On the eve of the Japanese occupation in 1942, A.F. Lasut took part in a native militia training program organized by the colonial government of the Netherlands East Indies, namely the Corps Reserve Officier (CORO), or Reserve Officers Corps, in Bandung. Lasut was even involved in combat to hold back Japanese troop attacks at Ciater, Lembang, near Subang (Mardanas Safwan, Arie Frederik Lasut, 1981, p. 28).

Safwan notes that during the Japanese occupation (1942–1945), Lasut did not continue a military career but instead returned to work as a geological assistant at the Geological Survey, which during the Japanese period was referred to as “Bandung Tititsutiyo Zaiyi.” He devoted his expertise in mining as part of efforts to maintain vital sectors for Indonesia, together with R. Sunu Sumosusastro, despite operating under Japanese control (Safwan, 1981, pp. 40–41).

A.F. Lasut carried out various activities in mining investigation and management, including studies of jarosite at Ciater (Subang); sulfur at Telagabodas and Wanaraja (Garut); and coal mines at Cisaat–Sukabumi, Ngandang–Rembang, Bayah–Banten, and Jalen–Watulimo (Tulungagung). He also investigated coal reserves at Kali Bendo and Kali Watugemuk. In addition, Lasut was involved in oil mining activities at Bongas (Cirebon) and Cepu, where production increased in 1943 before declining toward the end of the Japanese occupation. These activities took place within the context of harsh colonial exploitation, particularly in Bayah, which was notorious for the suffering of romusha (forced laborers). Consequently, Lasut’s technical work cannot be separated from the broader context of popular suffering and the dynamics of the struggle toward Indonesian independence (Safwan, 1981, pp. 41–42).

Safwan (1981, pp. 43–44) further states that A.F. Lasut also played a role in continuing and opening mining enterprises outside Java, especially in Sumatra. These activities included the Ombilin–Sawahlunto and Bukit Asam coal mines, whose production declined due to damaged facilities, as well as the opening of the Logas coal mine, which was considered prospective. Oil mining activities in North Sumatra were also continued to support Japan’s war needs, while in 1943–1944 new drilling and exploration were conducted at Kenaliasem, Senami, Tempino, and Sungai Gelam. Most of these mining and geological activities were under the technical supervision of A.F. Lasut together with R. Sunu Sumosusastro, enabling both of them to master strategic mining maps and information at that time.

Based on his conviction that the Japanese occupation was temporary, Lasut was also active in mentoring young personnel within the Geological Service in Bandung, instilling a spirit of nationalism and readiness to take over the mining sector once Japanese power weakened in the Pacific War. One of the young figures he mentored was R.I. Subroto (Safwan, 1981, p. 45).

One piece of evidence of Lasut’s activities during the Japanese occupation is the inclusion of his name among the “Names of individuals and bodies (associations) awarded the Service Emblem pursuant to Osamu Seirei No. 2 of the 20th year of Showa (2605), ‘Regulation on the Service Emblem to the Military Government,’” as published in Kan Po (Government Gazette) No. 62, Month 3, 2605.

A.F. Lasut, together with R. Ali Tirtosoewirjo, who worked at Tisitu Tyuuososyo kinmu (Mining Investigation Office) Nitoo Gizyutukanpo and Tisitu Tyuuososyo kinmu Yontoo Gizyutukan, received an award in the form of the “Bintang Matjam No. 4.”

Another piece of evidence of A.F. Lasut’s activities is the report on the inventory of hot springs in Java and Madura entitled Hotsprings in Djawa and Madura. In the preface written in Bandung on June 26, 2604 (1944), Lasut stated that the report was a compilation of literature on hot springs, prepared on the basis of the geological–mining bibliography of the Netherlands East Indies up to 1932, and supplemented with reports and archives of the Mining Service during the Japanese occupation (Tisitutyosatzyo). The hot spring data were classified by residency, with Chapter I containing descriptions of location, physical and chemical properties, discharge, and deposits, and Chapter II presenting a concise list with references to topographic maps at a scale of 1:50,000 and a distribution map at a scale of 1:1,000,000. (Written by Atep Kurnia, edited by Eko Suryanto).

Sumber: Koleksi Perpustakaan Pusat Survei Geologi (PSG), Badan Geologi, Jl. Diponegoro No. 57, Bandung

Biografi Arie Frederik Lasut (6): Zaman Pendudukan Jepang

Menjelang pendudukan Jepang pada tahun 1942, A.F. Lasut sempat mengikuti pelatihan milisi bangsa bumiputra yang diselenggarakan pemerintah kolonial Hindia Belanda, yaitu Corps Reserve Officier (CORO) atau korps perwira cadangan di Bandung. Lasut bahkan terlibat dalam pertempuran untuk menahan serangan pasukan Jepang di Ciater, Lembang, dekat Subang (Mardanas Safwan, Arie Frederik Lasut, 1981, hlm. 28).

Safwan menyatakan bahwa pada masa pendudukan Jepang (1942-1945), A.F. Lasut tidak melanjutkan karier militer, melainkan kembali bekerja sebagai asisten geologi di Jawatan Geologi yang di masa pendudukan Jepang disebut sebagai “Bandung Tititsutiyo Zaiyi”. Ia mengabdikan keahliannya di bidang pertambangan sebagai bagian dari upaya mempertahankan sektor vital bagi Indonesia, bersama R. Sunu Sumosusastro, meskipun berada di bawah kendali Jepang (Safwan, 1981, hlm. 40-41).

A.F. Lasut melakukan berbagai kegiatan penyelidikan dan pengelolaan pertambangan, antara lain Yarosit di Ciater (Subang), belerang di Telagabodas dan Wanaraja (Garut), serta tambang batubara di Cisaat–Sukabumi, Ngandang–Rembang, Bayah–Banten, dan Jalen–Watulimo (Tulungagung). Ia juga melakukan penyelidikan cadangan batubara di Kali Bendo dan Kali Watugemuk. Selain itu, Lasut terlibat dalam kegiatan pertambangan minyak di Bongas (Cirebon) dan Cepu, yang produksinya sempat meningkat pada 1943 sebelum menurun menjelang akhir pendudukan Jepang. Aktivitas tersebut berlangsung dalam konteks eksploitasi kolonial yang keras, terutama di Bayah yang dikenal dengan penderitaan romusha, sehingga kegiatan teknis Lasut tidak terlepas dari konteks penderitaan rakyat dan dinamika perjuangan menuju kemerdekaan Indonesia (Safwan, 1981, hlm. 41-42).

Safwan (1981, hlm. 43-44) menyatakan bahwa A.F. Lasut juga berperan dalam melanjutkan dan membuka usaha pertambangan di luar Jawa, terutama di Sumatera, Kegiatan tersebut mencakup tambang batubara Ombilin–Sawahlunto dan Bukit Asam yang produksinya menurun akibat kerusakan fasilitas, serta pembukaan tambang batubara Logas yang dinilai prospektif. Kegiatan pertambangan minyak di Sumatera Utara juga dilanjutkan untuk mendukung kebutuhan perang Jepang, sementara pada 1943–1944 dilakukan pengeboran dan eksplorasi baru di Kenaliasem, Senami, Tempino, dan Sungai Gelam. Sebagian besar kegiatan pertambangan dan geologi tersebut berada dalam pengawasan teknis A.F. Lasut bersama R. Sunu Sumosusastro, sehingga keduanya menguasai peta dan informasi strategis pertambangan pada masa itu.

Berlandaskan keyakinan bahwa pendudukan Jepang bersifat sementara, A.F. Lasut juga aktif membina tenaga muda di lingkungan Jawatan Geologi di Bandung  dengan menanamkan semangat kebangsaan dan kesiapan mengambil alih sektor pertambangan ketika posisi Jepang melemah dalam Perang Pasifik. Salah satu tokoh muda yang dibinanya adalah R.I. Subroto (Safwan, 1981, hlm. 45).

Salah satu bukti aktivitas A.F. Lasut pada masa pendudukan Jepang adalah namanya tercantum sebagai salah seorang dari “Nama-nama orang dan badan (perkoempoelan) jang dianoegerahi Lambang Kebaktian menoeroet Oesamu Seirei No. 2 tahoen Syoewa 20 (2605) ‘Peratoeran tentang Lambang Kebaktian kepada Pemerintahan Balatentara’”, sebagaimana yang dimuat dalam majalah Kan Po (Berita Pemerintah) No. 62, Boelan 3, 2605.

A.F. Lasut bersama R. Ali Tirtosoewirjo yang bekerja di Tisitu Tyuuososyo kinmu (Kantor penyelidikan tambang) Nitoo Gizyutukanpo dan Tisitu Tyuuososyo kinmu (Kantor penyelidikan tambang) Yontoo Gizyutukan menerima penghargaan berupa “Bintang Matjam No. 4”.

Bukti lain aktivitas A.F. Lasut adalah laporan inventarisasi mata air panas di Jawa dan Madura berjudul Hotsprings in Djawa and Madura. Dalam kata pengantar yang ditulis di Bandung pada Juni 2604 (1944), Lasut menyatakan bahwa laporan tersebut merupakan kompilasi literatur tentang mata air panas yang disusun berdasarkan bibliografi geologi-pertambangan Hindia Belanda hingga 1932, serta dilengkapi laporan dan arsip Jawatan Pertambangan pendudukan Jepang (Tisitutyosatzyo). Data mata air panas diklasifikasikan menurut keresidenan, dengan Bab I memuat deskripsi lokasi, sifat fisik-kimia, debit, dan endapan, serta Bab II berisi daftar ringkas beserta rujukan peta topografi skala 1:50.000 dan peta sebaran skala 1:1.000.000. (Penulis ATEP KURNIA, editor EKO SURYANTO)