Cranequin versus windlass-- which is more efficient? -- myArmoury.com

T. Brandt

Simple question, really. In terms of mechanical efficiency-- or, effort-to-energy-- which of these devices is better for spanning crossbows? One would assume the cranequin, given the longer handle, but it seems like larger arbalests are coupled with windlasses.

Second... strange, but have there been any attempts to build a crossbow (pre-modern times) with an integrated spanning device? As in, like having a cranequin-style crank sticking out of the side, or something to that effect. It would take much effort and likely be a show piece, but I'm curious.

Dan Howard · Posted: Fri 16 Oct, 2015 2:18 pm Post subject:

The windlass requires two hands,. The cranequin only requires one. The cranequin is a lot smaller and can be used while sitting in the saddle. According to Bradbury (p.149) both devices could be used on a 1200 lb crossbow but the cranequin needed about 35 seconds to span while the windlass only required about 12 seconds.

Pieter B. · Posted: Fri 16 Oct, 2015 3:32 pm Post subject:

I'm not sure if it matters for whatever you need this information for, but the windlass predates the cranequin. In fact the cranequin appeared quite late in the middle ages.

Benjamin H. Abbott · Posted: Fri 16 Oct, 2015 6:02 pm Post subject:

I believe I've read about crossbows with integrated cranequins, though I don't recall seeing pictures of them. Cranequins tended to weigh at least a few pounds, so this would have made the crossbow heavier to hold and aim.

Philip Dyer · Posted: Fri 16 Oct, 2015 6:51 pm Post subject:

T. Brandt · Posted: Sun 18 Oct, 2015 4:19 am Post subject:

Okay, further questions... also to do with physics.

1. We're familiar with the Penobscot bow design. The question is, however, could such a design be applied to the steel prod of an arbalest? Or is the nature of steel nonapplicable to such a design?

2. Penobscot, again. One could think of it as two sets of limbs bound together, in a sense. But from a mechanical standpoint, would placing yet another set of limbs have any advantage, or simply be a redundant addition of weight?

http://whitewolfarchery.com/customimages/big/WWM1.jpg

So, in that case, think of yet another limb-set placed between the two original ones.

Lafayette C Curtis · Posted: Tue 20 Oct, 2015 8:24 am Post subject:

Probably not worth doing on a crossbow meant as an individual weapon, since the increased mass from the extra prods would absorb much of the extra potential energy and the resulting increase in the bolt's speed and power would be too small to justify the extra weight and bulk. The Chinese had several multiple-prod crossbow designs but they were apparently all meant to be trestle-mounted siege crossbows. http://myArmoury.com/talk/viewtopic.php?p=267702