The south pylon of the £1.9bn Mersey Gateway bridge has been completed, marking the project’s highest point in the River Mersey estuary.
The south pylon now stands at 125m high, while the north pylon, which is due to be completed in the next few days, measures 110m high. The smaller central pylon, which is due to be finished in November, will be 80m high.
The Mersey Gateway project said that having the two outer pylons taller than the central pylon would give Halton’s new bridge a unique look among other major bridges in the UK.
A specialist automatic climbing system is being used to construct the bridge pylons. This equipment builds one vertical 5m section at a time then repeatedly “climbs” upwards to create the next section until the structure is complete.
The south pylon has been completed in 30 sections, and 27 sections for the north pylon. Twenty-one sections will be built for the central pylon.
A total of 2,230m3 of concrete was poured for the south pylon – almost enough to fill an Olympic-sized swimming pool – and 1,890m3 for the north pylon.
“Hitting the highest point on the project is a significant milestone and it’s a testament to the tenacity and expertise of our construction crews who have worked extremely hard, often in challenging conditions, to get the job done. We’ll be holding a special site celebration to thank all of the teams involved,” said Merseylink project director Gareth Stuart.
Merseylink said that the next phase of work, which involves installing steel stay cables to connect the three bridge pylons to the main bridge deck, will begin in the next couple of weeks.
Two specially constructed giant bridge building machines started work on the bridge in September this year, enabling construction of the 1,000m reinforced concrete bridge deck.
The six-lane river crossing is due to open in autumn 2017.