Maintaining Excellent Air Quality During Intensive Excavation Under 5-star Hotel

Project Overview

London’s Claridge’s Hotel was founded in 1812 and its long history has seen it recognised as a bastion of English hospitality. Over the years, its reputation for hosting royalty has led to it being dubbed ‘an annexe to Buckingham Palace’. The hotel’s superior service has been patronised by notables including Queen Victoria, Cary Grant, Audrey Hepburn and Alfred Hitchcock.

To augment the hotel’s already stellar status, the building is undergoing an innovative expansion into its subterranean space. The resulting five story ‘iceberg basement’ will house a swimming pool, gym, wine store and chocolatier, alongside new staff quarters and a conference centre. The additional 65,000ft³ will sit directly beneath the Grade-II hotel’s famously decadent tea rooms and restaurants.

Challenge

Hotel owners Maybourne engaged contractors McGee to engineer a solution to their ambitious plans. They stipulated that all work had to be carried out while the hotel, tea rooms and restaurants were in full operational use. Given the prestige of the hotel, guests would need to be completely undisturbed.

McGee mined a series of vertical shafts, installed new pilings and dug out five three-metre high basement levels to accommodate the new facilities. This intensive and dangerous work required a thoughtful health and safety plan. Primarily, they needed a flawless ventilation system to protect the health of the contractors working below. Without an adequate and tailored system, there wouldn’t be enough good quality air below to support the
personnel carrying out the tasks below ground.

Solution

The project called for 30,000m³ of material to be excavated – a feat that would produce enormous amounts of dust. Without an intensely powerful ventilation solution, the tunnelling and digging simply wouldn’t be able to go ahead.

RVT assessed how much air was needed and where the air needed to get to before proposing a solution consisting of Ventex 300M and 450S Centrifugal Fans combined with extensive ducting. The Ventex Centrifugal Fans were well suited to the cavernous environments opened up by McGee’s contractors. The ducting ensured that the right quantities of air reached the necessary parts of the shafts to ensure safe work. Both flexible ducting and in-built galvanised ducting was used to arrive at the final solution.

The whole system was tailored to fit within budgetary constraints and RVT conducted regular site visits to ensure that the air quality levels were
optimised for building personnel. In addition to the overall ventilation system, RVT also provided filtering equipment for use on specific pieces of plant to control hazardous exhaust fumes within the enclosed underground spaces.