Hercules Hydraulic Damper

HERCULES Hydraulic Dampers (HHD)  also known as Shock Transmission Units (STUs) or Lock-Up Devices (LUDs), are specialized structural connectors designed to respond according to the velocity of movement. These devices remain flexible during slow movements—such as thermal expansion, contraction, or creep—ensuring that no undue stress is imposed on the structure under normal conditions.

However, in the event of rapid dynamic actions such as seismic loading, braking, or impact forces, the hydraulic damper instantly transitions into a rigid link, effectively transferring or distributing high-intensity loads between the superstructure and substructure. This temporary stiffening action provides crucial protection against sudden load surges.

HERCULES Shock Transmission Unit (HSTU)  are engineered and tested by i-Lab Testing & Research Centre, in accordance with the following international standards:

• EN 15129:2009 — Anti-Seismic Devices, covering functional requirements, design criteria, and testing procedures for fluid viscous dampers and shock transmission units.

• AASHTO Guide Specifications for Seismic Isolation Design — Bridge design and detailing requirements for energy-dissipating and force-limiting devices.

HERCULES STU/500/±50mm installed for the First Thai–Lao Friendship Bridge over the Mekong, connecting Nong Khai Province and the city of Nong Khai in Thailand with Vientiane Prefecture in Laos, survived the 7.7 earthquake that struck the Sagaing Region of Myanmar.