The Pole Vault Pole

ByMatt Shuler

ECIV 303: Fall 2010

Pole Vaulting

• Pole Vaulting: An event in track and field in which an athlete known as a “vaulter” uses a pole to propel them over a cross bar.

• The athlete must run while holding the pole, plant the pole in a rigid box in the ground and jump off the ground at the same time, and then perform a gymnastic maneuver to propel them over the bar.

• World Record: Men: 6.15m (20’2”) Women: 5.06m (16’8”)

wais.org.au polevaultpower.com

Life.com

Polevaultpower.com

Life.com doitpoms.ac.uk

Box Dimensions

http://www.npvca.com

So What Must a Pole Go Through??????

GOOD!

Lojovaultassualt.com

Not Good!

Pole Range of Motion

• Bending Pole– Material on Tension Side

must Stretch-180 Degree Bend: Must Stretch 2.18%

– Material on Compression Side must Compress-180 Degree Bend: Must Compress 2.2%

– Pole Must Start to Oval-1.5% Decrease in axis length in tension/compression plane.

Ekevadand Lundberg J Biomech, 30, 259 (1997)

http://coachr880.com/id87.html

Materials of Choice

Fiberglass• Material made from extremely fine

fibers of glass.• Types of Fiberglass used:

– E-Glass-Tensile Strength: 3,450 MPa d Density: 2.57 g/cm^3

– S-Glass-Tensile Strength: 4,710 MPa d Density: 2.48 g/cm^3

– Both Types: Tensile Strength=Compressive Strength

Carbon Fiber• An extremely strong, thin fiber,

consisting of long, chainlike molecules of pure carbon that are made by charring synthetic fibers such as rayon in the absence of oxygen.

• Carbon Fiber- Tensile Strength: 5,650 MPa d Density: 1.75 g/cm^3

• 4x Rigidity of Fiberglass• 2/3 Compressive Strength of

Fiberglass but depends on how alignment of material

• Cost more than fiberglass

gltproducts.com

Tensile Stress vs. Percent Strain

Jeff Watry: Pole Vault And The Pole

The Pole Making Process

• Vaulting Poles Range in Length from 10’-17’• The “Stiffness” of a pole given its length

depends on the diameter of the pole• Poles are measured to correspond to a

vaulter’s body weight-to account for a factor of load-(the vaulters body weight moving as the vaulter leaves the ground)

The Pole Making ProcessStep: 1

• Choose Mandrel Size– Hollow steel tube-sized for the

length and inner diameter of the pole

• 1st Layer of Material– Mandrel is rapped cress-cross

style in both directions with chosen material : resin impregnated fiberglass or carbon fiber

– Resin-hydrocarbon secretion: used for adhesive properties

– 1st Layer: Gives pole flexibility, durability, and fortifies pole circumference

howitsmade.com

The Pole Making ProcessStep 2

• Cut Fiberglass/Carbon Fiber Patterns are heat rolled onto the mandrel-resin helps it bond.

• Sail Piece is added last– Controls how the pole bends

Bruce Caldwell-EssX Poles

The Pole Making ProcessStep 3

• Mandrel and Fiberglass are put into a oven– Stage 1: Steam is used to heat

the oven to 175° F• This liquefies the resin so

that it resaturates the fiberglass

– Stage 2: Oven gradually rises to 300 ° F• This solidifies the

resin-”curing” it• Curing-toughening or

hardening

Bruce Caldwell-EssX Poles

The Pole Making ProcessStep 4

• Pole is then subject to a stress test– Stress Test- Tests pole for

deformities and defects: pole will fail if any defects are present

– Stress Test- Puts a permanent natural bend in the pole: poles are only meant to bend one way• Gives the pole a soft side

and stiff side

howitsmade.com

The Pole Making ProcessStep 5

• Pole is given a “Flex Number”– Flex Number Test: Pole is

supported 6” on both ends of the pole. A 50lb weight is then added to the mid point of the pole. The distance in cm that the pole deforms is the flex number.

– Flex Number are used to help vaulter transition form one pole to the next.

– Flex Numbers are used to only measure relative stuffiness, not the total load that the pole can support

Pole Failure

Causes of Failure• Overload

– When vaulter applies more force than the pole can withstand

– When pole is overloaded: the pole will develop “bruises” or permanent deformations in the fibers-eventually leading to failure

• Fatigue– Crack-caused by a strike to the

pole-failure usually happens on the tension side of the pole

elitetrack.com

uytierra.blogspot.com

Works Cited

• Jeff Watry: Pole Vault and The Pole– http://www.stabhoch.com/epvc/polevaultandthepole.p

df• INFORMATION FOR TRACK & FIELD/ATHLETICS

COACHES Athletics Outstanding Performer---The Vaulting Pole– http://coachr880.com/id87.html

• Bruce Caldwell- Essx Poles– http://www.essxpv.com/

• How its Made– www.howitsmade.com