High-Tech issues, real-world equivalencies and questions

[Xplo]

Originally Posted by Icelander

But there are other tasks than chopping, prying and hammering that a knife is useful for. For example, a sturdy combat knife is used for a myriad of things when rigging improvised traps around a bivouac, preparing demolition charges, eating a field-stripped MRE, making field repairs on damaged load-bearing kit, etc.

See, to me, a knife isn't an "improvised" tool for those things; it's the right tool for the job.

For all of these things, a Sykes-Fairbairn knife is less desirable than a solid survival knife.

But probably to an extent that's below GURPS' resolution, IMO. Now, if you were trying to do those things with a large machete or a piece of sheet steel sharpened on a rock...

[joelbf]

Originally Posted by Icelander

Areal density 1.19 lbs. translates into a typical weight of 5-6 lbs. for torso coverage of an adult human, even if we assume that the vest doesn't cover it quite completely.

Which, incidentally, fits typical concealable vests if you check those examples you can find online.

It might be an errata. In any case I agree with you if you must cover the entire gurps-torso, that's why I wrote chest (might have served me better to write upper chest). A 30x30 cm sheet of that magic material would cover most of my ribcage (from the front), and I'm of medium build and 185cm tall, giving me a chest area above human average (probably a lot smaller than the vest-carrying average). It all depends on cut-offs, definitions and coverage needed to gain the guprs protection. An analogy would be trauma plates protecting the entire gurps-torso, which isn't true irl.

It's probably a bit of a stretch but given the way trauma plates are treated I don't know if it's an error.

[Icelander]

Originally Posted by Xplo

See, to me, a knife isn't an "improvised" tool for those things; it's the right tool for the job.

For all of these things, a purpose-designed doohicky probably exists. A knife is not the perfect tool (in GURPS terms, a full tool kit designed for it) for any of these things, but it's useful for it nonetheless and in the field often proves enough. Hence, it's an improvised tool that gives a bonus to the skill roll.

Originally Posted by Xplo

But probably to an extent that's below GURPS' resolution, IMO. Now, if you were trying to do those things with a large machete or a piece of sheet steel sharpened on a rock...

Are you sure?

I'm quite sure that some of the better designed survival knives might rate a +1 or +2 to some tasks over a Sykes-Fairbairn (while the Sykes-Fairbairn should probably be Fine (Balanced) to compensate, being designed exclusively for fighting).

I'm just trying to benchmark which real world knives qualify for 'fighting knives', which qualify as 'working knives' and which ones are a compromise. Marketing text is usually not reliable enough and I can't personally test every knife.

[Icelander]

Originally Posted by Boobis

It might be an errata. In any case I agree with you if you must cover the entire gurps-torso, that's why I wrote chest (might have served me better to write upper chest). A 30x30 cm sheet of that magic material would cover most of my ribcage (from the front), and I'm of medium build and 185cm tall, giving me a chest area above human average (probably a lot smaller than the vest-carrying average). It all depends on cut-offs, definitions and coverage needed to gain the guprs protection. An analogy would be trauma plates protecting the entire gurps-torso, which isn't true irl.

It's probably a bit of a stretch but given the way trauma plates are treated I don't know if it's an error.

GURPS High-Tech includes a new rule for armor that covers only a part of a hit location.

If the intention of the Concealable Vest is to cover only the upper chest, I think it should note that as partial coverage and state that it provies only a n-in-6 chance of protection (just covering the ribcage would be the Vitals plus about 3-in-6 or 4-in-6 if the GM is particularly nice (which I wouldn't be with this kind of inadequate coverage)).

Covering just the front and back of the upper chest leaves the sides bare and that would be a pretty major flaw since in many firing stances (Weaver, Center Axis Relock, etc.), the side is at least partially exposed to the opposition. A vest like what you're proposing would be rejected by all police departments of which I'm aware.

But note that even just a 2 sf coverage of this material would result in a vest that was ca 3 lbs. There is more to the vest than just the ballistic material (even though some manufacturers do weight just the ballistic segments of their vests, in Small, when they give their 'typical' weights in marketing hype). There's fastenings, the plate pocket and the carrier itself (concealable vests encase the ballistic fibre in softer fabric for greater comfort and less visibility under clothing).

And even though 1 lbs. might sound like a pittance, it's a 50% margin of error. Which is far more than I'll accept.

There really are 2 lbs. vests out there. They're just Level IIA or II and give very partial coverage. And there really are concealable Level IIIAs out there. They're just a lot heavier than 2 lbs.

[joelbf]

Originally Posted by Icelander

GURPS High-Tech includes a new rule for armor that covers only a part of a hit location.

If the intention of the Concealable Vest is to cover only the upper chest, I think it should note that as partial coverage and state that it provies only a n-in-6 chance of protection (just covering the ribcage would be the Vitals plus about 3-in-6 or 4-in-6 if the GM is particularly nice (which I wouldn't be with this kind of inadequate coverage)).

Covering just the front and back of the upper chest leaves the sides bare and that would be a pretty major flaw since in many firing stances (Weaver, Center Axis Relock, etc.), the side is at least partially exposed to the opposition. A vest like what you're proposing would be rejected by all police departments of which I'm aware.

But note that even just a 2 sf coverage of this material would result in a vest that was ca 3 lbs. There is more to the vest than just the ballistic material (even though some manufacturers do weight just the ballistic segments of their vests, in Small, when they give their 'typical' weights in marketing hype). There's fastenings, the plate pocket and the carrier itself (concealable vests encase the ballistic fibre in softer fabric for greater comfort and less visibility under clothing).

And even though 1 lbs. might sound like a pittance, it's a 50% margin of error. Which is far more than I'll accept.

There really are 2 lbs. vests out there. They're just Level IIA or II and give very partial coverage. And there really are concealable Level IIIAs out there. They're just a lot heavier than 2 lbs.

I'm not suggesting a vest, I'm toying around with numbers trying to figure out if it is an errata or just resolution artifacts.

The rules for trauma plates (High-Tech p. 67) to me clearly indicates that you don't need to protect the sides in order to gain a full (6 in 6 all around) protection. I can't recall ever reading gurps rules suggesting that you are hit from "the side" regarding armour, only front and back. While this isn't "correct" from a simulation point of view it certainly fits my view of the intended resolution of details in GURPS.

Anyhow as a GM I would probably say vitals + 3 in 6 (survival is fun) and ignore the (possible/probable) 50% margin of error.

[Icelander]

Originally Posted by Boobis

I'm not suggesting a vest, I'm toying around with numbers trying to figure out if it is an errata or just resolution artifacts.

The rules for trauma plates (High-Tech p. 67) to me clearly indicates that you don't need to protect the sides in order to gain a full (6 in 6 all around) protection. I can't recall ever reading gurps rules suggesting that you are hit from "the side" regarding armour, only front and back. While this isn't "correct" from a simulation point of view it certainly fits my view of the intended resolution of details in GURPS.

Anyhow as a GM I would probably say vitals + 3 in 6 (survival is fun) and ignore the (possible/probable) 50% margin of error.

As a GM, I'd tell players that weight correlated with desired coverage. If they want full level IIIA coverage, their vest weights about 5 lbs.

If they're comfortable with partial level II (DR 9/3), then they can have their 2 lbs. vest.

[Anthony]

As far as I can tell, GURPS is just allowing trauma plates to cover the entire torso location, when in reality the coverage from front and back plates ranges from about 50% for straight-on shots to nearly zero for side shots. It may well be doing the same thing for vests -- vests generally have more coverage, but it still tends to be well under 100%.

[Crakkerjakk]

Originally Posted by Anthony

As far as I can tell, GURPS is just allowing trauma plates to cover the entire torso location, when in reality the coverage from front and back plates ranges from about 50% for straight-on shots to nearly zero for side shots. It may well be doing the same thing for vests -- vests generally have more coverage, but it still tends to be well under 100%.

Towards the end of my time in the Corps, they had us range coaches start teaching people to shoot at a target while standing with your shoulders square, instead of the traditional side-on stance. Apparently a lot of guys who were used to shooting side-on at the range were having rounds slip through the arm-holes in their interceptor vests when they got shot in the shoulder.

I wasn't a grunt, just a comm pogue, so I'm not sure how the professionals did it.

[Icelander]

Originally Posted by Anthony

As far as I can tell, GURPS is just allowing trauma plates to cover the entire torso location, when in reality the coverage from front and back plates ranges from about 50% for straight-on shots to nearly zero for side shots. It may well be doing the same thing for vests -- vests generally have more coverage, but it still tends to be well under 100%.

Well, yes.

But that doesn't change the fact that the TL 8 Concealable Vest claims to be 'the lightest and most concealable vest currently on the market'.

I can't find a 2 lbs. NIJ Level IIIA vest anywhere, even one that only covers the torso partially.

[safisher]

Originally Posted by Icelander

There really are 2 lbs. vests out there. They're just Level IIA or II and give very partial coverage. And there really are concealable Level IIIAs out there. They're just a lot heavier than 2 lbs.

To be blunt, please don't spread misinformation like this because your ten minute Google search did not find it. There are manufacturer's products which you will not find on Google. One can find IIIa vests in the 1.7-2.2 lb. range. Total weight depends on size, minute changes in coverage, and the "wear" strength of the ballistic panel carrier.

Now as to the coverage issue, this was simply a continuity and complexity issue. It would require another roll for each hit to see whether the bullet struck an unarmed portion of the torso, and/or a change of that N number based on stance. That was too much fiddling and too cumbersome in play. Often it becomes necessary to balance fun and "realism" and in those cases, I lean toward the latter.