The world's largest clock is in Mecca: the religious centre of time for the global Muslim community

In the holiest city of Islam the world's largest clock rises as a monumental symbol of both technology and faith. The Makkah Royal Clock Tower is not just a clock on an extreme scale, but a centre where religious rhythm, astronomy and global community meet. Here time becomes visible, audible and lived, a part of the shared life of the Muslim world.

Text: Andreas J. Weber

In the middle of Mecca, the holy city of Islam, right next to the Great Mosque and the Kaaba, stands the Makkah Royal Clock Tower. The tower rises a good 600 metres above the city's dense buildings and completely dominates the horizon. In any city it would dominate the townscape. In Mecca it becomes instead an architectural extension of the holy geography. Here, where millions of people gather every year for the pilgrimage hajj, where the body moves in circles around the Kaaba and where the gaze is oriented towards the qibla, time has a particular significance. It is not only chronological but ritual. It governs prayers, fasts, holy days and the movements of the pilgrims. It is this time that the clock tower makes visible.

A clock built on an extreme scale

The clock in Mecca is literally monumental. Four dials, one facing each point of the compass, mean the time can be read from the whole city. Each dial measures about 43 metres in diameter. The minute hand is roughly 23 metres long and the hour hand around 17–18 metres. Each hand weighs several tonnes. The great engineering challenge was not only the size but the wind. At this height the wind pressure can reach over 200 kilometres an hour. The solution was to construct the hands in carbon fibre, in some parts built up in over a hundred layers of composite, and to make them completely self-supporting in a so-called cantilever construction, balanced with counterweights at the centre. The dial itself is also slightly concave. This is a decisive detail: the concave shape keeps the hands within the profile of the building and protects them from the most extreme forces of the wind. That means external guide tracks or mechanical rings around the dial can be avoided, which would otherwise have ruined the aesthetics of the facade.

Behind the hands sits one of the world's most powerful tower clocks. Each movement weighs over 20 tonnes and drives hands that together weigh several tonnes. The gears are over a metre in diameter and made in special alloys with extreme wear resistance. The system is redundant. There are several parallel drive systems, reserve motors and extra sets of hands. The whole system is continuously monitored and synchronised with exact atomic time. The energy supply is complemented by solar panels.

The visibility of the clock was decisive. The solution was an LED-based lighting design with over two million points of light. Each point of light is placed at an exact distance in order to merge from a distance into a uniform luminous surface. The colour choice, green and white, is both functional and symbolic. Green gives high contrast for the human eye and is at the same time a colour with strong religious and cultural significance in Islam. The dials are legible at up to eight kilometres' distance. The facade around the clock faces consists of around 98 million glass mosaic tiles in 13 colours. A large part of these contain 24 carat gold leaf. The tiles function both as ornamentation and as protection against UV radiation, heat and sandstorms. The temperature difference between day and night can amount to 70 degrees. Every material in the facade is tested for extreme climate conditions.

Around the dials themselves there is a clear religious iconography. Above the dials run large panels with Arabic calligraphy. On two sides stands the takbir, the expression “Allahu Akbar” – God is greatest. On the other two sides is found the shahada, the Islamic declaration of faith: “There is no god but Allah and Muhammad is the messenger of God”, a cornerstone of Islamic faith. In the middle of the dial is found the coat of arms of Saudi Arabia, which binds together religion, state and public time. The numerals are designed in a style that connects to Islamic aesthetics, and the whole dial is built up so that script, ornament and time form a coherent visual whole. Beneath the clock faces runs a calligraphic band inscription with text from the Quran's that is traditionally interpreted as words about the prophet Muhammad: ”And We have not sent you except as a mercy for the worlds”, which clearly ties the tower's measurement of time to Muhammad's role and the Islamic revelation. At the top of the tower thrones an enormous crescent moon in carbon fibre. It houses several floors, including a prayer room, and functions as a modern minaret in both a symbolic and a functional sense. Here architecture, symbol and ritual are united in one and the same form.

Perrot – from the tower clocks of the Black Forest to the world's largest clock

When the world's largest clock in Mecca was to be built, the project turned to a company with deep roots in the European tower clock tradition. Perrot Turmuhren was founded in 1860 in the Black Forest by Johann Immanuel Perrot and has since then been family-owned over several generations. For more than a century and a half the company has developed a clear niche: the construction and manufacture of tower clocks, church bell systems and public time systems for churches, mosques and civil buildings. In the beginning Perrot built mechanical clocks for church towers around Central Europe, but the business has gradually developed to cover electromechanical and digitally controlled systems, synchronised with modern time standards. This ability to unite the craft tradition with contemporary engineering is central to the company's identity. Perrot represents a continuity where classic tower clock technology is not replaced by new technology but integrated with it. When the commission in Mecca was formulated, precisely this type of competence was required. The project needed a player who both understood the tower clock's historical function as a public marker of time and could reshape it in a global, high-technology and religiously charged context. For Perrot that meant scaling up its experience to a level never previously tested.

In the Makkah Royal Clock Tower, Perrot delivered the four movements that drive the gigantic dials. Each system is dimensioned for continuous operation under extreme climate conditions and constructed with redundancy and monitoring to guarantee that time never stops. In this lies also a symbolic dimension: in a city where time structures religious acts the clock must be absolutely reliable. Perrot's work in Mecca is therefore not just a technical commission but a further development of the tower clock's cultural function. In the European tradition the tower clock marked the city's rhythm, working life and public time. In Mecca it marks the rhythm of the prayers, holy days and religious coordination on a global scale. The company's long experience of working with churches and religious institutions has here been given a new and larger stage. The project in Mecca also shows how a historic craft company can become a player in global engineering. From small workshops in the Black Forest to one of the world's most complex and symbolically charged structures stretches a line of continuity. Perrot stands in this context not only as the supplier of a clock, but as the bearer of a tradition where public time, technology and faith have always been intertwined. In the Makkah Royal Clock Tower this tradition reaches its most monumental form. Here a 19th-century craft meets a 21st-century megastructre and becomes a clock that does not only show the time, but organises it for a global religious community.

Time as religious practice

In Islam time is a religious category. The five daily prayers are determined by the position of the sun. The fast during Ramadan begins and ends at specific times every day. The Islamic calendar is lunar and requires observation of the moon. The clock tower in Mecca makes this time visible and global. Through light, sound and exact time indication, prayers and holy days are synchronised across the whole world. When the light in the tower shifts or the call to prayer sounds, it becomes a signal that unites believers from Indonesia to Morocco. There have also been ideas about establishing Mecca as an alternative prime meridian for the world's time, as a religious parallel to Greenwich. Even if this is not implemented in practice it shows how strong a symbolic significance the clock tower has as a global centre of time.

The clock tower also functions as a modern minaret. A powerful loudspeaker system sends the call to prayer out over the whole city. Light signals mark the prayer times. The tower communicates both visually and audibly. In the spire there is a prayer room 600 metres above the ground, one of the highest located religious rooms in the world. The Makkah Royal Clock Tower is more than the world's largest clock. It is a place where time, space and faith melt together. It is a clock that does not only measure seconds but organises a religious life. The hands move over a dial where the name of God is written. The light signals the rhythm of the prayer. The crescent moon crowns the building and houses a prayer room high above the city. Beneath the tower pilgrims move in circles around the Kaaba. In Mecca time is not measured only in seconds. It is measured in prayers, in movements, in faith and in a global community that shares the same rhythm.