Fast hoists speed high-rise construction in London

Two high-speed Alimak Scando 2837 passenger hoists and an Alimak 4000 kg-capacity ‘Mammoth' transport hoist are speeding the construction of the 147 m Strata Tower in London, UK.

All three hoists are mounted onto a specially built aluminium tower that minimises hoist installation and dismantling times and reduces the number of ties to the building.

According to contractor Brookfield Construction in London, the 90 m/min, twin-cage passenger hoists travel to the top of the tower in just over 90 seconds. That compares to over 6 minutes using conventional hoists.

Matthew Hewitt, Brookfield's project manager, said, "At peak times, we have to get 400 men to working height, so the reduction in travel time for one return trip alone is equivalent to a saving in excess of £1000 per day. Add to this the time to get materials to height during the working day, and the savings during the two-year life cycle of this project will be substantial."

The three hoists, on site since September and rented from Universal Builders Supply Ltd (UBS) in Huntington, Cambridgeshire, travel on masts attached to a single, specially built aluminium tower, which is tied to the 43-storey Strata Tower.

This tower, which is also supplied by UBS for the 60-week rental period, reduces the space required for the hoists. It also cuts the number of ties to the building, which minimises the number of cladding panels that need to be left off during construction.

Tony Faulkner, managing director of UBS, said, "The UBS towers are also far quicker to install and remove, so there are major savings at the start and the end of the project. The time and cost savings which the UBS system provide are even more critical with the financial constraints facing the construction industry in the current economic climate."

The double-masted Mammoth hoist carries up to 4000 kg of materials or 45 people, travels at a maximum speed of 40 m/min, and has a 4.2 x 3 m cage. "The Strata Tower is an innovative construction and incorporates unusual materials that cannot be accommodated in standard size hoists", said Mr Hewitt, "The Mammoth hoist is a real advantage for us as it means we can hoist all the large panels and non-standard materials to the levels they are needed."

The Strata Tower complex comprises two residential buildings with 408 apartments. They will house three wind turbines to generate power for the complex, and energy costs are expected to be 40% less than the UK housing average. Strata will briefly be the tallest building south of the River Thames.