Tuban Port Underwater Sill




PT Semen Gresik Indonesia

The Tuban Port was a port where large ships loaded and exported thousands of tons of cement from PT Semen Gresik. However, because of the port's inability to dock ships with more than 10.000 DWT (deadweight tonnage), PT Semen Gresik needed to expand the port to three or four times its capacity. To achieve this goal, they extended the piers from a length of 175 m to 400 m and dredged the sea bottom from depth of 7 m to a depth of 13 m.

By request of PT Semen Gresik, Wiratman was involved in the project and presented an alternative solution. The underwater sill innovation that he proposed proved to be effective in holding back sedimentation and relatively inexpensive to construct as well.

The underwater sill proved effective in diminishing the sedimentation rate from 1.5 meter per year to only 0.45 per year, eliminating the need to dredge the pool every year, thus improving the port's capability to load and unload the ships docked there.

This innovation received the 2003 lndonesian Construction Works Award from the Minister of Settlement and Regional lnfrastructure in December 19, 2003. The project was also chosen as the subject of the dissertations of two graduate students studying under Professor lsao lrie, who admired the innovation of Wiratman.