Risk assessment and RISK reduction in the new FprEN 13814-1:2018. Part 330 January 2019
/ by Gianni Chiari /
Gianni Chiari continues his article on risk assessment in rides.
Happy 2019 to everyone. This new year is one full of hopes and expectations. From a technical point of view, if the European Committee for Standardization (CEN) sticks to its program, we should finally see the publication of the new European technical standard EN 13814-2019, in 3 parts:
- Design and manufacture
- Operation, maintenance and use
- Requirements for inspection.
We will keep you informed on developments, and when the standard is published we will prepare a specific article.
In the meantime, we’ll once again look at risk assessment. I hope it is clear from previous articles how important this is in today’s safety strategy. Let me take a short step backwards that I think will help better understand how risk assessment can be applied from a practical point of view.
For many consumer products and machines in general, all technical and safety features are set in the beginning, and the designer/manufacturer takes care of “everything”. Therefore, the user simply has the task of installing and/or using the product and/or the machine according to the instructions provided by the manufacturer.
Another fundamental distinction is the intended use, in the sense that there is a major difference between a professional user and a consumer. This affects the characteristics of the product and also has repercussions in terms of the operating instructions.
We will perhaps examine these aspects more in the future. For now we will remain on the topic of amusement park rides and what happens in practice. When a park orders a new attraction from a manufacturer, a specific technical process commences.
First of all, the “scope of supply” needs to be clearly identified. In my more than 30 years’ experience, only very rarely has a ride been delivered ready for use. Perhaps coin-op kiddie rides are among the very few that only require a connection to the power supply and little else.
For rides, on the other hand, things are different and indeed very complex. A park installs a new ride in a context, and often is responsible for equipment and devices that have a direct influence on the ride’s safety. I could make a very long list of these, but I prefer to give you just a few important examples.
Normally, at a contractual level, parks state that they will equip the attractions with special fences, access points and exits. Consequently, does the designer/manufacturer need to take into account these aspects when developing the DRA (Design Risk Assessment)? And if so, how?
It would be easy to say “the park will take care of it”, but I think that it is neither correct nor prudent to leave it at this.
The DRA prepared by the designer/manufacturer will on the other hand analyse these aspects and give useful indications to the park on developing its OURA (Operation and Use Risk Assessment).
Here are some examples:
1) Location of the new attraction in the park
Pay attention to safe distances due to movements of the passenger units and the corresponding safety envelope. The manufacturer will provide the measurements of the safety envelope and the park will check in its OURA whether the fences that will be installed respect the safe distances.
The park must also provide the spaces required for access by emergency and rescue vehicles, according to local regulations. In this case too the park, through its OURA, will verify and document whether there are access ways and spaces for manoeuvring fire engines, ambulances, aerial work platforms, etc.
These have the function of keeping the public a safe distance from the dangerous parts of the ride or preventing falls from a height. Depending on the type of attraction and its movements, there are minimum characteristics to be respected for such barriers. European standard EN 13814:2004, point 18.104.22.168, classifies these into categories:
Classification of zone demarcation systems
Zone demarcation systems are classified as follows:
J1 – predominantly visual zone demarcation systems: coloured stripes on the floor or fixed steps, poles, cones or equivalent.
J2 – physical zone demarcation systems: flexible devices, such as ropes, chains, cords, etc., which need not withstand horizontal forces.
J3 – physical zone demarcation systems: rigid devices, such as fencing or railings which can withstand horizontal forces.
Which type should be used? The designer should indicate in the DRA the minimum required category: for example, J3.
As the park will be responsible for supplying this, the person preparing the OURA will decide which type of fencing to install, how it should be designed, which characteristics it must have in terms of dimensions and shape, how far it must be from the ride to guarantee the safety envelope, and so on.
3) Accesses and exits
The same is true as for the fencing. In the DRA the designer needs to specify the minimum category of gates required, while in the OURA the park will establish in detail what kind of gates will be installed. In this case too, European standard EN 13814:2004 offers assistance, by defining 5 categories of accesses/exits, in point 22.214.171.124:
Classification of access and egress openings in fences and railings
The number of openings in fences and railings shall be limited to the number and width necessary for safe access and egress. Each opening shall not be more than 2.5 m wide. The access and egress openings are classified as follows:
K1 – openings without any direct control;
K2 – openings controlled by attendants;
K3 – openings provided with barriers or gates indicating the access to a restricted zone by limiting the flow of persons (e.g. mechanical gates, turnstiles, etc.);
K4 – openings provided with barriers or gates where the locking and unlocking are actuated by the operator or attendant;
K5 – openings provided with barriers or gates, the closed state of which, enables the ride to start.
For each defined category of rides, or for each group or single ride being in the same ride category and having the same specific features, the minimum requirements for access and egress openings will be expressed by the above classification under 6.2.
The park is responsible for defining in detail all of the characteristics of the accesses and exits, in other words, of any gate. I should simply underline how there is a close interaction between DRA and OURA when taking the example of a class K5 gate.
If the designer in the DRA requires a K5 gate and the park needs to build it as it is outside of the manufacturer’s scope of supply, a problem will arise in interfacing between the attraction control system and the gate installed by the park. In fact, class K5 provides for interlocking between attraction and gate. In other words, the attraction can only start if the gate is closed (and I add, locked). So there must be reliable sensors on the gate that tell the ride “I’m closed. You can start safely”. Who then decides what sensors are installed on the gate? How do these interface with the ride’s control system?
Through these simple examples I hope to have clarified even more why it was decided to formalise the DRA and OURA in the new European standard.
The practicality and usefulness of using European standard EN 13814 as the interface between manufacturer and park should also be clear. An acronym can suffice to give correct and complete information on a safety aspect that otherwise could require very long analysis and discussions. Clarifying right from the beginning “who does what and how”, including interfaces, is essential to avoid the risk of encountering unexpected difficulties, and even worse to not cover certain safety aspects.
In the next articles we will continue to examine risk assessment. There are still a number of interesting aspects that are worth investigating.
Read the –> Part 4
Taken from Games&Parks Industry Gennaio 2019, page 72
Gianni Chiari / Member of CEN/TC 152, ASTM F 24, ISO/TC254 Technical Committees and “Una Giostra per Tutti” project manager. email@example.com