ROGER HARRISON | ARAB NEWS
Wed, 2012-03-21 16:35
They make a powerful symbol in the evening sky: A dimming orb and a curving jet of water, a scene of breathtaking beauty that man has yet to equal with any artificial construction.
That simple graceful jet of water is the final glorious result of a very complex piece of engineering. In the manner of the swan, the fountain is all grace and poetry above water level, but working furiously underneath.
The fountain that dominates the Jeddah skyline today is the second one built as a landmark for the city, both within the perimeter of the Salam Palace. The first, built between 1980 and 1983, was very much after the style of the freshwater fountain in Lake Geneva and reaches 140 meters (460 ft). It lofts about seven tons of water into the air at any one moment at a nozzle speed of around 200 km/h (124 mph).
Constructed to complement the Salam Palace Island, the plume of the first fountain reached 120 meters. SETE Technical Services (Latsis Group) built both fountains. In a rare interview in 2005, George Antonopoulos, chief operations officer for SETE said the height of the first fountain was insufficient. “It was not impressive enough compared with the surroundings. It was a huge palace, Jeddah is a huge city and expanding — everything is big. 120 meters was a good height, but the scale was just not impressive enough.”
Thus, the decision was made to build a fountain of singular majesty, one that would reach well over 300 meters.
“Of all our achievements in the Kingdom over the past 30 years,” SETE Technical Services Chairman Richard Bacos said, “the Jeddah Fountain is certainly the most visible. It makes us feel very proud every day of every month of every year.”
A fountain on such a grand scale presented unique challenges. Most fountains use fresh water; the Jeddah fountain uses seawater. The abrasive qualities of salt and suspended particles of sand presented unique problems. Corrosion — a particular threat with salt water — had to be minimized, as frequent replacement of pipes would push maintenance costs upwards.
The enormous pumps, power supply and pipe-work had to be positioned as near the jet as possible to counter the resistance built up by the flow of water through the lines and not obtrude into the view of the palace. The theoretical solution was simple; put them under water. Easy to say, but achieving it was far more difficult.
The causeway carrying the pipes to the jet and the island it is mounted on was retained. The rest of the support structure was built specifically for the new fountain.
The pump room and electrical sub-station buildings were built in Rabigh where SETE was constructing an oil refinery.
“The buildings — pump-house and electrical substation — were constructed on a 90-meter long submersible barge,” said Antonopoulos. “Seven thousand tons of concrete were used constructing the pump house alone, which is the height of a five story building.”
The completed structures were towed to Jeddah where the seabed had been leveled to receive them. The barge was submerged so that the buildings, which were just buoyant, could be floated off and maneuvered into position, sunk and fixed in their final position. Access corridors were built and once pumped dry, the buildings were fitted out.
“All the machinery and logistics are 20 to 30 meters down under water,” said Antonopoulos “in order to blend with the surroundings of the architecture.”
The main pump house accommodates three huge centrifugal pumps and 18 auxiliary pumps for cooling, lubrication of the main pumps and drainage.
“After the design stage, it took two or three years to ‘settle’ the operation,” said Antonopoulos, “There was no track record we could capitalize on for building something like it. Everything we started from scratch and in the first years we were obtaining information as we proceeded, which we developed and applied to certain aspects of the design.”
Each of the 3.50 MW pumps delivers 625 liters of seawater per second. Two of the three pumps installed power the water jet and deliver 1,250 liter of water per second. The third is available as backup. Sulzer made the huge pumps in Switzerland and builders come yearly to check and service them. After nearly thirty years, the machines are in immaculate condition in their clinically clean engine room.
The project continually presented new challenges and SETE produced new and innovative answers. “It was two years of constant development on a learning curve the whole way,” commented Antonopoulos. “The fountain has been operating now for twenty years with planned maintenance; so far, no major problems.”
The job of building this unique fountain kept one of the most intriguing challenges right to the end of the line.
On the 350-meter journey from the pumps to the jet, the diameter of the pipes steadily decreases from 800 mm to 126 mm to increase the velocity of the water to a maximum to achieve the height
“Because there was no track record of seawater mega-fountains, we found tremendous wear on the nozzles.” He explained that the wear is caused by the combination of the sheer force of the water, seawater salt burden and micro abrasives in suspension. “It is like hydro-blasting a piece of steel.”
The water leaves the nozzles at 42-bar (609.16 psi) and at the incredible speed of 375 km/h. The plume hangs in the air for 15 seconds or so and weighs in excess of 18 tons (18,750 kg).
There was industrial experience of seawater fountains — but not at the water velocity, pressure and height specifications of the Jeddah fountain. Every month, the nozzles had to be replaced.
SETE engineering set to work and developed a special alloy, tough enough to allow the nozzles to last for years.
“This was one of the results of collecting data and information and improving over the settling period,” said Antonopoulos. “We now have a very specialist body of knowledge on high pressure seawater.”
Even the lighting of the enormous plume presented challenges. Five hundred high intensity spotlights mounted on five custom-built islands illuminate the jet. The technology of overcoming corrosion by seawater was well known. What also had to be tackled — and was — were the effects of the battering given to them by thousands of tons of water an hour falling on them from several hundred feet.
The elegance and simplicity of the plume high above the pump room belies the maintenance and care given to the machinery that produces it. The whole operation is computer controlled and has a comprehensive maintenance system. Ten technicians are dedicated fulltime to the fountain’s operation, including rotating specialists and electricians. In addition there is continuous support from the departments responsible for the operation and maintenance.
“We shut the fountain off for only two reasons,” said Costas Benissis, the then operations maintenance manager. “One reason is for planned maintenance — usually once a year. So far, we have not had to shut off for any problem or unplanned event.”
The other reason is less obvious. If the prevailing northern wind reverses direction and blows from the south, the curtain of spray from the plume would carry into the gardens of the Salam Palace and kill the grass and plants. This finally puts to rest the myth that the fountain jets fresh water. The only fresh water in the entire self-contained fountain complex is for cooling the electric motors of the main pumps and for the air-conditioning in the pump-house.
The annual inspection takes around three weeks: “We follow this annual inspection routine very strictly,” said Benissis. “You cannot cut corners.”
It was a fitting tribute to the modesty of the designers and engineers who created the fountain that their focus on overcoming the challenges and their insistence had been on “getting it right”. For nearly twenty years they overlooked what to most people would have been almost their first question about the fountain.
Towering over Jeddah at — on a calm day — a majestic 312 meters (1,023.62 feet), Antonopoulos and Benissis confirmed that the fountain was the world’s tallest seawater fountain. The plume is taller than the Eiffel Tower, which stands 300.51 meters (986 feet high.
So next time you look at the gauzy pink veil of water trailing in the evening breeze with a billion shimmering droplets with the ruddy glow of the dying sun, and the muse beckons you to poetic thoughts about the eternal cycle of our fragile existence, just remember two things: You are looking at a modestly unclaimed world record. And it was engineers, not poets who put it there.
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