Bidang kajian dalam jurnal ini termasuk sub rumpun Ilmu Teknik Sipil dan Perencanaan Tata Ruang, Keteknikkan Industri, Teknik Elektrinika dan Komputer, Teknik Kebumian dan Perkapalan. Jurnal Riset Rumpun Ilmu Teknik diterbitkan 3 kali setahun : April, Agustus dan Desember. Print ISSN : 2829-0178, Online ISSN : 2829-016X Jurnal ini terakreditasi SINTA 5 (Surat Keputusan Direktur Jenderal Pendidikan Tinggi, Riset, dan Teknologi Nomor 10/C/C3/DT.05.00/2025 tanggal 21 Maret 2025 tentang Peringkat Akreditasi Jurnal Ilmiah Periode I Tahun 2025) dimulai dari Volume 1 Nomor 2 Tahun 2022 sampai Volume 6 Nomor 1 Tahun 2027.
Evaluasi dan Peningkatan Kinerja Proyek menggunakan Metode Earned Value Analysis dan Metode Crashing
Construction project control requires careful planning to avoid delays and cost overruns. This study aims to evaluate the performance of the CBT Laboratory Building construction project at the Faculty of Medicine, Wahid Hasyim University, Semarang, in terms of cost and time using the Earned Value Analysis (EVA) method, and to analyze acceleration alternatives using the crashing method. The method used is a quantitative approach with a case study, based on project data such as the Budget Plan (RAB), S-curve, and work progress reports. The analysis was carried out using the Earned Value Analysis (EVA) method to assess project performance in terms of cost and time through indicators such as CV, SV, CPI, and SPI. Furthermore, an acceleration analysis was conducted using the crashing method to determine the optimal alternative for overcoming project delays by considering time and cost efficiency. The results of the Earned Value Analysis indicate that the project experienced delays and cost overruns, as shown by SPI < 1 and CPI < 1. The estimated project completion time increased to 227 days, longer than the initial plan of 217 days, while the estimated final cost reached RP 5,451,241,064.85, exceeding the initial budget. Acceleration efforts using the crashing method show that adding adding labor is more efficient than working hours (overtime), resulting in a project duration of 212 days with lower costs of RP 5,658,221,364.08. Thus, the Earned Value Analysis method is effective for evaluating project performance, while crashing can be a solution for acceleration by considering time and cost efficiency.
Analisis Pengaruh Konfigurasi dan Dimensi Dinding Geser (Shear Wall) terhadap Persyaratan Simpangan dan Torsi Struktur Bangunan Gedung
Indonesia is in an earthquake-prone region, therefore, designing building constructions that can withstand seismic loads is crucial in civil engineering. Reinforced concrete shear walls are one of the vertical structural fundamentals that are effectively used in multi-story buildings to withstand lateral forces due to earthquake and wind loads. Structures that use shear walls can increase stiffness and reduce horizontal deviations (deflections) of buildings, which contribute to the stability and safety of structures based on the SNI 1726:2019 standard. This study aims to analyze the effect of shear wall configurations on deviation and torsion requirements in multi-story building planning. The study object is a 6-story reinforced concrete building model in a specific earthquake zone. The design and modeling were performed using structural analysis software, taking into account columns, beams, slabs, and shear walls. The analysis results show that optimal placement of shear walls at the building edges significantly reduces horizontal drift, torsion, and shear forces, and improves the structural performance level compared to structures without shear walls or those with less effective placement. Structures with shear walls have optimal stiffness in absorbing lateral forces, making them more resistant to damage from the planned earthquake.
Copyright (c) 2026 JURAL RISET RUMPUN ILMU TEKNIK https://creativecommons.org/licenses/by-sa/4.0
Rekayasa Ulang Metode Pekerjaan Pengecoran dan Bekisting untuk Meningkatkan Kinerja Waktu dan Biaya Proyek Gedung Bertingkat
Time delays and cost overruns remain major problems in building construction projects, particularly in concrete structural works that dominate project duration and cost. This study aims to evaluate the application of re-engineering in concrete structural work methods on the time and cost performance of multi-storey building projects. A quantitative approach using a case study method was employed through comparative analysis between the existing method and alternative methods. The analyzed alternatives include ready-mix concrete with Sika Viscocrete 8007 admixture and semi-system formwork as Alternative I, ready-mix concrete with system formwork as Alternative II, and ready-mix concrete with Sika Viscocrete 8007 admixture combined with system formwork as Alternative III. The results show that all alternatives perform better than the existing method with a duration of 243 days. Alternative I reduced the duration to 208 days with cost efficiency of IDR 55,781,730 or 0.214 percent. Alternative II reduced the duration to 203 days with cost efficiency of IDR 187,553,261 or 0.724 percent. Alternative III achieved the best performance with a duration of 168 days, accelerating 75 days and providing the highest cost efficiency of IDR 243,334,991 or 0.941 percent. The study concludes that re-engineering effectively improves project time and cost performance, with Alternative III as the optimal method.
Design and Development of a Marine Current Power Plant Using a Horizontal Axis Turbine of The Naca S814 Propeller
The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.
Analisis Penggunaan Butterworth pada Saat Proses Tank Cleaning Di MT. Marina Prospeirty
This research is motivated by the importance tank cleaning process on tankers to prevent cargo contamination, maintain cargo quality, and ensure crew safety. MT. Marina Prosperity, a chemical/oil tanker, uses the Butterworth system as the primary method for tank cleaning at every cargo change. However, in practice, technical and operational constraints are still found that affect the results of tank cleaning. The research method used is descriptive qualitative with data collection techniques through direct observation on the ship, interviews with the Chief Officer and Boatswain, and documentation studies in the form of log books and SOPs. Data were analyzed by focusing on three aspects, namely work efficiency, work safety, and operational procedures for using Butterworth. The results show that the use of Butterworth can increase time and energy efficiency compared to manual methods, with an average cleaning time of 2–4 hours per tank depending on the type of cargo. From a safety aspect, Butterworth reduces the need for crew to enter the tank, thereby reducing the risk of exposure to chemicals and hazardous atmospheres. However, work effectiveness and safety are greatly influenced by the condition of the equipment, the stability of water pressure, and the crew's discipline in implementing the SOP. On several occasions, steps such as nozzle cleaning, manual mopping, and safety meetings were not consistently performed, resulting in residual load in certain areas. With routine equipment maintenance, close supervision, and ongoing crew training, Butterworth can be optimized to produce more effective, safe, and standards-compliant tank cleaning process.
Upaya Percepatan Penanganan Kondisi Substandard Submarine Pipeline Penerimaan Avtur menggunakan Metode Double-Ended Draining dan Oil Bubble Trap
Submarine pipelines are vital infrastructures in aviation fuel distribution, carrying high risks of operational disruption, safety issues, and environmental pollution. In 2025, the aviation fuel receiving submarine pipeline at Integrated Terminal Ampenan was deformed due to mechanical pulling by MT Anargya I, causing system shutdown. This incident created risks of seawater intrusion, marine pollution, and potential fuel shortages at Lombok International Airport. This study evaluates the effectiveness of applying a double-ended draining method combined with an oil bubble trap as a fast, safe, and sustainable solution for submarine pipeline repair. Using a case study and descriptive-analytical approach based on the Continuous Improvement Program (CIP), the research analyzed quality, cost, delivery, safety, environmental, and workforce aspects. The results showed the method effectively drained aviation fuel without seawater contamination, prevented marine spills, maintained fuel quality within specifications, and completed repairs before critical stock levels were reached. Additionally, it provided significant cost savings compared to emergency supply operations and achieved zero safety incidents and environmental pollution. The integration of double-ended draining and oil bubble trap proved to be an effective, adaptive innovation with strong potential for replication and standardization in other aviation fuel submarine pipeline systems.
Design and Construction of a Wave Power Plant Using a Recoil Starter on a Prototype Ship
This research aims to design and develop a prototype wave power plant that utilizes the vertical motion of a buoy as a source of mechanical energy, which is then converted into electrical energy using a recoil starter mechanism. The system is designed to be installed at the stern of a prototype ship. The vertical movement of the buoy caused by ocean waves is transmitted to the recoil starter through a drive rope, producing a stable one-way rotational motion. This rotation is further transmitted to a gearbox to increase rotational speed before driving a DC generator. The electrical energy generated is stored in a 12 VDC battery, supported by a buck–booster converter to stabilize the output voltage. This study employs an experimental engineering approach to evaluate system performance based on empirical test data. The main components of the system include a buoy as a wave energy collector, a recoil starter as the initial rotating mechanism, a DC generator as the electrical energy producer, a buck–booster converter as a voltage regulator, a 12 VDC battery as an energy storage unit, and a monitoring system based on an ESP32 microcontroller integrated with a PZEM-017 sensor. Experimental results show that the recoil starter operates effectively in driving the generator under both no- load and buoy-loaded conditions. Increases in generator rotational speed are directly proportional to increases in output voltage and current. The PZEM-017 sensor demonstrates a high level of measurement accuracy, approaching 100% when compared with a multimeter. Overall, the proposed wave power generation system functions reliably and shows potential for further development as a small-scale alternative renewable energy source.
Perbandingan Volume Stock Batubara dengan Metode Pengukuran Menggunakan Laser Scanner Leica Ms60 dan Drone Dji Matrice 4e Studi Kasus di PT. XYZ
The coal mining industry requires accurate stockpile volume measurements for inventory and production reporting. Conventional methods have limitations in accuracy, efficiency, and safety. This study compares the accuracy and efficiency of coal stockpile volume measurements using a Terrestrial Laser Scanner (TLS) Leica MS60 and an Unmanned Aerial Vehicle (UAV) DJI Matrice 4E, validated by the ASTM D6172-98 standard. Conducted on five Run of Mine (ROM) coal stockpiles covering 13,500 m² at PT XYZ, Lahat, South Sumatra, the TLS method used 43 scan positions, while the UAV employed 430 aerial images with specific flight parameters. Data were processed using Leica Infinity, Surpac, and Agisoft Metashape. The results showed volumes of 94,076 m³ (TLS) and 94,965 m³ (UAV), with a difference of 889 m³ (0.95%). Volume deviations ranged from 0.48% to 1.89%, with an average of 1.42%, all within the ASTM tolerance (<2%). Time efficiency analysis revealed that the UAV method required 200 minutes (3.33 hours), saving 63.3% (approximately 6.17 hours) compared to the TLS method (570 minutes). The largest efficiency gain occurred during field data acquisition, with an 85% reduction in time. This study confirms UAV photogrammetry as a valid, accurate, and efficient alternative for coal stockpile volume measurement in mining.
Penanganan Masalah dalam Praktik Keinsinyuran: Evaluasi Uji Petik Preservasi Jalan di Kota Manado
This study evaluates the implementation of spot-check testing for road preservation works in Manado City, specifically on the Kairagi–Mapanget segment, the Manado City–Wori boundary, and the Liwas Terminal Access Road, to identify existing problems and assess the effectiveness of engineering-based mitigation efforts. The objective is to examine construction quality compliance with technical specifications and identify operational challenges encountered on site. The methodology encompasses the measurement of asphalt layer thickness and density via a core drill, the examination of contract documents, the analysis of laboratory test results, and the execution of field observations. The findings show that most samples meet the required standards, although several locations require corrective action. Challenges arise from weather conditions, heavy traffic, equipment limitations, and the need for adaptation to updated technical regulations. Operational mitigation strategies, staff training, the use of core drill technology, and digital documentation were found to enhance accuracy and efficiency in evaluation. The research demonstrates the value of stakeholder collaboration and capacity building in supporting quality control for road preservation works. A multidimensional approach is effective in resolving technical and operational complexities in urban road projects.
Analisis Permasalahan Pembebasan Lahan pada Pekerjaan Pembangunan Jalan
An essential stage in road infrastructure development is land acquisition, which frequently causes project delays due to its complex legal, social, and economic challenges. This study aims to identify the factors that hinder the land acquisition process in the Manado Outer Ring Road (MORR) 3 Phase 4 Construction Project and to assess how these constraints affect the progress of construction activities. The research was conducted using a qualitative case study approach, with data collected through field observations, document reviews, and interviews. The findings indicate that delays in land acquisition are caused by discrepancies in legal status and land ownership, differing perceptions of compensation value, insufficient public socialization, and weak institutional coordination. These issues lead to disruptions in the construction schedule and potential increases in project costs. The study demonstrates that land acquisition necessitates a more cohesive strategy, facilitated by enhanced communication and community engagement, fortified land acquisition management frameworks, and precise verification of ownership data. The results indicate that there must be broader mitigation strategies to prevent similar challenges in future infrastructure projects.
Pengaruh Substitusi Fly Ash pada Semen dengan Tambahan Limbah Polyehtylene Terephthalate (PET) terhadap Sifat Beton Self Compacting Concreate (SCC)
Self-Compacting Concrete (SCC) requires a high cement content, which contributes to increased carbon emissions; therefore, this study evaluates the effect of partial cement substitution with fly ash (5%, 10%, and 15%) and the addition of Polyethylene Terephthalate (PET) waste (0.5% and 0.7%) on the mechanical properties of SCC with a target strength of f’c 30 MPa. The research employed laboratory experimental methods, including fresh concrete tests (slump flow, L-box, and V-funnel) and hardened concrete tests (compressive, tensile, and flexural strength) at 7 and 28 days. The results indicate that fly ash substitution enhances compressive strength, with the highest value of 49.59 MPa achieved at 5% fly ash at 28 days, exceeding normal concrete (34.73 MPa). The addition of PET tends to reduce compressive strength due to increased porosity; however, it significantly improves flexural strength, as the combination of 5% fly ash and 0.5% PET achieved 4.7 MPa compared to 2.9 MPa for normal concrete. Overall, the combination of fly ash and PET waste shows potential for application in structural elements requiring high flexural performance.
Identifikasi Kandungan Merkuri (Hg) dan Tingkat Keasaman (pH) pada Sungai Takaras Terdampak Aktifitas Pertambangan Emas di Kecamatan Rakumpit
Takaras River is a river basin that is vulnerable to pollution, particularly from the mercury usage in small-scale gold mining. This study aims to identify water quality based on mercury (Hg)and pH levels in the Takaras River. Samples were taken at two locations using a purposive sampling method. Results showed indications of mercury use on former gold mining land around the Takaras River altought the mercury content level was below 0.075 µg/L or 0.00075 mg/L in sample 1 and 2. Based on the test results, the acidity level (pH) in the two water samples from Takaras River is 3.86 and 3.84 in sample 1 and 2, compared to the maximum pH quality standard of 6-9 for Class II water, it is concluded that the scale of acidity in Takaras River is very low, indicating that the water quality in the Takaras River is highly acidic, abnormal, and shows signs of serious pollution. The implications of low pH levels in the Takaras River can cause damage to the Takaras River ecosystem, a decline in soil quality and fertility, and an increase in heavy metal toxicity in the environment surrounding the river.
The Effect of Thermal Conditions on Airflow and Heat Transfer in a Test Object: An Experimental Study
This research aims to analyze the influence of thermal conditions; specifically the temperature difference between the test object and the environment; on the characteristics of air flow and heat transfer around it. The object of this study is a test piece subjected to free air flow under various temperature conditions; focusing on the convection heat transfer phenomenon. The main problem addressed is how temperature variations affect the convection heat transfer coefficient; heat transfer rate; and heat flux; as well as changes in air velocity and pressure profiles. Therefore; the objective of this research is to quantitatively compare and assess these thermal and fluid parameters through an experimental study approach and Computational Fluid Dynamics (CFD) simulation. The methodology involves direct measurement of temperature and pressure parameters under low and high-temperature conditions; which are then processed to determine the convection coefficient (); heat transfer rate (); and heat flux (). The main findings indicate that at low-temperature conditions; the heat transfer coefficient () was found to be 53.26 ; the heat transfer rate () was 24.99 W; and the heat flux () was 537.87 ; with a pressure drop of 0.86 Pa. In conclusion; thermal conditions play a crucial role in determining the dynamics of air flow and the efficiency of heat transfer; the greater the temperature difference (); the higher the potential heat transfer rate; establishing a strong correlation between thermal conditions and the convection phenomenon.
Copyright (c) 2026 JURNAL RISET RUMPUN ILMU TEKNIK https://creativecommons.org/licenses/by-sa/4.0
Analisis Daya Prototipe Superkapasitor Berbasis N-Glc dan Elektrolit Na2SO4
The increasingly complex global energy problem drives the need for efficient, low-cost, and environmentally friendly energy storage systems. This study aims to analyze the power performance of two symmetric supercapacitor prototypes using Nitrogen-doped Graphene-Like Carbon (N-GLC) as the electrode material and 1 M as the electrolyte, with different electrode substrates: aluminum and copper. Both prototypes were tested through charging and discharging processes using resistive loads of 470 ohms and 560 ohms for 5 minutes. The analyzed parameters include voltage, current, power, and output energy. The results show that the aluminum electrode achieved a higher maximum charging power of up to 18 mW; however, its energy discharge efficiency was very low at only 0.87%. In contrast, the copper electrode demonstrated a more balanced charging and discharging performance with an energy discharge efficiency of 19.4%. Analysis also indicates that the copper substrate maintains better voltage stability after 6 hours of storage compared to aluminum, which experienced significant degradation. Thus, the copper electrode is superior in maintaining the power and stability of a simple N-GLC-based symmetric supercapacitor system.
Efektifitas Metode Amalgamasi dan Metode Flotasi pada Proses Pengolahan Emas di Wilayah Pertambangan Rakyat (WPR)
The amalgamation and flotation methods are widely used by miners because the methods are simple, fast and easy. The purpose of this study was aims to test the effectiveness of gold recovery using the amalgamation and flotation methods in conventional gold processing. The research methods used were observation and testing using the amalgamation and flotation methods in conventional gold processing. The effectiveness analysis was carried out by calculating the percentage of gold produced in the amalgamation and flotation processing methods. The test was carried out on 10 samples, each weighing 10 kg. The amalgamation process used a Hg solution, while flotation used a detergent reagent. The total primary gold processing using the amalgamation method was 11.46 grams, while the total primary gold recovery using the flotation method was 12.15 grams. The results of gold processing using the flotation method were higher than those using amalgamation because flotation can separate gold more efficiently from ore containing various impurity minerals. Meanwhile, the amalgamation method, which uses mercury, tends to be less effective and loses some of the gold because it only binds very fine and dispersed gold particles, while flotation can handle ore with lower gold content and larger gold particles.
Pengaruh Jam Kerja Pemakaian Minyak Lumas terhadap Suhu Mesin Diesel Generator di Kapal
Generators are one of the important auxiliary aircraft needed on ships for power generation. During the operation of a diesel generator, continuous rotation occurs resulting in friction and erosion of the moving parts. The supporting factor for the smooth running of a diesel engine is a lubrication system that is supported by good lubricating oil quality, besides that it also needs to be supported by an adequate and good cooling system. The use of lubricants is one of the most important factors to ensure the performance of diesel engines. The lubricant is in charge of maintaining the condition of the engine so that it remains stable. This study aims to analyze the effect of using lubricating oil beyond the operating hours limit on engine heat. Furthermore, it also discusses steps to ensure diesel engine temperatures remain normal. This research was carried out during the practice of sailing on a ship for approximately one year. This study uses a descriptive quantitative research method. The primary data obtained directly utilizes observation methods, and documentation. Secondary data was obtained from existing articles and journals. The data analysis techniques used are descriptive analysis and inferential analysis. The results of this study show that the working hours of lubricating oil use have a significant influence on the increase in the temperature of diesel generator engines as evidenced by hypothesis tests on two engine units, namely AE1 and AE2. In the AE1 unit, a t-value of 18.467 with a significance of 0.000 was obtained, while in AE2 the t-value was 14.289 with a significance of 0.000. The significance value in both units is less than 0.05 so it can be concluded that the working hours of lubricated oil have a significant influence on the temperature of the genarato diesel engine on the ship.
Pengembangan Paving Block Berbasis Fitorimediasi sebagai Solusi Mitigasi Banjir Perkotaan
The problem of urban flooding is a growing issue due to high population density, increasing volumes of plastic waste, and the reduction of water absorption areas. The use of conventional paving blocks, which are impermeable, further exacerbates flooding conditions because they do not allow water to infiltrate into the soil. This study aims to develop an innovative plastic waste-based paving block incorporating rice straw and sugarcane bagasse, along with the integration of phytoremediation concepts as a solution for urban flood mitigation. The method employed was an experimental approach involving the following stages: material preparation, plastic incineration, material mixing, molding, and testing of water absorption capacity and compressive strength. The results showed that paving blocks with a combination of plastic waste, rice straw, and sugarcane bagasse had the highest water absorption rate of 34% and compressive strength of 21 kg/cm², meeting SNI standards. The addition of natural materials containing silica was proven to enhance the material’s porosity and strength. Additionally, the application of phytoremediation using water hyacinth has the potential to improve the quality of water seeping into the soil. Thus, this phytoremediation-based paving block innovation can serve as an effective alternative solution to reduce flood risks while supporting sustainable waste management and environmental stewardship.
Analisis Selisih Suhu Komponen Panel LVMDP Menggunakan Alat Infrared Thermography di PT. Dongjin Indonesia
The Low Voltage Main Distribution Panel (LVMDP) is a critical component in industrial power distribution systems, functioning to regulate, control, and distribute electrical energy to various production equipment. During operation, LVMDP panels often operate under high electrical loads, which may lead to temperature increases in their components. Undetected temperature rise can result in performance degradation, equipment failure, and even fire hazards. Therefore, an effective monitoring method is required to detect the condition of electrical components at an early stage. This study aims to analyze the temperature difference (ΔT) of LVMDP components using the Infrared Thermography method as part of predictive maintenance. The research employs a quantitative descriptive approach with data collected through direct observation from July 1 to July 31 at PT. Dongjin Indonesia. The data consist of hotspot and ambient temperatures measured from several panel components, which are then analyzed to calculate the temperature difference (ΔT) as an indicator of component operating conditions. The results indicate that the highest temperature difference is 26.5 °C in the capacitor bank, while the lowest is 4 °C in other components. All ΔT values are below the threshold limit of 50 °C, indicating that the LVMDP components are in safe operating conditions and do not require corrective actions. Thus, Infrared Thermography is proven to be an effective method for early detection of component conditions and can enhance the reliability and safety of industrial power distribution systems.
Integrasi Kerentanan Fisik Pesisir Berbasis Coastal Vulnerability Index (CVI) dalam Evaluasi Arahan Pemanfaatan Ruang RTRW
Coastal areas are highly dynamic and increasingly exposed to physical pressures such as coastal erosion, shoreline change, inundation, and sea-level rise. In Indonesia, most coastal vulnerability studies remain focused on physical mapping and have not been systematically integrated with spatial planning evaluation. This study aims to analyze physical coastal vulnerability using the Coastal Vulnerability Index (CVI) and integrate the results with the Regional Spatial Plan (RTRW) in the coastal areas of Mangarabombang and Laikang Sub-districts, Takalar Regency. A quantitative spatial approach was applied using eight parameters, which were reclassified into vulnerability scores, transformed into CVI values, and classified using quartile methods. The results show that high and very high vulnerability classes dominate the coastal area. Spatial integration reveals that several development zones intersect with high vulnerability levels, indicating potential spatial mismatch. This study confirms that CVI can be operationalized as a spatial evaluation tool to support adaptive and risk-based coastal planning.
Strategi Pengendalian Hambatan Approach Surface Runway 27 untuk Kesiapan Cat II di Bandar Udara Ngurah Rai
The growth of aviation activities at I Gusti Ngurah Rai International Airport, Bali, has led to the rapid development of surrounding areas, potentially obstructing protected airspace. Obstacles on the approach surface of Runway 27 have become a critical concern, particularly for precision approach Category II (CAT II) operations, which require obstacle-free approach areas. This study aims to analyze obstacles within the approach area of Runway 27 and develop effective control strategies. Using a descriptive qualitative approach, data was collected through field observations, interviews, and documentation studies. The analysis follows the Obstacle Limitation Surfaces (OLS) standards according to ICAO and national regulations. The findings reveal obstacles such as mangrove vegetation, antennas, and ship activities in the Benoa Harbor area, which are located within the approach surface and could potentially impact the OLS limits. While these obstacles generally comply with existing regulations, their proximity to the threshold may reduce the safety margin of flight operations and limit CAT II implementation on Runway 27. This study proposes technical, operational, regulatory, and preventive strategies to improve obstacle control, enhancing aviation safety and ensuring the readiness for CAT II operations at the airport.
Perancangan Instalasi LED Floodlight Berbasis Standar ICAO Annex 14 pada Main Helipad Fly Bali Heliport
Air transportation plays an important role in supporting mobility, tourism, and emergency activities such as medical evacuation and search and rescue (SAR). One of the essential supporting facilities for helicopter operations is a heliport, which must meet safety standards, including an adequate lighting system. This study aims to design an LED floodlight installation system for the Main Helipad of Fly Bali Heliport based on the international standard ICAO Annex 14 Volume II, while considering the corrosive coastal environmental conditions. The research method used is an engineering design approach with quantitative analysis of illumination requirements and current carrying capacity (CCC). Data were obtained through literature studies based on ICAO, FAA, and CAP 437 standards, as well as field observations. The design process includes determining the number and placement of floodlights, technical specifications, and electrical installation systems, including cable and protection selection. The results show that the configuration of four LED floodlight units is capable of producing a minimum illumination of 10 lux evenly across the TLOF and FATO areas in accordance with ICAO standards without causing glare. The use of Avlite AV-HL-FL floodlights with IP66 protection is suitable for coastal environments. The electrical installation system using NYY 2×2.5 mm² cables and a 2 Ampere MCB ensures system safety and reliability. Therefore, this design can enhance heliport operational safety and support optimal night operations.
Pengembangan Sistem Buoy untuk Pemantauan Suhu Permukaan Laut dan Evaluasi Kinerja Panel Surya
Sea Surface Temperature (SST) is an important parameter in oceanographic studies because it influences climate dynamics, ocean circulation, and marine ecosystems. Continuous monitoring of SST in open sea areas requires a reliable system capable of operating autonomously. This study develops a solar-powered ocean buoy designed to measure sea surface temperature while simultaneously evaluating the performance of a solar panel as the main energy source. The system uses a DS18B20 sensor to measure SST and an INA219 sensor to monitor the voltage, current, and power of the solar panel, while an ESP32 microcontroller functions as the central data processing unit. The results show that sea surface temperature tends to remain relatively stable with small daily variations, whereas the temperature and performance of the solar panel exhibit larger fluctuations due to direct exposure to solar radiation and changing weather conditions. Solar panel performance also shows significant variations in current and power depending on the intensity of sunlight. To analyze the influence of SST variations on solar panel performance, a statistical analysis using Analysis of Variance (ANOVA) was conducted. The ANOVA results, based on the calculated F-value and the significance value (p-value) at a confidence level of α = 0.05, indicate that SST variations have a significant effect on solar panel performance, demonstrating that the proposed solar-powered buoy system can operate autonomously and has potential for long-term SST monitoring in offshore areas.
Simulasi Analisa Aliran Daya Pekerjaan Evakuasi Daya Penyulang Kintamani di PT PLN (Persero) UP3 Bali Timur dengan Software ETAP
This study aims to analyze the technical and economic impact of power evacuation work on the 20 kV distribution system at PT PLN (Persero) UP3 East Bali. The main problem studied is the high losses and poor voltage profile on the downstream side of the Kintamani feeder. The method used is load flow simulation using ETAP software with a comparative approach to conditions before and after power evacuation. The results showed that the active losses decreased from 1.017 MW to 0.626 MW (efficiency 38.45%), accompanied by an increase in the end voltage from 16.32 kV to 18.72 kV and 19.38 kV, thus meeting the SPLN 1:1995 standard. The reduction in losses resulted in energy savings of 3,425,160 kWh/year. From the economic side, a payback period (PBP) of 1.40 years was obtained, which shows that the project is financially feasible. In addition, the improvement of network performance also contributes to the reliability of the distribution system and the continuity of the distribution of electrical energy to customers. Thus, power evacuation work has been proven to be effective in improving power distribution efficiency, improving voltage quality, and providing significant economic benefits.
Pengaruh Model Pembelajaran Direct Learning Terhadap Kemampuan Diagnosis Kerusakan Kendaraan pada Pembelajaran Teaching Factory di SMK
This study aims to analyze the effect of direct learning on engine components toward students' vehicle diagnostic abilities in vocational education. Employing a quantitative approach with an ex post facto design, the sample consisted of 80 students selected using simple random sampling from a population of 100 students. Data were collected using validated and reliable questionnaires. The data analysis techniques included descriptive statistics, classical assumption tests, and simple linear regression analysis. The results show that direct learning has a positive and significant effect on students’ vehicle diagnostic abilities, with a significance value of 0.000 < 0.05 and a coefficient of determination (R²) of 0.264. This indicates that direct learning contributes 26.4% to the improvement of students' diagnostic abilities. The findings emphasize the importance of practical, hands-on learning approaches in vocational education. These approaches not only enhance students' understanding of automotive theory but also improve their diagnostic skills. The study highlights that systematic learning and direct interaction with engine components are key factors in developing students' competencies, making them more effective in real-world vehicle diagnostics.
Perancangan Fasilitas Produksi dengan menggunakan Metode Computerized Relative Allocation of Facilities Technique (CRAFT) pada UMKM Gethuk Lindri Niki Eco
The development of MSMEs in the traditional food sector requires business actors to increase production capacity. MSME Gethuk Lindri Niki Eco plans to build a larger facility to meet increasing demand. However, the layout planning is still based on rough drawings and experience, which can lead to inefficient material movement. This study aims to provide an overview of recommendations for a more efficient production facility layout using the CRAFT method. The research method involves collecting data on production processes, departmental areas, and material movement frequency. Moreover, an Activity Relationship Chart (ARC) is compiled to identify the close relationships among departments. The results of the analysis are visualized with a Block Plan. Furthermore, the layout is optimized using the CRAFT method. The results show that the recommended layout reduces the total material movement distance from 60.96 meters to 58.19 meters or a reduction of 4.53%. In addition, material handling costs also decreased from Rp. 780.64 to Rp. 766.19 or a savings of 1.85%. Thus, the application of the CRAFT method resulted in a more efficient production layout at the Gethuk Lindri Niki Eco MSME.
Analisis Kinerja Simpang Bersinyal Jalan Raden Kusno – Jalan A. Djaelani – Jalan Sujarwo di Kabupaten Mempawah
Population growth and socio-economic activities increase traffic volume, affecting the performance of the Raden Kusno – A. Djaelani – Sujarwo signalized intersection. This study aims to analyze the intersection’s current performance, estimate its condition over the next five years, and formulate alternative treatment strategies. The research data include geometric characteristics, signal timing, vehicle speed, and traffic volume obtained from CCTV recording over a three-day observation period from moning to evening, as well as population and vehicle data for projection. The intersection performance was analyzed using the PKJI 2023 approach and VISSIM simulation. Under current conditions, the intersection operates at LOS E with delays of 45,12 seconds (PKJI 2023) dan 60,56 seconds (VISSIM). In the five-year projection, delays increase to 48,97 seconds with LOS E (PKJI 2023) and 131,29 seconds with LOS F (VISSIM). Modifying the signal from four to three phases with a 70-second cycle improves the current condition to LOS C, with delays of 24,50 seconds (PKJI 2023) and 29,43 seconds (VISSIM). For the five-year projection, adding a continuous left-turn lane results in LOS D with 27,04 seconds (PKJI 2023) and LOS C with 32,01 seconds (VISSIM).
Pengaruh Kerusakan Mechanical Seal terhadap Kinerja Hidraulik Steering Gear di Kapal AHTS Logindo Stamina
The steering gear is a vital component in ship operations, functioning to control the ship’s direction accurately. The reliability of this system highly depends on the performance of the hydraulic system, where the mechanical seal plays a key role in maintaining system pressure and preventing oil leakage. This study aims to identify the main factors causing mechanical seal damage and analyze its impact on the performance efficiency of the steering gear AHTS Logindo Stamina. Qualitative data were obtained through participatory observation and in-depth interviews with the second engineer. Meanwhile, quantitative data were gathered by measuring technical parameters such as oil pressure, operating temperature, and rudder movement time, which were then compared with SOLAS standards. This damage results in oil leakage through the mechanical seal gap, abnormal noise in the hydraulic system, and a significant decrease in working pressure of -25,86%. The operational impacts include the occurrence of steering gear failure alarms, decreased hydraulic efficiency of 25.87%, and the risk of system failure that could endanger ship maneuverability. This study recommends preventive maintenance through oil quality monitoring, environmental condition control in the steering gear room, and periodic mechanical seal replacement in accordance with operational standards to maintaining optimal steering system performance.
Evaluasi Efektivitas Pengelolaan Sampah TPS 3R Melalui Pemilahan dari Sumber
Urban waste management has become a complex challenge due to population growth, urbanization, and economic activities contributing to higher waste generation. Effective waste management systems are required to reduce waste disposed at final disposal sites. This study aims to evaluate the effectiveness of waste management at the TPS 3R Pedalangan Bersinar facility in Semarang City by examining waste separation from the source. The research applied a quantitative approach using mass balance analysis to assess the balance between incoming waste, processed waste, and residual waste in the system. Primary data were collected through field observations, interviews, and operational monitoring for six consecutive days, while secondary data were obtained from the Semarang Environmental Agency. Results show community-based waste banks in Pedalangan demonstrate a high level of effectiveness with a recovery factor reaching 100%, indicating optimal recycling performance and strong community participation. Meanwhile, the TPS 3R facility processes an average waste volume of 16.61 m³/day with reduction of 10.32 m³/day and residual waste of 6.29 m³/day, resulting in a recovery factor of approximately 0.62 categorized as moderate effectiveness. Therefore, strengthening household waste separation, improving operational management, and increasing community participation are recommended to enhance waste reduction and support sustainable urban waste management systems.
Studi Temperatur Beton Massa pada Masa Pengerasan (Hardening Time) Menggunakan Suhu Air Dingin dan Kadar Fly Ash
Modern infrastructure development often involves the use of mass concrete in large structural elements such as pile caps and foundations. However, massive concrete volumes trigger a significant temperature increase due to the heat of hydration that is difficult to dissipate, posing a risk of thermal stress and structural cracking. This study aims to analyze the temperature rise behavior of mass concrete and evaluate the effectiveness of combining chilled water and fly ash substitution in minimizing these thermal cracking risks.The research method employs a quantitative approach through laboratory testing at PT Adhimix RMC Plant Kaligawe. Specimen blocks measuring 40 x 40 x 100 cm were divided into three variations: normal concrete (BN), concrete with chilled water and 15% fly ash (BAF), and concrete with 25% fly ash (BF). Temperature was monitored using thermocouples at the core and surface for 14 days, then validated using the Portland Cement Association (PCA) formula. The results indicate that the integration of chilled water with 15% fly ash and the use of 25% fly ash significantly controlled extreme temperature surges at the 5th hour. The combination of chilled water and 15% fly ash produced the lowest core temperature of 37.3°C, far below the control concrete which reached 62.4°C. This proves that the combination of precooling methods and fly ash substitution is effective in reducing the heat of hydration during the early hardening period, although the use of 25% fly ash was found to be more stable in maintaining mass concrete temperature.
Analisis Productivity PC 300 pada Kegiatan Coal Getting di PT. Asmin Bara Bronang
This study was conducted at PT. Asmin Bara Bronang, Sepan Uring Village, Kapuas Tengah District, Kapuas Regency, Central Kalimantan Province, with the aim of analyzing the productivity and influencing factors of the PC 300 excavator in coal getting activities to support the achievement of production targets. The objective of this research is to analyze the actual productivity and the factors affecting it in Sector 7 coal getting operations. The research method used field observation with a quantitative descriptive analysis approach. The results show that the productivity of the PC 300 excavator ranges from 127.12 to 224.29 tons/hour, with an average of 173.98 tons/hour. In several conditions, the productivity is still below the company’s target of 180 tons/hour. The analysis indicates that productivity is influenced by material conditions, particularly the Hardgrove Grindability Index (HGI) value of 47, which reflects relatively harder material with coarser particle size, and a moisture content of 22.71%, causing the material to be sticky and cohesive, thereby affecting the bucket filling process. In addition, operational factors such as bottom loading patterns, limited number of tailgate dump trucks, and suboptimal selection of dump truck types also contribute to productivity performance. Based on the findings, it can be concluded that the productivity of the PC 300 excavator has not consistently met the company’s target. Therefore, improvement efforts are required, including the implementation of top loading methods, increasing the number of tailgate dump trucks, optimizing the selection of hauling equipment, and controlling material conditions that affect the digging process.
Perancangan Mine Sequence untuk Mendukung Target Produksi Bulan April pada Tambang Nikel Laterit Pit Hill16 PT Hillconjaya Sakti
This study is motivated by the discrepancy between production targets and actual field performance caused by dynamic operational conditions, such as equipment productivity and effective working time. The objective of this research is to redesign the production target and develop a more realistic mine sequence using a rolling plan approach at Pit Hill16. The method includes analyzing the productivity of loading and hauling equipment based on cycle time data, calculating effective working time, and determining production targets using the rolling plan method. Furthermore, mine sequence design is developed based on the adjusted production targets. The results indicate that the productivity of loading equipment is 241.98 BCM/hour for the EC480DL excavator and 123.27 BCM/hour for the EC210DL excavator, while hauling equipment productivity is 40.24 BCM/hour. The April production target based on the rolling plan is 275,913 BCM, which can be achieved through mine sequence design with a volume of 277,839 BCM, resulting in a difference of +1,926 BCM, still within acceptable planning tolerance. Therefore, the rolling plan approach is proven to produce a more adaptive and realistic mining plan under actual field conditions.
Pemanfaatan Biomassa sebagai Sumber Energi Terbarukan untuk Mendukung Ketahanan Energi Nasional: Analisis Bibliometrik
This study aims to analyze the development of studies on the use of biomass as a renewable energy source to support national energy security using a bibliometric approach. Research data were obtained from the Scopus, Web of Science, and Google Scholar databases with a publication range of 2015-2025. The analysis was conducted using VOSviewer and Biblioshiny. The results show a significant increase in publication trends in the last decade, especially in the period 2016-2024, reflecting the increasing academic attention to biomass as a solution in the energy transition. Keyword visualization shows that biomass is closely related to concepts such as combustion, thermal efficiency, calorific value, and pelletizing. China is the country with the highest publication contribution, while Indonesia is strategically positioned due to its abundant biomass waste potential. Overall, biomass has great potential to support energy diversification, reduce dependence on fossil fuels, and strengthen national energy security in a sustainable manner.
Copyright (c) 2026 Tika Gajah, Baitul Maharani Lubis, Bidara Jelita Maha, Erza Arkan Zharif, Muhammad Ashbar As-Silmy https://creativecommons.org/licenses/by-sa/4.0
Analisis Bisnis Model dan Kelayakan Investasi Bangunan Menara Telekomunikasi
Magelang City faces the challenge of limited land availability, with a total area of only 18.58 km2 and a high population density. Consequently, telecommunications infrastructure development requires a precise strategy. This study aims to analyze the business model and investment feasibility of Pole and Greenfield type telecommunication towers in Magelang City. Using a descriptive quantitative approach, this research processes secondary data from PT Dayamitra Telekomunikasi Indonesia by applying feasibility analysis based on Life Cycle Costing (LCC), Net Present Value (NPV), Internal Rate of Return (IRR), Break-Even Point (BEP), Payback Period (PP), and Benefit-Cost Ratio (BCR). The results indicate significant differences in cost structures; Pole towers proved to be more efficient, requiring an initial capital outlay of only 28.8% of the total capital required for Greenfield towers. Greenfield towers generated an NPV of Rp13.07 billion with an IRR of 20%, while Pole towers generated an NPV of Rp2.46 billion with a higher IRR of 23%. Pole towers have proven to offer a faster return on investment and better operational cost efficiency, making them the most strategic option to support network densification and the implementation of 5G technology in urban areas with spatial constraints like Magelang City.