Kajian Ketersediaan Alat Mekanis pada Operasi Penambangan Batu Andesit di PT Mandiri Sejahtera Sentra Kecamatan Tegalwaru, Kabupaten Purwakarta Provinsi Jawa Barat

Abstract

Abstract. PT Sentra Sejahtera Mandiri Tbk is one subsidiary company of PT Indocement Tbk which produces raw material for making concrete in the form of split stone from andesite. The company is located in District Tegalwaru, Purwakarta, West Java Province. To support the production of relatively large targets, the company is using a mechanical device in the form of 3 units of CRD (Crawler Rock Drill), 12 units of dump trucks, and 5 units of excavators. Andesite to mining process goes well, then the availability of mechanical devices that work must be maintained. The way to assess the preventive maintenance (preventive maintenance) and regular maintenance (planning maintenance) managerial system is also closely related to the value of the availability of a mechanical device at PT Mandiri Sejahtera Sentra. Presentation on preventive maintenance with statistical methods with the length of the class 6, obtained by 50.27% effective for transporting tools and 47.66% for the excavating tool, 0% for drilling. This value must still be improved in order to maintain the availability of tools that use in the mines of PT Mandiri Sejahtera Sentra. Further planning maintenance during the month of October 2015, the excavator 06 (Breaker) has the lowest value of service accuracy is only 52.4%, is very susceptible to damage due to regular service affects the damage to the engine and other components. From the research, it was found the smallest availability value indicated by DT - 08 (Beiben LBZF46EA) to the value of physical availability 37.65%, 41.27% mechanical availability, use of availability 33.46% and the effective utilization of 30.51%. , and it was found the biggest availability value indicated by DT - 07 (Beiben LBZF46EA) to the value of physical availability 94,39%, 96,27% mechanical availability, use of availability 81,46% and the effective utilization of 73,64%.

 

Abstrak. PT Mandiri Sejahtera Sentra Tbk merupakan salah satu anak perusahaan PT Indocement Tbk yang memproduksi bahan baku pembuatan beton berupa batu split yang berasal dari batuan andesit. Perusahaan ini berada di Kecamatan Tegalwaru, Kabupaten Purwakarta, Provinsi Jawa Barat. Untuk menunjang target produksi yang relatif besar, perusahaan ini menggunakan alat mekanis berupa 3 unit CRD (Crawler Rock Drill), 12 unit Dump Truck, dan 5 unit Excavator. Agar proses penambangan batuan andesit berjalan dengan baik, maka ketersediaan alat (availability) mekanis harus selalu tersedia. Cara tersebut dengan mengkaji pemeliharaan pencegahan (preventive maintenance) dan perawatan berkala (planning maintenance) juga sistem manajerial yang berhubungan erat dengan nilai ketersediaan alat (availability) mekanis di PT Mandiri Sejahtera Sentra. Presentase kegiatan preventive maintenance dengan metode statistik dengan panjang kelas 6, didapatkan efektifitas sebesar 50,27% untuk alat transporting dan 47,66% untuk alat excavating, 0% untuk drilling. Nilai ini masih harus ditingkatkan agar menjaga ketersediaan alat yang digunakan di tambang PT Mandiri Sejahtera Sentra, selanjutnya planning maintenance selama bulan oktober 2015 menunjukkan excavator 06 (Breaker) memiliki nilai service accuracy yang terendah hanya  52,4%, ini sangat rentan terhadap kerusakan dikarenakan servis berkala sangat berpengaruh terhadap kerusakan mesin dan komponen-komponen lainnya. Dari hasil penelitian, didapatkan nilai availability terkecil ditunjukan oleh DT – 08 (Beiben LBZF46EA) dengan nilai physical availability 37,65%, mechanical availability 41,27%, use of availability 33,46% dan effective utilization sebesar 30,51%. Sedangkan nilai terbesar dimiliki DT – 07 (Beiben LBZF46EA) dengan nilai physical availability 94,39%, mechanical availability 96,27%, use of availability 81,4%, dan effective utilization 79,53%.