BPPT-lock was developed by the Agency for The Assessment and Application of Technology (BPPT) and was awarded patent in 2012. The hydraulic stability (KD) of BPPT-lock armor unit was compared to Tetrapod, Dolos and Xbloc armor units. The results indicate that, BPPT-lock performs far better KD in comparison to each of these armor units. A comparative analysis on the economical use of material was also carried out among BPPT-lock, Dolos, Tetrapod and rough stone and rounded stones for similar design condition, the armor unit weight is 4.68ton, 4.97ton, 9.95ton, 19.89ton, and 39.79ton respectively, means that BPPT-lock is more efficient in this comparison. Considering its feasible performance, BPPT-lock is designed as the armor units for the maintenance and reparation of the existing rubble mound breakwater of Pacitan Coal Fired Power Plant port. The 110 m parts of the existing breakwater was hardly damaged and the new structure is designed to stand against a 30 yrs RP waves of Hs = 7m. BPPT-lock armor unit of W = 11 ton on the breakwater slope 1:1,5 is implemented. The first phase construction works was completed in December 2018 and visual observation has shown the great integrity and stability of BPPT-lock armor units.

A new international seaport is under construction at Patimban area of Subang Regency, West Java, Indonesia. This Port’s navigation channel runs from the position of –6m LWS to –17m LWS of the existing depth with total length of 3,762 m. The original design considers that the existing sedimentation rate is low along the channel. The Cipunagara River which shows continuous delta expansion of about 1.00m to 1.25m toward navigation channel. In reference to the successful application of Underwater-sill (UWS) structure in controlling the siltation rate into the navigation channel of Kumamoto Port in Japan and Tuban Port in East Java Indonesia, the possible application this type of structure was carried out. The calculation has resulted that installation of UWS with height of 1.0 m, 1.5m, 2.0 m, and 4.0 m respectively decrease the sedimentation rate to be 0.09 m per year, 0.06 m per year, 0.022 m per year and 0.022 m per year. The present economic feasibility study concluded that 2m height UWS which is designed for minimum service life of 30 years with development interest rate at 10 percent per year and an annual inflation rate at 10% gives the most economic investment.

A rubble mound slope structure was designed to protect a decaying cellular steel sheet pile cofferdam breakwater which has been partially damaged. Reparation of this decaying cofferdam breakwater to its original form is considered uneconomic. Considering three basic design requirement, i.e. economic feasibility, environmental sustainability, and structural reliability and constructability, the rubble mound slope design has been proposed as a retrofit structure against 4.7m height of a 100yrs return period design wave. In this design, the existing vertical cofferdam stands originally at the harbour side, whereas the new additional rubble mound structure is attached to the cofferdam at the sea side creating together a new horizontal composite breakwater. The existing cofferdam supports the rubble mound structure at the harbour side, whereas the rubble mound structure provides protection against direct wave attack. This retrofit design of structure requires less 25% of materials volume and costs 30% cheaper than a full standalone rubble mound breakwater type. This less requirement of materials will consequently have positive impact on environment and natural resource conservation. The design of rubble mound slope that is directly attached to the existing breakwater will enable its easy construction by using vehicles that stand on the top of the existing breakwater. This article describes the design consideration including discussion on the structural reliability of the retrofitted breakwater.

A new breakwater is on demand to replace the function of an existing steel sheet pile cellular-cofferdam at TPPI Tuban Port of East Java. The existing breakwater has been partially damaged due to severe corrosion and hard attack by monsoon waves. An open frame structure of spun pile vertical-wall breakwater is proposed as an alternative design. The spun pile is a pre-stressed concrete hollow cylinder pile with outer diameter 1800mm and thickness of 200mm. The spun pile lengths vary between minimum 28m to maximum 33m according to the position of hard soil against seabed. The new breakwater is designed to stand against 100yrs RP wave with Hs = 4.7m. Wave height variations around the structure are simulated using Boussinesq Wave module of MIKE21 software, while SAP2000 is used to calculate the strength of superstructure to withstand existing loads and certain load combinations. Plaxis software is used mainly to analyze substructure using existing soil data. This article describes the design process of spun pile vertical wall breakwater, started from loads calculation, then define load combinations, analyze structure in SAP2000, analyze structure in Plaxis, determination of specification and dimension, to design drawings creation.

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