Heathrow Terminal 5

Heathrow Terminal 5 is one of Europe’s largest and most complex construction projects. With 16 major projects and over 147 sub-projects, it has encompassed a vast and hugely complex programme of works. Lauded by many as a template for major construction projects of the future, Terminal 5 has pushed the boundaries of traditional construction by harnessing innovation and best practice from other industries and translating it into mainstream construction management.

In addition to the main terminal building, Terminal 5 also consists of two satellite buildings (the second of which will be completed by 2010), 60 aircraft stands, a new air traffic control tower, a 4,000 space multi storey car park, the creation of a new spur road from the M25, a 600 bed hotel, the diversion of two rivers and over 13 kilometres of bored tunnel, including extensions to the Heathrow Express and Piccadilly Line services.

This work encompasses a multitude of construction related skills including civil engineering, building, highway engineering, mechanical and electrical engineering, tunnelling, railway engineering, specialist systems technology and project logistics management.

The 16 inter-connecting core projects included:

Airside and landside civils
Earthworks
Airfield
Western Perimeter Corridor including the Twin river diversion
Landside campus

Buildings
Main terminal building – T5A
Satellite building- T5B
Heathrow’s new air traffic control tower
The energy centre

Rail and tunnels
Heathrow Express extensions
Piccadilly Line extensions
Airside road tunnel
Tracked transit system

Others
IT systems
Baggage
Special projects including the M25 spur road
Logistics and temporary site facilities

Project Overview

Heathrow T5A and B and associated construction projects are the biggest contracts EA have ever been involved with. AMEC project manager George Adams wanted EA involved at an early stage of the project as part of the design team responsible for thermal expansion compensation of all pipe work systems. A contract was signed for 30 days of upfront flexibility analysis. Specification criteria were very stringent including a design life expectancy of 30 years. EA used it's unrivalled experience in expansion design to work out the minimum amount of expansion bellows required. The task was further complicated by the modular design for the offsite fabrication of the pipe modules. Despite this the final design still used well over 1500 expansion joints. EA's Multiply expansion joint technology ensures that the anchor forces are kept to a minimum while absorbing large movements in pipe runs over 1.5km long. Many design changes during construction added to the overall challenge but the final result is a safe and long lasting installation which started up without any problems.

EA was also involved with the supply of pressurisation systems and deaertaion. The original design was done by PB Power in London. The systems are some of the largest we have seen in the UK with system contents of 570l for the heating circuit and over 1 million l for the chilled water. Due to the large load changes expected within the heating installation a Transfero pump controlled system with a total of 4 pumps and a maximum capacity of 28 000 l per hour was chosen. In total 4 x 5000 l pressureless expansion vessels with 100% capacity were required. for the primary circuit alone. For the chilled water installation a compressor system was selected to give maximum levels of resilience. 5 x 2200l pressurised vessels with 100% acceptance were selected to cope with the contraction and expansion of the primary chilled water system. No fewer than 8 compressors supply the vessels with air and keep the system at a constant pressure within +/- 0.2 bar. All systems were skid mounted to speed up installation and reduce the potential for errors on site.

Both chilled and heating systems were fitted with Vento pressure step degassers to keep the system free from air. Due to the large volumes each system needed several degassers for optimum performance.

Products Supplied by Engineering Appliances

TRANSFERO
Primary Heating System
COMPRESSO
Primary chilled
VENTO
Pressure Step Degassers
EXPANSION JOINTS
Pipe work