41T71_Load Safety for Road Transport-nina Day

8/6/2019 41T71_Load Safety for Road Transport-nina Day

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Load safety for road transport

Nina DaySenior Engineer, HSL









Why is load security an issue?

• Shed loads can cause significant

disruption on the highways

• Shed loads can cause significant delayduring unloading

• Load movement can affect the stability

of vehicles and lead to rollovers

• Load movement can cause product and

vehicle damage• Load movement can leave the load

“stuck” on the trailer



Why do loads shift?

An unsecured item on a trailer is not part of

the trailer

The item and the trailer will move

independently of each other just as a

passenger in a car will move independently

if they don’t put their seatbelt on

Load security relies on ensuring that the

load and the trailer do not move

independently of each other



On the road, loads tend to shift when the vehicle is braking, or when the

vehicle is turning

The main ‘hotspots’ for load shift are:

• roundabouts

• slip roads

• long (fast) corners







The load securing system

Securing a load for transport is normally achieved through a combination of:

• the vehicle structure (the headboard and any side walls)

• blocking, dunnage, chocks, cradles etc

• lashings (webbing or chain)

There are other ways of securing loads but these are the most common



Whatever method or combination of methods is used, the basic aim is

always to secure the entire weight of the load going forward, and half the

weight of the load to the side.

This basic principle is established in the DfT Code of Practice, Safety of

Loads on Vehicles.

It is also specified in the European Best Practice Guidelines for Cargo

Securing.

It applies to all loads on all vehicles, except for unstable loads and

vehicles undertaking a ferry crossing, in which case 70% of the weight of

the load to the side must be secured.



Friction cannot be relied on to hold the load in place



Static vs dynamic friction

Static friction Dynamic friction



How to stop loads moving

When assessing a vehicle at the

roadside, the question is “what if…?”

If the load started to slide (or topple

over if it’s a tall load), what is

preventing it from falling off the

vehicle?

It can never be assumed that the load

won’t move if it’s not secured, however

heavy it is



Unstable loads

Unstable loads need to be

supported so they don’t topple

from the vehicle

The support needs to be at the

height of or as high as the

position of the centre of gravity

of the load







As a general rule, curtain-sided

trailers should be treated as flatbeds

The structure is for weather

protection

Straps suspended from the roof are

not load securing

The structure they are attached to is

not designed for load securing



BS EN 12642

BS EN 12642 is the European Standard for trailer construction

Trailers in the UK do not have to be built to the Standard

EN 12642 specifies two types of trailer – a basic “L” trailer and a reinforced“XL” trailer

“XL” curtainsiders are built to take 40% of the payload onto the side curtains

“XL” trailers are substantial and there is a weight penalty to using them



Side slats

Side slats can provide load

containment and support to

unstable loads

Side slats are only as strong

as the structure they are

attached to



Containment vs restraint

The containment provided by

the vehicle structure doesn’t

mean that the load doesn’tneed to be restrained.



Loads can, and so, smash their

way through side slats, side walls,

and bulkheads if they are allowed

to move freely within the trailer





Chocks, blocking and dunnage

Some loads, like steel coils, are

best carried in specialised

vehicles

Loads likely to roll should bechocked

Large gaps between the load

and the headboard, and

between the loads and thesidewalls, should be filled





Lashings

Lashings can be webbing straps or

chain

Rope is usually not a good idea –

it’s easily damaged and thebreaking strength is much lower

than webbing or chain

Rope may be fine for lifting loads

(like FIBCs) – but no one lifts at50mph





Lashings and their labels

These are typical labels for webbing lashings.

The STF (measured in daN) is the Standard

Tension Force. This is essentially how taut a strap

needs to be effective.

Users often only look at the LC (Lashing Capacity)

and assume the strap will hold a load of the same

weight – this is not correct.



Calculating the number of lashings



Strap angle

The angle of the strap is very

important

If the angle is too shallow, the

strap is essentially useless



Types of lashing

Frictional lashing is the most

common and the lashing should

be as close to vertical as possible

Direct lashing should be as close

to horizontal as possible and the

lashings should be equalised

Choke lashings can be used for items like pipes





Damage to lashings

Webbing straps are very vulnerable

to damage

They should not be used over sharp

or abrasive corners

Any tears, nicks, fretting or other

damage should be grounds for

replacing the lashing



Other methods of restraint

Lashings don’t have to be used if

another method provides an

equally effective means of

securing





Enforcement

Not prescriptive on use of lashings

Poor practice usually easy to spot



Information asked for

• What the load is, whether it’s hazardous, and how heavy it is

• Who loaded and where, and how much involvement the driver had

• Who the driver is employed by and who owns the vehicle

• Where the load is going and how close that is

• Whether it’s a multi-drop load and if drops have already been made• Has it already moved?

• Is it likely to move (inadequate load restraint)?

• Are there any other issues?











The three rules of load securing

No relative movement of the load and trailer

Load to the bulkhead

Support unstable loads



Getting it right

Use the right vehicle

Choose the most practicable lashings

Think about the transport chain



Date post:	07-Apr-2018
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41T71_Load Safety for Road Transport-nina Day

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