Project Director Ken Larsen has confirmed that Alstom has almost completed the construction of a new state-of-the-art 2,160MW combined cycle gas turbine (CCGT) power station for RWE npower at its Pembroke site in Wales.
The £1 billion project began in summer 2009 and plant construction will be essentially completed in the first quarter of 2012.
Pembroke Power Station will be the largest combined cycle plant in the UK and is the seventh gas turbine project in the UK using the KA26 gas turbine. It was the second contract awarded to Alstom by RWE npower in less than two years, following the Staythorpe power station in Nottinghamshire. Ken Larsen said: “This will be one of the most efficient gas burning power stations in Europe, with up to 60% thermal efficiency, and it will certainly be a key asset of RWE npower for the future.”
Alstom are the principal Engineering, Procurement and Construction (EPC) Contractor leading for the execution of the project and also have a long-term operation and maintenance contract. The company is a key player in the UK, having constructed twenty gas-fired power plants, which produce over 12GW.
Main contractors for the project are Shaw Group UK Ltd, who erected the Heat Recovery Steam Generators. Dornan Engineering Limited provided the power cabling and control systems installation, ZRE were the main shaft line mechanical erection contractor and Sisk UK Ltd were responsible for the civil works. The mechanical cranes were installed by Morris Material Handling Ltd, the water treatment plant was installed by Hager + Elsässer Ltd and Motherwell Bridge Ltd provided the main water tanks. Lectec Services were responsible for the general lighting and power systems, whilst Tyco provided the fire systems and Quadrant Security installed the security systems. Gas storage was provided by BOC Ltd and Interserve Industrial Services were responsible for the installation of insulation and cladding for the piping systems. DWLS Ltd installed 50 ursig modules weighing from 200 to 270 tonnes each. A number of small local contractors, such as Port Engineering, were also used for miscellaneous construction activities.
The new Pembroke Power Station has been constructed on the site of the previous oil-fired power station and comprises five operating units, each of which operate as an independent power plant and comprise a gas turbine, steam turbine and generator. The design of the building is one of Alstom’s standard concept designs for a combined cycle gas turbine layout for five units, optimised in conjunction with RWE npower.
The project comprised two types of construction: assembled equipment in a package unit format (such as the gas turbine, steam turbine, generator, transformers, medium/high pressure pumps, electric motor drives and boiler components) and miscellaneous materials. The miscellaneous materials included: steel work and cladding, pipe work, valves, power cabling, control systems, tanks, pressure vessels, pumping units, heating ventilation, air conditioning systems, small power systems and security systems including CCTV and intruder detection systems.
As several of the key components of the power station came fully assembled, the project was able to facilitate an accelerated construction process. As a result, the civil engineering construction and the mechanical and electrical engineering construction have been performed ahead of the contract programme. A key example of innovative construction techniques was the offsite full prefabrication of the Feed Water Towers that were transported in modules from the fabrication facility in France.
A comprehensive programme of civil works was also been carried out. This included ground improvement works, foundation engineering, foundation construction, building superstructure construction, reinforced concrete superstructure, landscaping, roads and drainage.
Ken Larsen said: “The construction of Pembroke so far has been a success in every manner. First of all, the cooperation between Alstom and the RWE has been second to none. The performance of the key stakeholders – the civil, mechanical and electrical contractors, and the worldwide suppliers – has been excellent. Indeed, the equipment has been supplied from all over the world – Mexico, USA, China, Western Europe and the UK – and it has been delivered either on time or ahead of time, to very high standards.
“The project demonstrates a major success for the UK engineering construction industry, an industry that has been through a very difficult time in the last twenty years and is reduced on a year-to-year basis due to the downturn in general engineering construction projects. The project is seen as a major success and is backed by the three major trade unions.
“From an industrial relations point of view, the project is seen by all as a tremendous success and there has been excellent cooperation between all the parties.”
However the project was not without its complications, as Ken Larsen went on to explain:
“The construction was carried out to an accelerated pace, which presented many challenges to the team. I think first of all, logistics had to be carefully considered: getting the heavy oversized cargo onto the site was very challenging, especially as the cargo came in by both road and sea transport. The various consignments were transported and offloaded at site, some over a transportation weight of 300 Tonnes , on occasion, logistical operations were exacerbated by weather conditions.
“There were also many regulations, laws, standards and requirements that we had to obey and follow. This was particularly apparent in relation to Environment, Health and Safety: any large industrial projects operating in the UK now have to fully comply with the very onerous EHS standards that are now mandatory by law. When you consider the location, design, logistics, the presence of over 2,000 construction operatives to support the build of the plant, the complex build team, the time scale, the industrial relations criteria, the environmental, health and safety legislation and the fact that we had to build the plant to a certain quality, it must be conceded that, as a turnkey package, it was a very complex project.”
One of the key features of the project has been the impressive standards of Health and Safety. Earlier this year, the projected was audited by the British Safety Council (BSC), who conduct comprehensive audits and in the case of Pembroke, Alstom and all of the key stakeholders, scored 98.64% across 57 different parameters. As a result, the project was awarded the BSC ‘Sword of Honour’ for EHS excellence, the highest award in the UK industry.