An ancient boat recently unearthed near the Luy Lau citadel in Thuan Thanh town, Bac Ninh province reveals sophisticated construction techniques. Experts believe it may date back to Vietnam's Ly or Tran dynasties.
Refined boatbuilding techniques revealed
On May 3, Nghiem Van Hach, Deputy Director of Bac Ninh's Department of Culture, Sports and Tourism, announced the department’s initial findings on the value, structure, and construction techniques of the newly discovered ancient boat.
Excavation site of the ancient boat near Luy Lau citadel, Thuan Thanh town, Bac Ninh.
Following an emergency excavation, the entire structure of the boat has been uncovered, allowing researchers to assess its scale, design, materials, and craftsmanship.
The relic consists of two intact hulls, located within the former riverbed of the Dau River, oriented east–west—perpendicular to the river's current north–south flow. The two hulls, which are similar in size and design, are positioned 2.3 meters apart at their closest point.
Experts confirmed that the two hulls, each over 16 meters long and between 1.95 to 2.2 meters wide, were joined at the bow by a wooden panel. The deepest part of the hulls measures about 2.15 meters.
The ancient boat was made entirely of wood, without using any metal fasteners.
At the front, a T-shaped plank approximately 6.5 meters long locks the two hulls together. The stern features structures believed to have housed a rudder system.
The base of each hull is carved from a single tree trunk (monoxyl), with a maximum diameter close to one meter - requiring massive timber to construct. The sides were built from 7 to 8 planks per hull, each measuring 22–34 cm in width and around 4.5 cm thick. Both hulls follow the same design and are divided into six compartments.
The most intricate craftsmanship is found at the boat's bow and stern.
The boatbuilders used mortise-and-tenon joints, where planks were slotted together and secured with wooden pegs. The most advanced features are found at the bow and stern, where monoxyl bottoms are joined to side planks and reinforced by four identical wooden columns (5cm x 5cm), a construction method never before recorded in ancient Vietnamese or global shipbuilding.
Estimated to date back to Ly–Tran dynasties
While the precise age is pending C14 analysis, initial assessments suggest the boat was likely built during the Ly (11th–13th century) or Tran (13th–14th century) periods. Its dual-hull structure and monoxyl base echo boat designs from the Dong Son culture, showing an evolution in Vietnamese maritime engineering.
Researchers preliminarily conclude that the ancient boat had two hulls.
Comparative studies with Chinese and global maritime records suggest the boat may date from the 11th to 14th centuries and likely not later than the 15th century. Some experts believe the design also shows influence from southern regions.
Historical documents mention similar boats. The Viet Su Luoc records that in 1106, during the Ly dynasty, “the king ordered the construction of a Vinh Long two-bottom boat.” Likewise, the Dai Viet Su Ky Toan Thu notes that in 1124, “the king built the Tuong Quang boat, a dual-hull vessel.”
Based on global boat records, scholars date the vessel to the 11th–14th century (Ly–Tran dynasties).The artifact has been moved for research and sample analysis.
While the C14 dating results are still pending, the discovery affirms the existence of this type of watercraft in Vietnam’s history, with strong evidence linking it to the Ly dynasty through historical accounts.
Given the current condition of the site and expert recommendations from the Institute of Archaeology, Bac Ninh’s Department of Culture, Sports and Tourism has proposed preserving the boat in situ as the optimal solution for protection and cultural promotion.