The most common mode of failure in stacks is vibration due to Vortex Shedding, here are some common Engineering solutions to address this vibration in an economical manner.


Meca provides damping pads for stacks. Generally these are an economical solution for stack heights from about 50 ft [15.2 m] to 150 ft [45.72 m].

It’s a very easily solution to implement on New Stack designs. Damping pads have been used for about 40 years, and have proven to be very reliable.


Tuned Mass
Dampers (TMD)

A Tuned Mass Damper (TMD) is device that is added to the top portion of the stack that increases the damping of the stack, which will suppress wind induced vibration.


Tuned Liquid
Dampers (TLD)

Meca has partnerships with companies that design Tuned Mass Dampers (TMD) and Tuned Liquid Dampers (TLD). These are typically used on stacks that are 150 ft [45. m] and taller. There are many factors that determine whether a TMD or TLD is more appropriate.


Vortex Shedding SolutionAdvantagesDisadvantages
Damping Pad
  • Easy to install on NEW stacks
  • Low Cost
  • Doesn’t require much change to stack design
  • Can only withstand 200º F
  • Adds flexibility to stack
  • Can’t easily be installed on EXISTING stacks
  • Anchor bolts need to have approximately 2.5″ longer projection
Tuned Mass Damper (TMD)
  • Provides the greatest damping
  • Can visually see if the TMD is working
  • All stainless steel components
  • Relatively low weight and wind drag
  • Higher Cost
  • Needs to be near the top of the stack
  • Complicates the design if there are attachments near the top of stack (piping, L&P’s, etc.)
Tuned Liquid Damper (TLD)
  • Shape can be altered to fit available space
  • No moving parts, only internal liquid slosh
  • Can be used as a platform
  • Can only be used in certain situations
  • If stack temperature is high, then steps must be taken to prevent boiling of liquid
  • Cannot visually see if liquid is present at grade
  • Many clients have the perception that they will corrode due to the presences of liquid
Continuous Helical Strakes
  • Design is simple
  • Very common and understood by many
  •  Due to increased wind drag, increases wind load by 30 to 50% (leads to adding significant amount of steel to stack)
  • They do not work if there is another tall structure within 15 diameters of the stack
  • They are very difficult to fabricate
Segmented Strakes
  • They are easy and cheap to fabricate
  • They do not always work, and should never be used