not split and was light for the uprights, light and strong wood for slats, wood from the crotch of a branch as his adze handle, all very carefully set and cured, hardened etc. Very high tech.

Where the Aussie Natives had their woods, they are dense and strong and with fire hardening and proper shaping, in the hands of a trained professional they will easily make such wounds. I would love to be able to show you show you how and why certain woods make decent weapons if the right materials are properly selected and masterfully made into the weapon. It just seems that you seem to be using a misguided set of metrics to do your testing with, using very modern items which are even ahead of the sword you are trying so desperately to prove had to be what caused the wound.

It also appears that you have been pushing this for over 2 years now, and are only up to conflating modern medical chisels with sword tech of 800 yrs ago. You keep denying the answer that YES, WOOD CAN AND WILL MAKE SUCH WOUNDS AND IT DOES NOT HAVE TO BE METAL.

I suggest the mods close the article to further comments as the initial author is rehashing points from over 2 years and actually has no real new data other than he can only get that shaped wound with modern equipment and whatever way he is using to try to get that slice. Note, not to replicate the way the original cut had to have happened, but to replicate the Supposed Slice to get just that precise shape wound. when it appears to be a spall and shatter rather than a slice at all. It sounds like your 'science' is being warped to fit the idea, rather than to take the data and fir the ideas to the data. THAT is why you keep getting told that Yes, it Was a WOODEN Weapon (note, 'wood' does Not means 'soft') that did that damage, and that is part of why archaeologists were excited about it being a non-metal weapon wound, even though it Looks SIMILAR, steel swords often caused spalling, and very RARELY actually 'sliced pieces of skull off'. Usually crushed it along a line and spalled pieces off along that line.

And you are asking "Where did I see it", I have that from real world experience and DOING. I was a Professional Arms maker for Historical Recreation Groups and actually have people quote me as far as certain points of sword construction. I had to go through CIA investigation when I sold and sent swords to Canada, because that made me an 'International Arms Dealer'.

I strongly suspect testing bias because you plain do not believe in the wooden blade idea. Scientific bigotry towards the Aboriginals? You make it sound like they were too stupid to come up with a weapon that could do that with their limited means. I make the point that the damage is inconsistent with a steel sword (SWORD, not a Machete) due to lack of follow through and deeper wound and that a modern boomerang is NOT going to be a quality, professionally hand made for real hunting vs quick crap to sell to tourists who do not know any better? And is Certainly not a properly crafted Fighting Boomerang, built for actual combat if you got it for under a couple hundred dollars. I doubt they will let go of 'Real' Weapons due to the Souls they hold. If they sell it, it will have no soul to it, and it is just tourist trash.

 

[Steelwolf]

The Macassan style knives do not appear for another 300 years from the time of this incident, and are not a cleaving weapon anyways, they were a thrusting and slicing weapon, not built for cleaving skulls.

 

[be unique]

You were doing but where did you see boomerang cut bone? There are many examples of swords slicing skull in Google. Richard III of England is shown and the forensic archaeologist there says someone has questions to answer about Kaakutja. I've given examples of tests of boomerang , sharpened to dimensions of blades in Sydney Museum . They should give some result like a blunt axe still shows it could chop to some extent. The blunt garden spade slid into pigskull , boomerang bounced off with shallow groove 20mm long , and just cut the skin on Synbone.

In post #17 the doco shows a plastic ruler fitted into Kaakutja's skull from his left side. The right molar tooth was grazed and it's possible for a thin blade to do that. Can't see a wooden weapon flexing enough. There's an example of a keris 470mm length, width 20mm weight 300g of nickel-iron. Kaakutja was not cleaved , he was sliced.

Here's a quote from a blade Forum , probably by an Indonesian:

"This kind of weapon and ability still exist in surakarta ( central java ), yogyakarta ( java ) and bali.
Some art collector can identify which “keris” that produce before 19th century. They check it in metalurgy laboratory, and they found some characteristic about keris before 19th century, there are :
1. Keris made from original iron ore or iron sand and meteorit stone.
2. That method produce unpure iron metal. Who has many kind of metal in some compotition like titanium, cobalt, alumunium.
3. Keris more light but strong and sharp. Maybe there is titanium characteristic.
4. To make this pattern, after forging metal, they put the keris in high acid liquid ( maybe HCl ).
Although we know that keris has strength like damascus sword, i still don’t know are there nanotube in it."

 

[Steelwolf]

Even with your 'Keris' which is often called a Kriss, they are much later than some 800 years ago, which is when that skull is from. I would suggest you look up a copy of Stone's Glossary of arms and armor I would suggest that you do not have the old technology to be able to properly harden and shape a wooden implement, you plain have not been trained in it, the shaping and hardening processes. With those weapons it was not a matter of just taking a piece of wood and making that shape with it. the grain and structure of the wood had, HAD, to match the type of form and shape needed for the weapon.

You are still not getting it though, you are trying to compare stuff from the Modern World to a wound that was caused some 800 years ago plus, when there WERE No Metal Implements in that area, so the wound HAD to be caused by either stone or wood, and since stone in the area is not suitable for toolmaking, the hardened woods are it. And a modern person, unless they have lived the life in the Bush essentially living the way the Old Peoples did, then you have no way of PROPERLY recreating the weapon, all you are doing is making something of the supposed right shape, yet having none of the structural properties that a Real Weapon would have had.

It is like the difference between a cheap Pakistan knife made with recycled countertop vs a Hand Made custom knife by a professional. Also in the use of it, it is the difference between someone who has swung an axe and someone who has made their living that way, there is a HUGE difference in the experience and skills training of combat, and if you have not been so trained, with that weapon, then you are essentially a novice who is trying to get an exact morphology out of similar blades. Making a modern version of an ancient tool, unless you follow all of the old ways of doing it, is just something that Looks like the item, so Of Course the modern version is not going to do so great. It is likely a similar weapon that caused the groove in the skull that healed as the one that never got the chance to heal. So, since there are many ways that the bone can split and flake, so your limited testing is not very good proof, and certainly not proof that would stand scientific scrutiny in a peer reviewed paper.

 

[be unique]

So we can take it that you have never seen boomerang cut bone? Our major problem is density: Iron is 7 tons cu/m, mulga is 1 ton. Hot air will never give the same strength to wood which is made of wood.

"The period during which the keris buda, and its immediate predecessor, came into being was the Early Classical Period (end 7th Century to end 9th Century). This period of Javanese history was heavily influenced by Indian culture and ideas. "

 

[Steelwolf]

If the weapon used would have had more density and been thinner as in an iron or steel weapon, it would have carried the wound into the bone further, as I have pointed out before. A lighter weapon, being used at higher speed, can cause damage similar to steel. Speed of impact makes a huge difference as to the spalling effects on bone and the amount of damage that was done points to a wooden weapon of light weight that was Expertly Used.

The setup that you use is important too, where was the target placed with regard to the attacker. Did you have the test piece at head height and on a semi-flexible mount? Did you then run the same test multiple times trying it from different angles and different types of speed? Do you have any experience at all in the martial arts, actual training wise? And yes, this is very important because Most of us have no clue about the damage that can be done by various weapons types. Without the training it skews your results.

I have gone out and done the field work, and tested each and every new blade design that I built, and there were several. One of my most favored was the Celt-Iberian Falcatta, which looks very similar to the Kukri of the Ghurkas, and yet it was used by the earliest horsemen on the Spanish Steppes, the earliest examples made of bronze. It cut with more devastating effects than a straight blade of similar weight and size, and it had to do with the Exact Shape, not a generalized shape, but a specific one that has a particular mathematic curve behind it: the Bernouli spiral, where it gives the same angle to the cut all the way along the swing, as well as the mass distribution.

The wooden tools were built specific to that piece of wood, and if you cannot see and feel the 'soul' of the wood, if you are not enough of a woodworker to be able to pick out a superior piece of the material, with Just the right shape to it's growth for the tool you need. They did not just go out and grab any old piece of a certain material and expect top results, they were very picky and precise about what got made into what, and for weapons, which were THE TOP of the Tech and status symbol classes, they chose the very best with the exact right features for their weapons.

As a swordmaker, I had a lot of Knifemakers wanting to know the differences between a knife and a sword, because each of them usually try to build a sword, but try to make it a big knife, like how machete's are made. The problem with that is that swords are very different than a knife. Knives are made to cut, in a controlled fashion, they are hardened steel and very hard, tempered back just enough to keep them from being Too brittle, but as you know, steel knives can be snapped off, and that will not work for a sword, let alone the balance and harmonic tuning of the item.

(Talking swords of medieval and rennassance eras, later saber and the Japanese Katana and the Samshir are all slicing weapons and differently built, but have much in common with their European and earlier counterparts) Generally speaking a sword is more of an impact weapon, as most targets are armored to some degree, and so they are not hardened and are thicker than a knife would be. The edge on most swords was actually closer to that of a cold chisel for metal rather than a wood chisel as under impact the thinner edge would chip or break, imperiling the weapon.

The balance and tuning is different, in a knife they are one and the same, and the balance point should be right at the guard of the blade or right under the first finger, the tuning points will be ahead and behind that only a little bit, so it is not as important, but the motion and feel of the blade in hand and how the edge presents itself are of utmost importance behind the hardness and edge keeping ability, in a sword the balance needs to be about 3 inches forward of the guard and there will then be two tuning points, the percussion and repercussion points. The percussion point is the 'sweet spot' in a sword (or baseball/cricket bat) and the placement of the repercussion point is of vital importance, in a single hand weapon it needs to lay directly under the center finger in the middle of the hand, the strongest part of your hand, and line up with the wrist, so that any vibration of the blade is allowed for as it will vibrate to either side of that point and Not be jarred or jangled out of the hand. If you have ever hit something holding onto the end of the bat and gotten a nasty surprise of impact then you will know how important it is to have that impact redirected so as to not shatter your own hand every time you hit something with your sword.

Most knifemakers do not know of this difference in physics behind swords, but know that of knives well. I had been a high end Navy Welder, so I knew my metallurgy and construction techniques. And it is EASY to make something that Looks LIKE a Sword, but does not at all Act like a sword, if it does not have all of the metallurgy and costruction technique along with the exact proper mass distribution in the whole weapon. Do you see what I mean here? It is easy for you to make something that may LOOK like an Aussie Aboriginal Fighting 'rang, a Warrior's Wonna, and yet have it completely fail and may as well be balsa wood because you do not know the specific techniques in making that item.

Knapping Flint should be easy, right? Give it a whirl, first you have to be able to identify the right materials and places to get it, then find the right nodule, then prepare it correctly knocking off the chalk parts and revealing the harder metamorphised core, being able to heat treat the stone so that it is more workable under the hammerstone, and then learning percussive and pressure flaking techniques both...is not the sort of thing that most modern people are going to take the time to sit down and really Learn the full craft to Master Level, and that is what it is going to take for you to have a reasonable representation weapon for your testing, unless you go in with the understanding that you have neither the skill at weaponsmaking of that specific sort, nor do you have the specific martial arts training for that weapon, and ANY sort of weapons training is, by definition, martial arts.

Again, you give the indigines too little credit. You should see some of the industrial accidents that happen with wood, soft wood makes excellent spears, fire-harden the point makes it that much better, and Soft woods are what Europeans and most in Asia were able to use, Australia has some of the very hardest woods in the world, and the damage that can come from even softer wooden weapons can equal or exceed what is seen in that skull. A 1/16 inch radius edge of properly, Expertly Hardened Aussie hardwood wonna, with it's curved edge, is going to do more damage than a straight edge, and the angle of attack and the speed of the attack are going to make all the difference.

You appear to be trying to FORCE an interpretation, over the top of expert advice and testimony, my question now is:

WHY? Why are you pushing this view? Why are you so sure that properly built and wielded wooden implement could not do this when you have been told by an expert on the subject of weapons and swords that your interpretation does Not Fit, that there were no other choices of material except possibly fire hardened bone? The Verbal Historical Record of The People in the area show No Visitors until somewhat later, so you need to come up with something that they would have had, and a steel weapon is obviously not going to be a fit since they did not HAVE that technology, and there was no other source for it there.

 

[Steelwolf]

The person is stating (I read the actual article too) that there were no metal sword blades like that then, so that was not that kind of weapon being used. I think you are twisting the meaning of his statement by using only part of it, the part that agrees with your theory, excluding the bits you do not care for that do not fit Your Theory.

Also, it was 800 years in the actual article, so you have changed the quote.

By the way, a lil bit of my work:

And

Go together, Navigator's Stilletto, Dual Use, Is also a pair of dividers, 15th century.

And I did another 12 plus years of this work aside from the puttering and playing around I did on my own. I laso had people come to me for serious testing, many Computer Games were made with consultation from me about how weapons would work, scale of damage etc. I was good friends with the people who created Warcraft, and all that came after it. So I DO have a bit of real, hard data, and decades of experience to back it up, and yes, I used the swords as they were built to tool quality, not just show.

I used to split wood with my broadswords, kindling with a shortsword. I Really DO Know about what I am talking, and do not need to be insulted, thank you

 

[be unique]

The elder's quote is from doco narration text - 700 years. "A blade" means ...what? If mulga wood sliced bone why did he say "something is wrong" ? He should have said , "Yeah we made blades that zapped a dudes block off".