Jetting with TSHD for clearing submerged wrecks
Type:
Presented during:
CEDA Dredging Days 2026
Authors:
J. Van Drom
Abstract
The removal and identification of submerged wrecks often requires excavation of accumulated sediments to allow diver access or crane operations. Traditional methods can be slow, obstructive, and limited in deep or dynamic environments. Recent applications of jetting with TSHD's via the LMOB demonstrated an efficient alternative. Two recent case studies illustrate the potential of this method. At Fairy Bank, Belgium (2024), TSHD Meuse River was deployed to uncover the stern of a World War I UB-III submarine for archaeological identification. Operating with optimized jetting parameters such as the loading the hopper loaded with water, pump in Medium the optimal Gear to increase flow rates, and timing operations at low tide, the TSHD achieved high production rates, creating pits that deepened the seabed by up to 7 m and reached overall water depths of approximately 24 m. Divers confirmed the wreck's identity without structural damage, although natural infill of sediments over time was observed. At the Elbe River, Germany (2025), TSHD Breydel supported the recovery of submarine U-16, buried at depths up to 30 m water column. Over five short and effective jetting sessions, pits were created around bow, stern, and midsection to provide access for divers and the grab of the floating crane. Despite tidal currents causing impact offsets of up to 10 m, adaptive positioning ensured high production rates. The formed pits eventually enabled safe sling installation, and the wreck was successfully recovered. Both projects confirm that jetting with TSHDs is a successful technique for wreck clearance. It allows efficient excavation in non-cohesive soils while minimizing direct contact with wreck structures. Lessons learned include adapting flow rates to sediment properties and water depths, countering tidal conditions, and integrating real-time survey feedback. This method has clear potential as a reliable tool for both archaeological investigations and operational wreck removal projects.