What if trees had ? ratings in kN? John Morton Snohomish County - - PowerPoint PPT Presentation

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What if trees had ? ratings in kN? John Morton Snohomish County - - PowerPoint PPT Presentation

Jun 20, 2023 130 likes •611 views

What if trees had ? ratings in kN? John Morton Snohomish County SAR Everett Mountain Rescue water-rescue6@scvsar.org ?? ?? ITRS 2015 ? John Morton Snohomish Co SAR (WA) & Everett Mountain Rescue Helicopter Rescue Team Lead Rope

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What if trees had ratings in kN?

John Morton Snohomish County SAR Everett Mountain Rescue

water-rescue6@scvsar.org

?? ??

ITRS 2015

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John Morton

Snohomish Co SAR (WA) & Everett Mountain Rescue Helicopter Rescue Team Lead Rope Rescue instructor Water Rescue Team leader Hovercraft pilot & Rescue Swimmer Instructor for several Tech Rescue specialties …and a little airplane design work “on the side”

Credits & References

How to Determine Tree Strength and Build Tree Anchors Rick Weber ITRS 2010 ITRS 2015

U.S. Forest Service Silvics Manual

http://na.fs.fed.us/spfo/pubs/silvics_manual

Engineering References Wind Load on Structure Fluid Dynamics Aerodynamic Turbulence Audubon Society

Field Guide to TREES

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SLIDE 3

John Morton Mark Miller Credits & References

How to Determine Tree Strength and Build Tree Anchors Rick Weber ITRS 2010 ITRS 2015

U.S. Forest Service Silvics Manual

http://na.fs.fed.us/spfo/pubs/silvics_manual

Engineering References Wind Load on Structure Fluid Dynamics Aerodynamic Turbulence Audubon Society

Field Guide to TREES

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SLIDE 4

Objective:

If it can be done responsibly… Define a field- applicable way for rescuers to determine if a “small” tree can be used as a rescue anchor

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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A lot of trees in good locations get bypassed as “too small”

Traditional go/no-go for rescue anchor:

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helmet sized or larger

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? Diameter Circumference

Helmet: 28 inch circumference Basketball: 30 in Volleyball: 26 in 2-liter soda bottle: 14 in Tennis ball: 8.5 in Beer bottle: 7.5 in

24”

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SLIDE 7

Compression

Shear

We are worried about pulling on a tree with a rescue system…

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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We are worried about pulling on a tree with a rescue system… What happens to that same tree during wind?

ITRS 2015 John Morton (water-rescue6@scvsar.org)

Shear

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SLIDE 9

We are worried about pulling on a tree with a rescue system… What happens to that same tree during wind?

ITRS 2015 John Morton (water-rescue6@scvsar.org)

Shear

Effect of rescue system?

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SLIDE 10

Shear Turbulence reduces wind energy below canopy

Free Air Wind Speed

“Sail area” varies along length of trunk Bending moment varies along trunk Some tree species root structures are “bending resistant” vs “bending prone” “Aspect ratio” (height vs spread) varies among tree species “Bendiness” of crown varies among species

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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SLIDE 11

Turbulence reduces wind energy below canopy

Effect of Turbulence

Reduces effective wind on smaller trees

Wind-based “rating” on orange cedar is less -- only turbulent wind impacts its sail area

Free Air Wind Speed

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SLIDE 12

Account for Turbulence effects below canopy

  • f mixed tree species

(Cheers for USFS Silvics data!)

Trees are often in a canopy of mixed species

approaching North Rim, Grand Canyon

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SLIDE 13

Shows 12 ITRS species

Profiles shown at SCALED height

shown with Circumference=28inch ratings from 65 mph wind

Each species has an “aerodynamic profile”

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SLIDE 14

ITRS 2015 John Morton (water-rescue6@scvsar.org)

Tree modeled as 20 spindled cylinders supported at a single base

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Repeat for each tree segment each inch of circumference each wind speed each tree species

Engineering: wind force acting

  • n a cylindrical structure

Result: tree anchor rating in kN

Magic!

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SLIDE 15

Water_Oak C \Wind 35 40 45 50 55 60 65 70 75 80 85 90 16 3.6 4.7 5.9 7.3 8.8 10.5 12.3 14.3 16.4 18.7 21.1 23.7 17 4.3 5.7 7.2 8.9 10.7 12.8 15.0 17.4 20.0 22.7 25.6 28.8 18 5.3 6.9 8.7 10.8 13.0 15.5 18.2 21.1 24.2 27.5 31.1 34.9 19 6.3 8.2 10.4 12.8 15.5 18.4 21.6 25.1 28.8 32.8 37.0 41.5 20 7.6 9.9 12.5 15.4 18.7 22.2 26.1 30.2 34.7 39.5 44.6 50.0 21 9.0 11.8 14.9 18.4 22.3 26.5 31.2 36.1 41.5 47.2 53.3 59.7 22 10.5 13.7 17.3 21.4 25.9 30.8 36.2 42.0 48.2 54.8 61.9 69.4 23 12.4 16.2 20.5 25.3 30.6 36.4 42.7 49.5 56.8 64.7 73.0 81.8 24 14.6 19.0 24.1 29.8 36.0 42.9 50.3 58.3 67.0 76.2 86.0 96.4 25 17.0 22.3 28.2 34.8 42.1 50.1 58.8 68.1 78.2 89.0 100 113 26 19.3 25.2 31.9 39.4 47.7 56.8 66.7 77.3 88.7 101 114 128 27 22.3 29.1 36.9 45.5 55.1 65.5 76.9 89.2 102 116 132 147 28 25.1 32.7 41.4 51.1 61.9 73.7 86.4 100 115 131 148 166 29 28.6 37.4 47.3 58.4 70.7 84.1 98.7 115 131 150 169 189 30 31.9 41.7 52.8 65.2 78.8 93.8 110 128 147 167 188 211 31 36.1 47.2 59.7 73.7 89.2 106 125 145 166 189 213 239 32 40.0 52.3 66.2 81.7 98.8 118 138 160 184 209 236 265 33 44.8 58.5 74.0 91.4 111 132 154 179 206 234 264 296 34 50.1 65.4 82.8 102 124 147 173 200 230 262 296 331 35 56.1 73.3 92.8 115 139 165 194 225 258 293 331 371 36 61.5 80.3 102 125 152 181 212 246 282 321 362 406 37 69.4 90.6 115 142 171 204 239 277 319 362 409 459 38 75.6 98.7 125 154 187 222 261 302 347 395 446 500 39 84.0 110 139 172 208 247 290 336 386 439 496 556 40 92.4 121 153 189 228 272 319 370 424 483 545 611 Rating of anchor at 0.6m (kN)

Results: Anchor ratings per species vs C vs wind (separate HD table)

Anchor ≥ 32kN

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Helmet

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Anchor rating (32kN) vs wind speed

(horizontal anchor placed 2ft/0.6m above ground) ?

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65-ITRS

Wind Ratings calculated at Free Air Wind Speed of 65mph

Species Wind Rating @ 28in Wind Rating @ Full Size Wind-rated Anchor Wind-rated High-D Ponderosa_Pine A=59 kN @ C=28in A=17291 kN @ C=119in Anchor: C>23in HD: C>29in W.Red_Cedar A=65 kN @ C=28in A=34862 kN @ C=151in Anchor: C>22in HD: C>29in Bigleaf_Maple A=65 kN @ C=28in A=6368 kN @ C=95in Anchor: C>22in HD: C>29in W.Hemlock A=68 kN @ C=28in A=11730 kN @ C=109in Anchor: C>22in HD: C>28in Smooth_Hickory A=86 kN @ C=28in A=1945 kN @ C=61in Anchor: C>21in HD: C>26in Loblolly_Pine A=91 kN @ C=28in A=15485 kN @ C=102in Anchor: C>20in HD: C>26in Red_Alder A=91 kN @ C=28in A=3254 kN @ C=68in Anchor: C>20in HD: C>26in Douglas_Fir A=94 kN @ C=28in A=72746 kN @ C=153in Anchor: C>20in HD: C>26in Water_Oak A=95 kN @ C=28in A=16979 kN @ C=105in Anchor: C>20in HD: C>26in Engelmann_Spruce A=103 kN @ C=28in A=6013 kN @ C=78in Anchor: C>20in HD: C>25in Quake_Aspen A=214 kN @ C=28in A=412 kN @ C=33in Anchor: C>17in HD: C>21in White_Ash A=230 kN @ C=28in A=1622 kN @ C=46in Anchor: C>17in HD: C>21in

Summary Table with helmet and full-size ratings from trees tested by 65 mph free air wind speed

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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SLIDE 18

85-ITRS

Wind Ratings calculated at Free Air Wind Speed of 85mph

Species Wind Rating @ 28in Wind Rating @ Full Size Wind-rated Anchor Wind-rated High-D Ponderosa_Pine A=101 kN @ C=28in A=29569 kN @ C=119in Anchor: C>20in HD: C>25in W.Red_Cedar A=111 kN @ C=28in A=59616 kN @ C=151in Anchor: C>19in HD: C>24in Bigleaf_Maple A=111 kN @ C=28in A=10890 kN @ C=95in Anchor: C>19in HD: C>24in W.Hemlock A=116 kN @ C=28in A=20058 kN @ C=109in Anchor: C>19in HD: C>24in Smooth_Hickory A=147 kN @ C=28in A=3325 kN @ C=61in Anchor: C>18in HD: C>23in Loblolly_Pine A=156 kN @ C=28in A=26480 kN @ C=102in Anchor: C>17in HD: C>22in Red_Alder A=156 kN @ C=28in A=5565 kN @ C=68in Anchor: C>17in HD: C>22in Douglas_Fir A=161 kN @ C=28in A=124400 kN @ C=153in Anchor: C>17in HD: C>22in Water_Oak A=162 kN @ C=28in A=29036 kN @ C=105in Anchor: C>17in HD: C>22in Engelmann_Spruce A=176 kN @ C=28in A=10283 kN @ C=78in Anchor: C>17in HD: C>22in Quake_Aspen A=367 kN @ C=28in A=704 kN @ C=33in Anchor: C>15in HD: C>18in White_Ash A=394 kN @ C=28in A=2774 kN @ C=46in Anchor: C>15in HD: C>18in

Summary Table with helmet and full-size ratings from trees tested by 85 mph free air wind speed

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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 “Normally” rooted in “normal” forest soil (not sand, or clinging to edge of cliff)

  • Determine tree species

(or use limiting species applicable to area)

  • Measure circumference of tree

at 2 feet above ground

  • Check 2-year table for go/no-go

(confirm area and date range)

 Anchor very low on small trees Rules for applying “wind rating” to small trees  Tree is healthy, not structurally compromised  Symmetrical base & root tops  No voids, erosion or other root compromise  “Normally”

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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 “Normally” rooted in “normal” forest soil (not sand, or clinging to edge of cliff)

  • Determine tree species

(or use limiting species applicable to area)

  • Measure circumference of tree

at 2 feet above ground

  • Check 2-year table for go/no-go

(confirm area and date range)

 Anchor very low on small trees Rules for applying “wind rating” to small trees  Tree is healthy, not structurally compromised  Symmetrical base & root tops  No voids, erosion or other root compromise  “Normally”

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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Identify tree species,

  • r use largest Circumference

Minimum Circumference for ANCHOR Minimum Circumference for HIGH-D Ponderosa_Pine or UNKNOWN specie >23in >29in W.Red_Cedar >22in >29in Bigleaf_Maple >22in >29in W.Hemlock >22in >28in Smooth_Hickory >21in >26in Loblolly_Pine >20in >26in Red_Alder >20in >26in Douglas_Fir >20in >26in Water_Oak >20in >26in Engelmann_Spruce >20in >25in Quake_Aspen >17in >21in White_Ash >17in >21in Trees smaller than helmet-sized (28 in circumference) may be used as rescue anchors by following these criteria.

Applies from Mmm-20xx through Mmm-20xx

If in doubt about anchor integrity, use other material or back up anchors as appropriate.

 Tree is living & structurally sound  Tree has vertical trunk, including base  Rooted in normal soil (not sand or gravel), without voids  Tree has symmetrical base at ground level Measure circumference around tree @ 2 ft above ground (incl for H Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies [location description defining region familiar to rescue team] .

Identify tree species,

  • r use largest Circumference

Minimum Circumference

for ANCHOR

Minimum Circumference

for HIGH-D W.Red_Cedar or UNKNOWN species >24in >32in Trees smaller than helmet-sized (28 in circumference) may be used as rescue anchors by following these criteria.

Applies from Mmm-20xx through Mmm-20xx

If in doubt about anchor integrity, use other material or back up anchors as appropriate.

 Tree is living & structurally sound  Tree has vertical trunk, including base  Rooted in normal soil (not sand or gravel), without voids  Tree has symmetrical base at ground level Measure circumference around tree @ 2 ft above ground (incl for H Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies [location description defining region familiar to rescue team].

Field decision/measurement sheet for using small trees (limited by area and date)

Laminated in each rigging kit ITRS 2015 John Morton (water-rescue6@scvsar.org) Field Guide – front side

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Region: ITRS --- seasonal wind = 65 mph

Circumf (inches) wind tested at 65mph

Douglas_Fir Engelmann_Spruce Loblolly_Pine Ponderosa_Pine W.Hemlock W.Red_Cedar Bigleaf_Maple Quake_Aspen Red_Alder Smooth_Hickory Water_Oak White_Ash

14 9 8 8 5 6 6 6 12 7 7 8 13 15 11 11 10 6 8 7 8 16 9 9 10 17 16 14 14 12 8 10 9 10 22 12 11 13 22 17 17 17 15 10 12 12 12 28 15 14 16 28 18 21 20 18 12 15 14 15 36 18 17 19 36 19 25 25 22 15 18 17 18 44 23 21 23 45 20 30 30 27 17 21 20 21 55 27 26 28 56 21 35 36 33 21 26 24 25 67 32 31 34 70 22 41 42 39 25 30 28 29 81 39 36 39 85 23 48 50 45 29 34 33 34 98 45 42 46 103 24 55 58 53 33 40 38 39 115 52 48 55 121 25 62 68 60 39 46 44 45 135 61 56 64 143 26 71 77 70 45 52 50 51 160 69 65 73 167 27 81 90 79 51 59 57 57 183 79 75 84 193 28 94 102 91 59 67 64 65 214 91 86 94 230 29 105 118 102 66 76 73 73 239 104 99 108 257 30 121 134 117 75 85 81 81 281 121 111 120 297

Send NewGuy up ahead of the rigging team to measure and flag trees pink

pink

  • r gree

een,

labelled as: WIND TESTED @ 31 kN

(shown for 2-ft high anchor)

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Field Guide – reverse side

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SLIDE 23

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WIND TESTED @ 53kN

 More anchor choices  Faster setup  Use (and carry) less gear  Better rope alignment  Less potential for rope damage  Less rope stretch

So, once we broaden our view…

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WIND TESTED @ 53kN

101kN 19kN 161kN 10kN 20kN 29kN 13kN 46kN 8kN

 More anchor choices  Faster setup  Use (and carry) less gear  Better rope alignment  Less potential for damage  Less rope stretch

Wind tells us about credible rescue anchors

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Anchor ratings at 2 ft high

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Me & My Team

  • Add to & refine tree species aerodynamic profiles
  • Measurements during high wind to calibrate turbulence model
  • Improve methodology based on comments and suggestions?
  • Add profiles for high wind with leaves on deciduous species??

You & Your Team

  • Decide for yourself if tree anchor data is useful to your team
  • Send questions, suggestions & tree species of interest to:

John Morton, email: water-rescue6@scvsar.org

Next Steps…

Shave some conservatism & Deploy into the field

ITRS 2015

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SLIDE 26

Typical ITRS caveats

  • More testing and research is good (and ongoing)
  • Carefully consider new data, and apply it prudently
  • Do the right thing for your team & your mission

Conclusions

  • Helmet size as a go/no-go anchor criteria is too conservative
  • Smaller trees are credible rescue anchors based on having

survived wind loading, allowing more effective rope systems

  • Model results are consistent with testing to date
  • As always, decisions during rescue operations must align with

training and field-appropriate tactics

NO SCIENCE PROJECTS DURING RESCUE MISSIONS!

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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SLIDE 27

Trees do have wind ratings in kN!

John Morton Snohomish County SAR Everett Mountain Rescue

water-rescue6@scvsar.org

53kN

tested

ITRS 2015

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SLIDE 28

Questions?

John Morton

Snohomish County SAR / Everett Mountain Rescue water-rescue6@scvsar.org

Turbulence model Aerodynamic model Results tables Results summary Anchor limits Model MAGIC! ITRS Region Field Guide Conclusions & Next Steps Central Cascade

(west slopes)

Field Guide Getting a Field Guide for other regions & species

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Modeling “Wind Rating” on smaller trees

1) wind impacting particular tree? 2) force on tree from that wind? 3) load on rescue anchor with equivalent force

Red-green tree species living within gray tree canopy. Force on green sized tree?

FREE AIR WIND

Turbulence

reduces effective wind

  • n smaller trees

lower in canopy ?

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Modeling Aerodynamic Profile

FREE AIR WIND

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Aero profile is narrower than tree

  • utline to reflect

wind passing through branches

Particular tree modeled as cylinders connected on a spindle. Wind on each cylinder

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Modeling “Wind Rating” on smaller trees

1) wind impacting particular tree? 2) force on tree from that wind? 3) load on rescue anchor with equivalent force

Particular tree modeled as cylinders connected on a spindle. Wind on each cylinder

FREE AIR WIND

Turbulence

reduces effective wind lower in canopy ?

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SLIDE 32

FREE AIR WIND

From ground level, line up aerodynamic profile of particular tree with turbulence profile of canopy

“Wind Rating” on smaller trees

1)wind impacting particular tree? 2)force on tree from that wind? 3)load on rescue anchor with equivalent force Particular tree modeled as cylinders connected on a spindle. Wind on each cylinder ?

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SLIDE 33

FREE AIR WIND

“Wind Rating” on smaller trees

1)wind impacting particular tree? 2)force on tree from that wind? 3)load on rescue anchor with equivalent force Calculate force on each cylinder along spindle, based on lever arm and wind at height ?

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SLIDE 34

FREE AIR WIND

“Wind Rating” on smaller trees

1)wind impacting particular tree? 2)force on tree from that wind? 3)load on rescue anchor with equivalent force Engineering: wind load on cylinder at height Calculate force on each cylinder along spindle, based on lever arm and wind at height ?

Other details:

  • Unit conversion to SI/metric
  • Deflection angle for upper part of

“bendy” species (e.g. Aspen)

  • Derating for species with failure-prone

root systems (e.g. Alder, Hemlock)

effective wind lower in canopy

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“Wind Rating” on smaller trees

1)wind impacting particular tree? 2)force on tree from that wind? 3)load on rescue anchor with equivalent force

__kN Convert bending force from wind load applied at height to equivalent force applied at 2 anchor points:

0.6m high, horizontal pull 2m high, 45 deg down pull

Repeat for each tree segment to determine equivalent anchor loading

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SLIDE 36

But wait! Don’t order yet because you also get…

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ITRS 2015 John Morton (water-rescue6@scvsar.org)

Region: CentCascade --- seasonal wind = 75 mph

Circumf (inches) wind tested at 75mph

AK.Yellow_Cedar Douglas_Fir Pacific_Yew Ponderosa_Pine Silver_Fir Sitka_Spruce W.Hemlock W.Red_Cedar W.White_Pine Bigleaf_Maple Black_Cottonwood Red_Alder

14 6 12 7 7 8 6 8 8 6 8 11 10 15 8 15 9 9 10 7 10 10 8 10 14 12 16 11 19 11 11 12 9 13 12 10 13 17 16 17 13 23 14 13 15 12 17 16 12 16 21 20 18 16 28 17 16 18 14 20 19 15 20 25 25 19 19 34 21 20 22 18 24 23 18 24 30 30 20 23 40 25 23 26 21 29 27 21 28 36 36 21 27 47 29 28 31 25 34 33 26 33 42 43 22 32 55 34 33 36 30 40 38 31 39 49 52 23 37 63 39 39 43 36 46 45 36 45 57 60 24 42 73 45 45 50 41 53 51 42 52 65 70 25 49 83 52 52 57 47 61 59 49 60 74 81 26 55 94 59 60 67 54 69 67 55 68 87 92 27 63 108 66 68 75 61 78 76 64 77 101 106 28 72 125 75 78 87 70 89 86 72 86 114 121 29 81 140 84 88 100 78 101 97 82 97 131 139 30 92 161 94 100 111 87 113 109 92 108 146 161

Identify tree species,

  • r use largest Circumference

Minimum Circumference

for ANCHOR

Minimum Circumference

for HIGH-D Sitka_Spruce or UNKNOWN species >21in >28in W.White_Pine >21in >28in AK.Yellow_Cedar >21in >28in Pacific_Yew >20in >27in Ponderosa_Pine >20in >27in Silver_Fir >20in >26in W.Red_Cedar >20in >26in Bigleaf_Maple >19in >26in W.Hemlock >19in >26in Black_Cottonwood >18in >24in Red_Alder >18in >24in Douglas_Fir >17in >24in Trees smaller than helmet-sized (28 in circumference) may be used as rescue anchors by following these criteria.

Applies from Dec-2014 through Oct-2016

If in doubt about anchor integrity, use other material or back up anchors as appropriate.

 Tree is living & structurally sound  Tree has vertical trunk, including base  Rooted in normal soil (not sand or gravel), without voids  Tree has symmetrical base at ground level Measure circumference around tree @ 2 ft above ground (incl for H Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies north of White River (Enumclaw), and west of Cascade crest.

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SLIDE 37 AK.Yellow_Cedar Rating of horizontal anchor at 0.6m (kN) Complete: 10/7/2015 10:25:37 PM C \Wind 35 40 45 50 55 60 65 70 75 80 85 90 14 1.5 2.0 2.5 3.1 3.7 4.5 5.2 6.1 7.0 7.9 8.9 10.0 15 1.9 2.5 3.2 3.9 4.8 5.7 6.7 7.7 8.9 10.1 11.4 12.8 16 2.4 3.2 4.0 4.9 6.0 7.1 8.4 9.7 11.1 12.7 14.3 16.0 17 2.9 3.8 4.9 6.0 7.3 8.7 10.2 11.8 13.5 15.4 17.4 19.5 18 3.6 4.7 5.9 7.3 8.9 10.6 12.4 14.4 16.5 18.8 21.2 23.8 19 4.3 5.6 7.1 8.7 10.6 12.6 14.8 17.1 19.6 22.3 25.2 28.3 20 5.1 6.7 8.5 10.4 12.6 15.0 17.6 20.5 23.5 26.7 30.2 33.8 21 6.0 7.8 9.9 12.2 14.8 17.6 20.6 23.9 27.5 31.3 35.3 39.6 22 7.0 9.2 11.6 14.4 17.4 20.7 24.3 28.2 32.3 36.8 41.5 46.5 23 8.1 10.6 13.4 16.6 20.0 23.9 28.0 32.5 37.3 42.4 47.9 53.7 24 9.3 12.2 15.4 19.0 23.0 27.4 32.1 37.2 42.7 48.6 54.9 61.6 25 10.7 14.0 17.7 21.9 26.5 31.5 37.0 42.9 49.3 56.1 63.3 71.0 26 12.2 15.9 20.1 24.9 30.1 35.8 42.0 48.7 55.9 63.6 71.8 80.5 27 13.7 18.0 22.7 28.1 34.0 40.4 47.4 55.0 63.1 71.8 81.1 90.9 28 15.8 20.6 26.1 32.2 39.0 46.4 54.4 63.1 72.5 82.5 93.1 104 29 17.7 23.1 29.2 36.1 43.6 51.9 60.9 70.7 81.1 92.3 104 117 30 20.0 26.2 33.1 40.9 49.5 58.9 69.1 80.2 92.0 105 118 133 31 22.3 29.1 36.8 45.4 55.0 65.4 76.8 89.1 102 116 131 147 32 25.1 32.8 41.6 51.3 62.1 73.9 86.7 101 115 131 148 166 33 28.6 37.3 47.2 58.3 70.5 83.9 98.5 114 131 149 168 189 34 31.4 41.1 52.0 64.2 77.6 92.4 108 126 144 164 185 208 35 34.5 45.1 57.1 70.4 85.2 101 119 138 158 180 204 228 36 38.7 50.5 63.9 78.9 95.5 114 133 155 178 202 228 256 37 42.2 55.2 69.8 86.2 104 124 146 169 194 221 249 279 38 47.1 61.5 77.8 96.1 116 138 162 188 216 246 278 311 AK.Yellow_Cedar Rating of High-D at 2m pulled 45deg (kN) Complete: 10/7/2015 10:25:37 PM C \Wind 35 40 45 50 55 60 65 70 75 80 85 90 14 0.6 0.8 1.0 1.2 1.5 1.8 2.1 2.4 2.8 3.2 3.6 4.0 15 0.8 1.0 1.3 1.6 1.9 2.3 2.7 3.1 3.6 4.1 4.6 5.1 16 1.0 1.3 1.6 2.0 2.4 2.9 3.4 3.9 4.5 5.1 5.8 6.5 17 1.2 1.6 2.0 2.4 2.9 3.5 4.1 4.7 5.5 6.2 7.0 7.9 18 1.4 1.9 2.4 3.0 3.6 4.3 5.0 5.8 6.6 7.6 8.5 9.6 19 1.7 2.3 2.8 3.5 4.3 5.1 5.9 6.9 7.9 9.0 10.2 11.4 20 2.1 2.7 3.4 4.2 5.1 6.1 7.1 8.2 9.5 10.8 12.2 13.6 21 2.4 3.1 4.0 4.9 6.0 7.1 8.3 9.6 11.1 12.6 14.2 15.9 22 2.8 3.7 4.7 5.8 7.0 8.3 9.8 11.3 13.0 14.8 16.7 18.7 23 3.3 4.3 5.4 6.7 8.1 9.6 11.3 13.1 15.0 17.1 19.3 21.6 24 3.8 4.9 6.2 7.7 9.3 11.0 12.9 15.0 17.2 19.6 22.1 24.8 25 4.3 5.6 7.1 8.8 10.7 12.7 14.9 17.3 19.9 22.6 25.5 28.6 26 4.9 6.4 8.1 10.0 12.1 14.4 16.9 19.6 22.5 25.6 28.9 32.4 27 5.5 7.2 9.2 11.3 13.7 16.3 19.1 22.2 25.4 28.9 32.7 36.6 28 6.4 8.3 10.5 13.0 15.7 18.7 21.9 25.4 29.2 33.2 37.5 42.0 29 7.1 9.3 11.8 14.5 17.6 20.9 24.5 28.5 32.7 37.2 42.0 47.1 30 8.1 10.5 13.3 16.5 19.9 23.7 27.8 32.3 37.1 42.2 47.6 53.4 31 9.0 11.7 14.8 18.3 22.2 26.4 30.9 35.9 41.2 46.9 52.9 59.3 32 10.1 13.2 16.7 20.7 25.0 29.8 34.9 40.5 46.5 52.9 59.8 67.0 33 11.5 15.0 19.0 23.5 28.4 33.8 39.7 46.0 52.8 60.1 67.9 76.1 34 12.7 16.5 20.9 25.9 31.3 37.2 43.7 50.7 58.2 66.2 74.7 83.8 35 13.9 18.2 23.0 28.4 34.3 40.9 48.0 55.6 63.9 72.6 82.0 91.9 36 15.6 20.4 25.8 31.8 38.5 45.8 53.7 62.3 71.6 81.4 91.9 103 37 17.0 22.2 28.1 34.7 42.0 50.0 58.7 68.1 78.2 88.9 100 113 38 19.0 24.8 31.4 38.7 46.8 55.7 65.4 75.9 87.1 99.1 112 125

Anchor rating tables High-D rating tables

Up to 12 tree species

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But wait! Don’t order yet because you also get…

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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SLIDE 38

OK, now you can order.

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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SLIDE 39

Region: CentCascade --- seasonal wind = 75 mph

Circumf (inches) wind tested at 75mph

AK.Yellow_Cedar Douglas_Fir Pacific_Yew Ponderosa_Pine Silver_Fir Sitka_Spruce W.Hemlock W.Red_Cedar W.White_Pine Bigleaf_Maple Black_Cottonwood Red_Alder

14 6 12 7 7 8 6 8 8 6 8 11 10 15 8 15 9 9 10 7 10 10 8 10 14 12 16 11 19 11 11 12 9 13 12 10 13 17 16 17 13 23 14 13 15 12 17 16 12 16 21 20 18 16 28 17 16 18 14 20 19 15 20 25 25 19 19 34 21 20 22 18 24 23 18 24 30 30 20 23 40 25 23 26 21 29 27 21 28 36 36 21 27 47 29 28 31 25 34 33 26 33 42 43 22 32 55 34 33 36 30 40 38 31 39 49 52 23 37 63 39 39 43 36 46 45 36 45 57 60 24 42 73 45 45 50 41 53 51 42 52 65 70 25 49 83 52 52 57 47 61 59 49 60 74 81 26 55 94 59 60 67 54 69 67 55 68 87 92 27 63 108 66 68 75 61 78 76 64 77 101 106 28 72 125 75 78 87 70 89 86 72 86 114 121 29 81 140 84 88 100 78 101 97 82 97 131 139 30 92 161 94 100 111 87 113 109 92 108 146 161

Identify tree species,

  • r use largest Circumference

Minimum Circumference

for ANCHOR

Minimum Circumference

for HIGH-D Sitka_Spruce or UNKNOWN species >21in >28in W.White_Pine >21in >28in AK.Yellow_Cedar >21in >28in Pacific_Yew >20in >27in Ponderosa_Pine >20in >27in Silver_Fir >20in >26in W.Red_Cedar >20in >26in Bigleaf_Maple >19in >26in W.Hemlock >19in >26in Black_Cottonwood >18in >24in Red_Alder >18in >24in Douglas_Fir >17in >24in Trees smaller than helmet-sized (28 in circumference) may be used as rescue anchors by following these criteria.

Applies from Dec-2014 through Oct-2016

If in doubt about anchor integrity, use other material or back up anchors as appropriate.

 Tree is living & structurally sound  Tree has vertical trunk, including base  Rooted in normal soil (not sand or gravel), without voids  Tree has symmetrical base at ground level Measure circumference around tree @ 2 ft above ground (incl for H Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies north of White River (Enumclaw), and west of Cascade crest.

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    

 Actual Silvics-listed tree species, 12 max  Full-rated anchor in your agency (kN)

 Free air wind, near-maximum this season

John Morton (water-rescue6@scvsar.org)

 Very short text defining your region  Date range 2 years max

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SLIDE 40

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SLIDE 41

? From previous local wind data monitoring, wind in foothills & backcountry ≥ KPAE+12mph 11-Dec-2014: KPAE=61mph. Free air wind=73mph

Example: Determine your Free Air Wind speed for your area based

  • n published weather

data, such as WeatherUnderground historical records

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SLIDE 42

Wind rating Field Guide for Cascade Mountains north of Seattle

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ITRS 2015 John Morton (water-rescue6@scvsar.org)

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Region: CentCascade --- seasonal wind = 75 mph

Circumf (inches) wind tested at 75mph

AK.Yellow_Cedar Douglas_Fir Pacific_Yew Ponderosa_Pine Silver_Fir Sitka_Spruce W.Hemlock W.Red_Cedar W.White_Pine Bigleaf_Maple Black_Cottonwood Red_Alder

14 6 12 7 7 8 6 8 8 6 8 11 10 15 8 15 9 9 10 7 10 10 8 10 14 12 16 11 19 11 11 12 9 13 12 10 13 17 16 17 13 23 14 13 15 12 17 16 12 16 21 20 18 16 28 17 16 18 14 20 19 15 20 25 25 19 19 34 21 20 22 18 24 23 18 24 30 30 20 23 40 25 23 26 21 29 27 21 28 36 36 21 27 47 29 28 31 25 34 33 26 33 42 43 22 32 55 34 33 36 30 40 38 31 39 49 52 23 37 63 39 39 43 36 46 45 36 45 57 60 24 42 73 45 45 50 41 53 51 42 52 65 70 25 49 83 52 52 57 47 61 59 49 60 74 81 26 55 94 59 60 67 54 69 67 55 68 87 92 27 63 108 66 68 75 61 78 76 64 77 101 106 28 72 125 75 78 87 70 89 86 72 86 114 121 29 81 140 84 88 100 78 101 97 82 97 131 139 30 92 161 94 100 111 87 113 109 92 108 146 161

Identify tree species,

  • r use largest Circumference

Minimum Circumference

for ANCHOR

Minimum Circumference

for HIGH-D Sitka_Spruce or UNKNOWN species >21in >28in W.White_Pine >21in >28in AK.Yellow_Cedar >21in >28in Pacific_Yew >20in >27in Ponderosa_Pine >20in >27in Silver_Fir >20in >26in W.Red_Cedar >20in >26in Bigleaf_Maple >19in >26in W.Hemlock >19in >26in Black_Cottonwood >18in >24in Red_Alder >18in >24in Douglas_Fir >17in >24in Trees smaller than helmet-sized (28 in circumference) may be used as rescue anchors by following these criteria.

Applies from Dec-2014 through Oct-2016

If in doubt about anchor integrity, use other material or back up anchors as appropriate.

 Tree is living & structurally sound  Tree has vertical trunk, including base  Rooted in normal soil (not sand or gravel), without voids  Tree has symmetrical base at ground level Measure circumference around tree @ 2 ft above ground (incl for H Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies north of White River (Enumclaw), and west of Cascade crest.

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SLIDE 43

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Identify tree species,

  • r use largest Circumference

Minimum Circumference

for ANCHOR

Minimum Circumference

for HIGH-D Sitka_Spruce or UNKNOWN species >21in >28in W.White_Pine >21in >28in AK.Yellow_Cedar >21in >28in Pacific_Yew >20in >27in Ponderosa_Pine >20in >27in Silver_Fir >20in >26in W.Red_Cedar >20in >26in Bigleaf_Maple >19in >26in W.Hemlock >19in >26in Black_Cottonwood >18in >24in Red_Alder >18in >24in Douglas_Fir >17in >24in

Applies from Dec-2014 through Oct-2016

    Ratings based on ANCHOR @ 2 ft and HIGH-D @ 7 ft

Wind rating data applies north of White River (Enumclaw), and west of Cascade crest.

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SLIDE 44

Region: CentCascade --- seasonal wind = 75 mph

Circumf (inches) wind tested at 75mph

AK.Yellow_Cedar Douglas_Fir Pacific_Yew Ponderosa_Pine Silver_Fir Sitka_Spruce W.Hemlock W.Red_Cedar W.White_Pine Bigleaf_Maple Black_Cottonwood Red_Alder

14 6 12 7 7 8 6 8 8 6 8 11 10 15 8 15 9 9 10 7 10 10 8 10 14 12 16 11 19 11 11 12 9 13 12 10 13 17 16 17 13 23 14 13 15 12 17 16 12 16 21 20 18 16 28 17 16 18 14 20 19 15 20 25 25 19 19 34 21 20 22 18 24 23 18 24 30 30 20 23 40 25 23 26 21 29 27 21 28 36 36 21 27 47 29 28 31 25 34 33 26 33 42 43 22 32 55 34 33 36 30 40 38 31 39 49 52 23 37 63 39 39 43 36 46 45 36 45 57 60 24 42 73 45 45 50 41 53 51 42 52 65 70 25 49 83 52 52 57 47 61 59 49 60 74 81 26 55 94 59 60 67 54 69 67 55 68 87 92 27 63 108 66 68 75 61 78 76 64 77 101 106 28 72 125 75 78 87 70 89 86 72 86 114 121 29 81 140 84 88 100 78 101 97 82 97 131 139 30 92 161 94 100 111 87 113 109 92 108 146 161

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SLIDE 45

Region: CentCascade --- seasonal wind = 75 mph

Circumf (inches) wind tested at 75mph

AK.Yellow_Cedar Douglas_Fir Pacific_Yew Ponderosa_Pine Silver_Fir Sitka_Spruce W.Hemlock W.Red_Cedar W.White_Pine Bigleaf_Maple Black_Cottonwood Red_Alder

14 6 12 7 7 8 6 8 8 6 8 11 10 15 8 15 9 9 10 7 10 10 8 10 14 12 16 11 19 11 11 12 9 13 12 10 13 17 16 17 13 23 14 13 15 12 17 16 12 16 21 20 18 16 28 17 16 18 14 20 19 15 20 25 25 19 19 34 21 20 22 18 24 23 18 24 30 30 20 23 40 25 23 26 21 29 27 21 28 36 36 21 27 47 29 28 31 25 34 33 26 33 42 43 22 32 55 34 33 36 30 40 38 31 39 49 52 23 37 63 39 39 43 36 46 45 36 45 57 60 24 42 73 45 45 50 41 53 51 42 52 65 70 25 49 83 52 52 57 47 61 59 49 60 74 81 26 55 94 59 60 67 54 69 67 55 68 87 92 27 63 108 66 68 75 61 78 76 64 77 101 106 28 72 125 75 78 87 70 89 86 72 86 114 121 29 81 140 84 88 100 78 101 97 82 97 131 139 30 92 161 94 100 111 87 113 109 92 108 146 161

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Field Guide – reverse side

After tested by 75mph wind, 24-inch circumference West.Hemlock

(smaller than helmet)

is more than adequate for a rescue anchor WIND TESTED @ 53 kN

(shown for 2-ft high anchor)

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SLIDE 46

WIND TESTED @ 23158 kN (96mph) FAILED ≤29309 kN (108mph)

101kN 19kN 161kN 10kN 20kN 29kN 13kN 46kN 8kN

Douglas Fir survived 96mph, then failed ≤ 108mph 2 yr later. Note: eroded terrain at roots Info: 108mph wind would give wind rating on “helmet” tree of 88kN (if inside 2 yr window)

Wind tells us about credible rescue anchors

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Anchor ratings at 2 ft high

PINK and GREEN ratings at 75mph

53kN

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SLIDE 47

Trees do have wind ratings in kN!

John Morton Snohomish County SAR Everett Mountain Rescue

water-rescue6@scvsar.org

53kN

tested

ITRS 2015 John Morton (water-rescue6@scvsar.org)

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