Qinghai-Tibet Railway, China

Building a 1118 km railway line at what could easily be the top of the world is a task fraught with mind-boggling challenges.

One of the key projects in China’s tenth five-year plan (2001 – 2005), the Qinghai-Tibet rail connection was expected to have immense political, military and economic significance for The People’s Republic.

More than 50 years ago, Chinese politicians like Mao Ze Dong and Chou En Lai had already made a case for the construction of a railway line connecting the far western regions of China to the central government in Peking.

The first 846 km long segment between Xining and Golmud was launched in 1959 and completed in 1979. Plagued by problems involving the physical condition of workers, financial constraints, and sub-zero temperatures, the project came to a standstill for the next 20 odd years.

Construction of the remaining stretch of line between Golmud and Lhasa was resumed from both ends only in June 2001.
 

The Challenge

• With more than 85% of the route lying at altitudes ranging between 4000 m and 5100 m laying the line was an unprecedented engineering feat deserving serious respect.
   
• Among the challenges of construction at high altitudes in extremely inhospitable terrain is the rarefied air that makes breathing difficult and adversely affects stamina.
   
• Windstorms, sandstorms and earthquakes further caused hazardous conditions to become even more inhuman.
   
• Machines and mixers fared no better with lack of water at the barren plateau at that daunting height.

The 1118 km Qinghai-Tibet railway line has immense political, military and economic significance for The People’s Republic.

The Solution

The construction firm, China Railway Co. Bureau No. 3, opted to beat the odds with Putzmeister’s truck-mounted concrete pumps, including the M 36-4, capable of pumping up to 90 m3 /h. The Putzmeister M 36-4 was used at altitudes between 4800 m and 5000 m, but because of the thin atmosphere, the vehicle’s diesel motor was unable to develop full power. The general rule of thumb dictates that power is derated by 10% for every 1000 m of altitude; this drop in power affects the delivery output of the concrete pump. Despite these odds, the M 36-4 was able to develop a pump performance of up to 30 m³/h.

The M 36-4 Putzmeister was operated by two machinists who had to constantly brave conditions that ranged from lack of oxygen to permafrost that froze the soil to as deep as 5 m down, and summer thaws that resulted in slush and landslides. They also had to deal with difficulties in the classification of concrete aggregate and in maintaining the desired grading curve. But they soldiered on.

By the time the final stretch of the line had been laid between Golmud and Lhasa in 2006, an extraordinary amount of resources had been put to the test, including Putzmeister’s expertise. Both have stood the test of time.

The Putzmeister M 36-4 was used to tackle the atmospheric challenges posed by altitudes ranging between 4000 m and 5100 m.

Concrete Takeaways

• The seemingly impossible railway line that tested everyone’s prowess has reduced a three day road trip from Golmud to Lhasa to as little as 18 hours.
• 80,000 labourers and technicians worked at diminished capacity due to the high altitudes.
• The historic 1118 km Qinghai-Tibet rail connection was almost 50 years in the making. Putzmeister was brought into the picture in 2001 and delivered by 2006.