How passenger safety systems on major rides need to be kept updated.
 
DOUBLE SAFETY FOR RIDES IN WHICH PASSENGERS RIDE HEAD DOWN
by Enrico Fabbri

Major attractions require a system that ensures rider safety even in the event of a major component failure. Let’s then look at what ‘redundant’ safety means. All rides on which the passenger rides upside down, or more generally those on which the rider is almost completely lifted from the seat, must have a safety system that complies with the strict regulations of EN-13814. Operators must therefore verify that their attraction is up-to-date and, if necessary, make appropriate changes.

The reason why a more rigid restraint system is required is due to the fact that a possible passenger fall could lead to death or serious injury. This is why the European standard establishes very stringent minimum requirements. Riders are secured in their seats by a lap bar or shoulder bar; there are also mechanisms to ensure that the bars remain in a safe position while the ride is moving. So what features do these bars and mechanisms require?

The lap bar is generally constructed from a steel tube whose diameter and thickness relate to the maximum acceleration that the passengers are subjected to. When passengers ride upside down, they push on the bar with their own weight, plus the dynamic acceleration generated by the ride’s movement. Generally, it is considered that the minimum thickness of the steel tube must be at least 2.5mm to prevent problems due to corrosion, which is often not visible.

Then there is the coupling between the bar itself and the safety mechanism, which usually involves at least 2 points. This is very important, as the mechanism as a whole must hold even if one of the 2 fixing systems yields.

In the figure on the right we can see what it means to have a ‘redundant’ system: specifically it means that the mechanism must work even when one of the 2 components fails. Of course, one of the 2 fixing points may give way (due to a broken weld or hidden rust) and therefore the second coupling must be strong enough to continue to guarantee passenger safety.

Now let’s look at the passenger safety mechanism. This is generally a system provided with mechanical latches that engage in a toothed bar so as to allow appropriate adjustment of the bar’s angle of action. All manufacturers develop their own systems; some use special hydro pneumatic cylinders that basically perform the same action as the latch. Applying the reasoning of ‘redundant’ systems seen above, it is therefore necessary to have 2 independent safety mechanisms, one for each side that the bar is fixed to. If latches are used, the mechanical holding springs must be the highest quality, and it is preferable to have at least 2 metal springs for each latch (in case one fails).

We come now to the monitoring systems. Before starting the ride, it is necessary to check that the passenger bar is closed and that the safety mechanism is activated. Therefore, a sensor must be fitted that signals when the bar has been lowered. Other sensors are also needed, positioned on each latch, to signal that the mechanism is properly engaged.

As can be seen, this is a complex series of systems that requires a high level of professionalism in the design stage. For this reason, the costs relating to the safety of each individual passenger can easily reach € 2,500. Finally, it must be remembered that passenger safety mechanisms need to be inspected often and tested every day before using the ride with passengers.

 

 

 

Written by Mr. Enrico Fabbri enrico@fabbrirides.com
Article originally published in Games Industry (Italy) magazine
Original date: November 2017

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