Load Restraint for Managers
(Both Consignors and
Transport Company Managers!)
File name: LR for Managers 13Aug14.pdf Our Ref:
Mike Robertson MD & Eng Mgr 0425 001 086 [email protected]
About this Pack
Please Note:
The technical advice on Chain of Responsibility and Load Restraint in this pack, is intended for general educational purposes only, and does not constitute
certified engineering advice for any particular situation.
The Intellectual Property herein is owned by Engistics Pty Ltd and is supplied on the condition that it not be used for commercial gain, or resold in any manner
without our written permission. Queries may be directed to: Mike Robertson, Engineering Mgr
0425 001 086
Load Restraint is part of your CoR
u The Chain of Responsibility
covers Mass, Loading & Dimensions, so it includes Load Restraint.
u Court Cases show that
CONSIGNORS do have a clear responsibility to ensure that Load Restraint complies
u If you freight is specialised /
difficult, this obligation is more onerous
u Proper Packaging is part of
Consignors responsibility 3
The large consignor, transport company and driver were ALL guilty after this 2011 fatality
Load Restraint is part of your CoR
u Minimum = check transport company practices,
if in doubt = seek certification
u Best practice = Consignors develop their own LR guidelines for
their products (gives common Carrier standards and removes driver guesswork)
u Consignors Beware:
u Load shift = rollover
u High CoG loads = rollover
Fatal rollover 2012 = Consignor in Court late 2014
u Codes of Practice are
The law is worded:
Loads must be restrained to prevent unacceptable movement during all
expected conditions of operation. The load restraint system must, therefore, satisfy the following requirements:
i. The load should not become dislodged from the vehicle.
ii. Any load movement should be limited, such that in all cases where
movement occurs, the vehicle’s stability and weight distribution cannot be adversely affected and the load cannot become dislodged from the vehicle. Loads that are permitted to move relative to the vehicle include loads that are effectively contained within the sides or enclosure of the vehicle body such as:
a) Loads which are restrained from moving horizontally (limited vertical movement is permissible);
b) Very lightweight objects or loose bulk loads (limited horizontal and vertical movement is permissible);
c) Bulk liquids (limited liquid movement is permissible);
Load Restraint Law
6
Based upon Performance Standards
To achieve the movement limits from the previous page:
u The law is based on “minor crash” G-Forces
u Loads must be restrained against forces equal to:
0.8g 80% of the weight forwards 0.5g 50% of the weight rearwards 0.5g 50% of the weight to either side 0.2g 20% of the weight upwards Don’t forget…..
And so that the vehicle's stability is not adversely affected
Load Restraint and CoR
Consignors
u Confirm that Transport Companies are competent and compliant
u Large volume or specialised freight is best done by Company based LR guideline sheets (eg steel industry)
u Loaders trained to avoid obvious faults
Transport Companies must have: u SOPs / Guidelines
u Good LR equipment
u Driver training
u Specific task? = specialised equipment!
Truck drivers
u Trained in “why” and “how”
Receivers – must report issues! 7
Visual based LR guides are best
16 tonne with only 1 chain, but safe, legal and very efficient!
Types of Load Restraint
l Many loads in Australia use tie-downs. l Friction is critical for the tie-down method
l Most general freight is contained / blocked to comply
9
Friction is Critical
Friction is a function of only:
l The friction factor (Usually called the
friction Coefficient) – the “grip” between two surfaces, and
l The down-force
– Down-force is a combination of:
● The weight of the object
+
● The vertical force down from
lashing tension Ff = µ x Down-force Down-force = M x g + Ft
M
F
tF
fFriction factor between the surfaces,
“
µ
“
LOAD RESTRAINT - Case Study
Forward Sliding Forces- 10 tonne Load
60 degrees
45 degrees
Sliding resistance due to friction from weight alone
Sliding resistance due to friction from one chain clamping
8.0 tf 6.0 tf Emergency Braking Friction µ = 0.40 1 Chain @ 45 degrees 4.0 tf 5.5 tf 7.0 tf 8.5 tf 2 3 Forward
Force Restraint Forces Timber Pallet
5.0 tf
8mm Tpt chains @ 45 degrees
11
LOAD RESTRAINT - Case Study
8.0 tf 6.0 tf Emergency Braking Friction µ= 0.25 1 Chain 2 3 4.5 tf 3.5 tf 2.5 tf Friction µ = 0.40 1 Chain @ 45 degrees 4.0 tf 5.5 tf 7.0 tf 8.5 tf 2 3 5.5 tf Friction is more important than the number of Lashings! Forward Force Restraint Forces Timber Pallet Restraint Forces Galv. Steel Pallet 5.0 tf 60 degrees 45 degrees 1 Chain Friction µ= 0.60 9.0 tf 6.0 tf Restraint Forces Anti-slip Matting
Forward Sliding Forces - 10 tonne Load
Containment of General Freight
The classic question :
u Should we strap the Gates?
OR
u Strap the Freight?
OR
u Buy Load Rated Curtains and “Never need Straps again* ”?
12
Containment of General Freight
Question:
u Should we strap the Gates or the Freight?
Answers
u There is no such thing as standard gates
in Australia
u Road Authorities just assume that gates
are adequate
u Unstrapped gates only OK for about
200-250kg pallets
u Strapping over the gates almost triples
their sideways capacity, so ~ 600kg/pallet
13
Gates have usually only 2 off 50 x 8mm flat bars as the retaining feet – &
bend very easily. This gate is wrongly
reversed
Containment of General Freight
Answers
u Typical Ratings are:
u Ensure that all gates are
in good working order
u Consider specifying
better quality gates and insist on a load rating
u FULLY contained loads
do NOT need to have lashings for 0.2g up 300kg 300kg 600kg 600kg 600kg 600kg
u Pallets >600kg MUST be lashed over the freight, or
have superior gates
Typical limits for “dumb” gates
Containment of General Freight
Load Rated Curtains:
u Good solution for FULL loads, single drop, no gap
u Poor solution for PART loads, multi drops, gaps
u Mediocre solution for multi drop of small boxes
u Check the ratings, Mass per pallet Space or Width?
u Beware any rating that specifies pallet type
= poor design assumptions
u Always fit anchor points for manual lashings inside
the curtain (to secure part loads)
u Consider the ALC Curtain guideline
Failure Risk Vs Speed
17
Forward Force and Risk Variation
1. 5 to 20 kph – Speed around the delivery or pick-up site ? 2. 40 to 60 kph – Around town speed ?
3. 100 kph – Highway speed ?
QUESTION - How does initial speed affect the risk?
At what initial speed would EMERGENCY BRAKING
generate the biggest LOAD RESTRAINT HAZARD?
Forward Force and Risk Variation
l Braking force is high enough.... l BUT because of slow speeds
energy is low
l This means only a short time at
high forces
l Therefore even if the load
moves, it only moves a short distance
M
How does initial speed affect the risk?
5 to 20 kph
Time
G-Force
G-Force Due to Braking
0.2g 0.4g 0.6g 0.8g
19
Forward Force and Risk Variation
l Braking force starts to rise.... l BUT because of heat effect on
the brakes & tyres, the braking force levels out
l The force lasts a long time, but
often doesn't get above a level that causes load shift
M
How does initial speed affect the risk?
100 kph
Time
G-Force
G-Force Due to Braking
0.2g 0.4g 0.6g 0.8g
Forward Force and Risk Variation
l Braking force rises
l And reaches a point where
loads can shift if not properly restrained
l The force also lasts for a long
enough time to be catastrophic
M
How does initial speed affect the risk?
40 to 60kph
Time
G-Force
G-Force Due to Braking
0.2g 0.4g 0.6g 0.8g
M
M M M
M
So URBAN DELIVERIES = Worst LR RISK21
" COR brings Consignors into Load
Restraint, so get a system
" The Law is based upon Performance
Standards (crash g forces),
" Low Friction = HIGH RISK
" Containing general freight within limits
" Lash the Gates and Heavy pallets
" Rated Curtains rely upon no gaps
" Maximum Risk in Local Delivery
situation (40 - 60 km/hr)
Summary
Friction µ = 0.40 2 3 1Engistics will be holding our one day “In Depth” Load Restraint Courses in September 2014 in Sydney, Brisbane, Melbourne and Perth