The Prophet’s Holy Mosque in Medina, Saudi Arabia, is one of the largest buildings in the world. It is the site of the original mosque built by the Prophet Mohammed in 622, originally a 30m x 35m open air building with a raised platform for the reading of the Qu’ran. The building was doubled in size within seven years, and has been enlarged numerous times since to accommodate the vast numbers of the faithful who come there to pray.
It is now two stories tall. The main prayer hall occupies the entire first floor, and the roof is flat and paved, designed as space for prayer. According to the official website of the government of Saudi Arabia, the mosque is now 100 times its original dimensions and can hold half a million worshipers at a time.
Over the main prayer hall are 27 domes made of FRP, made by Premier Composites Technologies of Dubai. The domes rest on square bases that feature openings to transmit light into the prayer areas below. The domes can also slide sideways on metal tracks to open the prayer space to the sky, and provide shade for worshipers on the roof, helping to deal with extreme temperature conditions. The light weight of the material is key to the sliding design.
According to the Premier Composites website:
Innovative techniques were developed for the production of 27 sliding domes for the Prophet‘s Holy Mosque in Medinah.
The lightweight composite domes provide a mobile roof to the internal courtyards, sliding open and closed to counteract extreme temperature changes and control and support the air-conditioned environment of the mosque.
The domes are made from a sandwich of glass fibre and epoxy resin composite with a thermoplastic foam core. This material is strong, durable and extremely lightweight with as little as 15% of the weight of an equivalent dome built in concrete. Low thermal expansion means there are no shrinkage problems and edge flanges give them stiffness for a bolted panel-to-panel connection.
The richly decorated interior domes are fabricated in maple wood veneer and western red cedar.
The PCT team was responsible for all 27 sliding domes when they were based in Germany, trading as a separate company.