“Tangla” refers to a high-altitude region within the Tibetan Plateau. This remote area is recognized for its unique geographical features and the remarkable human endeavor that traverses it. The name is synonymous with both a mountain range and a record-setting railway station.
The Tanggula Mountain Range
The Tanggula Mountains form a central part of the Qinghai-Tibet Plateau, extending across the Tibet Autonomous Region and into Qinghai province. Their main ridge averages over 5,000 meters (16,404 feet) in elevation, with Geladaindong, the highest peak, reaching 6,621 meters (21,722 feet). The climate is harsh, marked by very low air temperatures, intense solar radiation, and distinct wet and dry seasons.
A key characteristic of this environment is widespread permafrost, ground that remains frozen for at least two consecutive years. This frozen ground poses challenges for plant life and soil stability. While deeper layers are stable, the active layer near the surface thaws in summer, turning the ground into a bog-like consistency. This seasonal thawing and refreezing, known as frost heaving and thaw settlement, creates unstable soil conditions.
Vegetation in the Tanggula Mountains is sparse, primarily consisting of alpine meadows and grasslands. Common species include hardy herbaceous perennials like Stipa purpurea, Carex moorcroftii, and Kobresia pygmaea, which have adapted to the cold, dry conditions and nutrient-poor soils. These plants often exhibit slow growth, a common adaptation to the short growing season and limited resources at such elevations. Despite challenging conditions, some studies indicate vegetation expansion in parts of the Tibetan Plateau due to warming temperatures, though human activities like grazing can also impact plant communities.
Tangla Railway Station and the Qinghai-Tibet Railway
The Tangla Railway Station is the world’s highest railway station, located at 5,068 meters (16,627 feet) above sea level. It opened on July 1, 2006, along the Qinghai-Tibet Railway, which connects Xining to Lhasa. The station’s location was specifically chosen to offer travelers expansive views of the surrounding high-altitude landscape.
Constructing the Qinghai-Tibet Railway through the Tanggula Mountains presented significant engineering challenges. The railway traverses continuous permafrost, prone to instability as temperatures fluctuate. Engineers faced issues like frost heaving and thaw collapse, further complicated by the fragile high-altitude ecosystem and low oxygen levels.
To overcome these obstacles, innovative techniques were employed to maintain the permafrost’s stability. These included crushed roadbeds, which allow air circulation to keep the ground frozen, and the installation of heat pipes and ventilation pipes to regulate ground temperatures. In some sections, stone embankments were constructed, and bridges were built over permafrost areas to minimize disturbance to the ground. These engineering solutions protect the railway infrastructure while also considering the delicate ecological balance of the plateau.