Sand for Indoor Arena...
Areas in British units (FEET):
    14,688 ft² - Indoor arena 72 x 204
+ 16,224 ft² - outdoor arena 78 x 208
= 30,912 ft²  ProEquus OT40


Sand Calculations - Indoor Arena: (based upon 4" sand depth)
Indoor arena (72 ft W) x (204 ft L) x (4 inch Depth)
= 181.33 yd³ (cubic yards)
@ AVG (1.25 tons / 1.00 cu yard) - per Lane Mountain
= 226.6625 tons
= 2.14 railcars

Sand Calculations - Outdoor Arena: (based upon 4" sand depth)
Indoor arena (78 ft W) x (208 ft L) x (4 inch Depth)
= 200.3 yd³ (cubic yards)
@ AVG (1.25 tons / 1.00 cu yard) - per Lane Mountain
= 250.375 tons
= 2.37 railcars

Total, Outdoor + Indoor Arenas ...
Tons ...
   226.6625 tons
+ 250.375 tons
= 477.0375 tons

LOADS ...
    2.14 railcars
+ 2.37 railcars
= 4.51 loaded railcars
NOTE: in order to meet the maximum LOAD allowed on the nearest railroad spur, about 5 miles away, we may need to load fewer tons of sand into each railcar (meaning maybe 6-7 loaded railcars, at less than 106 tons / car).
Reason:  It will be much more economical to ship an extra railcar or two to within a few miles from the job site, than to load the railcars to their maximum capacity, and then have to truck the sand 50 miles roundtrip for multiple trips.
Comparison: a few hundred extra dollars (for an extra railcar or two)
is still better than a few hundred more dollars for every truckload roundtrip,
approximately 15 tons / trip = 30 round trips

Simple, web-based Sand Calculating Tool - enter your dimensions and depth, and click "Calculate" - will open in a new window.

Ordering/transporting INFO:
Option 1) Direct from Lane Mountain Silica
FOR Burlington Northern Trainmaster Terry Nice:
Track is 352, Valley, WA 99181
Have covered hoppers @ 106 tons/car
2 hoppers / car
To BNSF, refer to "BNSF 406 series" cars