Finding fully submersible brake motors became a quest worthy of a Norse legend for the engineer in charge of maintaining the world famous Valhalla ride at Blackpool Pleasure Beach, one of the UK’s premier tourist destinations.
Valhalla has been scaring the wits out of unsuspecting pleasure-seekers for over a decade. Based on a traditional log flume but using Viking longboats, it is a dark ride nearly a kilometre in length. Special effects encountered along the way include fireballs, water torrents, snowstorms, screams, howls, thunder and lightning. Each boat drops down rapids, sails through waterfalls, twists and turns on its axis, rocks and rolls. Riders are drenched, frozen, blasted by winds and almost tipped over a long, long drop – all in the name of fun!
Not surprisingly, behind the smoke and mirrors Valhalla is a masterpiece of engineering which has to be carefully maintained to the highest safety and performance standards.
One of the critical parts of the ride is the entry/egress station. This is beautifully constructed to set the tone of the ride, while providing clear routes to and from the boats. It is also where returning boats are marshalled and made ready for the next riders. As the ride has a capacity of 2000 people per hour and each journey lasts approximately six minutes, the need to handle the boats efficiently is paramount.
In fact the handling seems effortless, thanks to a clever and totally discrete automated system. The returning boats are directed into a canal-like passage, which seems only just wider enough to accommodate them. However, they progress along the passage unaided while they are visually checked and any water in the bottom is pumped out, until they arrive at the loading station ready for the next group of eager passengers.
In fact the boats are being driven by underwater booster wheels. These are actually flanges upon which are mounted uninflated car tyres, which nip the hulls and power them forward.
There are 24 boosters, with each wheel driven by an electric motor immersed in the canal, fully underwater and therefore hidden from view. A series of proximity sensors control the motors and thereby ensure their orderly and timely passage along the canal.
The motors were supplied by Rotor UK of Wellingborough as part of a recent project to install the automatic boat handling system. They are IP67-rated units, so are protected against the effects of constant immersion to a depth of 1m.
Steve Hughes, Director of Engineering and Projects, explains that with the limited space available, submersible motors were the only viable option. He says: “We want our paying guests to have a total experience, which includes hiding the practical and mechanical elements from view. Providing wide, safe walkways meant we were very limited for space and the motors had to go under the water.”
Efficient handling necessitated not only that the boats could be propelled forward, but that they could also be stopped and held in a number of intermediate positions, ready to proceed when needed.
Steve recalls: “The solution for this requirement seemed obvious – brake motors. These would be compact, so fit into the canal. Further, as integral units they would be easy to install and reliable for long term operation.
“However, we soon discovered that IP67 brake motors are about as common as Viking jet skis and began to contemplate the prospect of a complete redesign.”
Fortunately one company – Rotor UK – was able to meet Steve’s needs and the original design could be implemented. Rotor UK is part of the global Regal Group and has a product range that includes industrial, marine and ATEX motors, plus many specialist motors. All of its standard motors can easily be fitted with a brake, so the Valhalla project was well within its capabilities.
Steve says: “When we spoke to Rotor and confirmed that they would be able to meet our exact requirements, it felt like an ancient curse being lifted. Of course our guests are never aware of the trials and tribulations that go on behind the scenes. That is how it should be – to them Valhalla should be the ride of a lifetime, not an engineering marvel!”
Go to www.rotor.co.uk to find out more about brake motors and other products from Rotor.