The Drukpa & Bridge Building

A (very!) Brief History of the Drukpa

The Drukpa (translating as 'Dragon People') are the inhabitants of the country of Bhutan (Druk Yul in Bhutanese, meaning 'Land of the Thunder Dragon') in Southern Asia. The Drukpa are partly descendants of the first humans to reach the Himalayan region and also partly descended from later Tibetan and Mongol settlers. As part of the wider Human global migration, over the course of 100,000 years, groups of humans made their way across the Middle East, into Southern Asia and up into the Himilayan Mountains in approximately 2,000 BCE. 

The indigenous peoples, known as the Monpa, lived in relative isolation within the steep mountain valleys until the 7th Century CE, when Tibetan migrants, known as the Ngalop people, fleeing political turmoil or following religious teachers, crossed the Himalayan passes to settle in the fertile valleys of western and central Bhutan. Over time, they became the dominant cultural and political force in Bhutan, absorbing the earlier Monpa populations and establishing the foundations of the modern Bhutanese state. The Ngalop brought with them Tibetan agricultural practices, language, and, importantly, Vajrayana Buddhism. 

The Tibeto-Mongol invasions of Bhutan, launched in 1644 and 1648, were driven by a rivalry between two religious leaders: the 5th Dalai Lama in Tibet and a lama who had fled Tibet and unified the Bhutanese valleys. Two huge Tibeto-Mongol forces invaded, but their formidable cavalry proved useless in Bhutan's steep, densely forested terrain. Relying on guerrilla tactics and retreating into an impregnable network of fortress-monasteries called dzongs, the Bhutanese decisively repelled both invasions, capturing Mongol weapons and cementing Bhutan’s survival as an independent nation. 

Bhutan holds a unique position in world history: it was never formally colonised by the British Empire or any other foreign power. It is one of the few Asian nations to maintain continuous sovereignty throughout the colonial era. This was accomplished by intense diplomatic manoeuvring, territorial sacrifices to British India, and a period of "semi-colonial" dependency. 

Tensions over the fertile border plains bridging the Indian lowlands and the Himalayas culminated in the brief Duar War (1864–1865), resulting in Bhutan's defeat and the harsh Treaty of Sinchula, which stripped the nation of 20% of its territory in exchange for an annual British subsidy. 60 years later, Bhutan and the British signed the Treaty of Punakha in 1910; in a calculated bargain to guarantee absolute domestic sovereignty and prevent British occupation, Bhutan became a de facto protectorate by ceding control of its foreign policy to the British. Following Indian independence, this arrangement was carried forward via the 1949 Treaty of Friendship with the Republic of India, which maintained Bhutan's internal autonomy while guiding its external relations, a semi-colonial legacy that remained in place until a 2007 treaty revision finally granted Bhutan full, unguided independence on the global stage.

Due to the absence of direct, outside rule, the traditional culture of Bhutan has never experienced the repression imposed on other indigenous groups. Traditional Bhutanese culture is a holistic way of life deeply intertwined with Vajrayana Buddhism and the guiding philosophy of Gross National Happiness, prioritising spiritual well-being and environmental harmony over purely material progress. This rich heritage is visibly preserved through daily spiritual rituals, the practice of thirteen traditional arts, and vibrant annual festivals (Tshechus) featuring sacred mask dances. Socially, Bhutanese identity remains remarkably strong, characterised by egalitarian and often matrilineal rural customs, a deep respect for community, and the everyday wearing of national dress—the gho for men and the kira for women.

The Drukpa & Bridge Building

In the steep, flood-prone valleys of Bhutan, building a central bridge pier into a raging mountain river is impossible. Instead, indigenous builders constructed massive wooden cantilever bridges, known as Bazam. These bridges allow wide expanses to be crossed without risking annual destruction caused by the Monsoon. These structures blend ingenious ancient engineering with Bhutanese national architecture. They feature distinctive interlocking wooden beams and shingled roofs, often serving as both footbridges and historical landmarks. 

Wooden Cantilever Bridges : STEM

The design of a traditional cantilever bridge relies on massive, horizontally projecting timber beams that carry the structure's load from a single anchored end. To counteract the immense torque (turning force) created by these overhanging beams, builders embed the shoreward ends deep within heavy stone anchor towers; the sheer weight of the stone presses down on the timbers, balancing the rotational force and preventing the structure from tipping into the river. 

These beams are stacked in progressively overlapping layers, with each tier projecting slightly further out than the one below it to smoothly transfer structural stress back to the stable foundation. Ultimately, these opposing cantilever structures serve as a solid platform to support a final, simpler short beam that closes the central gap, allowing the two sides to effectively meet in the middle and complete the span.

STEM Task : 

• Build a wooden cantilever bridge, following the instructions in the video above. 

• Test its structural strength by adding masses to the middle.

• Extension - Vary the overlap of the wooden 'beams', how wide a gap can you bridge before it loses structural strength?