Hub River thermal power plant

Located 70 km west of Karachi, the Hub River thermal power plant was the first private energy-production project in Pakistan to receive international funding and support from commercial banks. It consists of four generating oil-fired units each rated at 323 MW gross output, located along the Arabian Sea, at the mouth of the Hub River, in the province of Baluchistan. This power plant with a capacity of 1,292 MW includes two remarkable construction features: a water intake built in the sea 200 metres from the shore, and a smokestack measuring 200 metres in height and 23 metres in diameter.

Background

In 1987, the Government of Pakistan invited the private sector to submit proposals for the design, funding, construction and management of thermal power plants. Among the twenty proposals received, only two were recognised. These proposals called for the construction of a 600 MW power plant that would provide electricity to the Water and Power Development Authority. However, the sites proposed by each group were not suitable: either for economic or environmental reasons. The Government of Pakistan then chose an appropriate site to build a 4 x 323-megawatt power plant at the mouth of the Hub River, and asked both preselected parties to combine their efforts to promote the project. The site located at the mouth of the Hub River in Baluchistan province was selected to provide easy fuel supply from Karachi and a connection to the WAPDA transmission network, across the almost uninhabited Baluchistan desert.

Technical overview

The civil engineering package included various civil engineering works: construction of a seawater intake, construction of the power plant and its associated structures, including a 200-metre smokestack, earthworks for platforms, and digging of two hydraulic canals to supply the power plant with seawater, previously desalinated and demineralised, and its eventual discharge into the Hub estuary. The seawater intake and the smokestack are unique given the complexity of their design. The seawater intake was constructed in the ocean, 200 metres off the shoreline to prevent any risk of silting. Dry construction was possible thanks to the erection of a large provisional platform 300 metres in length and 50 metres in width reclaimed from the sea (190,000 m3 of backfill material). Completion of the six sequential cribs to accommodate the seawater intake and the cast concrete front channel required special techniques, given the nature of the ground.
The 200-metre smokestack comprises a continuous reinforced concrete casing 0.32 to 0.75 metres thick, equipped with two stationary platforms weighing 150 tonnes each, one located mid-height, the other at the summit. These two platforms serve to guide the four internal metal drums designed to evacuate smoke. The exterior envelope was constructed using sliding formwork with a throughput of 4 to 5 metres a day. Erecting this envelope was the chief difficulty. While we were placing the interior metal equipment, we had to wait for the correct balance between the speed of travel of the sliding formwork, the quantities of concrete to pour according to wall-thickness requirements, and its resistance at the exit of the casing, dependent on the outside temperature.

Given its ability to facilitate the design and implementation of a complex contractual and financial project, Campenon Bernard SGE was entrusted with the civil engineering tasks.

IMPACT

From the outset of the project, we were able to position ourselves as a builder, and especially a contractual and financial builder. As a result, succeeded in persuading the French authorities to participate in funding the project. It is thanks to this funding that the engineering project came to life. A focal participant of Pakistan’s energy development, and covering 23% of the new energy requirements, the Hub River thermal plant is designed to benefit the public. This project is unique, duplicable and forward-looking. It is unique, in that this is the first time the World Bank has participated in a private project as a lender and guarantor. It is duplicable, given the needs for energy and infrastructure in developing countries and the funding problems these countries experience. Lastly, it is forward-looking for building and public works firms since it provides them with opportunities in new sectors.

Project participants

Client
Hub Power Cy (Hubco)

Key figures

Implementation dates
May 1993 to May 1997    

Earthworks
1,109,000 m3

Concrete
116,500 m3

Reinforcement
7,300 t