In November 1948, in Yogyakarta, A.F. Lasut, Head of the Central Mining and Geology Service (PDTG) under the Ministry of Prosperity of the Republic of Indonesia (RI), compiled a report documenting the organization’s activities from 1945 to 1947, titled Berita Tahun 1945-47 (Report for the Years 1945-47). The report was subsequently republished in 1962 by the Directorate of Geology, Department of Basic Industry/Mining.

The report reveals that 1946 was a pivotal year in the development of the PDTG. By the end of that year, the organization’s administrative and institutional stability remained precarious amid the ongoing struggle for independence and political uncertainty. Although the territory of the RI remained relatively extensive following the Linggadjati Agreement, mining and geological activities could not proceed smoothly because of inadequate transportation links and continuing instability (Lasut, 1962: 4).

Report compiled by A.F. Lasut in 1948. Source: Google Books/Laporan yang disusun oleh A.F. Lasut tahun 1948. Sumber: Google Books.

In the field of geology, activities remained severely constrained by the war and the relocation of offices. The Geological Mapping and Mineral Exploration Section were unable to carry out their scientific work. A large number of geological maps were destroyed by fire when the evacuation site was attacked, and only map tracings (calques) of Java were successfully salvaged. Although no new mineral exploration was undertaken, efforts were made to revive earlier investigations, particularly those concerning cinnabar in Purwakarta and coal in Tulungagung. In the same year, topographic and geological surveys were conducted in Tirtomoyo, Jalen, and Karangkobar, primarily to assess areas with potential for kerosene production (Lasut, 1962: 8).

After supervisory activities had been curtailed in late 1945 because of the war, volcanic monitoring resumed in 1946 at several observation posts – Tangkuban Parahu, Papandayan, Ciremai, Merapi, Kelut, and Ijen – with four posts stationed at Merapi. While several volcanoes remained relatively quiet, Merapi exhibited high-temperature solfataric activity. Significant events occurred at Mount Semeru in October and November 1946, when eruptions ejected sand, ash, and rock and generated pyroclastic flow (gloedwolk) that swept down the southeastern slopes. There were concerns that these materials could trigger floods and lahars; consequently, new instructions were drafted to protect the local population (Lasut, 1962: 12-15).

The Paleontology Section had not yet commenced operations because it had received no materials from the Mapping Section; instead, its staff had been seconded to work at the oil company in Cepu (Lasut, 1962: 15). Similarly, the Geological Museum had not yet been established by November 1946 because of the PDTG’s unstable institutional status. After the museum’s collections had been relocated to Tasikmalaya and Magelang, the process of gathering materials began on November 17. The collection comprised minerals and metals, fossils from Trinil and Sangiran, batu lintang (“meteorites”), andesite, and and 200 types of rocks. Although a shortage of materials limited the production of mock-ups and models, the museum nevertheless managed to hold an exhibition at the Pasar Malam Pembangunan (Pembangunan Fair) in December (Lasut, 1962: 15-16). Meanwhile, the Cartography Section provided personnel to produce battle maps of West Java and to meet the mapping needs of the PDTG (Lasut, 1962: 16).

In the Engineering Geology Section, the PDTG conducted investigations related to construction and public safety. In 1946, surveys were completed for the Cibuduk Reservoir, fill-soil sites at Blok Sieuneun and Kampung Kondang, and the proposed Kali Sampean Dam. The Cibuduk site revealed porous tuff breccia and soft alluvial deposits, both of which were prone to leakage and instability. The investigation therefore recommended anchoring the foundations in hard tuff breccia and porous layers filled with clay cores. At Sieuneun and Kondang, highly permeable soils contributed to landslides, necessitating improved drainage and the relocation of the village. Meanwhile, the investigation of the Kali Sampean site remained inconclusive because drilling operations were hampered by the rainy season (Lasut, 1962: 16-19).

Artesian drilling operations continued despite significant challenges. Because drilling sites were generally located far from urban centers, monitoring progress – particularly in Banten – was difficult. After the Bandung workshop and warehouse fell into Dutch hands, the drilling equipment still in operation was located at Situbondo, Tulung, Eretan Kulon, and Baureno, while the equipment in Banten could not yet be inspected. Activities focused on cleaning out old wells, completing wells where work had stalled since 1941, drilling new wells, and investigating sources of clean water from deep aquifers. By the end of 1946, several of these tasks had been completed (Lasut, 1962: 19-20).

Wartime constraints were also keenly felt by the Laboratory Section. When the PDTG left Bandung, not all laboratory equipment could be transported; only a few essential items, including platinum, had been sent to Yogyakarta beforehand. Laboratory personnel were subsequently reassigned to branches of mining companies outside Bandung. In 1946, the Laboratory Section secured facilities at the Tirtomoyo mining company and in Surakarta. In addition to conducting laboratory work, the section prepared to convert the Tirtomoyo facility into a sulfuric acid plant and handled personnel administration for staff from other sections based in Surakarta (Lasut, 1962: 22-23).

Technical investigations produced a crucial assessment concerning the future of the Tirtomoyo mining company. The copper content of the deposit was too low to justify continuing operations as a copper mine. Taking into account the available materials and machinery, a plan was therefore developed to convert the facility into a sulfuric acid plant. Because nitrate materials required for the lead-chamber process were difficult to obtain, the contact process, incorporating a pre-contact stage, was selected. Preparations proceeded as far as the completion of a pilot contact furnace; however, trials of sulfuric acid production could not be continued, and the project was ultimately confined to laboratory-scale work. The laboratory also planned to produce natural phosphate through the establishment of a plant at Ijo, Kedu (Lasut, 1962: 22-23).

Ombilin Mining, circa 1935. Source: KITLV 179168 (digitalcollections.universiteitleiden.nl)/Pertambangan Ombilin sekitar tahun 1935. Sumber: KITLV 179168 (digitalcollections.universiteitleiden.nl)

In the field of law and inspection, 1946 marked a transitional period from the colonial mining system to the regulatory framework of the RI. Until the end of the year, colonial-era regulations – including the Indische Mijnwet (Mining Law), Mijnordonnatie (Mining Ordinance), and Mijnpolitie-reglement (Mining Police Regulations) – remained in force while new mining laws and related regulations were being drafted. Although security concerns and a shortage of experts hindered inspection activities, examinations were conducted at mining companies in Java extracting gold, sulfur, lead, copper, coal, phosphate, manganese, and other minerals. The section also processed mining permit applications (Mijnbouwvergunning) and maintained a registry of mining companies (Lasut, 1962: 22-25).

Toward the end of 1946, the administrative organization was strengthened through Instructions No. 1/HT/46 and No. 3/HT/46. The first instruction required mining companies, as well as holders of contracts, concessions, and permits, to register with the PDTG in Magelang. The second regulated minerals not covered by the Indische Mijnwet and outlined procedures for applying for permits. Both instructions came into effect on January 1, 1947. In this context, the Law and Inspection Section worked to recover mining data and archives that had been lost during the evacuation of the Bandung office (Lasut, 1962: 25-29).

The Corporate Section faced a formidable task: taking over, rehabilitating, and reorganizing mining enterprises that had previously been under the control of the colonial government or Japanese entities. During the Japanese occupation, the section had been virtually inactive, as mining operations were managed by conglomerates such as Mitsui Kozan, Nippon Chisso, and Ishihara Sangyo. Following the transfer of authority to the RI, the section was tasked with restoring state-owned mining enterprises, such as Ombilin and Bukit Asam, while also managing former Japanese and private companies that had temporarily come under RI control (Lasut, 1962: 29).

The general condition of these companies was poor because of the devastation caused by “scorched-earth” tactics. Consequently, reconstruction became the immediate priority. Former Japanese enterprises were evaluated according to their potential usefulness to the public. Recovery efforts were hampered by shortages of skilled personnel and equipment, disrupted distribution networks, and the lack of external trade connections. Nevertheless, some mining operations in Java and Madura resumed, including the Ciater jarosite mine and the Telaga Bodas sulfur mine (Lasut, 1962: 29-30).

The Dutch blockade also influenced production policies. With coal imports from Sumatra obstructed, several coal mines in Java continued to be exploited to meet domestic demand. A zelfbedruiping (self-sustaining) system was implemented at the Cisaat mine in Sukabumi and the Ngandang mine in Rembang, despite rising production costs. Conversely, the Kliripan and Karangnunggal manganese mines and the Tayu phosphate mine were forced to delay or curtail production because their exports could not be shipped. To increase revenue, some companies developed nevenbedrijven (ancillary enterprises), including the manufacture of calcium carbide, sodium sulfide, paper, and agricultural tools.

Amid the revolutionary climate, corporate management had not yet been fully centralized. Some mines were operated directly by their workers, approaching a form of anarcho-syndicalism. The PDTG sought to promote greater centralization and coordination, a process that ultimately led to the separation of the Cepu Oil Mine into an independent agency (Lasut, 1962: 29-30).

Biografi A.F. Lasut (9):

LAPORAN KEGIATAN TAHUN 1946

Pada November 1948, di Yogyakarta, A.F. Lasut sebagai Kepala Pusat Djawatan Tambang dan Geologi (PDTG), Kementerian Kemakmuran, Republik Indonesia (RI) berhasil menyusun laporan tahun 1945 hingga 1947 organisasi tersebut, dengan judul Berita Tahun 1945-47. Laporan tersebut kemudian dipublikasikan lagi oleh Direktorat Geologi, Departemen Perindustrian Dasar/Pertambangan, tahun 1962.

Dari laporan tersebut, kita dapat mengetahui bahwa tahun 1946 merupakan masa penting dalam perkembangan PDTG. Pada akhir tahun tersebut, keadaan pemerintahan dan organisasi PDTG masih belum sepenuhnya mantap karena berada dalam suasana perjuangan dan ketidakpastian politik. Meskipun wilayah RI setelah Persetujuan Linggadjati masih relatif luas, pekerjaan pertambangan dan geologi belum dapat berjalan lancar karena buruknya perhubungan dan keadaan yang belum jelas (Lasut, 1962: 4).

Dalam bidang geologi, kegiatannya masih dipengaruhi perang dan pemindahan kantor. Urusan Perpetaan Geologi dan Pentjaharian Galian belum dapat menjalankan pekerjaan ilmiahnya. Sebagian besar peta bumi ikut terbakar ketika pengungsian diserang, dan hanya calques (salinan) peta Jawa berhasil diselamatkan. Pencaharian bahan galian belum dilakukan, tetapi menghidupkan kembali penyelidikan lama dijalankan, antara lain cinnaber di Purwakarta dan batubara di Tulungagung. Pada tahun sama dilakukan pengukuran topografi dan geologi di Tirtomoyo, Jalen, dan Karangkobar, terutama untuk pemeriksaan daerah yang berpotensi menghasilkan minyak tanah (Lasut, 1962: 8).

Setelah pada akhir 1945 kegiatan pengawasan dikurangi karena perang, pada 1946 pengamatan gunungapi kembali dilakukan di sejumlah pos, yaitu Tangkuban Parahu, Papandayan, Ciremai, Merapi, Kelut, dan Ijen, dengan empat pos di Merapi. Sejumlah gunungapi relatif tenang, sedangkan Merapi menunjukkan aktivitas solfatara bertemperatur tinggi. Peristiwa menonjol terjadi di Semeru pada Oktober dan November 1946, ketika letusan menghamburkan pasir, abu, dan batu serta menghasilkan gloedwolk (awan panas) ke lereng tenggara. Material tersebut dikhawatirkan menimbulkan banjir dan lahar. Karena itu disusun instruksi baru untuk melindungi penduduk. (Lasut, 1962: 12–15).

Tangkuban Parahu Crater, 1932. Source: KITLV 49458 (digitalcollections.universiteitleiden.nl)/Kawah Tangkuban Parahu tahun 1932. Sumber: KITLV 49458 (digitalcollections.universiteitleiden.nl)

Urusan Palaeontologi belum menjalankan kegiatan karena tidak memperoleh material dari Urusan Perpetaan. Pegawainya diperbantukan kepada Perusahaan Minjak di Cepu bekerja (Lasut, 1962: 15). Demikian pula Museum Geologi belum berdiri hingga November 1946 karena kedudukan PDTG belum stabil. Setelah koleksi Museum Bandung dibawa ke Tasikmalaya dan Magelang, pada 17 November pengumpulan dimulai. Koleksinya meliputi bahan tambang dan logam, fosil Trinil dan Sangiran, batu lintang, andesit, serta 200 jenis batuan. Keterbatasan bahan membatasi maket dan model, tetapi Desember museum menyelenggarakan pameran di Pasar Malam Pembangunan (Lasut, 1962: 15–16). Sementara itu, Urusan Kartografi menyumbangkan tenaganya untuk peta pertempuran Jawa Barat dan kebutuhan PDTG (Lasut, 1962: 16).

Stegodon fossil on display at the Geological Museum, as photographed by Von Koenigswald. Source: De Locomotief, December 27, 1935/Fosil Stegodon yang dipamerkan di Museum Geologi, sebagaimana dipotret oleh Von Koenigswald. Sumber: De Locomotief, 27 Desember 1935.

Di bidang Teknik-Geologi, PDTG menjalankan penyelidikan terkait pembangunan dan keselamatan masyarakat. Pada 1946 diselesaikan penyelidikan Waduk Cibuduk, tanah uruk Blok Sieuneun, Kampung Kondang, serta bakal Bendungan Kali Sampean. Cibuduk menunjukkan breksi tufan berpori dan aluvial lunak yang berpotensi menyebabkan kebocoran dan pergeseran, sehingga fondasi dianjurkan pada tufbreccie keras dan lapisan berpori diisi klei-kern (inti lempung). Di Sieuneun dan Kondang, tanah mudah ditembus air menyebabkan longsor sehingga drainase dan pemindahan kampung diperlukan. Sementara itu, penyelidikan Kali Sampean belum menghasilkan kesimpulan karena pemboran terhambat musim hujan (Lasut, 1962: 16–19).

Pekerjaan pemboran artesis dilanjutkan meskipun menghadapi kendala berat karena lokasi pemboran umumnya jauh dari kota, sehingga perkembangan pekerjaan, khususnya di Banten, sulit dipantau. Setelah bengkel dan gudang Bandung jatuh ke tangan Belanda, alat bor yang masih digunakan berada di Situbondo, Tulung, Eretan Kulon, dan Baureno, sedangkan peralatan Banten belum dapat diperiksa. Kegiatan diarahkan pada pembersihan sumur lama, penyelesaian sumur yang terhenti sejak 1941, penggalian sumur baru, dan penelitian air bersih dari lapisan dalam. Hingga akhir 1946, beberapa pekerjaan tersebut telah dilaksanakan (Lasut, 1962: 19–20).

Keterbatasan akibat perang sangat terasa pula pada Bagian Laboratorium. Ketika PDTG meninggalkan Bandung, perlengkapan laboratorium tidak dapat seluruhnya dibawa. Hanya beberapa alat penting, antara lain platina, yang telah lebih dahulu dikirim ke Yogyakarta. Pegawai laboratorium kemudian diperbantukan ke cabang-cabang perusahaan tambang di luar Bandung. Pada 1946 Bagian Laboratorium memperoleh tempat di perusahaan tambang Tirtomoyo dan di Surakarta. Selain menjalankan pekerjaan laboratorium, bagian ini melakukan persiapan untuk mengubah perusahaan Tirtomoyo menjadi pabrik asam sulfat sekaligus menangani administrasi pegawai dari bagian-bagian lain yang ada di Surakarta (Lasut, 1962: 22–23).

Penyelidikan teknologis menghasilkan penilaian penting mengenai masa depan perusahaan tambang Tirtomoyo. Kandungan tembaga dalam cebakan terlalu kecil sehingga tidak dapat dipertahankan sebagai tambang tembaga. Dengan mempertimbangkan bahan dan mesin tersedia, disusun rencana mengubahnya menjadi pabrik asam sulfat. Karena bahan nitrat untuk loodenkamer-proces (proses kamar timbal) sulit diperoleh, dipilihlah contact process (proses kontak) melalui tahap voorcontact (kontak awal). Persiapan dilaksanakan hingga proef contactoven selesai dibuat. Namun, percobaan produksi asam sulfat tidak dapat diteruskan dan menjadi tugas laboratorium. Laboratorium juga merencanakan pembuatan natuur-phosphaat (fosfat alami) dengan pendirian pabrik di Ijo, Kedu (Lasut, 1962: 22–23).

Dalam bidang hukum dan inspeksi, tahun 1946 merupakan masa transisi dari sistem pertambangan kolonial menuju penataan pertambangan RI. Sampai akhir tahun, peraturan lama seperti Indische Mijnwet (Undang-Undang Pertambangan Hindia), Mijnordonnatie (Ordonansi Pertambangan), dan Mijnpolitie-reglement (Peraturan Kebijakan Pertambangan) masih berlaku, sementara hukum tambang dan peraturan terkait disusun. Meski kekurangan tenaga ahli dan keamanan menghambat inspeksi, pemeriksaan dilakukan terhadap perusahaan tambang di Jawa yang mengusahakan emas, belerang, timbal, tembaga, batu bara, fosfat, mangan, dan bahan galian lainnya. Bagian ini menerima permohonan Mijnbouwvergunning serta mendata perusahaan (Lasut, 1962: 22–25).

Menjelang akhir 1946, penataan administrasi diperkuat melalui Instruksi No. 1/HT/46 dan No. 3/HT/46. Instruksi pertama mewajibkan perusahaan tambang, kontrak, konsesi, dan izin mendaftarkan diri kepada PDTG di Magelang. Instruksi kedua mengatur bahan galian di luar Indische Mijnwet dan permohonan izin. Keduanya berlaku 1 Januari 1947. Dalam hal ini, Bagian Hukum dan Inspeksi mengumpulkan kembali data dan arsip pertambangan yang hilang akibat pengungsian kantor Bandung (Lasut, 1962: 25–29).

Bagian Perusahaan menghadapi tugas besar, yakni mengambil alih, memulihkan, dan menata perusahaan tambang yang sebelumnya berada di bawah pemerintah kolonial atau badan Jepang. Pada zaman Jepang, bagian ini praktis tidak bekerja karena urusan pertambangan diselenggarakan badan seperti Mitsui Kozan, Nippon Chisso, dan Ishihara Sangyo. Setelah kekuasaan beralih kepada RI, tugasnya mengembalikan perusahaan Tambang Negara seperti Ombilin dan Bukit Asam serta mengurus perusahaan peninggalan Jepang dan swasta yang sementara menjadi milik RI (Lasut, 1962: 29).

Kondisi perusahaan umumnya buruk akibat kerusakan politik bumi hangus. Oleh karena itu, pembangunan kembali menjadi langkah pertama. Perusahaan peninggalan Jepang dinilai berdasarkan kegunaan masyarakat. Kekurangan tenaga ahli, alat, distribusi, dan hubungan luar menghambat pemulihan. Namun, sebagian perusahaan di Jawa dan Madura kembali berjalan, termasuk tambang jarosit Ciater dan belerang Telaga Bodas (Lasut, 1962: 29–30).

Blokade Belanda turut menentukan kebijakan produksi. Karena impor batubara dari Sumatra terhambat, beberapa tambang batubara di Jawa terus dieksploitasi untuk kebutuhan dalam negeri. Sistem zelfbedruiping (swasembada) dijalankan di Cisaat, Sukabumi, dan Ngandang, Rembang, meskipun biaya produksi meningkat. Sebaliknya, tambang mangan Kliripan dan Karangnunggal serta fosfat Tayu harus menunda atau mengurangi produksi karena ekspor tidak mungkin dilakukan. Untuk meningkatkan pendapatan, beberapa perusahaan mengembangkan nevenbedrijven (perusahaan pendukung) seperti pembuatan karbid, natrium-sulfida, kertas, dan alat pertanian. Dalam suasana revolusi, pengelolaan perusahaan belum sepenuhnya terpusat. Sejumlah tambang dijalankan langsung buruhnya, bahkan mendekati anarcho-syndicalisme (anarko-sindikalisme). PDTG mendorong sentralisasi dan koordinasi. Tambang Minyak Cepu dipisahkan menjadi jawatan tersendiri (Lasut, 1962: 29–30).