Rollercoasters have come a long way in engineering terms. They have origins in fifteenth century Russia, but the latest generation of these machines have taken performance to another level, creating forces that demand the highest standards of engineering and maintenance. For this reason, one of a new breed of hypercoasters relies on Loctite engineering adhesives for its threadlocking and retaining needs
The Silver Star is a super-tuned 1620m-long, 73m-high hypercoaster that travels at speeds of up to 130km/h. Its performance equals the acceleration and G-force of a Formula One car, but without an engine. The speed and passenger load are constantly calculated to apply just the right amount of magnetic braking, but vibration needs to be kept to an absolute minimum, and this is where Loctite comes in.
The safety bars that hold passengers in their seats are checked every day and annually stripped down completely for detailed inspection. When re-assembling, the maintenance engineers use Loctite 243 to threadlock the bolts that connect the ratchet components to the main bar. This product is part of the Loctite range of threadlocking adhesives that prevent self-loosening and secure any threaded fastener against vibration or shock loads. It fills the gaps between mating threads and eliminates fretting corrosion by creating a unitised assembly.
Chief Engineer in charge of Silver Star maintenance, Hans Volz, explains: “Because Loctite 243 is medium strength, it is strong enough to withstand the loads and vibrations but can be disassembled for maintenance. It is perfect for us.”
Guide wheels are crucial to providing a fast but safe ride, and keep the train locked to the track from above, below and from the side. Like the safety bars, the wheel units are checked daily and subject to thorough inspection and re-assembly annually. The steel ball-bearing cages must be completely removed from the aluminium wheels during this process.
Because aluminium expands faster than steel, engineers warm the wheels to 70degC which allows them to simply push out the steel ball bearing cage. They then clean all surfaces with Loctite 7063. This is a general purpose cleaner and degreaser that leaves no residue and is suitable for use prior to adhesive bonding and sealing applications.
Loctite 638 is then applied to re-fix the cage. Widely used to secure bearings, bushes and cylindrical parts, this high strength retaining compound has been formulated to provide resistance to dynamic, axial and radial loads. It achieves maximum load transmission capability, uniform stress distribution and also eliminates fretting corrosion.
Bolts that secure the ball-bearing cage casings and those that fasten the wheels to the train are then threadlocked with Loctite 243. Engineer Achim Stoss concludes: “This product saves us a lot of time but does not compromise reliability in any way. It holds tight for as long as we need it to but we can still dismantle parts with hand tools.”
To find out more about Loctite engineering adhesives, go to the website at www.loctite.co.uk.