Huge Offset Side Branches Serve as Mass Dampers To Help Hyperion Redwood Grow Very Tall Without Wind Breakage

1      Structure of Hyperion Redwood

 

The overall structure of Hyperion redwood is well detailed in this excellent redwoods study (as SESE 49 in Appendix K):

How do tree structure and old age affect growth potential of California redwoods?

Stephen C. Sillett, Robert Van Pelt, Allyson L. Carroll, Russell D. Kramer, Anthony R. Ambrose, D’Arcy Trask

Ecological Monographs 2015 Vol: 85 (2) :181-212.
doi: 10.1890/14-1016.1

I use this study for some reference information but what follows are my own independent analyses and ideas.

Hyperion has a very unusual feature versus other very tall redwoods in the study.  About 30 meters up on the tree there are two huge branches that grow out from the trunk at near 90 degree angles for a couple meters and then turn straight upwards for twenty or so meters.  Both these branches are on the same side of the trunk and together weigh about 5,000 kg.

Hyperion has a volume of 550 cubic meters, of which about 140 cubic meters are above the huge branches growing out from the trunk thirty meters up.  The 140 cubic meters of volume has a total weight of about 55,000 kilograms (based on Hyperion’s total mass of 210 Mg and total volume of 550 cubic meters).

Therefore the upper 85 meters of Hyperion can be viewed as a 55,000 kg object with 5,000 kg of weight offset from but connected to the base.

 

2      Mass Dampers

 

Mass dampers are used in construction and design to help stabilize vibration from external forces.  For example very tall buildings will employ mass dampers to reduce sway so people do not feel sea sick in high winds as the top of the building sways.   Dampers are also used in automotive engines to reduce vibration.

Mass dampers add cost and complexity to structure design, and there is a trade off in materials and methods used in vibration dampening versus actual benefit.

As a result typical mass dampers are set up in a counterbalance system where the damper is about 10 percent of the mass of the object being dampened.  This then reduces vibration at the radial end of the vibrating object by about forty percent.

For more information see Wikipedia article on Tuned mass dampers.

 

3      Hyperion And Its Built In Mass Damper

 

Reviewing the redwood diagrams it is evident Hyperion redwood has very little breakage in its crown for such an old and tall redwood tree (1260 years old, 116 meters height).  There is no breakage in the top part of the crown, this is one reason why Hyperion has its great height.  Great location, great soil, nightly fog, and tucked into a valley for wind protection.

But Hyperion has something else going for it.  Those big side branches 30 meters up, with combined weight at ten percent of the trunk weight above them, serve as tuned mass dampers to reduce crown sway in high winds by about fifty percent.   The unique structure of Hyperion has contributed to wind breakage suppression, allowing Hyperion to grow very tall without interruption.

Thanks for reading.

Looking up Hyperion’s trunk from uphill side.  Hyperion’s large , low side branches are not shown in this photo.

One thought on “Huge Offset Side Branches Serve as Mass Dampers To Help Hyperion Redwood Grow Very Tall Without Wind Breakage”

  1. It sounds possible. There’s not scads to read about it like there are publications on pruning, planting or root growth. But even watching trees blow in wind, it’s evident it occurs at times. Observing trees leaves me guessing that branches or stems may mass-dampen during brief strong gusts like a couple seconds duration. Whereas during long gusts or steady strong winds, there canopy appears more in unison. I noticed one research report browsing the internet, so it’s on someone’s radar for study.

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