The need for ships to be equipped, including medical facilities and ship's doctor, is based on the number of crew members, voyage and the nature of the mission. According to the relevant regulations of the International Maritime Organization (IMO), engineering vessels usually only need to be equipped with basic first-aid equipment and a limited number of crew members trained to perform basic first-aid treatment, and do not need a specialized ship's doctor.
Because of the relatively fixed and confined scope of work of a construction vessel, in the event of a serious medical problem, the crew can be quickly transferred to a nearby hospital or other place with medical facilities as needed. In addition, having specialized doctors and medical equipment on board a construction vessel may add to the cost and complexity on board.
In summary, the small number of crew members on engineering vessels and the specialized nature of their tasks, coupled with the availability of medical resources at sea, have resulted in the absence of ship's doctors on board. This does not mean that engineering vessels do not pay attention to the health and safety of their crews, but is a reasonable arrangement based on the actual situation.