Amount of overlap on segmentata shoulder lames

[kazeryu]

One of the issues which has been troubling me about segmentata construction is deciding how much overlap there should be in the shoulder lames.

Looking at all the pictures of reconstructed segmentatas online, it seems that there is a very large variance in shoulder "width" - for some people the last plate hangs just over their shoulder, while on others it is resting almost down to their elbow.

While thinking on this issue, I decided to look at the numbers for some hypothetical layouts using the following shoulder lame widths:

Upper 8 cm, Lessers: 6, 6, 5, 5 cm.


Resulting Shoulder Width for overlap styles:

• just covering the rivets (~1 cm overlap) 27+ cm
  
  
• double overlap (two layers of metal at any point) 19.5 cm
  
  
• triple overlap (three layers of metal at any point) 15.5 cm
  

Pretty big difference!

As far as I know, the only evidence we have for the internal leathering is in mineralized fragments, so I don't think we can obtain a definitive answer by measuring an unearthed relic. (Please correct me if I'm wrong on this point!)

However, the sections which have been unearthed do seem to have something interesting to tell us about shoulder lame overlap. Let's compare the total width of the shoulder lames of the Corbridge and Newstead types: (I have included the "peak" on the center upper shoulder plate, when present)

(from Legio XX)

• Corbridge A: 7.6, 5, 5, 5, 5 = 27.6 cm
  
  
• Corbridge B: 9.5, 5, 5, 5, 5 = 29.5 cm
  

Other remains seem fairly consistent at around 5cm width for lesser shoulders, although one incomplete set appears to have been closer to 6cm.

(from Bishop's Newstead plans with irregular lames)

• "mean width" (approx) 12.1, 7.1, 4.8, 4.5, 3.4 = 31.9 cm
  
  
• max width 12.1, 7.3, 5.1, 4.5, 3.6 = 32.6 cm
  

This represents an increase in overall width of about 13.5% from Corbridge A to Newstead. There are four possible reasons for this:

1. Our sample size is too small to be meaningful
   
   
2. Roman shoulders started getting wider
   
   
3. Segs started covering more of the upper arm (to provide better protection)
   
   
4. Shoulder plate overlap increased (to provide better protection)
   

We can't do anything about #1, so we'll just set it aside for now. #2 seems highly unlikely since (as far as I am aware) there were no major empire-wide breakthroughs in sanitation or nutrition during that time period. At first glance, #3 & #4 seem to be equally probable. However, when considering that the width increase is heavily biased towards the upper shoulder and first lesser plate - seemingly at the expense of the terminal shoulder lames, I feel that #4 becomes more likely.

It seems debatable whether the existence of the manica is an argument for (they obviously needed extra protection sometimes) or against (redundancy) option #3.

Increasing overlap seems like a good idea not only for the person wearing the seg, but also for the seg itself. By increasing the area of each lame supported by its neighbours, it seems that the probability of a lame deforming when struck would be reduced.

Anyways, I would like to have a discussion about the amount of overlap in segmentata lames and would appreciate any comments or corrections to my thoughts.

In short -- how much overlap should there be?

Thanks,

[kazeryu]

No one has information or opionions on this topic?



If I asked a stupid question or made myself out to be an arrogant armchair-archaeologist, it's OK to tell me so. :oops:

[Gaius Colletti]

Its not a stupid question at all, if you like I could get you some measurements from my Corbridge A Deepeeka segmentata probably sometime later tonight or tomorrow if that would at all help

[Magnus]

You want the overlap to cover the rivet of the plate underneath it...1 cm or a bit more should do it, but it all depends where your rivet holes are.

[kazeryu]

Magnus - I agree that covering the rivets is the bare minimum, but what do you think of overlapping more than that? How much is too much? Do we have any conclusive historical evidence on this topic? etc.

Matt Colletti - yes, I would be interested in seeing those numbers if you don't mind.

[Titus Marius Secundus]

Hey Matt and Ventus, I hope you don't mind me being a third party in those measurments? :oops: I went on legio XX's site for lorica segmentata measurements to print on paper, but they don't print to size on paper. I am looking for details on the plate sizes for when I get around to making one. So if you have some kinda easy to read measurements, that'd be great! Cheers a bunch. That's if you don't mind!! Please don't do anything extra special
Sam

[Gaius Colletti]

Alright Ventus, I have the measurements. On my segmentata each of the first 4 , each plate is 3 and 1/16" wide when measured from the outside, the 5th plate is 3 and 3/4", and the 6th plate, the collar plate is 2 and 3/4 (please note, this plate was probably 3" before being folded over to avoid a sharp edge rubbing against the neck). From the inside(starting with from the arm, not from the neck area) , the first plate is still 3" because it is on the bottom of the stack, while the next two are only 2", a full 1 and 1/16" overlap! The 4th plate is 1 and 7/8" wide on the inside (basically an inch, this may have been a factory error, since every other plate the same size, the 5th plate is 1 and 7/8, and the 6th one is 2 and 3/4" (again the same from the outside the way it is positioned is under the 5th plate).

EDIT: Please keep in mind that for plates 5 & 6 (the most inner ones), that I only measured the interior plate, and not the two plates connected to them, via hinges. Unless of course you need those too, let me know

If this is too confusing, it is very hard to explain over words without being able to point them out, I will take a picture of a drawing I made and email it to you if you PM me your email. If I had any sort of experience with some sort of photoshop, or even had photoshop I would outline and mark the sizes of a picture of my armor, so you could see, otherwise sorry a drawing with the external and internal measurements is the best I can do. I would just post a picture of the drawing here, but I'd have to do it through my camera phone, and blah blah blah I am not good with that sort of thing.

[Gaius Colletti]

Feel free to follow the measurements I posted Sam, and if you would like a drawing of the picture I made, I too could email you one. If you need any other measurements, just let me know

[kazeryu]

Matt - I think I understood except in two spots...

is this correct?


[attachment=1386]DeepeekaCorbridgeA.jpg[/attachment]

[Titus Marius Secundus]

Thanks Matt, this seems like a tough thing to do! I wish it was simpler. I don't need anything now, but I will come back to the posts if I need the help, and maybe then you might still have pic measurements, I'm thankful for your offer though. I just find Legio XX's good, but not printable for copying :-( anyway, when the time comes! I will still be watching all of your progress!!!

[Gaius Colletti]

Ventus, you are correct, for the "collar" plate, it is still 2 and 3/4 on the inside because it is beneath the plate before it. Keep in mind that plate 5 will have the big hinged shoulder guard plate. Also keep in mind that the external numbers represent the entire plates length, even if it is not seen, and the internal numbers represent the visible parts only

EDIT: and plate one is also 3 1/16" as well both externally and internally, I just forgot to write that down

And glad I could be of service Sam

[kazeryu]

Does noone have any further thoughts on the amount of overlap? Does everyone agree that it should more or less just cover the rivets?

[Magnus]

Trust me...cover the rivet, and throw in a milimeter or two (or a 16th or so) and it will come together perfectly. Start at the outer shoulder guard, the smallest one, and work towards the collar/breast/back plate assembly.

If you start trying to get exact measurements based on someone else's seggie, you are going to botch yours. If you just stick to the above, yours will fit properly.

Here are some pics showing the overlap with me wearing the first Cor. A I made, and my B. They fit very well...the last thing you want is the armour to not cover far enough down your arm when u wear it.

[Gaius Colletti]

Ventus, please note that my measurements only take into consideration the actual "shoulder pieces" (ie not the chest/back" pieces that are hinged to the shoulder pieces on plates 5 & 6, what lthe legio xx site refers to as the chest plate, top back plates, and the upper shoulder guards: http://www.larp.com/legioxx/lorica.html ) I figured since they would be hinged anyways to the plates you wouldn't need any extra measurements.

Also, although I'm sure you have already noticed and realized this, my numbering of the plates is opposite of the legio xx site

[Gaius Colletti]

Matt, is appears that in your second and third pictures, the two smallest shoulder guards are brass, why is this? I don't mean to be a "stitch counter" I think it looks interesting