Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by yeomanbowman Thu Mar 02, 2017 2:20 am

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Post n°1

Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by yeomanbowman Thu Mar 02, 2017 2:20 am

Hi All,

Would anyone have any information on on either the Berkhamsted Castle and Glasgow Museum wooden prod crossbows, please. More specifically the dimensions and in the Berkhamsted case the type of wood. It would be much appreciated.

http://www.britishmuseum.org/research/collection_online/search.aspx?place=31781&plaA=31781-3-2

http://collections.glasgowmuseums.com/starobject.html?oid=242808

by OrienM Thu Mar 02, 2017 11:52 am

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Post n°2

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Thu Mar 02, 2017 11:52 am

Dimensions of the Birkhamstead prod can be found here on the forum: https://thearbalistguild.forumotion.com/t1387p25-wood-prods?highlight=wood+prods

For the Glasgow museum prod I've only been able to find photos, but no dimensions...hopefully someone here will know.

by yeomanbowman Thu Mar 02, 2017 12:11 pm

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Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by yeomanbowman Thu Mar 02, 2017 12:11 pm

Thank you Tinkerer! This is the jackpot.

by OrienM Thu Mar 02, 2017 12:23 pm

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Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Thu Mar 02, 2017 12:23 pm

Happy to help! I spent a lot of time hunting down info on historical wood and wood/sinew prods; I was quite excited when I found this post.

(I'll add, being 49" long I rather suspect the Birkhamstead prod was made for a large wall crossbow, and may have been sinew-backed originally. I'd love to look at it in person!)

Somewhere online, I found a pic of the Glasgow museum bow being examined...when compared to the person handling it it was obvious this prod is quite long as well, probably three feet or more. I'll post a link if I can find it again.

by OrienM Thu Mar 02, 2017 2:20 pm

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Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Thu Mar 02, 2017 2:20 pm

Found it!

Berkhamsted Castle and Glasgow Museum wooden prod crossbow 9d319b69969e32a8daa897d919bdc63b

A big bow; hard to tell, but my guess would be maybe 48" long, and 3x2" at center...?

I noticed an email link in the Glasgow museum page above...you might be able to request measurements directly from the museum (please post any response, if you do so... Very Happy

).

by Onager Lovac Thu Mar 02, 2017 7:56 pm

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Post n°6

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by Onager Lovac Thu Mar 02, 2017 7:56 pm

Wow, that is the most awesomest looking bow i've ever seen Shocked

.

by yeomanbowman Sat Mar 04, 2017 2:35 pm

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Post n°7

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by yeomanbowman Sat Mar 04, 2017 2:35 pm

Thanks again for the help. I did contact Glasgow Museum but all they have are images, no one has measured it, apparently. It has no more detail in 'The Real Fighting Stuff'. The prod I'll be using will be yew 2 x 1 3/4". I'll post as I go along.
Just had a though, do you think the deflex was steamed/boiled etc. in of the bow has just followed the string in use. Must have been difficult to brace if it started as a straight stave.

by OrienM Sun Mar 05, 2017 8:33 am

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Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Sun Mar 05, 2017 8:33 am

I think it was steamed and bent into deflex deliberately...just about all the original wooden prods I've looked at seem to have been made that way. In general, wooden prods tend to work best (IMO) with significant deflex for low string tension at brace, very thick, stiff limbs giving rapid weight increase during the draw, and a relatively short draw length compared to hand bows. The first link I posted above has lots of good design info.

by OrienM Sun Mar 05, 2017 8:38 am

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Post n°9

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Sun Mar 05, 2017 8:38 am

Onager Lovac wrote:Wow, that is the most awesomest looking bow i've ever seen .

It is a cool-looking bow! I just love the lumps and knots the maker left in the prod. The tiller is VERY strange IMO, with an unusual shape, weird steel-clamp "bridle" built into the stirrup, and no lugs or other features for a cocking mechanism. (More info about it can be found here on the forum: https://thearbalistguild.forumotion.com/t1016-unusual-prod-attachment )

by yeomanbowman Tue Apr 04, 2017 6:02 am

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Post n°10

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by yeomanbowman Tue Apr 04, 2017 6:02 am

I've had this back from the extremely helpful Glasgow Museum. The prod is 55mm not a bow. I can't see that working. 55mm thick prod!!! That's a lintel - i don't see it working. Berkhamsted Castle and Glasgow Museum wooden prod crossbow Fullsi10

Berkhamsted Castle and Glasgow Museum wooden prod crossbow Fullsi10

by OrienM Tue Apr 04, 2017 8:14 am

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Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by OrienM Tue Apr 04, 2017 8:14 am

Thank you for the update...awesome! I've been wondering about the dimensions of this for a while.

I actually do think the prod was functional. The proportions look "just right" to me despite the massive thickness. Someone carefully followed a ring on the back to prevent tension breakage, and the draw length looks fairly reasonable, too. Yew wood is very flexible, and often ends up thicker for a given draw weight than if a harder wood was used; extra-thick, very stiff limbs are required to counteract added deflex, as well. I imagine this drew at least 200#.

by hullutiedemies Wed Apr 12, 2017 8:52 am

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Post n°12

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by hullutiedemies Wed Apr 12, 2017 8:52 am

Great, now it can be calculated.
Using my own smaller yew bows as scale model and assuming ca. 200mm power stroke the weight should be about 3-4kiloNewton. So 800 pounds is probably not badly off.
I'd trust that bow take over 300J without problems.

That stirrup looks so flimsy that there might have been a windlass.

by Juniper Fri Aug 25, 2017 3:54 pm

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Post n°13

Re: Berkhamsted Castle and Glasgow Museum wooden prod crossbow

by Juniper Fri Aug 25, 2017 3:54 pm

There is a similar crossbow in the armoury of Alcazar castle in Segovia. I found most of these pictures on some russian site, tforum I think.
The same style of crossbow can be seen on Paolo Ucello's painting Battle of San Romano, i.e. semicircular prod socket attached with a hinged stirrup. Shape of the stock is also very similar. On high-res picture of the painting nocks for bastard strings are visible, and they are also present on the Alcazar crossbow.
Berkhamsted Castle and Glasgow Museum wooden prod crossbow Alcaza10