Crane Operation Research Articles

Vision-Based Productivity Monitoring of Tower Crane Operations during Curtain Wall Installation Using a Database-Free Approach

Tower cranes are generally used in modern construction projects due to their exclusive and flexible performance for material transportation in complex workspaces. Although traditional deep learning vision-based methods have proven their effectiveness in construction site monitoring, a shortage of realistic training images and inefficiencies in them have been an obstacle in achieving effective tower crane monitoring. To deal with this issue, this paper presents a database-free approach for timely productivity monitoring of tower crane operations. Using a synthetic model, the authors construct a research framework to effectively generate training images on deep learning–powered object detection. Additionally, an enhanced tracking algorithm collaborating with unsupervised clustering-driven postprocessing enables stable performance for tracking resources. Further, logical ontology-based activity recognition constructed on domain-specific knowledge takes place to estimate time-to-time operation of the tower crane. The curtainwall installation was selected to represent the dynamicity and variability of tower crane operations for which it has been difficult to apply traditional deep learning technologies. Results displayed that the intended framework successfully produced 300,000 training images in 1 h, about 500 times faster than human resources, and an enhanced tracker performed well even in the case of unsatisfactory detection results. It is also proved that a performance of activity analysis was acceptable to 93.58% accuracy. The results demonstrate that the proposed framework has proven remarkable data generation speed with little manual input and good performance of operational-level activity analysis. These findings can automate the monitoring process of tower cranes’ operations and the productivity of curtainwall installation, assisting construction project decision making. Furthermore, such efficient methods are less time-consuming and can handle background scene changes effortlessly, building customized models in less time and to less cost, thus buffering the practical gap of applying vision-based technologies into visually dynamic construction sites.

Studying the distribution of a tower crane support loads using computer modeling

Problem. The construction of modern industrial and civil structures is impossible to imagine without tower cranes. They are used in the construction of both low-rise and high-rise buildings and industrial structures. Tower cranes are simply irreplaceable in the construction of buildings, and in the construction of low-rise structures, these cranes have certain advantages over self-propelled jib cranes. Tower cranes are designed to mechanize construction and installation work, providing up to 98% of all lifting and handling operations during the installation of construction elements of buildings and structures, and are also widely used in various types of lifting operations. The advantages of tower cranes also include the optimal combination of virtually any vertical and horizontal lifting height to any point of the facility under construction. It is worth emphasizing the extremely large potential of the Ukrainian construction market and its need for a wide variety of tower crane models. Thus, tower cranes are one of the most popular types of equipment. Goal. The goal is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a support circuit, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. In this work, the tasks are achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods that take into account many factors.
 Methodology. The main objective of the work is to develop a methodology for determining the loads during operation on the supporting elements of a tower crane with a solid support contour, taking into account the spatial nature of the load and identifying patterns of change in the distribution of loads on the supports during crane operation. 
 Results. It was found that the load of the crane support elements is oscillatory with an amplitude of about 200 kN. When the crane boom is rotated by 135 degrees, support 4 can withstand the greatest load, which is 250 kN, and support 2 is almost unloaded – 5 kN. At a turn of β = 225 degrees, a similar situation occurs with supports 1 and 3, respectively. When the overhang changes, supports 1 and 4 can withstand the same loads in the range of 68 to 190 kN, and supports 2 and 3 can withstand loads from 190 to 50 kN. At the maximum outreach, the critical positions of the crane are when the boom angles are β=45 degrees and β=315 degrees, in which case the crane rests on almost three supports. Originality. This task is achieved by applying an advanced calculation methodology with the use of computer modeling tools that allow the use of labor-intensive calculation methods which take into account many factors. Practical value. Using the developed algorithm for calculating the loads on the crane supports, a computational experiment was conducted to determine the magnitude and nature of changes in the loads on the crane supports under different operating conditions: with different loads and variable outreaches, wind loads.

Active damping methods to suppress the payload swing by a 3‐degree of freedom cable‐driven parallel robot

AbstractMarine cranes play an important role in many hoisting scenes. However, due to the ship motion excitation and crane operation, the payload swing is unavoidable, hence putting the operators in danger. Thus, this paper proposes two active damping methods to suppress the payload swing by a 3‐DOF cable‐driven parallel robot (CDPR). First, the structure of the 3‐DOF CDPR is briefly introduced. Then, the dynamic model of the system is modeled as a constrained spherical pendulum with moving base excitations. Meanwhile, inspired by the air damping phenomenon, two active damping methods are presented to damp the payload swing naturally and smoothly. Furthermore, the payload swing under ship motion excitation and external hitting disturbances is analyzed, the influence mechanism of system damping parameters on the payload anti‐swing is discussed, and the robustness of the proposed damping methods is verified. By theoretical analysis and numerical simulations, some interesting discoveries are revealed: (1) the proposed damping methods can effectively suppress the big offset of payload swing angle inducing by external hitting disturbance, but the system might reach a dynamic equilibrium with a tilting hoist cable; (2) the phenomenon of “off‐center spherical pendulation” might be induced by improper setting of the damping parameters.

Correlation Between Work Monotony with Work Stress on Crane Operators in Terminal Nilam and Jamrud Tanjung Perak Harbour

Background: Work stress can happen to any worker, including crane operators. Monotonous work might cause work stress. Work stress can arise when workers do the same job and do it repeatedly without any variation in their work. Objectives: This study aims to determine whether there is a correlation between work monotony with work stress on crane operators in Nilam and Jamrud Terminals of Tanjung Perak Harbor. Methods: A cross-sectional study design was conducted between February - March 2021. The subjects in this study were 58 crane operators obtained from calculating the Slovin formula. The DASS 42 questionnaires were used in this study and instruments in the Indonesian version were validated. SPSS version 21 was used for descriptive and bivariate analysis in the form of contingency coefficient analysis and Spearman correlation. Results: The results showed that the average age was 38 years old and the average tenure was 6 years. All of the crane operators are male. In this study, it was found that most of the crane operators considered their work monotonous (75,9%). Meanwhile, work stress experienced by crane operators is dominant on a normal scale (34,5%), but other crane operators experience work stress ranging from mild to very heavy. The results also show a correlation between work monotony (r=0.570; p-value=0.000) and work stress on crane operators. Conclusions: There are several causes of work stress. Work monotony might cause work stress. It is important for crane operators to have variation in their job and for company to arrange proper rest time so the crane operators will have enough time to rest after long work hours. In addition, the researcher also suggests to further research to be able to conduct similar research related to other factors that can cause work stress. Variables of work burnout and work variation can be variables that can be considered for further research to determine the relationship with work stress.

Analysis of derrikingand slewing of the tower crane with consideration to driving mechanisms characteristics

The variational problem of the movement mode selection for the load outreach change mechanism during a steady-state tower crane slewing was formulated and solved in the paper, that ensures the minimization of the drive motor power. The variational problem is nonlinear, and so we used the modified PSO-Rot-Ring particle swarm met heuristic method for its solution. Low- and high-frequency oscillations of the outreach change mechanism elements during the start-up were detected in the optimization process. These oscillations are eliminated in the section of steady-state movement due to the selection of the motion boundary conditions.
 In order to increase the productivity during a tower crane exploitation the overlapping of the mechanisms operation is used. The article considers the overlapping of operations of the derriking and slewing mechanisms of the crane. To study the dynamic processes in the joint work of the derriking and slewing of the tower crane, a dynamic model was built. It takes into account the main movement of the derriking and slewing of the crane, as well as oscillation processes in the drive mechanisms and load oscillation on flexible suspension in two planes: in the plane of the derrikingand in the plane of slewing of the crane. The developed dynamic model takes into account the elastic-dissipative characteristics of the transfer mechanisms, as well as the dynamic mechanical characteristics of the drive motors, which describe the transient electromagnetic processes. On the basis of the developed dynamic model with the help of Lagrangeʼs equations six differential equations of the second order which describe a mechanical part of the mechanisms movement were found. In addition, the transient dynamic electromagnetic processes of each of the engines are described by four differential equations. As a result, a system of fourteen differential equations was obtained. It describes the common dynamics of the mechanical part of the crane mechanisms and electromagnetic processes in the electric engines of the derriking and slewing mechanisms. The obtained system of differential equations was solved by numerical methods with the help of developed computer program. For the actual construction of the tower crane in the overlapping work of the derriking and slewing mechanisms, kinematic, power, and energy characteristics were determined, which made it possible to estimate the actual loads in the elements of the construction and drive mechanisms. From the obtained results it was established that the elements of the construction and drive mechanisms are under significant dynamic and energy overloads.High-frequency oscillations of drive mechanisms at the beginning of the movement and low-frequency oscillations of elements of the construction and load were revealed. This significantly reduces the reliability of tower cranes, increases their energy losses, and affects the work of the crane operator and maintenance staff.

Модернизация системы обеспечения устойчивости железнодорожного крана КЖ-971 и оценка её эффективности

The weight of the load hanging on the boom of a railroad hydraulic crane KZH-971 creates a load moment that bends the crane slewing ring. To partially balance the load moment, a stationary counterweight is installed on the crane, rigidly fixed on a slewing platform. With an increase in the boom departure, the unbalanced part of the load moment and tensions in the slewing ring increases. In this article, to ensure a constant value of the unbalanced part of the load moment and reduce bending tensions, it is proposed to install a counterweight on the railroad crane with a telescoping system and the ability to rotate about the vertical axis for a work in cramped conditions. A strength analysis of the slewing ring for the change in maximum tensions from the use of a movable counterweight was carried out. An adaptive control system for the position of a movable counterweight has been modeled, with the help of which it will be possible to develop a device for convenient control from the crane operator’s cabin in the future. The advantages of using a movable counter-weight with the possibility of rotation relative the vertical axis are shown when performing loading and repair work in cramped conditions. The results of the strength analysis of the slewing ring with the location of loads in the main working positions are summarized.

СОЗДАНИЕ МАТЕМАТИЧЕСКОГО ОБЕСПЕЧЕНИЯ ДЛЯ ТОЧНОСТИ ВЫБОРА ТЕХНИЧЕСКИХ СВОЙСТВ КРАН-МАНИПУЛЯТОРА МЕХАНОСБОРОЧНОГО УЧАСТКА

The task is set to select and study information and measuring elements and actuating mechanisms for complex automation of CNC machines based on the analysis of mechanical assembly production sites in the field of mechanical engineering. Paper objective is to develop information support for measuring instruments and actuating mechanisms to implement the automation of a crane manipulator serving a flexible production site with mechanical assembly machines. The following problems are stated: technological analysis of the research object based on recursive procedures; determination of measurement operations and actuating mechanisms on the active elements of a flexible production site, including manipulator crane operations, turning, milling, radial drilling machines; study of the issue of designing a crane manipulator with a clamp; calculation of the power of the crane manipulator actuator to select the load capacity of its clamp. 
 The task is set to develop information support for measuring and actuating devices for machine-assembling machines and crane manipulators servicing the machine body. To determine the power of the manipulator crane drive, a mathematical model of the transmission and the required characteristics of the load release in braking mode are constructed.

Model of Twin Automatic Stacking Crane Operation Strategy with Dynamic Handshake Area in an Automated Container Terminal

This paper proposes a new idea for allocating a handshake area of an automated container yard. A block of automated container yards (CY) consists of two areas, which are the import (waterside) and export (landside) areas. The CY has two major activities (loading and unloading), where both are served by Twin Automatic Stacking Cranes (Twin-ASCs). A handshake area in the middle of the CY serves as a temporary slot for both ASCs. This situation causes an imbalance between the ASCs when the demands of each side differ significantly. Thus, we proposed using a dynamic location of the handshake area corresponding to the proportion demand of export and import containers. We developed a heuristics model and algorithms of ASC’s operations to compare the efficiency of the ASC operations between the fixed and the dynamic location. Based on our model and algorithm, we developed simulation software. Finally, we explored some numerical experiments to compare the performance of both policies in dealing with different export and import demand scenarios. Our result showed that the proposed approach outperformed the existing one in reducing unnecessary ASC movements.

Производственная среда автомобилестроения как один из факторов риска развития болезней системы кровообращения у работников

This study has shown that working conditions of basic occupational groups in the automotive industry involve combined exposure to several harmful occupational factors. Major harmful occupational factors include intense noise, vibration, work hardness and chemical levels; their intensity varies between permissible levels (the hazard category is 2.0) and harmful ones (the hazard category 3.1–3.2, harmful working conditions with hazard levels 1 or 2). This may induce occurrence or exacerbation of basic non-communicable diseases such as diseases of the circulatory system (CSDs), occupational and work-related diseases. CSDs were diagnosed in 37.7 % of workers employed at automotive productions. The most frequent diseases include hypertension (EH) that accounted for 28.2 %; cerebrovascular diseases (CVDs), 6.5 %; ischemic heart disease (IHD), 3.6 %. CSDs developed at an early age in workers exposed to harmful occupational factors belonging to the hazard category 3.1–3.2; these diseases became more frequent as work records got longer, and were more frequently exacerbated with acute cardiovascular conditions. We assessed the total cardiovascular risk using the SCORE scale and established that shares of people with high and very high cardiovascular risks were higher among painters, laboratory assistants responsible for chemical analysis, and repairmen. The attributive risk of new cardiovascular diseases ranged between 9.6 (turners) and 42.6 (repairmen) cases. The highest occupational CSDs causation was identified for repairmen and mechanics at mechanical assembly production; average causation was established for stampers, painters, laboratory assistants dealing with chemical analysis, crane operators, and turners.

Work environment of the automotive industry as a risk factor of diseases of the circulatory system among workers

This study has shown that working conditions of basic occupational groups in the automotive industry involve combined exposure to several harmful occupational factors. Major harmful occupational factors include intense noise, vibration, work hardness and chemical levels; their intensity varies between permissible levels (the hazard category is 2.0) and harmful ones (the hazard category 3.1–3.2, harmful working conditions with hazard levels 1 or 2). This may induce occurrence or exacerbation of basic non-communicable diseases such as diseases of the circulatory system (CSDs), occupational and work-related diseases. CSDs were diagnosed in 37.7 % of workers employed at automotive productions. The most frequent diseases include hypertension (EH) that accounted for 28.2 %; cerebrovascular diseases (CVDs), 6.5 %; ischemic heart disease (IHD), 3.6 %. CSDs developed at an early age in workers exposed to harmful occupational factors belonging to the hazard category 3.1–3.2; these diseases became more frequent as work records got longer, and were more frequently exacerbated with acute cardiovascular conditions. We assessed the total cardiovascular risk using the SCORE scale and established that shares of people with high and very high cardiovascular risks were higher among painters, laboratory assistants responsible for chemical analysis, and repairmen. The attributive risk of new cardiovascular diseases ranged between 9.6 (turners) and 42.6 (repairmen) cases. The highest occupational CSDs causation was identified for repairmen and mechanics at mechanical assembly production; average causation was established for stampers, painters, laboratory assistants dealing with chemical analysis, crane operators, and turners.

Multi-cable anti-swing system for cranes subject to ship excitation and wind disturbance: Dynamic analysis and application in engineering

Offshore cranes generally have low working efficiency, high operating risk, and low lifting accuracy under rough sea conditions. In this study, a Multi-Cable Anti-Swing System (MCAS) is proposed in terms of a 45-ton crane of a 27,000-ton multipurpose vessel of COSCO Shipping Group as a design prototype, and it is adopted to investigate the dynamic characteristics of the MCAS for cranes within an offshore environment. The MCAS is simplified as a restricted-pendulum with ship-motion excitations, and a wind load is incorporated into the dynamic model of the MCAS. Moreover, the dynamic characteristics of the MCAS are simulated and analyzed using Matlab/Simulink, and the experiments were performed on the laboratory prototype of the crane equipped with the MCAS. As indicated by the crane operation data, the payload swing amplitude was reduced by 85% with the MCAS, which notably increased the lifting efficiency of offshore cranes. The results of this study will contribute to the in-depth optimization and engineering application of the MCAS onboard ships.

The Effect of Training and Work Motivation on Operator Performance During the COVID-19 Pandemic

This research was conducted on a quay container crane operator at KSO TPK Koja. The quantitative research method was collecting data on 28 questionnaires and using SPSS version 21 applications to analyze data. The study used the validity, reliability, normality and hypothesis test. This study aimed to identify the influence of training and work motivation on operator performance during the COVID-19 pandemic at KSO TPK Koja. The result of this study showed that training and work motivation have a positive influence on operator performance, but training had no significant effect on operator performance. In addition, work motivation had a significant influence on operator performance.
 Keywords: Training, Work Motivation, Operator Performance, COVID-19

The Effect of Instructor Pedagogic Competency and Learning Motivation on Vocational Skills of Training Participants at BLK Cilegon City

This study aimed to analyze and determine the effect of instructor pedagogic competence and learning motivation on the vocational skills of trainees at BLK Cilegon City. The population consists of trainees who are members of the heavy equipment engineering profession, including forklift operator vocational training, excavator operator vocational training, and crane operator vocational training, totaling 120 people, with sample numbers of 92 people. The background of this research is due to the instructor’s pedagogic competence, learning motivation, and vocational skills that have yet to be evenly distributed to all training participants. Data collection is done by distributing questionnaires, observation, and documentation. The research method uses descriptive analysis with a quantitative approach. The data is then processed using the SPSS-25 application. The study results show that: 1) the instructor's pedagogical competence has a very significantly affects the trainees’ vocational skills. 2) learning motivation has a very significantly affects the trainees’ vocational skills. 3) the instructor’s pedagogical competence and learning motivation simultaneously has a very significantly affects the trainees’ vocational skills at BLK Cilegon City.Keywords : Instructor Pedagogic Competence, Learning Motivation, Vocational Skills

Occupational Health Risks for Workers Engaged in Copper-Nickel Ore Processing

Introduction: Despite all preventive measures constantly taken, high incidence of occupational diseases is still registered in workers of copper-nickel enterprises. Objective: To obtain new knowledge about the conditions, timing, structure and frequency of occupational diseases in order to develop methods for their more effective prevention in workers involved in pyrometallurgical copper-nickel ore processing. Materials and methods: We have analyzed incidence rates of occupational diseases in a cohort of 664 workers who processed copper-nickel ore in 2007–2020. Results: Working conditions during pyrometallurgical processing of copper-nickel ore correspond to hazard classes 3.2–3.4 with the chemical exposure being of paramount importance in the development of health disorders (45.6 % of cases). In 2007, 664 workers were examined and 158 occupational diseases were diagnosed in 65 (9.8 %) of them in the years 2008–2020, respiratory and musculoskeletal diseases being the most prevalent categories (50.6 % and 29.1 %, respectively) and chronic bronchitis and sensorineural hearing loss – the most prevalent diseases (27.8 % and 17.1 %, respectively). We established non-occupational disorders (arthralgia, osteochondrosis, early signs of hearing impairment, etc.) contributing to further development of occupational diseases. Smoking history (> 5 packs/year) was found to promote occupational diseases of the respiratory system (RR = 4.84; 95 % CI: 2.51–9.35). Crane operators (17.5 % of the workers) were found to be at highest risk of occupational diseases (366.1 cases per 10,000 workers). Conclusions: Based on data on previously registered occupational diseases, working conditions, length of service, occupation, and clinical conditions, criteria for five risk categories have been developed to predict occupational diseases by time, nosology, and severity of the course in metallurgists involved in copper-nickel ore processing.

Research on the Classification of Inherent Risks of Cranes Based on Interval Laminar Analysis Method-Index Method

In order to ensure the safe operation of cranes, from the perspective of the definition of inherent risk, the evaluation index of inherent risk of cranes was established. The interval hierarchy analysis method with better fuzziness was used to determine the index weights, determine the index scores of different levels, and use the integrated index method to establish a grading model, which was divided into four inherent risk levels according to the risk critical value. Application of the model to two cranes for example analysis, the results show that the model has good accuracy. The model provided a more scientific method for grading the inherent risk of cranes, which in turn provided a method of reference for grading the inherent risk of other types of special equipment.

An Iterative Re-Optimization Framework for the Dynamic Scheduling of Crossover Yard Cranes with Uncertain Delivery Sequences

In yard-crane scheduling problems, as loading operations take priority over unloading, the delivery sequence of unloading from the quaysides to the yard is uncertain. The delivery sequence changes may make crane scheduling more difficult. As a result, the crane operations schedules developed statically become suboptimal or even infeasible. In this paper, we propose a dynamic scheduling problem considering uncertain delivery sequences. A mixed-integer linear program is developed to assign tasks to cranes and minimize the makespan of crane operations. We propose an iterative solution framework in which the schedules are re-optimized whenever the delivery sequence change is revealed. A genetic algorithm is proposed to solve the problem, and a greedy algorithm is designed to re-optimize and update the solution. To make the updated solution take effect as soon as possible, regarding batch-based task assignment, the tasks in the scheduling period are divided into several batches. In this case, the instant requests arising from the delivery sequence change are added to corresponding batch tasks and re-optimized together with the tasks of this batch. In addition, a relaxation model is formulated to derive a lower bound for demonstrating the performance of the proposed algorithm. Experimental results show that the average gap between the algorithm and the lower bound does not exceed 5%. The greedy insertion algorithm can re-optimize the instant requests in time. Therefore, the proposed iterative re-optimization framework is feasible and has the advantages (necessity) of batch-based task assignment.

Research on Variable Universe Fuzzy Multi-Parameter Self-Tuning PID Control of Bridge Crane

The bridge-type bridge crane is a common lifting equipment used in modern factories and workshops. During the crane’s operation, the positioning of the trolley and the swing of the load can significantly impact the bridge crane’s safety and reliability. In this paper, we propose a variable universe fuzzy multi-parameter self-tuning PID (VUFMS-PID) control strategy for controlling the trolley’s movement. Our control strategy uses scaling factor variation to dynamically adjust the number of fuzzy control rules based on the system error and error rate of change. This approach improves control accuracy and enhances the crane’s stability and safety. Simulation results demonstrate that our proposed control strategy outperforms both the fuzzy PID and traditional PID control strategies. Specifically, it reduces the crane trolley’s positioning time and the maximum swing angle of the load. Our control strategy exhibits good adaptive ability and robustness, which further improves the stability and safety of the bridge-type bridge crane operation.

Study of the Master Bay Plan Problem Based on a Twin 40-Foot Quay Crane Operation

During the process of container ship transportation, the berthing time cost of the ship in port is extremely important. Container allocation and quay crane (QC) operation greatly affect the berthing time. Currently, few scholars have combined import/export container allocation and QC operation, making it urgent to study ship stowage and QC collaboratively. In this paper, a mixed-integer programming model is established for the ship multi-port master bay plan problem (MP-MBPP), based on the operation of twin 40-foot QCs. The aim of this model is to minimize container rehandling and the time required for twin 40-foot QCs operation movement. A variety of new stowing strategies have been designed, and the improved coded particle swarm optimization algorithm (PSO) is used to optimize the position of double-bays, reducing the number and distance of QC movements and minimizing ship berthing time. By comparing the impact of different stowage rules on ship berthing time through examples, verification shows that the proposed stowage model and solving algorithm can obtain optimized solutions. Under the same initial conditions, the double-bay stowage based on the twin 40-foot QCs can improve operation efficiency by at least 20.3%, compared to the single-bay with ordinary QC, verifying the effectiveness of the proposed method.

Machine Learning-Based Prediction of Dynamic Responses of a Tower Crane under Strong Coastal Winds

With the rapid development of the construction industry, tower cranes are increasingly used in coastal engineering. However, due to the complexity of their operating environment, tower cranes are vulnerable to typhoons, thunderstorms, and other extreme natural disasters. Therefore, it is becoming increasingly important to carry out safety warnings for the tower crane structure under the action of strong winds. In this paper, a real-time monitoring system for tower responses based on the Internet of things (IoT), which realizes long-term monitoring of the whole process of tower crane operation, was built. Based on the long-term monitoring data and the machine learning algorithm, two tower response prediction models were established. During the transit of super typhoon In-fa, the maximum displacement of the tower structure was predicted in advance, based on the measured wind speed data at the site, which is in good agreement with the displacement data monitored by the IoT. The results show that under strong winds, the non-working tower has a response lag, resulting in the fact that its maximum displacement does not correspond to the maximum wind speed moment at the site. This is mainly due to the weathercock effect of the tower in the non-working condition. The prediction model proposed in this paper can provide timely and effective safety warnings for the tower structure. It also can provide useful engineering references and scientific structural safety warning suggestions for the same type of tower cranes that do not have IoT monitoring systems installed.

Virtual reality enhanced multi-role collaboration in crane-lift training for modular construction

Crane lifts for bulky module installation greatly affect site safety and efficiency. However, few previous studies addressed collaborative training for a lifting crew in modular construction. Therefore, this paper aims to develop a virtual reality (VR) system for enhancing multi-role collaboration in crane-lift training. The system is developed by integrating full-, semi-, and non-immersive VR devices with role-specific functions designed for crane operators, riggers, and signalers in modular building projects. The system is objectively assessed by six groups of researchers with memory tests and proved more effective in group-based crane-lift training than the lecture-based approach, resulting in a 33% improvement in the trainees' memory stability. The system is also evaluated by the researchers and six industry practitioners who affirm that their understanding of the crane-lift process is enhanced through multi-role collaboration using the system. The developed multi-user VR system should facilitate safe and efficient delivery of modular buildings.