Steindorf, September 2023. The construction industry is one of the sectors with an above-average number of – sometimes serious – accidents at work. Falling attachments are also a risk of everyday life on construction sites. As the market leader in the development and production of fully hydraulic quick coupler systems, OilQuick has always been intensively involved in the topic of occupational safety and is in intensive dialog with machine operators, construction companies and the BG BAU. What contribution can safety solutions make in the area of quick couplers? What is the technical and legal status quo? What do machine operators want? What role does safety play in investment decisions? The manufacturer from Steindorf in Bavaria and Swabia brought together the different perspectives at a round table.
In discussion: Peter Winkler (BG BAU), Jürgen Sautter (M. Knecht), Tobias Schroth (LEONHARD WEISS) and Christian Rampp (OilQuick).
Mr. Winkler, the BG BAU keeps statistics on accidents involving quick couplers. What figures are we talking about?
Peter Winkler: Between 2010 and 2022, we investigated almost 100 accidents involving quick couplers, 8 of which were fatal.
In relation to the 99,380 workplace accidents reported to the BG BAU for 2022 in Germany’s construction industry, this appears to be a low figure for the time being.
Peter Winkler: Yes, but it has to be said that only around half of all earthmoving machines in Germany are operated by companies that are insured with BG BAU. In addition, accidents without personal injury are generally not reported, so we assume that the total number of accidents is much higher. Thank goodness not every falling attachment results in personal injury, but if someone is standing in the danger zone and is hit, it is almost invariably a serious accident with sometimes irreversible injuries. Every accident is one too many!
Mr. Sautter, you are a machine operator and a few years ago you caused an accident in which one of your colleagues was seriously injured. Can you briefly tell us what happened?
Jürgen Sautter: We were working on a trench at the time and I had just picked up the bucket during a tool change, pressed the locking button and started swiveling. I immediately noticed that the bucket was dangling, but by then it was already too late: the bucket fell out of the holder and trapped my colleague below. He had to be flown to hospital by helicopter with internal injuries and bruised fingers. Two fingers remained stiff, but I’m very glad that he has otherwise recovered well.
Is Mr. Sautter’s accident typical for accidents involving quick couplers?
Peter Winkler: Yes, accident investigations by BG BAU show that in most cases the cause is an unactuated or incorrect locking mechanism, for example in the case of incorrect locking against shafts and bores.
Mr. Sautter, then in your case the cause of the accident was such an incorrect locking mechanism?
Jürgen Sautter: Yes, the bolts are not fully engaged. But that sounds very technical, you have to be honest: it was my mistake, a human error. I was inattentive and not careful enough.
Do machine operators need to be better sensitized to the risk of accidents?
Jürgen Sautter: Most machine operators are convinced that something like this won’t happen to them, and that’s human nature. Today, as a person affected, I have a different view on the subject of occupational safety, but not everyone can have to experience such an accident. It is therefore not enough to talk about education or rules of conduct; we machine operators need technical solutions. Of course, we have a great responsibility, but here in Swabia we say: “Only those who don’t make anything don’t make mistakes”. Anyone who works on a construction site knows how much time and deadline pressure there is today. I’ve been a machine operator for 30 years and really have a lot of experience, but all it takes for an accident to happen is a moment’s lapse in concentration – my accident also happened on a hot, exhausting day just before the end of work.
Mr. Schroth, why is the time and deadline pressure in the construction industry that Mr. Sautter mentioned increasing so much?
Tobias Schroth: Construction site completion times are becoming ever shorter, and hourly machine rates, hourly wages and energy costs for fuel and oil have also become significantly more expensive. Machine operators therefore play a key role on construction sites today. They are largely responsible for adherence to deadlines and productivity, but also for sustainability, climate protection and profitability. Let’s assume that five trucks have to be loaded, each of which costs 80 euros per hour. For the truck drivers, foreman and site manager, the excavator driver is the decisive factor here. Every tool change takes time: open the quick coupler, put the tool down, pick up the new tool and lock it. Every minute of idling time for the five waiting trucks costs 7 euros. Pressure builds up. And stress is the ultimate source of errors, in every profession.
What can be done to minimize the risk of accidents?
Tobias Schroth: The machine operator certainly bears responsibility for the handling of his machine and for his colleagues in his working environment. As an employer, we also have a great responsibility for the people in our company and therefore for accident prevention. Qualified instruction for the machine and the associated attachments and annual safety training are crucial. At Leonhard Weiß, investing in modern safety technologies is at the heart of our occupational safety philosophy. For quick couplers, we use both mechanical safety catches and electronic sensor solutions. We want to support our machine operators with technical solutions to prevent accidents.
When it comes to technical safety solutions, the ball is in the quick coupler manufacturers’ court. Mr. Rampp, what is the status quo in the industry?
Christian Rampp: Most quick-change systems now work with variants of mechanical or electronic visual indicators. These locking controls in the form of pins or LEDs on the boom ensure that the machine operator can see the locking status at a glance. This visual indicator is important, but it must always be remembered that it is only user information. It cannot prevent an attachment from falling if the visual warning signal is overlooked or ignored due to an operating error. In our view, an additional engineering solution is therefore essential and a few years ago, in close cooperation with our customers, we developed the drop guard, a kind of “claw” that closes around the shaft on the attachment’s adaptation. Other safety-oriented manufacturers have since adapted similar technical solutions.
How open are machine operators to health and safety innovations?
Tobias Schroth: Well, the construction industry is conventional and not every innovation is accepted immediately. If you put yourself in the shoes of the machine operator, you can understand that. We’ve already talked about the time and deadline pressure – and no matter how sensible the innovation is that we introduce, for the machine operator it initially means a disruption or change to their established work processes. Take a look inside an excavator cabin, it looks like an airplane cockpit. Jürgen Sautter: It’s true that the digitalization of the excavator cab makes our working day more mentally demanding. With up to 100 tool changes a day, a display is constantly flashing and beeping somewhere and you have to concentrate incredibly hard. But I’m all the more grateful for every invention that protects me and my colleagues when I might have a bad day
. If that means a change for me – so what? It’s a small price to pay. If my excavator had been equipped with a technical solution earlier, the serious accident would not have happened. That’s why Knecht has pushed and supported the development of the OilQuick drop guard with great commitment.
The standards committee has reacted to the serious accidents in recent years and tightened the requirements for quick couplers in the new version of the EN 474 standard, which will be harmonized in August 2023. Do you think the increased requirements are sufficient?
Peter Winkler: The new version of EN 474 reflects the requirements that we at BG BAU have been using for several years as criteria for certification and for products on our promotion list. In this respect, we are definitely on the right track with the standard. But occupational safety is never “finished” and we will continue to actively participate in improving European safety standards as part of the standards committee.
Christian Rampp: Every improvement in safety standards is a step in the right direction and we welcome the obligation to supplement the visual display with an additional solution. However, the details do not go far enough for us, because even in the new version of EN 474, the safety concept is based on the assumption that machine operators do not make mistakes. The most frequent cause of accidents is therefore still not covered in a binding manner, namely that the quick coupler lock is not closed despite the visual display, warning signal and countercheck.
As there is no obligation to retrofit existing machines, it will take a generation of machines for the stricter standards to take full effect anyway, right?
Peter Winkler: There is no general retrofitting obligation. However, the risk assessment, which employers are obliged to carry out under the Industrial Safety Ordinance, must be adapted in the event of changes to the technical regulations. As a rule, this should lead to the result that quick couplers of the old design may no longer be used or must be retrofitted. We therefore hope that we will see an effect on the accident rate as soon as possible, but we won’t know for sure for a few years. With the BG BAU’s incentive programmes, such as financial support for retrofitting, certifications and the EuroTest prize for outstanding occupational safety innovations, we are using various levers to increase the willingness of users and manufacturers to voluntarily optimize accident prevention.
Tobias Schroth: I am convinced that many companies in the industry see it as a natural obligation to provide their employees with the safest possible work equipment. It is not always necessary to wait for standards and laws. LEONHARD WEISS is setting a good example here: in 2021, we upgraded all quick couplers on tracked and wheeled excavators to the highest safety standard currently possible. In the mini excavator segment, 65 existing machines were retrofitted. And we’re talking about around 150 machines here! This is a positive signal as to how companies treat people. We want to avoid accidents and have proven that we not only say this, but do our best to achieve it.
The international occupational safety campaign “Vision Zero” is committed to a world without accidents at work. What would you like to see to get one step closer to this vision in the area of quick couplers?
Peter Winkler: I would like to see a quick hitch system where the attachment can only be lifted once it has been correctly locked. There are initial approaches in this direction, but unfortunately it is technically very complex.
Tobias Schroth: I would like to see an intelligent system that excludes any form of operating error. Instead of countless new monitoring tools or warning signals for the machine operator, I would prefer a 100% secure locking system at the touch of a button. Of course, the machine operator must remain alert, but the technology should make it as easy as possible for him. Jürgen Sautter: I am perfectly happy with the occupational safety at my employer. But it would be nice if all machine operators could work with similarly safe machinery.
Christian Rampp: I would like to see all industry players join forces to achieve ambitious safety standards that are not the lowest common denominator, but instead use the latest technology to achieve the best possible accident prevention.
OilQuick would like to thank all round table participants:
Dipl.-Ing. Univ. Peter Winkler
BG BAU / Head of testing laboratory DGUV Test Prüf- und Zertifizierungsstelle Fachbereich Bauwesen
Jürgen Sautter
M. Knecht Tief- und Straßenbau GmbH / Machine operator
Tobias Schroth
LEONHARD WEISS GmbH & Co. KG /
Team Leader Applied Machine Technology
Christian Rampp
OilQuick GmbH / Head of Development
