Has anyone figured out the tensile strength of the silk threads of the various sized spiders? What sized spider would be capable of spinning a silk thread strong enough to support 50 pounds?
Considering that any giant spider worth its salt can restrain an arbitrarily large creature thrashing within its webs at anything below a low-to-mid difficulty (DC12), I would think that any (large-sized) giant spider's webbing could deal with 50 pounds. Since a giant wolf spider has various web-oriented abilities but not a "Web" ability, one might assume that a medium-sized spider produces webbing but not strong enough to restrain large targets, and thus perhaps not enough to support a 50-pound individual for long periods of time.
I have some arachnologist friends I might ask about this (I do know tensile strength of most spider silk is roughly equivalent to steel, but much greater by weight), but for the purposes of a game of magic, best to just go by the in-game rules. ;-)
I was looking for the smallest possible spider that could ride on a pack and spin a web strong enough to support a 50 pound character. A gnome walking around with a giant sized spider on his pack would be kind of conspicuous.
I came up with the following figures using simple ratios, which physics is rarely that simple. When it comes to the physics of increasing size and strength, it rarely is that simple, there are usually complex formulas and algorithms involved.
50# test steel fishing wire is only about .72 millimeters (about 1/50 of an inch), and spider silk is stronger than steel wire of the same diameter. And the thread of a golden orb weaver spider, the strongest spider silk, is .003 millimeters. So assuming a spider silk thread is 5 times stronger than steel (just a guesstimate, I have heard all kinds of numbers up to 100x) that means a thread 1/5th the size, or 0.142 millimeters, should support a 50# weight. That is 48 times the diameter of the GOWs thread. An average GOW weighs 4 grams, so one 48 times the size would be 192 grams, or 0.42 pounds. 0.42 pounds is 6.7 ounces, just a little bigger than a Goliath birdeater, which is a species of tarantula with a different body type than an orb weaver, but I get a general idea of how big it would be. So if you have a Golden Orb Weaver with a body length of 2 inches, width of 0.5 inches, depth of 0.5 inches, and a leg span of 6 inches and apply those proportions (Body 4 times longer than it is wide, leg span three times the size of the length of the body) to a spider the size of a Goliath birdeater. Since the monstrous Golden Orb Weaver would be slightly bigger, we will assume the weight of the Goliath represents just the body of of the Orb Weaver. So we have an Orb Weaver with a foot long by 3 inch wide body, and a leg span of 3 feet.
But if we make a spider that has the area of 48 regular Orb Weavers, we would end up with a body length of 18 inches, width of 6 inches, depth of 6 inches, and a leg span of 54 inches or 4.5 feet.
Has anyone figured out the tensile strength of the silk threads of the various sized spiders? What sized spider would be capable of spinning a silk thread strong enough to support 50 pounds?
Considering that any giant spider worth its salt can restrain an arbitrarily large creature thrashing within its webs at anything below a low-to-mid difficulty (DC12), I would think that any (large-sized) giant spider's webbing could deal with 50 pounds. Since a giant wolf spider has various web-oriented abilities but not a "Web" ability, one might assume that a medium-sized spider produces webbing but not strong enough to restrain large targets, and thus perhaps not enough to support a 50-pound individual for long periods of time.
I have some arachnologist friends I might ask about this (I do know tensile strength of most spider silk is roughly equivalent to steel, but much greater by weight), but for the purposes of a game of magic, best to just go by the in-game rules. ;-)
Even a blind squirrel finds a nut once in awhile.
I was looking for the smallest possible spider that could ride on a pack and spin a web strong enough to support a 50 pound character. A gnome walking around with a giant sized spider on his pack would be kind of conspicuous.
I came up with the following figures using simple ratios, which physics is rarely that simple. When it comes to the physics of increasing size and strength, it rarely is that simple, there are usually complex formulas and algorithms involved.
50# test steel fishing wire is only about .72 millimeters (about 1/50 of an inch), and spider silk is stronger than steel wire of the same diameter. And the thread of a golden orb weaver spider, the strongest spider silk, is .003 millimeters. So assuming a spider silk thread is 5 times stronger than steel (just a guesstimate, I have heard all kinds of numbers up to 100x) that means a thread 1/5th the size, or 0.142 millimeters, should support a 50# weight. That is 48 times the diameter of the GOWs thread. An average GOW weighs 4 grams, so one 48 times the size would be 192 grams, or 0.42 pounds. 0.42 pounds is 6.7 ounces, just a little bigger than a Goliath birdeater, which is a species of tarantula with a different body type than an orb weaver, but I get a general idea of how big it would be. So if you have a Golden Orb Weaver with a body length of 2 inches, width of 0.5 inches, depth of 0.5 inches, and a leg span of 6 inches and apply those proportions (Body 4 times longer than it is wide, leg span three times the size of the length of the body) to a spider the size of a Goliath birdeater. Since the monstrous Golden Orb Weaver would be slightly bigger, we will assume the weight of the Goliath represents just the body of of the Orb Weaver. So we have an Orb Weaver with a foot long by 3 inch wide body, and a leg span of 3 feet.
But if we make a spider that has the area of 48 regular Orb Weavers, we would end up with a body length of 18 inches, width of 6 inches, depth of 6 inches, and a leg span of 54 inches or 4.5 feet.