This article has been written by David Playfor, Specification Manager, Saint-Gobain Weber
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 board game 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.
First, they had to clear the ground, then make and install all the various buildings with queue line fencing, after which they constructed the famous Jaguar Shrine and coordinated the ride installations and landscaping.
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 then fitted into the concrete before 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.
Selecting the right products
When specifying products for technical projects such as the ones for Merlin Entertainments, it’s important that the contractor works closely with a trusted manufacturer that has the right level of expertise.
As with all the products used on World of Jumanji rides, the grout needed to be robust enough to withstand years of sustained weight and high levels of movement. For this reason, B&E Services specified Saint-Gobain Weber’s webercem advanced repair concrete.
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.
What’s more, it has a high proven EBA (Effective Bearing Area) and under test, achieves a higher compressive strength on full cure compared to other similar products, making it suitable for use on a theme park ride.
It is proven to sit underneath base plates, with no holes or voids. Any stress transferred through the base plate will go through the grout, removing all the stress from the steel and the concrete.
Battling the elements
While the theme park was 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.
Before starting work, the team from B&E Services were shown how to mix and apply the product.
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.
Shutters were placed around the base plates to contain the areas that needed grouting and were removed once the product, which had been hand poured, had reached initial set.
Project manager Wayne Lawrence from B&E Services said: “The challenge was in figuring out when to add a chamfer, as we had to ensure we had enough time to do so after removing the shutters. It was definitely a learning curve.”
Wayne’s team used a trowel to scrape back the grout to make a smooth 45-degree angle all the way around each base, which would futureproof the structure.
The grouting was completed in February 2023, before the ride was opened to the public – along with the rest of the World of Jumanji – three months later.
Wayne concluded: “We are particularly proud of this job, and it was great to see the ride in action when all the hard work was over.”
