DERRICK SUPPORTED STACKS Derrick supported stacks offer the advantage of high strength, with the benefit of a smaller "footprint". A flare stack can be supported up to 400 ft. high with a derrick, or tower not much larger at the base than the tower itself. A stack within a tower can be fitted with guides allowing the stack and tower to move independently. This independent movement allows for greater thermal expansion for high temperature waste gas streams. Derrick or tower supported flares have the following advantages: High strength for wind loading. Low maintenance costs, virtually no maintenance is required for flare derricks. Periodic inspections can verify the structure is sound, and that all bolts are secure. The required space for location of a tower or derrick-supported flare is much less than that required for a stack supported by guy wires. top