Protect a Load Mat Testing
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Protect A Load

Protect A Load Friction Mat Testing

Date : 16/01/2018
Ref: E00728
Author: Paul Dore,
BEMech, MIEAUST
Logistics Engineer, Engistics
Tel 0437 988 148
Reviewed: Mike Robertson
BEMech, CPEng, RPEQ
Managing Director, Engistics
Tel 0425 001 086

Report Contents/Overview

  • Friction Mat TestingIntroduction and Purpose of Testing
  • Background – Tie Down Restraint
  • Equipment and Set-up
  • Methodology
  • Results and Observations
  • Conclusion

Introduction/Purpose of Testing

  • Engistics has been engaged by Protect A Load to assist with testing the
    coefficient of friction of their Transport load matting (“Protect A Load Friction
    Matting”).
  • Typical Australian trailer decks are made of steel and load matting is used to improve the grip between the load and the steel deck.
  • The friction coefficient is a measure of the ‘grip’ between two surfaces. To
    determine this friction coefficient, we conduct tests by dragging loads and measuring the forces involved.
  • Tests to determine the friction coefficient have been conducted in both wet and dry conditions.
  • The test results published in this report only apply to the particular type of matting tested.
  • Protect A Load should be aware that these results do not apply to other
    types of matting/rubber and should ensure matting types and manufacturer/suppliers are not changed without confirming equivalent friction.

Background – Tie-down Restraint

  • Understanding Friction is critical for the tie-down method
  • Friction is the force that resists motion (grips) between two surfaces

Background Tie Down Restraint

The Straps pull DOWN! and Friction Holds the Load BACK!

Friction is a function of only:

  • The friction factor (Usually called the
    friction Coefficient) – the “grip” between two
    surfaces, and
  • The down-force

Down-force is a combination of:

  • The weight of the object
  • The vertical

Background Tie-down Restraint

Equipment and Test Setup:

Equipment and Test Setup

  • To measure the friction coefficient, a steel drum has been dragged across the matting.
  • The force required to drag the drum compared to the actual weight of the drum is a measure of the friction coefficient

Friction Coefficient = Drag Force (kg.f) / Drum Weight (kg)

Equipment and Test Setup:
Load Cell Calibration Certificate

Equipment and Test Setup: Load Cell Calibration Certificate

Equipment and Test Setup: Load Cell Calibration Certificate

Equipment and Test Setup: Load Cell Calibration Certificate

Equipment and Test Setup: Test Weight Measurement

Equipment and Test Setup

  • The steel drum was measured to be 733kg.
  • The drum was observed to be smooth on the underside and free of significant corrosion.

Methodology:

Methodology

Methodology

  • The load cell was setup in-line with the load.
  • The ‘Peak hold’ function was used to measure the tension at the point of load movement.
  • 5x tests were repeated with both wet and dry matting
  • The static friction coefficient was determined as below:

Friction Coefficient = Drag Force (kg.f) / Drum Weight (kg)

Methodology

  • Generous amounts of water were poured onto the rubber (below the drum) before repeating the test.
  • Lower friction coefficients were observed with water on the surface of the rubber.

Methodology

Results and Observations:

Results and Observations

Tests showed pleasing consistency of results.

Photo of test surface – After test Completion

Results and Observations

  • The mat surface was smooth and free of any surface wearing on completion of the test.
  • The drum did not bite into the matting. Results obtained are a true value of the steel/load mat friction coefficient.

Conclusion

  • The average coefficient of friction between the Friction Matting and a steel drum was determined to be μ=0.67 dry and μ = 0.6 wet
  • Engistics recommends utilising the wet coefficient of friction only for determining tie down restraints.
  • Testing has shown the rubber to be capable of achieving a consistent high level of friction.
  • Results and ObservationsPlease note that to achieve adequate restraint, additional consideration needs to be given to:
  1. Blocking
  2. Pre-tension
  3. Lashing Angles
  4. Weight of the Load