In traditional shipbuilding, outfitting work is often carried out on a large scale only after hull assembly. Pipes are cut and welded in narrow compartments, equipment is installed one by one after being lifted into place, and scaffolding must be erected before cables are laid. This "serial" mode is not only inefficient but also involves a lot of work at height with safety risks. Jiangsu Haizhongzhou Shipping Industry Co., Ltd. has fully implemented block pre-outfitting technology, shifting outfitting work from the dock to the block fabrication stage.
Block pre-outfitting means that while a block is still in the workshop or on the jig, outfitting items such as pipes, valves, equipment foundations, cable trays, and ventilation ducts are pre-installed. Every block leaving Haizhongzhou is required to be basically complete in terms of "structure + outfitting". Taking an engine room block as an example, the foundation and anchor bolts of the main engine are precisely positioned during the block stage, pipe flange connections are reserved, and even some cable trays are already welded. When the blocks enter the berth for assembly, workers only need to perform "connections" between blocks – connecting pipes with flanges, and joining cables via junction boxes – rather than starting from scratch.
The core support for block pre-outfitting is the 3D model. During the design stage, the route of each pipe, the position of each valve, and the height of each support are determined, generating a detailed "outfitting tray list". One block corresponds to multiple trays, containing pipe fittings, valves, supports, fasteners, and so on. The production department picks materials according to the sequence and rhythm of the trays, and on-site workers simply follow the drawings to complete the installation.
The benefits of pre-outfitting are manifold. First, efficiency improvement. On the open block jig, workers can work simultaneously from multiple angles without being confined to narrow spaces; in the dock, multiple trades can only enter sequentially or alternately, greatly reducing efficiency. Second, quality improvement. Welding pipes in a workshop environment, with controllable conditions and convenient positioning, ensures better weld quality and cleanliness. Third, safety improvement. A large amount of work is moved from height to ground level, scaffolding usage is reduced by about 50%, and the risk of falling from height is significantly lowered. Fourth, cycle time reduction. Haizhongzhou's statistics show that after adopting block pre-outfitting, the outfitting workload in the dock is reduced by about 60%, and the dock cycle is shortened by about 20 days.
For chemical tankers with complex piping systems, block pre-outfitting is even a "necessity". Stainless steel piping systems have extremely high cleanliness requirements – any rust contamination can lead to corrosion. Pre-fabricating and pre-installing pipes in the workshop allows strict separation of carbon steel work areas from stainless steel work areas, avoiding cross-contamination. Meanwhile, welding of stainless steel pipes requires back shielding with argon, and the workshop environment makes it easier to meet this process requirement than in the dock.
Block pre-outfitting is an important part of Haizhongzhou's integrated "hull-outfitting-painting" modern shipbuilding model. We firmly believe that work that can be done in the workshop should never be delayed to the dock, and work that can be done at ground level should never be lifted to height. This is the path to efficiency, to safety, and to quality.