MADINAH — A dispute between the Presidency of the Two Holy Mosques Affairs and a contracting company over payment of dues has left 250 giant umbrellas that provide shade to worshippers in the outdoor courtyards of the Prophet's Mosque in Madinah without maintenance for weeks, a source told Okaz/Saudi Gazette. The source said the Saudi Binladin Group has stopped maintaining the automated canopies after the company was unable to procure essential equipment and spare parts from SL Rasch, a specialized German company with which Binladin has a partnership agreement for maintenance. The source said the Binladin and SL Rasch also have disagreements over contract terms. "SL Rasch is not supplying Binladin with necessary equipment and parts for maintaining the umbrellas. These equipment and parts are not available in Saudi Arabia," said the source. He said Binladin has ordered the equipment and parts from SL Rasch but does not know how long it will take for the consignment to arrive. "The sunshades are normally in use from 7 a.m. to 5 p.m., but worshippers noticed that they were not unfolding during Friday prayers for the past three weeks," said the source. With a diameter of 25.5 meters, each umbrella weighing 40 tons gives cover to a 576 sq. meter area. They are set up in different heights to ensure the sun's rays do not seep through. Some of them have a height of 14.40 meters and others 15.30 meters when unfolded. When folded, they stand at a height of 21.70 meters. The sunshades have been designed to withstand winds blowing at a speed of 90 km per hour for 10 minutes and winds with a speed of 120 km per hour for 5 minutes. Like blooming flowers, the umbrellas are programmed to fold and unfold in a slightly punctuated sequence to avoid collision between their moving parts. Their near-silent operation is automatically aligned with changes in the daily temperature. They open each morning, creating a translucent ceiling, and retract each evening in less than three minutes. In summer, the open umbrellas provide daytime shade and reflect away much of the sun's radiant energy. When closed at night, they allow residual heat absorbed by the stone floors and walls to escape back into the atmosphere. The process is reversed in winter. When temperatures are relatively low, umbrellas are closed during the day to allow the winter sun to warm the site, and opened at night to retain heat near ground level.
