According to the 2017 London Tall Buildings survey, there are now 455 towers in the pipeline, of which 420 are marked out for residential use.
With an increasing number of new skyscrapers and tower developments set to transform the capital’s skyline, the demand for new and efficient high-level access systems is growing.
One of the beneficiaries of this increase in demand is Hertfordshire-based Brogan Group, which claims to be one of the few access contractors in the capital that can offer design, hire and installation of common user towers – so called because they are provided for the use of everyone on a project.
A common user tower is a temporary structure tied to a high-rise building during construction to provide a common means of access for all trades and goods while reducing the need to leave openings in the building.
Goods hoists can be attached to all three of the open sides of the tower, which might also incorporate an escape staircase.
By thus positioning hoists and temporary staircases in just one concentrated area of the building, work such as cladding can be carried out more efficiently on the entire envelope of the building, with the exception of only the one section where the common tower ties in.
This system also allows for the fit-out of the lower floors to commence earlier while the building is being constructed.
Fit-out can also be carried out rapidly as the tower/hoist combination allows contractors to fully exploit floor level openings and optimise the use of the floor heights when distributing cladding and installing prefabricated pods. The deck level can be set either flush with the slab level or above it depending on requirements.
Brogan’s latest project is the Madison Tower, a £150m, 54-storey residential development being built by Balfour Beatty for developer LBS Properties at Canary Wharf in London.
Here Brogan has just delivered its common tower – developed by Welsh specialist CAS Scaffolding in 2010 – together with a twin passenger/goods hoist and its latest product, the Colossus hoist which Czech manufacturer Stros developed for Brogan specifically for this project.
The CAS common tower was chosen due to its ability to accommodate the height of the prefabricated bathroom pods which Balfour Beatty wanted to get into the building via the Colossus hoist, rather than monopolise valuable tower crane time.
“The Madison project is unique because we have two large critical components – the bathroom pods and the curtain wall stillages – which must be transported vertically and distributed to the floor plate via the Colossus, up the common tower,” explains Jack Bird, Balfour Beatty’s façade manager on the project.
Considerable time and engineering assistance was required at the early stages of the design to ensure that Brogan could get the common tower and Colossus hoist to work with the pod heights, he adds.
As the name suggests, the Colossus hoist is Brogan’s largest hoist – in fact the company believes it is the largest of its kind currently on the market.
With a length of 5m, a width of 3.1m and a height also of 3.1m, the electrically-driven Colossus can safely carry 40 passengers or 4,000kg of equipment to a height of 350m at a speed of 40m/minute.
The Colossus, twin passenger/goods hoist and a staircase all run off the common tower to provide access to the building through an entry point just 3m wide. This means that the amount of façade and internal finishes that have to be left unfinished is kept to a minimum.
The combined system of common user towers and hoists for high-rise construction allows for faster and more efficient builds as lower floors can be fitted out while the upper floors are still under construction.
Brogan won the access contract – valued at more than £2m – following a competitive tendering process, having previously worked with Balfour Beatty on other major projects including Providence Tower and the London Olympic stadium reconfiguration.
Erection of the common tower and hoists began last month (February 2018) and the project is due for completion towards the end of next year.
This article was first published in the March 2018 issue of The Construction Index magazine, which you can read for free
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