How long does a ride last? The European standard defines that the minimum requirement for calculating the fatigue strength of a ride’s structure should be based on 35,000 operating hours, however how is lifespan calculated in practice?
 
THE RIGHT DURATION
by Enrico Fabbri
 
A few weeks ago, I was speaking to an Italian manufacturer of crane trucks, and together we were examining the cost of a used product compared to a new one. He explained that, after 20 years, a crane truck is at the “end of its life” and a major overhaul would be needed to “extend its life” further. I wonder why then it’s quite well known that a crane truck has a life of around 20 years yet almost no-one knows precisely how many years a ride can be used for. EN-13814 states that the minimum requirement for calculating the fatigue strength of the structure and the main components is 35,000 operating hours, but exactly how many years of operation does this number correspond to?

In simple terms, the designer of a ride/attraction needs to consider a standard operating cycle (for example, 90 seconds), then hypothesise the number of cycles the ride completes in one hour (for example, 20). Based on these assumptions, the conclusion can be made that for every hour of operation, the ride/attraction will have used up around 30 minutes of its lifespan. If the ride were operated for 10 hours a day, 365 days a year, it would reach the end of its life (the 35,000 operating hours specified in EN-13814) after around 20 years. If the same ride were, on the other hand, operated for 5 hours a day, 365 days a year, it would reach the end of its life after around 40 years.

Having said this, the manufacturer is responsible for defining the ride’s lifespan in the user and maintenance manual, also taking into account the significant inevitable effects due to corrosion, which may be expressed:
(a) in terms of effective operating hours remaining, using a ride operating hour counter;
(b) by establishing a fixed number of years to determine the end of its life.

In essence, if we were to call any manufacturer and ask for details on the lifespan of any specific ride or attraction, we would probably not have an immediate reply, and in the same way it is very likely that the manufacturer’s user and maintenance manual does not show this information.

To ensure greater clarity for customers, I feel that ANCASVI (through its Technical Committee) should recommend that all Italian manufacturers specify the minimum lifespan of a newly-constructed ride as a fixed number of years, for example, 20, regardless of how intensely it is operated. This then raises another question: what should the lifespan be of rides that have already been on the market for 20 or 30 years? How was fatigue calculated and quality control applied at the time?

It isn’t easy to answer this question, however I believe that it’s essential to do so in the most professional way possible. We know, in fact, that no ride/attraction can operate safely for an indefinite time, especially if the ride/attraction is subject to wear and exposed to the weather. Consequently, operators and inspectors need to be given effective guidelines. These should take into account both technical information on the attraction, where possible provided by the manufacturer (if still in business) as well as historical information of any known structural defects. In the event where significant defects have been reported, the lifespan of an existing ride should be lower than the norm.

Finally, I feel that this information should be readily available on the Internet to potential customers, allowing them to take suitable measures and make cost evaluations.

 

 

 

Written by Mr. Enrico Fabbri enrico@fabbrirides.com
Article originally published in Games Industry (Italy) magazine
Original date: January 2016

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