Very serious accident with the roller coaster "Jetline" at Gröna Lund amusement park, Stockholm

Summary

The roller coaster Jetline has been at the Gröna Lund amusement park in Stockholm since 1988. The track was 800 metres long and a ride took approximately one minute, with a maximum speed of 90 km/h. The trains had a capacity of 14 passengers, distributed between seven cars.

On Sunday 25 June 2023 a train carrying eleven passengers crashed after having travelled roughly one third of the way round the track. At the time, there were three trains operating on the rollercoaster and the other two trains were located next to the place where passengers get on and off the ride. During the accident three people fell out of the train, which resulted in the death of one person and one person suffering serious injuries. Two of the passengers who remained seated in the train were seriously injured and the others escaped with minor injuries.

The fire and rescue service, ambulance service and police were called, and all passengers had been taken care of one hour after they arrived. The rescue operation was under the prevailing circumstances conducted in an efficient manner.

The accident occurred when the control arm (part of the wheel suspension) at the very front of the train broke. The parts of the control arm with wheels on either side of the train came completely loose and fell off. This led to sharp decelerations when the car’s chassis sunk down towards the track and hit joints in the track structure.

The sharp decelerations resulted in the passengers being thrown forward against the lap bars. This resulted in three of the passengers falling out of the cars and some suffering serious internal injuries. The design and dimensioning of the lap bars contributed to the serious consequences for the passengers.

The break in the control arm occurred as a result of insufficient strength caused by defects in weld joints and because an essential part inside the tubular structure was missing. The control arm was one of five that was ordered and manufactured in 2019.

The investigation shows that when the control arms were ordered sufficient requirements were not set with respect to how they were to be manufactured and the manufacturing process itself. Nor were sufficient checks conducted of the workmanship during manufacturing and before the control arms started being used. The safety management system conducted at Gröna Lund did not result in adequate accident safety on the rollercoaster.

The investigation also shows there are deficiencies in the rules for amusement rides and insufficient public supervision.

The fact that the lap bars were not able to keep the passengers inside the cars during the accident and caused serious injuries means that there are reasons to consider whether the requirements with respect to the restraint of passengers on rollercoasters need to be changed.

Causes/Contributing factors

The accident was caused by failings in ordering, manufacturing and verification of new control arms on the trains operating on Jetline. This led to a control arm with insufficient strength being used on the train and breaking.

A contributing factor to the serious consequences of the accident was that the passenger restraint structure was not designed for the forces that arose.

Underlying factors for the accident at a systemic level were:

• The lack of a fixed and established method at the amusement park for identifying, assessing and managing risks associated with the attractions.
• Unclear rules concerning the operator’s responsibility for safety.
• Insufficient public supervision.

Safety recommendations

Gröna Lund AB is recommended to:

• Improve its safety work relating to attractions so this, as a minimum, ensures that:
• risks in the form of organisational and technical failings that may lead to accidents are continually identified, analysed and rectified,
• procedures are drawn up which ensure that replacement parts comply with the requirements originally set for the attraction in question,
• checks are tailored to the operating time of an attraction and identified risks,
• the entirety of the safety work is frequently followed up, evaluated and, when necessary, revised.

The Swedish Police Authority is recommended to:

• Conduct a review of the regulations concerning amusement rides. The aim of this review should be to increase the level of safety, including by ensuring that:
• amusement park and funfair companies’ responsibility for safety is highlighted more clearly, including the fact that this responsibility encompasses all the measures required in order for the attraction to have satisfactory accident safety,
• the need for systematic safety work is reflected,
• specific requirements for checks and inspections are introduced in order to ensure that an amusement attraction has not been subject to alterations or interventions that may reduce the safety of the attraction,
• the general advice concerning record-keeping is supplemented so that the record for each attraction also states what maintenance measures, alterations or interventions have been implemented on the attraction,
• references to applicable standards are updated,
• it is made clear that the requirements concerning operation and maintenance in applicable standards also encompass amusement attractions manufactured prior to 1 July 2006.
  
  
• If the review leads to the Swedish Police Authority making the assessment that sufficient changes are not possible at the level of regulations, the Police Authority should hand over the matter of necessary legislative changes to the Swedish Government.

The Swedish Government is recommended to:

• Take action to strengthen public supervision of amusement parks and funfairs. Stronger supervision should include the potential to implement continual supervisory measures and supervisory visits. These activities should also include advice and information for amusement park and funfair companies about the requirements placed on the safety of amusement attractions and how these can be complied with, for example through risk analyses and a systematic approach to safety work.
  

• When necessary, take action to ensure it is possible to bring about the changes to the regulations set out in the recommendation to the Swedish Police Authority (SHK 2024:07 R3), or that equivalent changes are implemented through legislation.

The International Association of Amusement Parks and Attractions (IAAPA) is recommended to:

• Disseminate SHK’s final report to its members and in its safety forums in order to provide members with evidence upon which to assess whether there is a need to alter requirements for restraint devices in rollercoasters. When providing such information, the observations in the report about the need for a systematic approach to safety work and the use of replacement parts in rollercoasters should also be highlighted.