SCUTUM, building and testing, some thoughts

[Hibernicus]

Fine- semantics. But do you actually mean that the dry wood...

Its not semantics.... wet and damp are two very different things when it comes to wood... damp wood draws the hide glue in more readily than dry wood. The dry wood needs to be primed in a sense. I've always known this...

My practical hands on knowledge comes from my grandfather who grew up learning wood on a farm in Quebec, then at 17 moved to Boston MA, USA to work in a shipyard. He taught me many things about wood working. Other things I learned from a furniture refinisher I worked for about 35 years ago.. made our own shellac, used real mucillage for resetting veneer...

Green wood is so much easier to work with hand tools than is modern kiln dried wood. Splitting for example, is smoother, faster and easier. Mortissing is a breeze. Augering a hole.. less sweat!

This is exactly why a great deal of excess selectivity isn't practical- if there's only so much useful wood in each tree and there's no industrial supply like there is today, it makes no sense at all to expect the kind of selection that goes into fine furniture for a purly funcitonal item that needs to work not to just look nice.

Not true. And it makes perfect practical sense. If you purpose grow wood you can make a tree grow with fewer branches maximizing the amount of knot free wood, cause certain types of branching that will result in stronger types of finished products... reference shipbuilding for example... sure it might take decades or even a lifetime.. You would manage your groves... keeping down new growth of any kind which minimizes competition for water and nutrients, also minimizes the potential for fire damage as grasses burn cooler and faster than brush.. you'd also keep branches from growing too low for the same reason... even the use of grazing domestic animals

And you aren't selecting wood for furniture. Those are two completly different sets of needs.

but, again, if the requirement were for hundreds or thousands of scuta, any significant selection would be impractical.

Of course it wouldn't. But, it would surely keep an overwintering army busy!

Besides, we do not know how many scutums an army needed annually.. What was the general attrition rate for scutums from everyday wear and tear? Maybe a legion only needed to replace 2% annually.. or 1% or 50%... we dunno!

It makes no sense anyway- you wouldn't want one layer to be stronger than the other because otherwise the scutum is weaker in one direction than the other. .....

Different woods have different characteristics, some weaker in one direction and stronger in another. Combining those characteristics to compliment each other, to create a stronger more durable item is a good
thing.

Combine two different woods with unique characteristis and skin them with hide and/or cloth and then set reinforcing strips and you now have a 5-6 layered shield.. very strong.

It seems clear to me that they had the technology and the tools, the skills and the practical knowledge, the time and resources to create such a complex item as a semicylindrical scutum.

How Roman of them!

[caiusbeerquitius]

Hibernicus, thanks for the pics and the info.
I am working on a republican shield after the Kasr-el-Harit find right now. I have the impression that it is slightly curved up- and downwards as well. (very slightly) A possible and probably sensible option for the imperial rectangular shields? What do you guys think?

Good work, keep it up!

[Tarbicus]

I have the impression that it is slightly curved up- and downwards as well.

Is that because of the thinning out towards the edges?

[Hibernicus]

NO ONE knows the exact shape of any of the semi-cylindrical scutums.

They have been crushed and warped and otherwise deformed over the centuries... the chord.. distance from edge to edge, straight across the back (not across the face) is unknown on any scutum.. just guesses.

It seems that some shield boards may have been tapered towards all edges.. but at least the sides. The edges across the top and bottom are very likely thinner than the central portion of the body of the scutum... this is based on the width of the metal shield edging that's been found and the spacing between the back of the umbo and any attached rivets.

The edges may also have been cambered much like a chisel edge. I believe that's from some of the Dura Europas scutums.

[Tarbicus]

Matt L had a good point about the corners, most of them not being rounded if we judge from found edgings. We almost knew the true shape of the Dura shield, if only the original restorers had opted to preserve the construction of the shield and not the fancy paintwork, according to James. :?

[adamparsons]

The edges may also have been cambered much like a chisel edge. I believe that's from some of the Dura Europas scutums.

This is certainly true of 6-11th century surviving shields in N-W europe, O.K they were single butted planks not ply, and nearly always had a rawhide edge, except for the odd Cu-Alloy clips over the rawhide on flash ones, and really rich examples like Sutton Hoo.

The Gokstad and Tirskom shields (as good as complete) show even board thickness ( 6-7mm ) but cambered tips (the outer 2-3")

Sorry this is not period, but I hope it has some relevance to the historic use of the cambering technique

[Matt Lukes]

Fine- semantics. But do you actually mean that the dry wood...

Its not semantics.... wet and damp are two very different things when it comes to wood... damp wood draws the hide glue in more readily than dry wood. The dry wood needs to be primed in a sense. I've always known this...

Okay, fair enough- what I meant was that it should have been obvious that I didn't mean soaking wet :lol: It is counterintuive that damp wood would absorb glue more effectively than dry wood- I wonder why?

Green wood is so much easier to work with hand tools than is modern kiln dried wood. Splitting for example, is smoother, faster and easier. Mortissing is a breeze. Augering a hole.. less sweat!

I heard that! I hate trying to carve or work super dry wood... splinter city!

This is exactly why a great deal of excess selectivity isn't practical- if there's only so much useful wood in each tree and there's no industrial supply like there is today, it makes no sense at all to expect the kind of selection that goes into fine furniture for a purly funcitonal item that needs to work not to just look nice.

Not true. And it makes perfect practical sense. If you purpose grow wood you can make a tree grow with fewer branches maximizing the amount of knot free wood, cause certain types of branching that will result in stronger types of finished products... reference shipbuilding for example... sure it might take decades or even a lifetime.. You would manage your groves... keeping down new growth of any kind which minimizes competition for water and nutrients, also minimizes the potential for fire damage as grasses burn cooler and faster than brush.. you'd also keep branches from growing too low for the same reason... even the use of grazing domestic animals

Certianly it's practical in some cases and has been done for various purposes in the past, but the fact remains that you haven't provided a single shred of proof that it was ever done for scuta... just because something can be done doesn't mean it was. It's just a huge, giant leap to make with no evidence and that's very bad form except as a very simple postulate and you presented it as likely fact.

but, again, if the requirement were for hundreds or thousands of scuta, any significant selection would be impractical.

Of course it wouldn't. But, it would surely keep an overwintering army busy!

Besides, we do not know how many scutums an army needed annually.. What was the general attrition rate for scutums from everyday wear and tear? Maybe a legion only needed to replace 2% annually.. or 1% or 50%... we dunno!

That's exactly my point with all of this- you can't present things as fact if they're just remote possibilities. If you'd started off saying 'it might have been' or 'one possibility could be' I'd have probably agreed that it was an interesting idea! :lol:

It makes no sense anyway- you wouldn't want one layer to be stronger than the other because otherwise the scutum is weaker in one direction than the other. .....

Different woods have different characteristics, some weaker in one direction and stronger in another. Combining those characteristics to compliment each other, to create a stronger more durable item is a good
thing.

Well that's kind of the point- so many layers gives a lot of strength such that the inner layer being of a different wood wouldn't necessarily be important. Besides again, sounding like a broken record, if you present it as a likely thing, you have to support it with more than just general theory- there has to be proof it was done in the form of artifacts or it remains just a theory no more or less valid than any other. You present it and advertise it as if it was definitely the case and that's just wrong. James describes the intact Dura scutum as being made of sycamore- just sycamore, no different species for the core strips.

It seems clear to me that they had the technology and the tools, the skills and the practical knowledge, the time and resources to create such a complex item as a semicylindrical scutum.

Again, just because it could have been done doesn't mean it was Sean- that's not valid logic. And it's not a particularly complex object- I made one in my living room and I'm only a self-taught amateur woodworker :lol:

[Matt Lukes]

NO ONE knows the exact shape of any of the semi-cylindrical scutums.

They have been crushed and warped and otherwise deformed over the centuries... the chord.. distance from edge to edge, straight across the back (not across the face) is unknown on any scutum.. just guesses.

But reasonable guesses- the mostly-intact Dura scutum, in its original state, seems to show the curve fairly well I think- the portion nearer the handle hole plus the corners at the bottom edge show a nice deep curve such as is shown on the vast majority of sculptural depictions...

It seems that some shield boards may have been tapered towards all edges.. but at least the sides. The edges across the top and bottom are very likely thinner than the central portion of the body of the scutum... this is based on the width of the metal shield edging that's been found and the spacing between the back of the umbo and any attached rivets.

Is this from a single set of artifacts? An umbo and edging all found in association with one another that is? If so, that's certainly telling...

[caiusbeerquitius]

Is that because of the thinning out towards the edges?

No, the shield bosses suggest that.

[Hibernicus]

You're right Matt, I can't prove that wood was purpose grown for scutums.

All I can do is show that wood has been purpose grown for a few thousand years.

Wood workers select wood for certain properties.

The fact that ash and birch were used they way they were used is the proof that the maker knew to use those woods the way he used them. It was on purpose, not an accident.

If you purpose grow wood for ships timbers, for spear shafts, tool handles, construction, fencing, furniture, basketry, charcoal, food etc why not for scutums? But, did they? Dunno.

Is it likely? I think so.
How likely? Haven't a clue.

[Matt Lukes]

Even if it was done, it would have only been in certain areas- as we all know, nothing was universal in antiquity. So it'd only have been a certain percentage of scuta that were made with purpose-grown wood, if any at all.

I disagree that it was likely anyway- many of the things you suggested were made with purpose-grown wood have very specific requirements that the process addresses, and you've already agreed that scuta didn't have 'requirements'. The fact that it has been done for thousands of years is actually irrelevant- only that which was done at the time scuta were being made counts. Is there really widespread evidence that it was practiced for so many things then? It's already been said that a number of Roman spear hafts were clearly not coppiced, and spear hafts are one of the things that would benefit most.

Very specialized things were often made from wood selected by hand because there was no other way to make them so they'd work as well- given that the strips that made up scuta weren't all even the same width suggests not every detail was looked to if it wasn't important- they were practical. And doesn't the idea contradict your initial claim that it was necessary to use old-growth timber for scuta? Coppicing and old-growth are don't really go together for the relatively short time period in question.

I think all this is making the whole thing MUCH to complicated- scuta weren't fine furniture, but things that were EXPECTED to be damaged and destroyed. They would be expected to take most of the hits instead of the soldier, right? Why then go to inordinant lengths to make something (supposedly) so much better with selected woods, purpose-grown for the task, etc., etc., when good enough seems to be the main Roman way of making things? It seems like a case of the old twice the work to go from 90% effective to 91%...

There are many, many examples of Roman practicality displayed in pieces only being finished on the side that'll be seen or the imperfections in an edge being on the back side of something. I don't think a scutarius would just use any old wood, or wood with serious defects in it, but I highly doubt there was significant selection involved either- it had to be functional, that's all. The 3-ply nature adds a lot to the strength of a scutum as compared to a plank shield, for example, and I'd expect it'd make up for some deficiencies in the wood as well.

The selection/ coppicing was all a secondary postulate anyway- the suggestion that

It has become obvious that we will not be able to properly test the integrity of these shields because the modern wood is generally grown under conditions that cause it to grow fast and thus cause it to be weaker. Slow growth (old growth) wood generally has denser grain and is stronger.

that still hasn't been addressed- do you have any evidence that scuta were made with wood that has a significantly tighter grain than the wood that's available today? Or that this grain tightness would actually have a significant impact on the performance of the scutum?

[Magnus]

The disposable scutum is a good way of looking at it...especially during war time. I'd be a lot easier to throw an extra layer of rawhide or leather on the facing, or beef up the edging to increase the strength of the shield, rather than having to wait for special wood to be grown to make the best, top quality strips for the lamination. Doesn't make a lot of sense.

Also, I'd like to know just how much more effective using this top quality wood would make the shield, vs regular wood. How much of the shield % is top quality vs regular anyway? Do we know? If it's made with multiple grades of wood, what does that indicate, perhaps nothing. The only way to prove this is by making many, many types of scuta and testing them vs all types of weapon damage using a very controlled environment and measures. I don't think this has been done yet.

But, I'm willing to bet that the difference between the woods is minimal, at least to the point where scutum production wouldn't be halted because the prime materials couldn't be had. And, if that is the case in antiquity (that they used what they had at the time), then it's pretty safe to see that anything went, based on availability.

[Hibernicus]

Its a known fact that, in general, old growth wood has denser grain than modern plantation grown wood. This makes it stronger.

I never claimed it was necessary to purpose grow wood for scutums just suggested it as likely.... as an opinion.

The semi-cylindrical scutum is a complex assemblage. Different varieties of wood selected for their particular qualities, assembled in such a way as to compliment each other, skinned and reinforced to add additional layers of strength and endurance to a variety stresses.

Since we do not know how many scutums had to be made per legion each year we can not say how non-selective a scutum maker would be.

Perhaps when huge numbers of shields had to be made they were made with the available wood.. so X quantity of birch, X quantity of ash....

Perhaps when urgency was not a factor the scutum maker would be much more selective in the wood he used, perhaps contracting to have certain types of woods grown knowing that he had to provide X number of scutums per year.

Perhaps, perhaps not.

[Magnus]

"Its a known fact that, in general, old growth wood has denser grain than modern plantation grown wood. This makes it stronger. "

But at what point does that stronger wood make a real difference in the scutum construction? Given the number of possible combinations in wood types used and densities of said woods, even in the same species of tree, where do you create the "standard"? Pretty hard to do. As I said before, we don't know how much damage or how long a scutum was made to last. While it's just an opinion, there is really no qualitative or quantitative anything to back it up with, because there has been no measure of this strength in controlled conditions.

Which really just leaves the lamination construction of these scuta as a purely aesthetic value vs authentic since we don't have any of these questions answered, and it's more piece of mind in terms of construction realism than anything else.

Then perhaps or perhaps not this is a silly topic...hahahaha!

[Hibernicus]

But at what point does that stronger wood make a real difference in the scutum construction?

The point at which it has to absorb a blow, flex against the weight of combatants, resist cuts, penetration and crushing..

Given the number of possible combinations in wood types used and densities of said woods, even in the same species of tree, where do you create the "standard"? Pretty hard to do.

Hard? Maybe. But, possible. The possible woods used are limited.. so far I believe that we only know of 5 species used. ... maybe someone knows with certainty.

Ash is stronger than birch where its used in the Fayum scutum and birch is a better choice for its use than would be ash. Why? Because of the nature of these woods. That's why I believe that the choice and use was deliberate based on knowledge of the properties of each species. That's the "standard".