Load Restraint for Managers

Transcription

1 Load Restraint for Managers (Both Consignors and Transport Company Managers!) File name: LR for Managers 13Aug14.pdf Our Ref: Mike Robertson MD & Eng Mgr

2 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

3 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 The large consignor, transport company and driver were ALL guilty after this 2011 fatality u Proper Packaging is part of Consignors responsibility 3

4 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 u Load shift = rollover High CoG loads = rollover u Codes of Practice are helpful tools for compliance Fatal rollover 2012 = Consignor in Court late

5 Load Restraint Law 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);

6 Based upon Performance Standards To achieve the movement limits from the previous page: u u The law is based on minor crash G-Forces Loads must be restrained against forces equal to: 0.5g 50% of the weight rearwards 0.2g 20% of the weight upwards 0.5g 50% of the weight to either side 0.8g 80% of the weight forwards Don t forget.. And so that the vehicle's stability is not adversely affected Simple in approach... But tricky in practical terms! 6

7 Load Restraint and CoR Consignors u u u Confirm that Transport Companies are competent and compliant Large volume or specialised freight is best done by Company based LR guideline sheets (eg steel industry) 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! Visual based LR guides are best Truck drivers u Trained in why and how Receivers must report issues! 16 tonne with only 1 chain, but safe, legal and very efficient! 7

8 Types of Load Restraint Courtesy of The Load Restraint Guide, NTC Many loads in Australia use tie-downs. Friction is critical for the tie-down method Most general freight is contained / blocked to comply 8

9 Friction is Critical Friction is a function of only: F f = µ x Down-force Down-force = M x g + F t F t 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 force down from lashing tension F f M Friction factor between the surfaces, µ Typically ~ 0.40 for timber 9

10 LOAD RESTRAINT - Case Study Forward Sliding Forces - 10 tonne Load 8.0 tf 8.5 tf tf Emergency Braking 5.0 tf 7.0 tf 5.5 tf 4.0 tf degrees Sliding resistance due to friction from one chain clamping 60 degrees 45 degrees Friction µ = 0.40 Sliding resistance due to friction from weight alone 8mm Tpt 45 degrees Forward Force Restraint Forces Timber Pallet 10

11 LOAD RESTRAINT - Case Study Forward Sliding Forces - 10 tonne Load 8.0 tf 6.0 tf Emergency Braking 5.0 tf 60 degrees 45 degrees 8.5 tf 7.0 tf 5.5 tf 4.0 tf degrees Friction µ = 0.40 Friction is more important than the number of Lashings! 5.5 tf 4.5 tf 3.5 tf 2.5 tf Chain Friction µ= tf 6.0 tf 1 Chain Friction µ= 0.60 Forward Force Restraint Forces Timber Pallet Restraint Forces Galv. Steel Pallet Restraint Forces Anti-slip Matting 11

12 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*? * The curtain salesman told me so..but its rubbish! 12

13 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 kg pallets u Strapping over the gates almost triples their sideways capacity, so ~ 600kg/pallet Gates have usually only 2 off 50 x 8mm flat bars as the retaining feet & bend very easily. This gate is wrongly reversed 13

14 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 600kg 600kg 600kg Typical limits for dumb gates 300kg 600kg u Pallets >600kg MUST be lashed over the freight, or have superior gates 14

15 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 15

16 Failure Risk Vs Speed CCTV footage from a Chinese Toll Collection Booth 16

17 Forward Force and Risk Variation QUESTION - How does initial speed affect the risk? At what initial speed would EMERGENCY BRAKING generate the biggest LOAD RESTRAINT HAZARD? 1. 5 to 20 kph Speed around the delivery or pick-up site? to 60 kph Around town speed? kph Highway speed? M 17

18 Forward Force and Risk Variation M How does initial speed affect the risk? 5 to 20 kph Braking force is high enough... BUT because of slow speeds energy is low This means only a short time at high forces Therefore even if the load moves, it only moves a short distance G-Force 0.8g 0.6g 0.4g 0.2g G-Force Due to Braking Time 18

19 Forward Force and Risk Variation M How does initial speed affect the risk? 100 kph Braking force starts to rise... BUT because of heat effect on the brakes & tyres, the braking force levels out The force lasts a long time, but often doesn't get above a level that causes load shift G-Force 0.8g 0.6g 0.4g 0.2g G-Force Due to Braking Time 19

20 Forward Force and Risk Variation M M M M How does initial speed affect the risk? 40 to 60kph Braking force rises And reaches a point where loads can shift if not properly restrained The force also lasts for a long enough time to be catastrophic So URBAN DELIVERIES = Worst LR RISK G-Force 0.8g 0.6g 0.4g 0.2g G-Force Due to Braking Time 20

21 Summary " 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 Friction µ = 0.40 " Maximum Risk in Local Delivery situation (40-60 km/hr) 21

22 Engistics will be holding our one day In Depth Load Restraint Courses in September 2014 in Sydney, Brisbane, Melbourne and Perth Contact: for details 22