Crew and Passenger positions and suits/powered armor

[GURPS Fox]

So, several of my settings that I'm working on have the infantry clad in power armor at, practically, all times. For several of my settings, the guy in the PA system and the PA system itself is roughly 250kg (or 551.156lbs if Google conversion is right) in mass alone. So far I've been using a 'Standard Human Multiple) using multiples of mass as the multiplier... but it can get some crazy volumes if I use it.

How would I represent this in the various calculations of the crew stations and passenger seats/standing areas?

[whswhs]

What do you figure is the effective density of the armored character?

* If his density is 1 tonne/cubic meter or 62.5 pounds/cubic foot, he can still float and swim, and won't need furniture any heavier than for a normal human (though it will need to be bulkier!). There will be a lot of empty space inside the suit (well, air-filled). His volume will be 3.67x that of a human, or about 8.8 cubic feet. His linear dimensions will be about 1.5x that of a human, or 9 feet tall, or SM +1.

* If the density of the suit is that of steel, or roughly 8x that of a human, then the wearer's 1x the weight of a human will occupy 1x the volume, and the suit's 2.67x the weight of a human will occupy 0.33x the volume, for a total of 1.33x. That's about 3.2 cubic feet. Furniture will only need to be slightly bulkier, but a lot stronger. Linear dimensions will be about 10% greater, so SM 0 or just barely into SM +1; you can probably treat it as SM 0.

* You could pick intermediate scale factors, such as 20%, 25%, or 30% linear increase. Say for example it's 25%. Then height, for example, goes up to 7.5 feet, which is well into SM +1. Volume is 1.95x that of a human. You might round this up to 2x; then the suit's 2.67x the weight of a human occupies 1x the (extra) volume, which means it's 2.67x the density, or about 2.67 tonnes per cubic meter—about a third as dense as steel.

The volumes of crew stations are going to be respectively 3.67x as big, 1.33x as big, or 2x as big.

[Aldric]

I'd just consider them as Heavy Battlesuits from UT, which are SM+1 and go from there. Are you using numbers from Spaceships?

[GURPS Fox]

Originally Posted by whswhs

What do you figure is the effective density of the armored character?

* If his density is 1 tonne/cubic meter or 62.5 pounds/cubic foot, he can still float and swim, and won't need furniture any heavier than for a normal human (though it will need to be bulkier!). There will be a lot of empty space inside the suit (well, air-filled). His volume will be 3.67x that of a human, or about 8.8 cubic feet. His linear dimensions will be about 1.5x that of a human, or 9 feet tall, or SM +1.

* If the density of the suit is that of steel, or roughly 8x that of a human, then the wearer's 1x the weight of a human will occupy 1x the volume, and the suit's 2.67x the weight of a human will occupy 0.33x the volume, for a total of 1.33x. That's about 3.2 cubic feet. Furniture will only need to be slightly bulkier, but a lot stronger. Linear dimensions will be about 10% greater, so SM 0 or just barely into SM +1; you can probably treat it as SM 0.

* You could pick intermediate scale factors, such as 20%, 25%, or 30% linear increase. Say for example it's 25%. Then height, for example, goes up to 7.5 feet, which is well into SM +1. Volume is 1.95x that of a human. You might round this up to 2x; then the suit's 2.67x the weight of a human occupies 1x the (extra) volume, which means it's 2.67x the density, or about 2.67 tonnes per cubic meter—about a third as dense as steel.

The volumes of crew stations are going to be respectively 3.67x as big, 1.33x as big, or 2x as big.

Well, they're based on Battletech's Nighthawk Mk XXI PA(L) system, which is somewhat form-fitting as far as I can tell. The difference between the Nighthawk and this PA system, it's 150kg lighter.

Would the same setup work with, say, humans that are roughly 180kg or anthropomorphic uplift morphs that can go up to 350kg as well?

Originally Posted by Aldric

I'd just consider them as Heavy Battlesuits from UT, which are SM+1 and go from there. Are you using numbers from Spaceships?

2e Vehicles, actually, given that I've got my hands on GURPS Vehicle Builder.

[Fred Brackin]

Originally Posted by GURPS Fox

W

2e Vehicles, actually, given that I've got my hands on GURPS Vehicle Builder.

This is covered on p.80 of Ve2 under "Battlesuit systems".

I don't have Gurps Vehicle Builder installed on this computer but I was one of the betatesters lo those many years ago. If i remember correctly Battlesuit System" was one of the choices from the "Crew and Passengers" folder.

[Varyon]

Originally Posted by GURPS Fox

So far I've been using a 'Standard Human Multiple) using multiples of mass as the multiplier... but it can get some crazy volumes if I use it.

This sounds like you're assuming the powered armor has the same density as the person wearing it. Unless your "powered armor" is a flesh-and-blood (and bone-and-muscle) organism, or is designed to float unaided in water, this is unlikely. So, a person in powered armor may weigh 250kg, but chances are good the armor has markedly higher density than the ~70kg person inside. A person has a density around 1 g/mL (same as water); a block of steel has a density around 8 g/mL. Assume the density of a suit of powered armor works out to roughly 50% that of steel (there's a lot of steel there, but also a lot of empty space, and synthetic muscle is probably less dense than steel, so 50% is probably good-enough for a back-of-the-envelope calculation). With the 70 kg pilot having a density of 1 g/mL, and the 180kg suit having a density of 4 g/mL, you're looking at an average density of 3.16 g/mL, which ultimately works out to your "guy in a suit" taking up about 1.15x as much volume as the guy would without the suit.

[GURPS Fox]

Originally Posted by Fred Brackin

This is covered on p.80 of Ve2 under "Battlesuit systems".

I don't have Gurps Vehicle Builder installed on this computer but I was one of the betatesters lo those many years ago. If i remember correctly Battlesuit System" was one of the choices from the "Crew and Passengers" folder.

From my attempts at using Battlesuit systems, it is far more useful for things like higher-end Battletech Battlearmor (i.e. anything a metric ton or more) than smaller units. Believe me, I've tried. Please note that, in addition to that, they're wearing it the entire time they're seated...

Originally Posted by Varyon

This sounds like you're assuming the powered armor has the same density as the person wearing it. Unless your "powered armor" is a flesh-and-blood (and bone-and-muscle) organism, or is designed to float unaided in water, this is unlikely. So, a person in powered armor may weigh 250kg, but chances are good the armor has markedly higher density than the ~70kg person inside. A person has a density around 1 g/mL (same as water); a block of steel has a density around 8 g/mL. Assume the density of a suit of powered armor works out to roughly 50% that of steel (there's a lot of steel there, but also a lot of empty space, and synthetic muscle is probably less dense than steel, so 50% is probably good-enough for a back-of-the-envelope calculation). With the 70 kg pilot having a density of 1 g/mL, and the 180kg suit having a density of 4 g/mL, you're looking at an average density of 3.16 g/mL, which ultimately works out to your "guy in a suit" taking up about 1.15x as much volume as the guy would without the suit.

So, I've been doing that wrong then? Because I've trying to figure out how to get this to work:

Originally Posted by MA Lloyd's GURPS Vehicles Additions, Chapter 6

Statistics for crew stations, passenger seats, mecha cockpits and so on assume the occupant will be a typical human - 1.5 to 2 meters tall, under a meter broad, around 150 pounds, and of course human shaped.

Multiply the volume of seats designed to hold suited humans by suit volume/4 if the suit is larger than 4 cf.

Seats designed for another species multiply all statistics by the average species weight/150.

Races with similar body plans can use stations designed for each other if their sizes are within a factor of 2, though not comfortably. It is often impossible to design a crew station that will work properly for two species with very different sizes or body plans, there really isn't any way to build mechanical controls that will work for both a human and a cidi for example, but if the GM permits it use the statistics for the larger species and multiply by 1.2.

[Varyon]

Originally Posted by GURPS Fox

So, I've been doing that wrong then? Because I've trying to figure out how to get this to work:

If you've got a suit volume already, that "multiply... by suit volume/4" part works fine. If you don't have a suit volume, then assuming someone wearing a suit that makes them 3x as heavy is also going to have 3x the volume is going to result in assuming the suits are far larger than they really should be (because the suit is going to be denser than the person wearing it). You just need to figure out a volume for your suit that makes sense.

[Fred Brackin]

Originally Posted by GURPS Fox

So, I've been doing that wrong then? Because I've trying to figure out how to get this to work:

At the level of detail you' appear to be attempting to work at you probably can not get this to work. After re-reading your original post you appear to be trying to figure out how large the chairs are after they've been designed to comfortably seat a person (not necessarily an average human) who's wearing a 550 lb Battlesuit.

Gurps and even Ve2 do not work at this fine a level of detail.

However, you'e mostly looking at SM+1 users weighing 700 lbs or more (like the Heavy Battlesuits in UT). Your Crew seats need to be able to handle 5x the weight (at least) which _might_ mean they need to be that much more expensive.

However, they won't need to be that much more bulky as Battlesuit systems are bound to be denser than human flesh, Also, the weight bearing frames of furniture take up a only a small portion of the furnitures volume.

A SM+1 Battlesuit like the one in UT is described as being 7 ft tall and would be circa 1.2x taller and proportionately broader. You could cube 1.2 and round up to 2 and make all Crew components take up 2x volume and _maybe_ cost 5x as much for the weight.

I caution you that all this is broadly-based guesswork. Everything about battlesuits is speculative.

Also, I think you're 500 lbs suits are too big for persons manning crew stations. I wouldn't go over the 150 lb suits in Basic or UT or even more likely the 45lb Space Armor.

[GURPS Fox]

Originally Posted by Varyon

If you've got a suit volume already, that "multiply... by suit volume/4" part works fine. If you don't have a suit volume, then assuming someone wearing a suit that makes them 3x as heavy is also going to have 3x the volume is going to result in assuming the suits are far larger than they really should be (because the suit is going to be denser than the person wearing it). You just need to figure out a volume for your suit that makes sense.

Damn, good to know.

Originally Posted by Fred Brackin

At the level of detail you' appear to be attempting to work at you probably can not get this to work. After re-reading your original post you appear to be trying to figure out how large the chairs are after they've been designed to comfortably seat a person (not necessarily an average human) who's wearing a 550 lb Battlesuit.

Gurps and even Ve2 do not work at this fine a level of detail.

However, you'e mostly looking at SM+1 users weighing 700 lbs or more (like the Heavy Battlesuits in UT). Your Crew seats need to be able to handle 5x the weight (at least) which _might_ mean they need to be that much more expensive.

However, they won't need to be that much more bulky as Battlesuit systems are bound to be denser than human flesh, Also, the weight bearing frames of furniture take up a only a small portion of the furnitures volume.

A SM+1 Battlesuit like the one in UT is described as being 7 ft tall and would be circa 1.2x taller and proportionately broader. You could cube 1.2 and round up to 2 and make all Crew components take up 2x volume and _maybe_ cost 5x as much for the weight.

I caution you that all this is broadly-based guesswork. Everything about battlesuits is speculative.

Also, I think you're 500 lbs suits are too big for persons manning crew stations. I wouldn't go over the 150 lb suits in Basic or UT or even more likely the 45lb Space Armor.

The thing is that the basic assault rifles in the setting are around (using a modified version of the sqrt(KE^1.04/Xsect^0.314)/13.3926=# of dice, but have 13.3926 replaced with 46.8741 to make the dice numbers more even from what I've been told) 9d+2 in general, with battle rifle rounds being around 14d+1, so the only way to get your soldiers to not rebel on you (even fanatical troops would pause a moment when facing such weapons) is clad them in power armor which has enough armor to at least blunt the impact.