Better Grav Vehicles For Starships

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heron61
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Better Grav Vehicles For Starships

Postby heron61 » Sun Apr 19, 2020 4:38 am

I was thinking about grav vehicles, and came up with 2 designs to replace the standard 4 dTon Air/Raft. The first version is 6 spaces, and follows all the rules, except that it uses an acceleration bench (4 seats/dTon or 2 seats/Space) as the back seat. Since it’s TL 13, I’m also assuming that this bench can shift to 2 roomier and more standard seats if there are only 2 passengers in the back seat. Given that Acceleration benches work on small craft and starships, I can’t see any reason why they wouldn’t work on vehicles. They can also fold up, which would add more cargo space, which could be very handy.

The second version only allots 0.5 space for life support, since that would theoretically supply short term life support for up to 10 people and the vehicle only holds a maximum of 6. Doing this reduces the size from 6 to 5 Spaces (at the cost of reducing the cargo space from 1 Space to 0.5 spaces). In any case, this vehicle is fast and safe for use in vacuum, making it a far better choice than the Air/Raft, and allowing it to be easily used to carry passengers and a little cargo to and from a ship in orbit. The larger version only costs 15% more than an Air/Raft (and is still less than the 300,000 Cr available for the Vehicle benefit), and the smaller 5 space version actually costs less than the Air/Raft, and both of them take up less space in a starship.

Small Light Grav Vehicle (TL 13)
6 spaces (base cost: 180,000 Cr)
Autopilot (enhanced): 10,000 Cr (Skill 2)
Control systems (improved): 5,000 Cr
Advanced Comms (range x 10): 500 Cr [10,000 km range)]
Computer/3: 2,000 Cr
Navigation System (basic): 2,000 Cr
Sensor System (improved): 15,000 Cr
Vacuum Protection: 60,000 Cr
Life Support: 10,000 Cr [1 space]
Acceleration Bench (seats up to 4): 1,000 Cr [2 spaces]
Entertainment System: 500 Cr
2 standard seats [2 spaces]
Cargo [1 space/500 kg]

Traits
Agility: +2
Autopilot Skill: 2
Communications Range: 10,000 km
Sensor Range/DM: 5 km/+1
Computer: 3
Speed: Very Fast
Range: 4,000 km
Shipping: 3 tons
Cost: 286,000 Cr

Smaller Light Grav Vehicle (TL 13)
5 spaces (base cost: 150,000 Cr)
Autopilot (enhanced): 10,000 Cr (Skill 2)
Control systems (improved): 5,000 Cr
Advanced Comms (range x 10): 500 Cr [10,000 km range)]
Computer/3: 2,000 Cr
Navigation System (basic): 2,000 Cr
Sensor System (improved): 15,000 Cr
Vacuum Protection: 50,000 Cr
Life Support: 5,000 Cr [0.5 space]
Acceleration Bench (seats up to 4): 1,000 Cr [2 spaces]
Entertainment System: 500 Cr
2 standard seats [2 spaces]
Cargo [0.5 space/250 kg]

Traits
Agility: +2
Autopilot Skill: 2
Communications Range: 10,000 km
Sensor Range/DM: 5 km/+1
Computer: 3
Speed: Very Fast
Range: 4,000 km
Shipping: 2.5 tons
Cost: 241,000 Cr
AnotherDilbert
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Re: Better Grav Vehicles For Starships

Postby AnotherDilbert » Sun Apr 19, 2020 9:43 am

I agree, smaller vehicles are better since space onboard spacecraft are at a premium.

But TL13 is a bit high, at least in the Spinward Marches. It's a lot easier to find TL11-12 repair facilities. Most small civilian spacecraft are TL12, I would try to match that.

1 Space is basically 250 kg, not 500 kg.

While I agree about Acceleration Benches, I would hesitate to squeeze four people into 2 Spaces, I would use at least 4 Spaces (the same as regular seating, but foldable).
heron61
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Re: Better Grav Vehicles For Starships

Postby heron61 » Sun Apr 19, 2020 11:07 am

AnotherDilbert wrote:
Sun Apr 19, 2020 9:43 am
While I agree about Acceleration Benches, I would hesitate to squeeze four people into 2 Spaces, I would use at least 4 Spaces (the same as regular seating, but foldable).
Except that in High Guard, Acceleration Benches seat 4 per dTon, and 2 spaces = 1 dTon, so I don't see a problem. Sure, it would be crowded, but you're sitting 4 people in the grav vehicle version of the back of a mid-sized sedan, which is perfectly doable, if also not the most comfortable way to travel. For a seat like that, 4 is crowded, 3 is OK, and 2 is as comfortable as a fairly small seating area is likely to get.

As a side-note TL D/13 isn't all that rare, even in the Spinward Marches - something like 2/3s to 3/4s of the subsectors in the Marches and Deneb have at least 1 world of TL 13 or higher. Sure, they're not all over the place, but you mostly don't need to get your grav vehicle fixed all that often.
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Re: Better Grav Vehicles For Starships

Postby Annatar Giftbringer » Sun Apr 19, 2020 12:26 pm

There way I understand it is that one space is one building block of 250 kg/0,25 dt, and the 0,5 dt per space is only for shipping - it shows how many useable buildings blocks that type of vehicle has per dton, so to speak.

This means that for a light grav vehicle, half of the total shipping size goes to engine, hull, chassis, base armor and all the other things that are “just assumed to be there”.

Also note that - once again this is how I understand it - the total shipping size isn’t necessarily the same as the vehicle’s size, it’s the amount of space needed to safely park and access the vehicle.
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Re: Better Grav Vehicles For Starships

Postby AnotherDilbert » Sun Apr 19, 2020 4:10 pm

heron61 wrote: ... and 2 spaces = 1 dTon, ...
No, not that easy:

Spacecraft are measured in displacement tons ≈ 14 m³. Vehicles are measured in metric tonnes = 1000 kg. Unfortunately 1 ton in HG (14 m³) is not the same as 1 ton in VH (1000 kg).

In general 1 Space = 250 kg, see e.g.:
VH, p6 wrote: A vehicle can carry 250 kg for every Space that is dedicated to cargo.
VH, p44 wrote: The only conversion that will be necessary is to turn the Mass of each weapon (usually listed in Kg or tons) into Spaces. This is done at a rate of 1 Space for every 250 Kg or 0.25 tons of Mass or part of.

Shipping size is just the needed storage space of the vehicle on a spacecraft (or presumably other garages).

Note:
VH, p44 wrote: To place a spacecraft weapon into a vehicle, simply multiply the tonnage of the weapon by four. This is how many Spaces it will consume, to a minimum of 1 Space. Unless it is to be placed in a fixed mount, it will also need a spacecraft style turret which, at one ton on a spacecraft, will mean another 4 Spaces is required.
A triple spacecraft turret with weapons of 1 Dton takes 7 Spaces on a vehicle.
heron61
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Re: Better Grav Vehicles For Starships

Postby heron61 » Sun Apr 19, 2020 10:50 pm

AnotherDilbert wrote:
Sun Apr 19, 2020 4:10 pm
heron61 wrote: ... and 2 spaces = 1 dTon, ...
No, not that easy:

Spacecraft are measured in displacement tons ≈ 14 m³. Vehicles are measured in metric tonnes = 1000 kg. Unfortunately 1 ton in HG (14 m³) is not the same as 1 ton in VH (1000 kg).

In general 1 Space = 250 kg, see e.g.:
VH, p6 wrote: A vehicle can carry 250 kg for every Space that is dedicated to cargo.
VH, p44 wrote: The only conversion that will be necessary is to turn the Mass of each weapon (usually listed in Kg or tons) into Spaces. This is done at a rate of 1 Space for every 250 Kg or 0.25 tons of Mass or part of.

Shipping size is just the needed storage space of the vehicle on a spacecraft (or presumably other garages).
That's an excellent point. OTOH, I see acceleration benches as being roughly the same as an economy airline seat (and an acceleration seat being the same thing as a first class airline seat). The back of a midsize sedan has roughly the same space as 2 economy airline seats, and you can squeeze 4 people into it, so I still think it's reasonable (if also far from comfortable) to say that a 2 space back seat can hold 4 uncomfortably, 3 adequately, or 2 in (very) modest comfort.
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Re: Better Grav Vehicles For Starships

Postby Condottiere » Mon Apr 20, 2020 11:06 am

1. Space appears to be more of an issue in hundred tonne Scouts.

2. If a higher technological level allows a more compact version, it's a consideration.

3. However, most manufacturers are likely to produce goods at the minimal cost at an acceptable consumer quality, so it's likely that will be at the lowest technological level that will allow it to operate satisfactorily.

4. If you can breakdown the air/raft, it should occupy less space; this is at the expense of time used to reassemble it in the hold.
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Re: Better Grav Vehicles For Starships

Postby heron61 » Fri May 01, 2020 7:58 am

I've discussed this before viewtopic.php?f=89&t=120056&p=915870&hi ... le#p915870, and one of the things that I think needs to be kept in mind is how freaking huge a 4 dton air raft is. Both a large SUV and a Humvee are both slightly less than 1.5 dtons, which if you double the size to get shipping weight, they're both still only 3 dtons. This means a 4 dton air raft would be a third larger than a 6 door SUV or a Hummer. So, I'd very definitely say that allowing 2 spaces to seat four in the vehicle equivalent of an acceleration bench - they'd be cramped and would efinitely be more comfortable if only 2 or 3 people were in the back seat, since a 3 dton grav vehicle (f it has similar dimensions to a Humvee) would be 5 m x 2 m x 2 m, meaning it has a nice wide back seat capable of seating 4 uncomfrotably.
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Re: Better Grav Vehicles For Starships

Postby AnotherDilbert » Fri May 01, 2020 12:55 pm

heron61 wrote: ... and one of the things that I think needs to be kept in mind is how freaking huge a 4 dton air raft is.
It was originally a 4 tonne truck, not a jeep.
LBB3 wrote: An air/raft can carry four persons plus four tons of cargo.

heron61 wrote: So, I'd very definitely say that allowing 2 spaces to seat four in the vehicle equivalent of an acceleration bench ...
I can't say you are wrong, just that I would not like to do it.

I reacted more to:
heron61 wrote:
Sun Apr 19, 2020 4:38 am
Cargo [1 space/500 kg]
One Space really should be 250 kg.
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Re: Better Grav Vehicles For Starships

Postby Condottiere » Sat May 02, 2020 5:10 pm

It's called a air/raft, besides the Dumarest reference and clever word play.

Four tonnes is about what we'd allocate to a twenty foot container.

It's supposedly open topped, but could have anti rollbars and maybe a cargo carrier as the roof.
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Re: Better Grav Vehicles For Starships

Postby Reynard » Sun May 03, 2020 1:34 am

The air/raft is Traveller's honorific to the iconic Jeep. Went every and anywhere and was known for that open top design no matter the weather. Just like the jeep, you can have many upgrades and variations of an air/raft, most certainly an enclosed version. I wonder what the Hummer version of an air/raft looks like.
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Re: Better Grav Vehicles For Starships

Postby Sigtrygg » Sun May 03, 2020 8:45 am

It's an honorific, of anything, to the standard Army 4 ton truck, not the jeep.

Jeeps don't carry 4,000kg of cargo and 4 people - you need a 4ton truck for that.

This is the sort of misconception that plagues Traveller, both from the fandom and artists over the years, saying it is like a jeep makes people think it is jeep sized which it is not.

It is a flying four ton truck.
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Re: Better Grav Vehicles For Starships

Postby Condottiere » Sun May 03, 2020 9:04 am

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Re: Better Grav Vehicles For Starships

Postby AnotherDilbert » Sun May 03, 2020 9:06 am

Sigtrygg wrote: It is a flying four ton truck.
Quite, a real 7 m truck, not a dinky little 3.5 m car:
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Re: Better Grav Vehicles For Starships

Postby Condottiere » Sun May 03, 2020 9:15 am

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Re: Better Grav Vehicles For Starships

Postby AnotherDilbert » Sun May 03, 2020 9:59 am

The German WWII version (courtesy of GM) was of course not so primitive:
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Re: Better Grav Vehicles For Starships

Postby phavoc » Mon May 04, 2020 1:07 am

I'm kind of surprised at the lack of grav limousines being carried by a yacht. Someone who can afford luxury at that level isn't going to use a speeder, let alone an air/raft to go to/from the surface, and especially not while on the surface. They are going to travel in luxury. And they aren't going to be stuck in a conformal hangar - they will want elbow room to dismebark from their vehicle. But I don't see this reflected in designs.
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Re: Better Grav Vehicles For Starships

Postby Condottiere » Mon May 04, 2020 10:47 am

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Re: Better Grav Vehicles For Starships

Postby Condottiere » Tue May 05, 2020 11:59 am

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Re: Better Grav Vehicles For Starships

Postby Condottiere » Sun May 17, 2020 12:31 pm

Tank Chat #103 | Laird Centaur | The Tank Museum

David Fletcher looks at this curiosity from the 1970's, a Land Rover with tracks. Currently housed in The Tank Museum's Vehicle Conservation Centre.

https://www.youtube.com/watch?v=luTIPzwXJEQ



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