Forklifts are a commonly used piece of equipment in many manufacturing facilities, and they are also highly dangerous, yet many of the risk mitigation methods routinely employed are unsophisticated and ineffectual. We can do better, writes Barry Hendy.
We have all seen the politicians on the evening news, touring a factory and wearing their obligatory hi-vis vests. Almost every factory that I visit requires that we put one on. It is the accepted safety practice in any workplace where there are forklifts in operation. I appreciate the concern for safety, but I am amazed that we accept this as the best we can do to protect us from one of the most dangerous pieces of equipment in a factory.
When we design any piece of automation equipment we are obliged by both law and morals to take all reasonable and practical actions to ensure the safety of everybody who comes into that plant. We undertake a detailed risk assessment and classify all the possible risks we can identify. For each risk we assess the likelihood of the occurrence (LO) happening, the frequency of exposure (FE), the degree of harm should it happen (DPH), and the number of people at risk (NP).
The rating in each factor is then multiplied to give a Hazard Rating Number (HRN):
HRN = LO x FE x DPH x NP
and that number classifies the risk.
| Hazard rating number (HRN) | |
| HRN | Risk description |
| 0 – 1 | Acceptable |
| 1 – 5 | Very Low |
| 5 – 10 | Low |
| 10 – 50 | Significant |
| 50 – 100 | High |
| 100 – 500 | Very High |
| 500 – 1,000 | Extreme |
| above 1,000 | Unacceptable |
Our responsibility as system designers is to then reduce this rating as much as practical and typically aim to get the number under 10.
If we run a risk assessment against a plain old forklift being driven around in a factory, the risk assessment would probably look something like this:
- Likelihood of occurrence: We know forklifts are dangerous so you would probably say: LO = 8.
- Frequency of exposure: The forklift is operating all day so: FE = 5.
- Degree of Harm: We all know a forklift can kill: DPH = 15.
- Number of Persons: That depends on your operation, but let’s say you have at least 3 people moving in your factory: NP = 2.
Our HRN = 8 x 5 x 15 x 2 = 1,200. A clearly unacceptable risk.
So, what are our mitigation actions? How do we bring this risk down to an acceptable level?
We require all forklift drivers to be licensed so the drivers understand the dangers and know how to control the vehicle. This will reduce the Likelihood of Occurrence, at least for a while until the driver becomes a bit complacent.
We can paint some lines on the ground, perhaps put in some bollards and walkways and institute some pedestrian rules. Maybe that can reduce the number of people at risk, and maybe the frequency.
We can instruct our staff and visitors to always make eye contact with the driver to be sure they have seen you.
And then we require a hi-vis vest. Apparently, this will make me more visible to the driver, but I have to say if the driver can’t see me without the vest, I think we really have a much bigger problem. I am not comfortable that the main protection between me and that deadly piece of equipment is a hi-vis vest.
At best, these actions will reduce our HRN to something like 2 x 4 x 15 x 1 = 120 – still Very High!
Safe Work Australia statistics tell us there are around five fatalities and 1,000 reported incidents in Australia each year involving forklifts. This is a significant and serious safety risk, and yet the best we can do to mitigate this risk is to wear hi-vis!
When looking to mitigate a risk, the “hierarchy of hazard control” is typically referenced. This directs that our most effective and preferred mitigation is elimination or substitution to remove the risk, and that personal protective equipment (PPE – ie. the hi-vis vest) is the least effective control method.
So, what can we do better? Thanks to the latest sensor, battery, and computing technology, we can now substitute the dangerous forklift with a significantly safer material handling system – an autonomous material handling vehicle with Category 3-rated safety features.
We have seen the traditional Automatic Guided Vehicle (AGV) successfully deployed for many years, providing safe and productive material handling in a range of industries. However, AGV deployments are rigid, expensive and complex, so they have not been an option for most facilities. The latest generation of autonomous vehicle brings a range of safety scanners, vision systems, industrial safety rated controls and central fleet management systems to enable fast deployment, flexible configuration, reliable operations and – most importantly – a high level of safety.
The autonomous vehicle will always travel at a safe speed and within its limits – it certainly will not be rushing to get to its lunch break. The mapping and fleet management system will allow zones to be designated as ‘slow down’, and you can be confident the vehicle will not become complacent – will always slow down. The 360-degree view area scanner will continuously monitor the area with no blind spots. The 3D Lidar camera will always be looking ahead for obstructions and not be distracted by a mobile phone.
The risk assessment on an autonomous mobile robot (AMR) will of course be subject to the actual deployment, but a vehicle like the OTTO 1500, with its area scanners and 3D sensors, is going to be highly unlikely to cause an injury, and then only a minor injury, while it remains constantly present to the same people.
HRN = 1 x 5 x 1 x 2 = 10
Under this assessment, the risk is low despite the AMR transporting loads up to 1,900kg at up to two metres per second.
The industry is having trouble deciding exactly what to call these next-generation AGVs with acronyms using some combination of Intelligent, Autonomous, Vehicle, Mobile, Robot… We are going with AMR. Whatever you call them, they provide a viable and effective substitution option to mitigate the Unacceptable-rated risks of the forklift. As engineers we are obliged to take all practical actions to reduce industrial risk.
And maybe, just maybe, we won’t have to be relying on the hi-vis vest as a key mitigation tool for one of the highest risk machines in our factories – the forklift.
Barry Hendy is the Managing Director of Andrew Donald Design Engineering (ADDE).
www.adde.com.au