Costs of variant grav vehicles?
- Thread starter rancke
- Start date
To me it's obvious that someone at GDW mixed up metric tons and displacement tons. The Air/raft described in the 1st Edition is (IMO) the size of a four door sedan, weighs 4 metric tons and can lift 4 more metric tons, pilot, passengers, and cargo included. I doubt it takes up more than 1 dTon, although you might arguably need 2 dTons of space to garage it.
Hans
Hi
Wouldn't 4 metric tonnes be kind of heavy for a vehicle the size of a four door sedan. For instance looking up on the internet I see that a modern Mercedes Benz E class car (which seems to me to be a fairly latge 4 door sedan) appears to weight only about 3825lb (or 1.91 metric tonnes),while a BMZ 7 series is about 4795lb, which is about 2.4 mt.
Regards
PF
Wouldn't 4 metric tonnes be kind of heavy for a vehicle the size of a four door sedan. For instance looking up on the internet I see that a modern Mercedes Benz E class car (which seems to me to be a fairly latge 4 door sedan) appears to weight only about 3825lb (or 1.91 metric tonnes),while a BMZ 7 series is about 4795lb, which is about 2.4 mt.
Regards
PF
The equipment to lift 8 metric tons, for weeks on end, would presumably more than that to roll 2 metric tons for a few hours. Again, the endurance is what gets you here.
Look up an Army 5 ton truck: http://www.olive-drab.com/od_mvg_www_deuce_m939.php
Look up an Army 5 ton truck: http://www.olive-drab.com/od_mvg_www_deuce_m939.php
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In MT most grav designs were prohibitively expensive. I guess they're not thought as urban utilitaries.
You can design some vehicles with reasonable prices. In one MTJ (IIRC) there were gidelines to do that. More or less were:
- Use fuel cells instead of fusion. You will have less autonomy, but probably more than you have with your TL7 ground ar in real world. Fusion is prohibitively expensive (aside from that I'm not sure traffic authorities would like to see thousands of fusion plants, no matter how small, flying into the city, as accidents may be quite heavy)
- Use standard grav modules (at kCr 1 per ton) instead of low energy modules (at kCr 25-300 per ton).
- Do not armor your vehicle. It adds price and weight (making higher the costs above). It's a civilian vehicle, you don't need it.
- You don't need state of the art sensors not communications. An anti collision radar and headlights, and a radio channel at most would suffice.
- Electronic controls, without computer will be enough. If you keep it truly cheap, you won't need too many of them.
- You don't need avionics (NOE flight is probably forbiden in populated areas) nor weaponry.
With those gidelines, you can build a grav utilitarian car for less than kCr 10.
BTW, the cargo is probably 4 tons of weight, as weight is the limiting factor for grav vehicles. When designing MT grav cars, I added (on the loaded weight) 100 kg per passenger/crew, as in the rules as they are any seat weights 20 kg, and the people that sits on it is forgoten (or weightless).
You can design some vehicles with reasonable prices. In one MTJ (IIRC) there were gidelines to do that. More or less were:
- Use fuel cells instead of fusion. You will have less autonomy, but probably more than you have with your TL7 ground ar in real world. Fusion is prohibitively expensive (aside from that I'm not sure traffic authorities would like to see thousands of fusion plants, no matter how small, flying into the city, as accidents may be quite heavy)
- Use standard grav modules (at kCr 1 per ton) instead of low energy modules (at kCr 25-300 per ton).
- Do not armor your vehicle. It adds price and weight (making higher the costs above). It's a civilian vehicle, you don't need it.
- You don't need state of the art sensors not communications. An anti collision radar and headlights, and a radio channel at most would suffice.
- Electronic controls, without computer will be enough. If you keep it truly cheap, you won't need too many of them.
- You don't need avionics (NOE flight is probably forbiden in populated areas) nor weaponry.
With those gidelines, you can build a grav utilitarian car for less than kCr 10.
BTW, the cargo is probably 4 tons of weight, as weight is the limiting factor for grav vehicles. When designing MT grav cars, I added (on the loaded weight) 100 kg per passenger/crew, as in the rules as they are any seat weights 20 kg, and the people that sits on it is forgoten (or weightless).
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Good ideas except for this part.
If a Grav Vehicle is to become ubiquitous, then NOE flight is essential ... like running to the store for more milk without needing to file a flight plan with the air traffic controllers.
Without avionics you can still go NOE, but at no more than 40 kph. I think it's more than enough for a civilian utilitarian grav vehicle. If you have to go quicker (you're going to another city to visit someone), then you just fly higher and can reach even 300 kph (like high speed trains today) without streamlining, or 750 kph with partial streamlining if you have grav lift enough. I think that should be enough...
And I forgot, about environment, basic environment will sufice if used on friendly atmospheres. If not so friendly, add basic life support and perhaps an airlock. Anything else it's just needless adding cost, weight and power needs (and that means money too...)
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Allow me to show you how those designs may look (MT rules). This is a Grav bike loosely based on the Trasea, but appling the gidelines given above. Of course is a civilian vehicle, thought as the bike the guy next door may have.
Now compare its cost with that of the Trasea (Cr 171600)...
Notes: as Open Toped vehicle, I reduced the volume required per seat to 1.5 kl, instead of the 2 kl listed. In the loaded weight, I included 0.1 ton because of the operator and 0.1 ton because of the passenger (as I posted above).
Now compare its cost with that of the Trasea (Cr 171600)...
Notes: as Open Toped vehicle, I reduced the volume required per seat to 1.5 kl, instead of the 2 kl listed. In the loaded weight, I included 0.1 ton because of the operator and 0.1 ton because of the passenger (as I posted above).
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ThunderChilde
SOC-13
On the size of an air raft.
Elsewhere on these boards, (or perhaps Mongooses) was was a thread about the actual size of classic trek ships, and the Galileo shuttle is about the size of a classic traveller air raft. That includes the warp nacelles. Make them AG modules, PP and Fuel Tankage and there you go, a sealed air raft.
Elsewhere on these boards, (or perhaps Mongooses) was was a thread about the actual size of classic trek ships, and the Galileo shuttle is about the size of a classic traveller air raft. That includes the warp nacelles. Make them AG modules, PP and Fuel Tankage and there you go, a sealed air raft.
E.D.Quibell
SOC-13
If you strip it to the bone you can go even lower. Without the radar and the radio you can get down to monthly salery prices. You could go even lower priced if you wished by making it smaller, dropping the duration and going config 0:
Sherlock Class Grav Bike
Designed by Ewan Quibell 2010-11-21
Updated 2011-05-08
CraftID: Sherlock Grav Bike, TL9, Cr 3,915
Hull: 1/1, Disp=0.074, Conf=4USL Open, Armor=1B, Loaded=0.961 tons, Unloaded=0.2235 tons
Power: 1/2, MHD Turbine=0.11 Mw, Duration=6/18
Loco: 1/2, Standard Grav=1 ton, MaxAcel=1.04 G, NOE=40 kph, Cruise=225 kph, Top=300 kph,
Comm: -
Sensors: Headlights x1
Off: Hardpoints=1
Def: +2
Control: Panel=Electronic x1
Accom: Crew=1 (Driver), Seats=Cramped x1
Other: Fuel=0.693 kl, Cargo=0.0445 kl, ObjSize=Small, EmLevel=Faint
Comment: Cost in Quantity=Cr 3,132
The Sherlock grav bike is the first offering from Inness Corporation from Pawel in the Home system. While the technology used is mature by Home standards the revelation is the use of a hydrocarbon turbine for the power source only made affordable due to the increased provision of bio diesel from New Home. While the fuel may be moderately expensive the cost of the Sherlock is not. Inness are targeting their grav bikes a younger market where the noise of the turbine and the rush of the air combined with the freedom an air/raft license gives only adds to the draw of the low price tag.
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In my design, the radar is mostly an anti-collision device, required in most high TL worlds (in MTU at least).
The radio is also a legal requirement to keep traffic control in touch, and is also used as trasponder (also for traffic control requirements).
The radio is also a legal requirement to keep traffic control in touch, and is also used as trasponder (also for traffic control requirements).
Well, with mass production discount, my design goes down to Cr 4952.
I guess those designs are thought for different targets. As you say, yours is for young motards, while mine is more the utilitarian urban kind (more safety systems, less pollutant power, etc).
Also the capability for a passenger points to an utilitarian vehicle too...
I guess those designs are thought for different targets. As you say, yours is for young motards, while mine is more the utilitarian urban kind (more safety systems, less pollutant power, etc).
Also the capability for a passenger points to an utilitarian vehicle too...
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E.D.Quibell
SOC-13
Carnegie Class Grav Bike
Designed by Ewan Quibell 2011-07-01
Updated 2011-07-01
CraftID: Carnegie Grav Bike, TL9, Cr 2,522
Hull: 1/1, Disp=0.056, Conf=0USL Open, Armor=1B, Loaded=0.9025 tons, Unloaded=0.8195 tons
Power: 1/2, Enh Int Combust=0.1008 Mw, Duration=12 hours
Loco: 1/2, Standard Grav=1 ton, MaxAcel=1.11 G, NOE=40 kph, Cruise=225 kph, Top=300 kph,
Comm: -
Sensors: -
Off: Hardpoints=1
Def: +2
Control: Panel=Enh Basic Mech x1
Accom: Crew=1 (Driver), Seats=None x1
Other: Fuel=0.0756 kl, Cargo=0.0074 kl, ObjSize=Small, EmLevel=Faint
Comment: Cost in Quantity=Cr 2,018
The Carnegie grav bike is absolute cheapest grav vehicle than can be produced.
If anyone can get it cheaper, or they think I've made a mistake somewhere, please let me know. I used 80% for "Open".
Best regards,
Ewan
Designed by Ewan Quibell 2011-07-01
Updated 2011-07-01
CraftID: Carnegie Grav Bike, TL9, Cr 2,522
Hull: 1/1, Disp=0.056, Conf=0USL Open, Armor=1B, Loaded=0.9025 tons, Unloaded=0.8195 tons
Power: 1/2, Enh Int Combust=0.1008 Mw, Duration=12 hours
Loco: 1/2, Standard Grav=1 ton, MaxAcel=1.11 G, NOE=40 kph, Cruise=225 kph, Top=300 kph,
Comm: -
Sensors: -
Off: Hardpoints=1
Def: +2
Control: Panel=Enh Basic Mech x1
Accom: Crew=1 (Driver), Seats=None x1
Other: Fuel=0.0756 kl, Cargo=0.0074 kl, ObjSize=Small, EmLevel=Faint
Comment: Cost in Quantity=Cr 2,018
The Carnegie grav bike is absolute cheapest grav vehicle than can be produced.
If anyone can get it cheaper, or they think I've made a mistake somewhere, please let me know. I used 80% for "Open".
Best regards,
Ewan
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E.D.Quibell
SOC-13
I usually put radar and radio in mine for the same reasons as you. I was just trying to go as low as you can.
Best regards,
Ewan
I'm affraid you miscalculated the acceleration, as formula is (tons of thrust/loaded weight)-1.
I'm affraid you forgot to substract this '1' (in truth I guess it should be 'gravitiy of the world in Gs' instead of plain '1'), so accelerations sould be (respectively) 0.04 G and 0.11 G, and cruise/top speeds 40/50 for the Sherlock and 144/180 for the Carnegie.
Sorry if your sells plummeted after this corrections...
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E.D.Quibell
SOC-13
I'm affraid you miscalculated the acceleration, as formula is (tons of thrust/loaded weight)-1.
I'm affraid you forgot to substract this '1' (in truth I guess it should be 'gravitiy of the world in Gs' instead of plain '1'), so accelerations sould be (respectively) 0.04 G and 0.11 G, and cruise/top speeds 40/50 for the Sherlock and 144/180 for the Carnegie.
Sorry if you sells plummeted after this corrections...
Thanks. I do know about these calculations, and I ask myself "If you can output 0.04 G ad infanitum (or for the duration of the fuel anyway) why can you only reach 50 kph? Why can't I reach max unstreamlined velocity (300 kph), but just take a long time to get there?"
And I've never found a good answer to the first question. Do you have one?
Best regards,
Ewan
