Night watch


Twenty-four hours aren’t always enough: Valentina Monaco inspects the safety of train projects around the world, working even when others are sleeping. Like now, in Istanbul, where thousands of people don’t think twice about travelling from Asia to Europe—beneath the Bosphorus.


leg 10  ■  Bursa ➡ Istanbul  ■  100 Km  ■  Arrival 19.11.2015, 11:00 pm  ■  Travel time 135 hrs  ■  19°C  ■  Total distance 55,650 km

In fact, there should be a siren howling right now—a loud, piercing tone that could be heard over the entire platform. But no matter how vigorously Valentina Monaco waves the small tube in her hand, nothing’s happening. Monaco, aged 42, audibly exhales, takes a second tube—a 10-centimeter-long cardboard roll—out of her jacket pocket, and breaks it in half. Dense smoke pours out of it, mixing with the smoke already emerging from the first tube in her other hand, and it all rises to the ceiling of the Üsküdar subway station. Just a few seconds later the smoke alarm goes off. A shrill tone sounds from all the loudspeakers, followed by an announcement in both English and Turkish: Please exit the station. A message on continuous loop. The escalators momentarily come to a halt, then start up again, now rising only upwards, out of the underground. Up above, the ticket barriers have already opened automatically. Monaco nods in satisfaction, steps onto one of the escalators and hustles over to the station’s control center. The fire alarm worked perfectly; all the safety systems switched on as planned. If this had been an actual emergency, the fire department would already be on its way. The technician on duty for Türkiye Cumhuriyeti Devlet Demiryolları, the Turkish railway company, can switch the alarm systems off.



Photo: istock/Deejpilot


The Bosphorus Bridge has spanned the strait since 1973. Nowadays one can travel both above and below the water’s surface.




It is half past midnight and Monaco already has a strenuous day’s work behind her. In Samsun, located on the Black Sea in Turkey, she was in an all-day meeting with railway technicians to discuss the technical details of a new railway line. Then her plane was late—a mechanical failure prevented takeoff. She didn’t arrive at Istanbul-Sabiha Gökçen Airport until ten o’clock in the evening, where she quickly hailed a taxi and barely caught the last subway, which brought her from Ayrılık Çesmes station to deep underground.


Project of the century

Now the second part of her workday begins. The metro lines in Istanbul shut down service right at the stroke of midnight. And, at the stroke of midnight, the stations and railway tracks come right back to life. Cleaning crews advance, electricians replace broken lights—and today Monaco is inspecting the subway’s safety systems on behalf of the Transport Ministry’s Directorate of Railways, Harbors & Airports Construction for general contractor OHL-Siemen

What she discovers on nights like this one could ultimately tip the scales as to whether TÜV SÜD as an independent third party gives its approval for the operations of one of the most spectacular railway projects of recent years. The Üsküdar subway station is no ordinary station. It is located directly on the shore of the Bosphorus. Just a few yards down the tracks the tunnel’s form changes: it dives beneath the famous strait for a distance of 1.3 kilometers. There are two round railway tunnels at a depth of 70 meters beneath the water’s surface connecting the continents of Europe and Asia. For ten years, starting in 2004, engineers from around the world built what is known as the Marmaray Tunnel. Since 2013, the intra-urban Metro subway runs through the structure, which— including the connecting tunnels—extends 13.3 kilometers. In late 2016 it is supposed to be authorized for long-distance trains as well, connecting the European side of Istanbul to the Anatolian high-speed train networks.


Seal the hatches

Seal the hatches

Because Istanbul is located in an earthquake zone, the tunnel is specially protected against water ingress. Gigantic floodgates also allow it to be hermetically sealed.


Illustration: GWER

 From the streets to the rails 

The problem

Enormous traffic jams are a daily occurrence in Istanbul, and the Turkish metropolis keeps growing by leaps and bounds. Current forecasts predict that more than 20 million people will be living here by the year 2025. It’s far too many for today’s already chronically clogged road network. Rail-based public transportation has just a niche role in the city. Only about one in ten of all journeys are made by subway or streetcar. The vast majority of people use buses or their own cars.


The solution

Istanbul is making massive investments to expand its rail network. A central project is the Marmaray Tunnel, connecting the European and Asian sides of the city. Up to 75,000 passengers per hour will be transported along this central axis from one continent to the other. While Istanbul is working on the Marmaray project, engineers and construction workers in Anatolia are also building a network of modern high-speed rail lines. Along with helping to rectify Istanbul’s problems with inner-city traffic, Marmaray will also help improve the transnational transport of goods across the Near East and further afield to China.




TÜV SÜD has been involved in the project as a consultant since 2012, which is when Valentina Monaco began her work here. Monaco, who has a degree in railway engineering, has regularly been flying from her office in Graz, Austria, to Istanbul to inspect designs, speak with project technicians and to critically evaluate installed facilities. As the only woman among dozens of men, she’s often had to assert herself—something she’s been very successful at—and vetoed things when engineering offices were too adventurous in their planning. She also learned to speak Turkish during this time, along with the five other languages she’s fluent in. And she has earned a great deal of respect due to her professional expertise and experience—on large railway projects in Italy and Mexico among others.

Right now, however, Monaco has turned her back on a good dozen subway technicians and is trekking by foot into one of the tunnel tubes. “My most important work tool is my feet,” she jokes. “And my eyes, naturally.” She’s using them to scan the track bed for potentially loose areas. She stops at a rail mounting. Monaco bends down, pulls at a bolt with her hands, pulls out a small spade and scrapes away some rust. Finally she draws a cross in white chalk next to the bolt and types a note on her smartphone. Later she’ll send a Marmaray Metro employee to this spot to tighten the bolt. About 1,100 meters further along there is a sliding steel door that connects the two tubes of the tunnel across the Bosphorus. The door must always remained closed to prevent smoke, poisonous gases or fire from getting into the other tube in the case of an accident or fire. Yet at the same time the door should be very easy to open so that passengers can get to safety if needed. Monaco grabs the handle with both hands, first pulls and then pushes the door open. She walks through it, releases the door and watches it close automatically. “Works,” she murmurs.


Technical masterpiece

As Monaco continues walking along the edge of the track bed, she passes a spot where the gray of the tunnel wall is a different color than the rest: “This is where the individual elements were connected to one another,” she explains. This is related to the special construction method used for the Marmaray Tunnel. The connecting tunnels on the European and Asian mainland were built by means of normal excavation, advancing with gigantic drilling machines. The tunnel’s central element, the passage stretching beneath the sea, was built using immersed tube construction. Eleven tunnel elements up to 135 meters long were prefabricated on land and towed out on transport ships. As freighters sailed by to the left and right—around fifty thousand pass through the strait annually—construction workers slowly flooded the elements and precisely placed them in a trench dug into the floor of the Bosphorus. After connecting the individual pieces, workers pumped the water out of the entire tunnel and then covered the outside of it with dirt.

An earthquake struck the region east of Istanbul in 1999. Measuring 7.4 on the Richter scale, it caused buildings and bridges to collapse, killing nearly twenty thousand people. Experts suspect that the next big quake could directly impact Istanbul itself. Just a few miles outside the metropolis is the North Anatolian Fault, where the Anatolian Plate is sliding in fits and starts past the Eurasian Plate, regularly rocking the region with tremors. For this reason, the Marmaray Tunnel has been engineered to withstand a quake up to a magnitude of 7.5. 

And what if water began flooding the tunnel? “In that case, it can be evacuated within minutes and hermetically sealed,” Monaco says. She’s standing in front of one of the four floodgates, smartphone in hand. On her command, a warning signal sounds, and then a yellow steel wall slowly slides down from above through this cross-section of the tunnel. Signaling equipment retracts out of the way of the floodgate. Monaco times how long it takes before the gate comes to a grating halt, locking into place on the track bed. “The system effectively prevents the ingress of water from reaching the subway stations,” she says.

Early in the morning, just before six o’clock and many miles later, Monaco steps outside of the Üsküdar subway station into the city. Istanbul’s Metro will be resuming operations in just a few minutes. Dawn is beginning to break, and the sun will rise in a good half hour. Monaco briefly watches a freighter, but then her gaze comes to rest on the lighted suspension bridge, which has spanned the Bosphorus since 1972. She takes a deep breath of the fresh morning air—and for quite some time continues watching the water’s smooth surface, beneath which she spent the night wandering back and forth.


Night in the tunnel

Taking an inspection tour with Valentina Monaco