The National Heavy Vehicle Regulator’s (NHVR) new load restraint guide includes detailed worked examples for a variety of load restraint cases, along with easy to follow steps and tips.
Below is one of 12 case studies included in the new guide.
Case study: Direct restraint using calculations
Load: 15 tonne front-end loader (as pictured above).
Direct lashing angles: For this example, we will determine the direct lashing angle effect using a simple calculation. To do this we need to know the following information in Table 1.
What is the mass of the load?
The total mass of the load is 15,000 kg
What is your direct lashing angle effect in the forward direction?
The rear chains provide the forward restraint. To determine the forward direct angle effect divide the distance between the tie points along the truck (F1) by the lashing length (L1): 3400 (F1) ÷ 3,500 (L1) = 0.97 (forward direct angle effect).
What is your direct lashing angle effect in the sideways direction?
Both the front and rear chains provide the sideways restraint. To determine the sideways direct angle effect divide the distance between the tie points across the truck by the lashing length for both chains:
- Front chain 300 (S2) ÷ 3,500 (L2) = 0.086 (sideways direct angle effect)
- Rear chain 300 (S1) ÷ 3,500 (L1) = 0.086 (sideways direct angle effect)
Note: 0.086 sideways direct angle effect is very low. At this angle the direct lashing will have less than 9 per cent effectiveness in the sideways direction. To meet the sideways restraint requirement of 7500 kg (50 per cent of the load mass), each chain would need to restrain 3750 kg. With only a 9 per cent level of effectiveness, the chain’s lashing capacity would need to be 43,750 kg. There are no chains available to provide this capacity.
- Do not transport this load until you have properly restrained it.
The sideways direct angle effect can be improved by increasing the distance between tie points across the truck. This can be done by using a diagonal tie point. See worked example Case 7.
For more load restraint case study examples, see the 2025 Load Restraint Guide or visit nhvr.gov.au/road-access/loading/case-studies.