Author: Barry Hembling
Quantitative risk assessment techniques are changing the way in which amusement rides are designed, inspected and operated. Modern rides are becoming dependent on computer-based technology with control systems allowing rides to perform increasingly complex functions at very high speeds. Passenger safety can depend on the correct operation of control systems and their failure could compromise safety.
Such developments mean that quantitative risk assessments are increasingly being applied to amusement rides.1 A quantitative risk assessment involves calculating the magnitude of a potential loss and the probability that such loss will occur. An acceptable risk is only understood or tolerated where the cost or difficulty of implementing an effective countermeasure exceeds the expectation of loss.
The importance of quantitative risk assessment techniques was confirmed by a November 2016 study on the generic safety-integrity requirements of amusement rides. The study, which had input from a steering committee of industry representatives, illustrated the benefit of applying quantitative risk assessment techniques to the themed entertainment industry.
Whilst quantitative risk assessment techniques have become commonplace in other industries, they have been slow in moving to the themed entertainment industry. The new study illustrates how such techniques can be used to determine the target safety-integrity level for control systems of diverse types of rides with the intention of encouraging their use. Having determined the target safety-integrity level, a designer can then use appropriate techniques, such as multiple channels or extensive internal diagnostics, to ensure that the rate of potentially dangerous control system failures is sufficiently low.
Even in advance of being compulsory, quantitative risk assessment techniques are quickly becoming established as industry best practice which anyone involved in the design, inspection or operation of rides may be expected to have considered or followed. In the event of an accident, parties could be shown to be at fault if the designed control system fails to satisfy a target safety-integrity level. Where quantitative risk assessment techniques have not been considered, parties might be required to justify why that was considered appropriate.
In terms of what these developments mean for those in the industry and the practical steps that can be taken the position is as follows:
1 A study of the generic safety-integrity requirements of fairground rides, A M Wray, Health and Safety Executive (RR1080 Research Paper), November 2016
Barry Hembling, Partner, Fladgate LLP (firstname.lastname@example.org)