The center of gravity (CoG) on the minibus is one of the fundamental parameters that affect the operation of the vehicle to maintain traffic safety. CoG greatly affects vehicle maneuverability due to load transfer between the front and rear wheels, such as when turning, braking, and accelerating. Therefore, this research was conducted to evaluate the operational safety of minibusses produced by the domestic car body industry. The case study was conducted on a minibus with a capacity of 30 passengers to be used in a mining area. Investigations on CoG were carried out based on the minibus specification data, especially the dimensions and forces acting on the wheels. Minibusses as test objects were categorized in two conditions, namely without passengers and with 30 passengers. The test results are expressed in a coordinate system (x, y, z) which represents the longitudinal, lateral, and vertical distances to the center of the front wheel axle. CoG coordinate values ​​without passengers are (2194.92; 7.11; 1327.97) mm and CoG coordinates with full passengers (30 people) are (2388.52; 13.04; 1251.72) mm. The test results show that the change in CoG at full load is not significant which indicates the minibus is safe when maneuvering under normal conditions.

In 2015, the Indonesian government issued regulations to accelerate the implementation of integrated Light-Rail Transit (LRT) in the capital region and its surroundings. In order to ensure its operational safety, experimental work is required to test components’ strength of the manufactured LRT structures. Following the JIS 7105 standard test method, the strain and deflection of the structures were measured by vertical load, compression, rotation, and three-point load support test. The critical area estimated in the railroad structure were conducted according to the finite element method, in which strain gauges are installed in areas where the stress concentration exceeds nominal pressure, namely notches, bends, and junction areas. The result shows that the maximum stress on the LRT train structure occurs at the door, where maximum compressive strain value is -1082 μe » -75.74 MPa on the left and the maximum tensile strain value is 597 μe » 41.79 MPa at the right door. The results of fatigue load analysis represent the average stress (σm) and voltage amplitude (σa) at the coordinate system located in the Søderberg triangle. Meanwhile, the camber value with the full vertical load still has a positive value of 3.03 mm, which indicates a safe limit.

Beberapa unit gerbong PPCW kapasitas 42 ton yang digunakan untuk pengangkutan semen, mengalami retak pada bagian rangka bawah. Untuk menegetahui penyebab terjadinya retak tersebut, dilakukan penelitian dengan cara mengukur tegangan yang terjadi pada saat gerbong beroperasi. Hasil penelitian berupa besaran tegangan rata-rata dan tegangan amplitudo yang diukur secara real-time pada berbagai kondisi jalan, dianalisis dengan menggunakan pendekatan diagram batas lelah. Hasil analisis menunjukkan bahwa tegangan pada beberapa titik berada pada daerah kritis atau diagram garis batas lelah. Hal ini merupakan penyebab terjadinya kerusakan struktur rangka bawah gerbong PPCW.

An XY-T Recorder is a measuring equipment that function to record data of statical-testing result and it is shown in the form of graphs. The graphs of appearance indicate actual-condition of output censor such as Loadcell (Force),LVDT(deflection), Strain gauge (Strains) or Pressure. Design and manufacture of XY-T Recorder based in this digital is intended to satisfy the limit of XY-T Recorder analog available in B2TKS. The result of calibration shows certain calibration of 0.13% at the level trust of 95% with the factor k=2 and it indicates the accuracy to be fairly good.The result of experiment has displayed output of graphs with pattern and value magnitudes of relatively equal to the XY-TRecorder analogKeywords : XY-T Recorder digital, statical-testing, XY-T Recorder analog, CalibrationAbstrak XY-T Recorder adalah suatu alat ukur yang berfungsi untuk merekam data hasil uji statis yang ditampilkan dalam bentuk grafik. Grafik yang ditampilkan menunjukkan kondisi aktual dari besaran yang keluar dari sensor seperti loadcell (gaya), LVDT (defleksi), strain gauge (regangan) ataupun pressure (tekanan).Perancangan dan pembuatan XY-T Recorder berbasis digital ini bertujuan untuk memenuhi keterbatasan XY-T Recorder analog yang dimiliki oleh B2TKS. Dari hasil kalibrasi menunjukkan ketidakpastian kalibrasi 0,13% pada tingkat kepercayaan 95% dengan faktor k=2, hal ini menunjukkan ketelitian yang cukup bagus, dan dari hasil uji coba pada saat pengujian menunjukkan keluaran grafik dengan pola dan nilai besaran yang relatip sama dengan XY-T Recorder analog.Kata Kunci : XY-T Recorder digital, Uji Statis, XY-T Recorder analog,Kalibrasi