Mandrill Mayhem, World of Jumanji

Mandrill Mayhem photos courtesy of Merlin Entertainments

Sony Pictures’ film franchise Jumanji continues to delight families almost 30 years after the first film was released. It has proved to be such a hit among people of all ages that Merlin Entertainments opened the world’s first Jumanji-themed park. The company, which manages over 140 global attractions - including the London Eye and Sea Life aquariums - spent years planning and designing the area at its Chessington World of Adventures Resort in Greater London.

World of Jumanji was officially opened in May 2023 and marks the single largest investment in the theme park in its history. It contains three rides – Mandrill Mayhem, Ostrich Stampede, and Mamba Strike – plus other Jumanji-themed activities, including a maze of pathways reminiscent of the boardgame in the film. 

There are also six World of Jumanji-themed bedrooms at the Chessington Safari Hotel, for those who opt to extend their stay.

FROM PICNICS TO PLAYTIME

To construct World of Jumanji, Merlin Entertainments contracted B&E Services Ltd as main contractor and for many of the construction elements.

The family business, based near Salisbury, has worked for Merlin Entertainments on several occasions at Chessington World of Adventures as well as many of its other theme parks, undertaking project management, steel works, theming works, ride erecting, and grouting. B&E Services was tasked with transforming a former picnic area into the World of Jumanji – a job which took 18 months from start to finish. The area’s main attraction is Mandrill Mayhem – the park’s first rollercoaster with inversion, meaning riders are turned upside down.

The ride mimics the film series sweeping the riders up in the long arms of a mandrill before being flipped upside down at 42 miles per hour, while dodging the hazards of the jungle. They then spiral to the summit of the 55-feet-tall Jaguar Shrine before falling and braving the adventure again – but this time backwards.

THE MAKING OF MANDRILL MAYHEM

For any theme park ride, safety is paramount. Crafting the illusion of danger without compromising safety requires precision engineering and careful manufacturing.

The experienced team began the process by installing the ride’s steel stanchions onto washers to level each one. Bolts were fitted into the concrete and the ride sections were connected. A total of 144 tons of steel track were used to build the rollercoaster – the equivalent weight of 96 hippos.

Once it was all rigid and held securely in place, the shims were removed so grouting could begin. Grout needed to be placed in the resulting gap between the concrete and base plates as equipment and machinery have precise tolerances for alignment. They therefore cannot be placed directly onto the finished concrete, so the grout becomes the load transfer between the concrete and the base plate.

WORKING WITH WEBER

In October 2022, Wayne Lawrence from B&E Services contacted Saint-Gobain Weber. Weber has always been a preferred manufacturer for Merlin Entertainments so the team from B&E Services are familiar with its products, having used them for several projects.

Under the guidance of Weber, webercem advanced repair concrete was specified. It is a high strength product that is primarily used to repair concrete but is versatile enough to be used as a precision grout for depths where other grouts may not be suitable. It can be applied to a depth of up to 500mm and will self-level due to its fluidity.

Weber’s Advanced range of products have a high proven EBA (Effective Bearing Area) and under test, each has a minimum of 45MPa strength. webercem advanced repair concrete achieved a higher MPa on full cure, making it suitable for use on a theme park ride.

All are proven to sit underneath base plates, with no holes or voids. Any stress transferred through the base plate will go through the product, removing all the stress from the steel and the concrete.

Weber arranged to visit Wayne and his team on site to offer advice on how to mix and apply the product. Shutters were placed around the base plates to contain the area that needed grouting.

BATTLING THE ELEMENTS

With the theme park closed for winter, grouting began in the days between Christmas and New Year 2022, which meant weather conditions were less than ideal. It rained a lot, meaning each area had to be thoroughly cleaned and cleared of mud before application began.

To stop cracking in the concrete bases, the ride manufacturer requested a chamfered edge. This ensures that water will run off the edges helping to maintain the durability of the application.

Wayne said: “It was a learning curve to understand the best point at which to add a chamfer, but Weber assisted us with advice and technical support to identify the best process”. The grouting was completed in February 2023.

Click Compare to help you choose the right product for your project, if you need further assistance please email technical@netweber.co.uk

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