Crane operation is a crucial profession that requires extensive technical knowledge along with situational awareness. Specifically, overhead crane operation requires knowledge of hazard identification, special attention to safety, and spatial awareness due to the nature of safety-critical lifting inside a facility. This case study involves crane operator trainees who have undergone three kinds of training: attending a theory class related to overhead crane operation, followed by operating a real crane, and finally, participating in virtual reality-based immersive training inside a simulated environment that resembles the real scenario. The “Hermippe Crane Training Questionnaire” consisting of 62 questions was developed and then filled out by the 13 training participants. This questionnaire serves as an assessment tool and measures participants’ competency across seven dimensions, which are developed from three renowned competence and safety models. Item- and subscale-level descriptive statistical analyses were conducted to analyse the participants’ responses in order to identify their competence level after training. This paper offers practical advice regarding future curriculum development for crane operation training by identifying strengths and gaps in the operators’ competence development. It also provides evidence of the importance of a mixed training method that combines theory, immersive, and hands-on training rather than only stand-alone traditional approaches.