Aug 15 2021

Alimak delivers access solutions for bridges and tunnels

Bridges and tunnels present a range of unique access challenges, with each project encompassing a specific set of requirements. This applies to temporary access solutions during the construction phase and permanent access requirements for the ongoing access during inspections, maintenance, and emergencies for bridges and tunnels.

The extensive range of Alimak construction hoists and industrial elevators are particularly well suited to the needs of bridge and tunnel applications, with a portfolio of successful installations located across the globe.

For temporary solutions used during construction, Alimak was entrusted with the provision of three specialist construction hoists for perhaps the most famous tunnelling project in the world; the Channel Tunnel undersea rail link between the UK and mainland Europe.

This construction hoist system delivered efficient and reliable access via a shaft 100 metres deep and 9 metres in diameter. A rolling 24-hour, three-shift system saw a staggering 1,200 workers transported via these construction hoists each day. The system encompassed one double-deck Alimak Scando 20/30 traveling at 28 metres per minute, as well as two Alimak Scando Super 28/37 units travelling even faster at 96 metres per minute. This provided the functionality required for this vast engineering feat, carrying up to 106 passengers and 8.8 tonnes of cargo in every trip. The system also proved its hard-wearing build quality, traveling an estimated 65,000 km during each year of operation.

For permanent solutions, Alimak’s range of industrial elevators are ideal. Alimak was commissioned to deliver a vertical access solution for the Rama VIII cabled-stay bridge, located inside the unusual form of the inverted Y-shaped pylon.

Not only does the bridge provide a vital crossing over the Chao Phraya River in Bangkok with a span of 300 metres, but it is also home to an observation platform offering a breathtaking 360-degree panorama of the city. The bespoke Alimak SE 500 elevator built on rack and pinion technology is specially designed to travel up one of the pylon legs at an incline of 13 degrees. It then transitions to a higher speed to complete the climb of the vertical section, reaching a height of 151 metres. This was achieved with a mainframe divided into five sections to allow for a curved guide rail in the lower section.

The rugged rack and pinion drive system first introduced by Alimak addresses the key challenges inherent in bridge and tunnel access. The hard-wearing design is capable of withstanding harsh conditions while lifting to great heights or descending underground.

There is no requirement for a separate machine room, which provides significant space-saving in applications where this is often a critical issue. Alimak’s elevators can also be adapted to travel through inclines, curves, and tight openings, which are commonly unavoidable due to a bridge or tunnel design parameters.

Get in touch to find out how we can meet the needs of your project.