Premise: There is an ancient buried city in a desert that you wish to plunder/unearth. The city is completely barred vs. extradimensional/incorporeal travel with powerful magic you can't dispel and multiple walls of force layered in sequence. The city is approximately 2 square miles buried 500 ft deep. [Edit note: There was a mythallar on site, so the Walls of Force cost no xp to make permanent in case y'all were wondering. Also, the builders used some unknown shaping properties to make the walls paper thin. You can assume a 23rd level party, with 9th level Druid, 11th level Cleric, and 10th level Wizard spells from Improved Spell Capacity, and epic spellcasting an option if all else fails.]
Sub-Thread One:
Figure out a way to enter and loot the city. It seemed to me that something together with magic under such crushing weight (125 million lbs of sand in merely 500 cubic feet) would be destroyed if a breach were opened as the sand would pour into the city.
Sub-Thread Two:
Much more involved, figure out a way to unearth the entire city so it can be reclaimed and rebuilt. Warning: Math alert.
Sub-Thread Three:
Figure out a way to raise the entire city up from the sand, as opposed to digging it out.
I did some "digging''
and found that the given weight by volume for a cubic foot of dry sand is ~80 lbs. (The sources varied from 75-90, but 80 seemed the most accurate). A totally solid 5 ft cube of sand is 125 cubic ft and weighs a whopping 11,250 lbs. That should give y'all an idea of how hard it is to excavate.
I thought about wind, but my preliminary calculations were not that promising.
http://www.usace.army.mil/publications/eng-manuals/em1110-2-1100/PartIII/Part-III-Chap_4entire.pdf
Using the simplest method I saw in the formulas: I tried calculating a wind strength of 180 mph, which is 264 feet per second.
(1) Many equations have been proposed to predict sand transport by wind;
G = 0.036 U5ft (O’Brien and Rindlaub 1936)
in which G = the dry weight transport rate in pounds per foot per day and U5ft = the wind speed at the 5-ft elevation in feet per second (U5ft > 13.4 feet per second).
G=.036*180
G=9.504 (Call it 9.5)
I'm guessing that "pounds per foot" means that the top surface area of exposed sand equals 1 ft square. Since we know that a cubic foot of sand weighs 80 lbs, this would imply that if a cubic foot of sand were subjected to a 180mph wind for 24 hours, it would lose ~12% of its mass. Interesting, but nowhere near what is needed to dig down deep, so I switched gears to shaping. (Reverse Gravity and Gate don't last long enough to do much)
Control Sand from Sandstorm p 112 offers some options but then also opens up some questions.
Clr3/Dr3
Long Range
Area: 10 ft/lvl long by 10 ft/lvl wide by 2 ft/lvl deep (S)
Duration: 10 mins/lvl
The caster can reduce one horizontal dimension by half and double the other.
Lower Sand: This effect causes sand to reduce its depth by as much as 2 feet per caster level, to a minmum depth of 1 inch. The dust and sand is lowered within a square-shaped depression whose sides are up to 10 feet long per caster level. In extremely large and deep sand piles, such as a sand dune, the spell creates a pit that sweeps creatures downward (without dealing damage), putting them at risk and rendering them unable to leave by normal movement for the duration of the spell.
Raise Sand: This effect causes dust and sand to rise in height, just as the lower sand version causes it to lower. Creatures and objects on top of the dust or sand are raised along with the top level of sand.
I have some questions about Control Sand.
1) Could a caster cast it again and then target the same area as the first spell to create a bigger depression in the sand?
2) Does the sand completely disappear or is it displaced?
3) When the spell duration expires, what happens to the sand? Does the sand more or less reappear when you made a depression or raised it, or is the movement a non-magical byproduct of the spell and so the sand from that point obeys the natural laws of gravity, etc.
Thanks for your input and ideas.
Sub-Thread One:
Figure out a way to enter and loot the city. It seemed to me that something together with magic under such crushing weight (125 million lbs of sand in merely 500 cubic feet) would be destroyed if a breach were opened as the sand would pour into the city.
Sub-Thread Two:
Much more involved, figure out a way to unearth the entire city so it can be reclaimed and rebuilt. Warning: Math alert.
Sub-Thread Three:
Figure out a way to raise the entire city up from the sand, as opposed to digging it out.
I did some "digging''
and found that the given weight by volume for a cubic foot of dry sand is ~80 lbs. (The sources varied from 75-90, but 80 seemed the most accurate). A totally solid 5 ft cube of sand is 125 cubic ft and weighs a whopping 11,250 lbs. That should give y'all an idea of how hard it is to excavate. I thought about wind, but my preliminary calculations were not that promising.
http://www.usace.army.mil/publications/eng-manuals/em1110-2-1100/PartIII/Part-III-Chap_4entire.pdf
Using the simplest method I saw in the formulas: I tried calculating a wind strength of 180 mph, which is 264 feet per second.
(1) Many equations have been proposed to predict sand transport by wind;
G = 0.036 U5ft (O’Brien and Rindlaub 1936)
in which G = the dry weight transport rate in pounds per foot per day and U5ft = the wind speed at the 5-ft elevation in feet per second (U5ft > 13.4 feet per second).
G=.036*180
G=9.504 (Call it 9.5)
I'm guessing that "pounds per foot" means that the top surface area of exposed sand equals 1 ft square. Since we know that a cubic foot of sand weighs 80 lbs, this would imply that if a cubic foot of sand were subjected to a 180mph wind for 24 hours, it would lose ~12% of its mass. Interesting, but nowhere near what is needed to dig down deep, so I switched gears to shaping. (Reverse Gravity and Gate don't last long enough to do much)
Control Sand from Sandstorm p 112 offers some options but then also opens up some questions.
Clr3/Dr3
Long Range
Area: 10 ft/lvl long by 10 ft/lvl wide by 2 ft/lvl deep (S)
Duration: 10 mins/lvl
The caster can reduce one horizontal dimension by half and double the other.
Lower Sand: This effect causes sand to reduce its depth by as much as 2 feet per caster level, to a minmum depth of 1 inch. The dust and sand is lowered within a square-shaped depression whose sides are up to 10 feet long per caster level. In extremely large and deep sand piles, such as a sand dune, the spell creates a pit that sweeps creatures downward (without dealing damage), putting them at risk and rendering them unable to leave by normal movement for the duration of the spell.
Raise Sand: This effect causes dust and sand to rise in height, just as the lower sand version causes it to lower. Creatures and objects on top of the dust or sand are raised along with the top level of sand.
I have some questions about Control Sand.
1) Could a caster cast it again and then target the same area as the first spell to create a bigger depression in the sand?
2) Does the sand completely disappear or is it displaced?
3) When the spell duration expires, what happens to the sand? Does the sand more or less reappear when you made a depression or raised it, or is the movement a non-magical byproduct of the spell and so the sand from that point obeys the natural laws of gravity, etc.
Thanks for your input and ideas.
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