Car carrying vehicles - preventing falls
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Document Type: Guidance Note
Keycode: web only
Category: Falls Prevention
Publication Date: 17 June 2005
Date First Published: 17 June 2005
Summary: This guidance note provides specific guidance for safer loading and unloading of vehicles from car carrying trailers, cab frames and tilt-tray trucks and advice on providing safe access for people working at height. Includes vehicle procurement and the design and construction of guardrails.
Car carrying vehicles - preventing falls" provides specific guidance for safer loading and unloading of vehicles from car carrying trailers, cab frames and tilt-tray trucks. This Guidance Note advises on providing for safe access for people working at height and includes vehicle procurement and the design and construction of guardrails.
Background
The risk of death or injury due to a fall from a truck or trailer exists and is foreseeable. Accident compensation data in Victoria shows that:
- 150 truck drivers a year in Victoria suffer a serious injury due to falling from trucks.
- These are 17% of all the serious injuries reported by truck drivers annually.
- About 70% of injuries from falls from trucks occur after jumping down or falling from the vehicle.
- On average, one person is killed after falling from a truck in Victoria each year.
- Any fall can kill or injure.
Falls can occur while working, climbing on or off or when cleaning a vehicle. Other injury types that can occur when working on a car carrier include slips and trips while moving about on the platform or deck; crush injuries if load restraints fail, a vehicle moves or if hydraulics fail; cuts or bruises from recoil of tie-downs; other sprains or strains from jumping off a trailer deck onto hard or uneven surfaces.
Figure 1: A robust guardrail to prevent the worker from a fall.
Identifying Hazards
A risk of a fall and subsequent serious injury exists when working at an unprotected height of over two metres, for example when accessing the platform or deck of a car carrier. The likelihood of a slip trip of fall increases with:
- slippery or potentially unstable surfaces
- sloping surfaces on which it is difficult to maintain balance
- close proximity to the unprotected edge, particularly when walking along the side of cars loaded on the upper decks of a trailer
- wide or large gaps between trailer components and between trailer and cab frame
- adverse workplace factors such as traffic conditions and the condition of the surrounding ground
- environmental factors, such as wind and rain
- difficulty maintaining balance while attaching load restraints.
Assessing Risks
If you own or operate a car carrier you are required to carry out a risk assessment of the hazards. Your risk assessment must cover the matters in these regulations:
1. Occupational Health and Safety (Prevention of Falls) Regulations 2003 (which should cover as a minimum the items listed in "Identifying Hazards" above).
2. Occupational Health and Safety (Manual Handling) Regulations 1999 (to prevent manual handling injuries).
3. Occupational Health and Safety (Plant) Regulations 1995 (which may apply to some vehicle components).
WorkSafe also recommends these matters be covered in your risk assessment:
4. the physical surroundings in which vehicles may be loaded or unloaded and the conditions during which the task is to be performed will differ at each delivery point. For example, traffic, weather and lighting conditions will differ at various times, making work more or less risky for the driver. Another example is when considering gantry access a gantry at the loading end will need to be matched by a gantry at the unloading end, eg depot-to-depot deliveries.
5. Access on the upper deck of a trailer may not always take place in a building or yard. Drivers may need to access the trailer to tie down loose lashings. Positioning of access ladders should not create additional hazards.
6. poorly designed or constructed ladders may increase the risk a driver is exposed to, by making it difficult to maintain balance or gain access to the platform.
When replacing vehicles and trailers
After assessing the risk, you should eliminate the possibility of falls, or if you can't, you should take steps to minimise the harm that could arise from a fall. Your decisions about solutions must be based on doing all that you can reasonably do to ensure that people are safe who work on car carriers, in the knowledge that falls from car carriers can kill or permanently disable.
Eliminating the risk of falls is the best practice solution and should be one of your selection criteria when purchasing new or replacement vehicles or trailers. Methods include buying trailers with solid sides or with solid framing that acts as a barrier to prevent falls, using single-deck trailers or using container-based methods eg shipping containers or freight crates.
If you design build or supply trailers then you should be aware that your customers require fall protection as part of the product. You should design build and supply trailers that include handrails or other methods such as solid sides.
Making current vehicles and trailers safer
For existing vehicles and trailers it is necessary to retrofit some form of fall protection. The first option is a permanent fixed physical barrier, eg solid sides. Where this cannot be achieved, for example due to the need to comply with the dimensional requirements of the Australian Design Rules (ADRs), a guardrail system should be installed.
Car carrier owners and operators have been able to install guardrails in almost all circumstances.
This Guidance Note gives two options for installing guardrails, platforms and ladders to prevent falls: 'good practice' or 'minimum requirement'. WorkSafe recommends that you achieve 'good practice' to make your current vehicle fleet safer.
Using Guardrails to Control Risk
Guidance on how to provide safe access to heights and ensure platforms are safe for work is found in Australian Standard AS 1657:1992 - Fixed Platforms, Walkways, Stairways and Ladders - Design, Construction and Installation. Efforts should be made to fulfil all the requirements of AS 1657.
However, the width limitations of the ADRs make it unlikely that any retrofitted trailer platform or access ladder could comply with all the provisions of this Standard. If the Standard cannot be fulfilled, then dimensional requirements may be the element that is compromised. Under no circumstances should the load-bearing requirements of AS 1657 be breached - guardrails etc must be able to resist the dynamic loads and forces placed on car carrying trailers during normal operation.
Fixed Guardrail Posts
All welding should be done to comply with the relevant Australian Standards (see "Further Information").
Good practice: fixed guardrail posts used in the construction of a guardrail system must comply with the relevant design codes for load-bearing contained in AS 1657 including Appendix A of the Standard, which lists the materials, dimensions and spacing of components of a typical guardrail system. If using Rectangular Hollow Section (RHS) WorkSafe recommends 40mm x 40mm x (at least) 4mm wall thickness RHS as good practice. Posts used in a guardrail system should be directly welded onto the platform body or bolted into a steel sleeve that is directly welded to the trailer. Figure 2 describes the type of recommended weld for attaching the post or sleeve to the trailer or cab frame body. Regular inspection of welds is recommended to check that cracking or damage arising from vibration is not occurring.
Figure 2: Example post attachment
Minimum requirement: the option of using guardrail posts of differing dimensions to those listed in AS 1657 does exist. Any components that differ from those listed in "Appendix A" of AS 1657 should comply with the relevant design load-bearing capacity contained in the Standard.
Particular reference should be made to section 2.1.2.2 of AS 1657 which sets out the load design for guardrails, and states:
'The guard railing shall be designed to withstand whichever of the following live loadings produces the most adverse effect:
(a) A force of 550 N acting outwards or downwards at any point on the top rail, edge or post.
(b) A force of 330 N per linear metre acting outwards or downwards on the top rail or edge.'
If you choose to construct guardrail posts of materials and/or dimensions differing from 'Appendix A' of AS 1657 or this Guidance Note, you should obtain a mechanical engineer's services and sign-off to validate that the component materials, dimensions and spacing meet the performance requirement.
The height of the guardrail posts should always be between 900mm and 1,100mm and should be constructed from steel posts with a cross section of at least 40mm x 40mm. It is recommended that steel post have a minimum 4mm wall thickness. Under no circumstances should a wall thickness below 3mm be used.
Pop-Up Guardrail Posts
In some circumstances, fixed posts may cause an adverse affect to a vehicle's performance, eg, wind drag that reduces fuel efficiency of a vehicle on an extended journey. Pop-up posts, common on bulk transport tankers, may be an option. There are existing designs, some of which are proprietary or patented systems.
Minimum requirement: a pop-up guardrail system must satisfy the design loading requirements in AS 1657 and must be able to be operated from ground level.
Good practice: if pop-up posts are required, fitting should be done by an experienced installer.
Guardrail Material
Minimum requirement: The material chosen for the guardrail must fulfill design loading requirements set out in AS 1657. Guardrail material must be flexible (to reduce the stresses placed on posts) and be durable. In all cases the vehicle maintenance regime must include regular checks of guardrail integrity.
A 6 mm diameter cable will meet the loading requirements contained in AS 1657. Synthetic webbing may comply depending on type and age but can fail under load, eg bending of the guardrail, and break down due to exposure to UV light and general wear and tear. Some types of synthetic webbing can be used if design loadings are met and frequent regular inspection occurs. Other flexible materials may meet the required design loading but should not be used because they may not resist the dynamic loads or may be prone to damage deterioration and rust etc.
Good practice: Ergonomic factors should also be considered. A wider diameter cable is preferable in order to have something substantial to grab hold of if a person loses their balance. A simple way to increase the diameter of the top guardrail cable is to cover the cable with a plastic coating or industrial hose.
Fixing and Placement of Guardrails
Minimum requirement: Guardrails must be straight, take into account ergonomic factors, and fulfil the load-bearing requirements of section 2.1.2.2 of AS 1657 (as given above) and the mounting requirements set by manufacturers and the relevant Australian standards for fixing the guardrails to the posts.
The top rail should be between 900mm and 1,100mm from the standing platform. If cables are used for guardrails, the lower limit (900mm) should allow for cable deflection which occurs when the design loading is applied to the top guardrail. For flexible guardrail materials the height of the top guardrail should be greater than 900mm to allow for this deflection.
Intermediate rails must be installed between the top rail and the platform to prevent a person falling under the top guardrail, eg for the safety of drivers who must crouch to tie down lashings on car wheels. This intermediate rail should be at least 450mm from the platform but not more than 560mm.
To fulfil guardrail design loading requirements, the guardrail must be able to be pulled taut to minimise deflection. Therefore the attachment between guardrail and post must be of adequate strength, and the attachment method must ensure the guardrail can be kept taut.
Attachment methods include eyelet & closed loop, swage (crimp-ferrel), and threaded lengths through the post with locking nuts. Figure 3 is an adjustable system using a turnbuckle with locknuts in a stainless steel cable guardrail (together with a cable tie through the loop to prevent the cable from falling or swinging if the turnbuckle unwinds due to vibration while the vehicle is in motion).
Figure 3: Minimum requirement for guardrail system.
Terminations must follow WorkSafe's rigging guidance and manufacturers' advice for secure attachment. Attachment principles for wire guardrails are set out in AS 2759:1985 Steel Wire Rope -- Application Guide (under review, refer also DR 01306 public comment document).
Good practice: the guardrail should be made from stainless steel cable and a proper splice used as shown in Figure 4. The cable should be attached to a closed steel loop welded to the post structure.
When attaching the cable to the post, the cable is swaged and the tension checked prior to cutting any excess cable. There are no turnbuckles or clamps.
Figure 4: Example good practice cable termination. Cable has an eyelet and is attached to a 6mm closed loop steel link and swaged.
Using Platforms to Control Risk
The width of a car carrying trailer, cab frame or tilt tray truck is dictated by vehicle design rules. When the carrier is loaded with vehicles there is not much available width remaining for access on the platform edge. The slope of many trailer designs increases the risk of a slip, trip or fall. On narrow platforms or slopes the risk increases if it is a steel surface, or is greasy or slippery.
Minimum requirement: slip prevention measures are applied to all platforms, slopes and removable ramps with a slope greater than 1 in 8 (or 7 degrees, refer AS 1657). For example use of a steel grating surface instead of plate, fixing of cleats, etc.
Good practice: in addition, slip prevention measures eg cleats, grip tape or a grit containing paint are applied to all narrow flat surfaces, to reduce the risk of slipping during wet conditions.
In situations where car carriers are regularly loaded or unloaded in a predictable location, such as depot-to-depot, purpose-built gantries are recommended.
Such gantries allow a person to work at height beside the car carrier to gain safe access to a cargo of 4 wheel drives or other similar large vehicles. Gantries or work platforms must provide fall protection in the area where work is done, for example over the cab, both ends of the tray, or part or all of the tray sides.
Figure 5: Platform with gaps covered.
Using Access Ladders to Control Risk
Access ladders must be fully contained within the maximum width dimension of the vehicles. This affects their construction, configuration and fitting. Ladders are also a cause of injuries and should be used only when there is no better alternative.
Stiles
Stiles are the side members that support the rungs or treads of a ladder. They are also known as side rails or stringers.
Minimum requirement: The material cross section as used in ladder stiles:
- Stiles of flat material should be between 50mm and 80mm wide and between 6mm and 30mm thick;
- Circular stiles should be between 40mm and 65mm outside diameter;
- Stile extensions above the platform should be equivalent to the height of the handrail (Figure 6).
The width between stiles should not be less than 375mm or more than 525mm.
Figure 6: Stile extensions should be equal to the height of the guardrail.
Rungs
Minimum requirement: rungs of access ladders should be at least 20mm in diameter or the equivalent thereof. Typically, rungs should not be spaced at less than 250mm nor more than 300mm apart. Rung spacings in the ladder should also be uniform within a tolerance of +/-5mm.
Good practice: rungs must be at least the depth indicated by AS 1657 (200mm or greater) and designed to reduce the likelihood of slips and trips, eg by anti-slip tread, grip tape etc. The trailer should be designed and built with the ladder integrated into the trailer so that it complies with Australian Design Rules (ADRs) as well as fulfilling good ladder design criteria.
Using Administrative Methods to Control Risk
Safe Work Practices
Minimum requirement: work instructions, training and supervision must be part of the system of work. Reliance on these methods of risk control will vary depending on the extent to which other methods are applied that control the risk. For example, safety rules, work instructions, training and supervision will be a necessary part of the system of work if overhead frames are used for transporting vehicles and guardrails cannot be fitted between the cab frame and the trailer. In this instance, the cab frame should only be accessed via a fixed ladder attached to the cab frame or a gantry fitted with guardrails. Gantries or vehicle ramps may be used when delivering vehicles between depots.
Employees should never cross over between a trailer and overhead cab frame where there are no fall protection measures in place.
A "pre-access inspection & tightening procedure" should also be in place to cover safe work practices before the driver accesses the vehicle platform, regardless of where the vehicle is.
Good practice: In some instances, the need to access the top platform of a car carrier can be eliminated. For example, tying down lashings that come loose during transit can often be carried out from underneath the top platform. Likewise, loading the top deck first will reduce the time spent working at height. If you rely on such an administrative control to prevent or reduce the amount of time people access the upper deck of the trailer, the work method should be documented as part of a Safe Operating Procedure (SOP).
A safe work procedure when considering a contract or job, is to determine the risks arising from the cargo being transported. For example, a work method may include declining certain vehicles if the design and configuration of the car carrier makes such work hazardous.
The law requires
Employers and self-employed persons have a range of general duties under the Occupational Health and Safety Act 2004 (OHS Act) to ensure employees and other people do not come to harm as a result of work activities (see sections 21, 22, 23 and 24 of the OHS Act). The Occupational Health and Safety (Prevention of Falls) Regulations 2003 specifically requires employers to ensure the risk associated with any fall hazard is eliminated or controlled so far as is reasonably practicable.
Acts and Regulations
- Occupational Health and Safety Act 2004
- Occupational Health and Safety (Prevention of Falls) Regulations 2003
- Occupational Health and Safety (Manual Handling) Regulations 1999
- Occupational Health and Safety (Plant) Regulations 1995
Acts and regulations are available from Information Victoria on 1300 366 356 or order online at www.bookshop.vic.gov.au.
View the legislation at Victorian Law Today at www.legislation.vic.gov.au.
Standards Australia
- AS 1657:1992 - Fixed Platforms, Walkways, Stairways and Ladders -- Design, Construction and Installation
- AS 1554 Part 1 -- Structural steel welding -- Welding of steel structures
- AS 2214 -- Certification of welding supervisors Structural steel welding
Copies of standards can be obtained by contacting Standards Australia on 1300 654 646 or by visiting the web site at www.standards.com.au.
