A while ago, a chief engineer working in shipbuilding consulted me for some advice regarding equipment layout. In recent years, with the rapid development of the national shipbuilding industry, the entire sector has presented a scene of prosperity, with various shipbuilding technologies and management models continuously innovating and advancing. Against this backdrop, many experienced chief engineers have transitioned into supervision roles. Due to their profound accumulated experience in marine engine operation and maintenance, they can leverage unique advantages in these supervision positions. Here, based on my own experience and understanding of the industry, I have summarized the following suggestions, hoping to provide useful references for personnel engaged in related work and assist everyone in becoming more proficient in equipment layout tasks within the shipbuilding industry.
The Engine Room (E.R.) is the core area of a ship, primarily encompassing the following: the ship’s propulsion system, power system, steam system, compressed air system, key parts of the ship’s safety system, the ship’s anti-pollution system, as well as various equipment and systems that support crew living. The location and dimensions of the engine room, and the layout of its internal machinery and equipment, are directly related to the reliable operation of the equipment and the safe operation of the ship, while also significantly affecting the vessel’s practicality.
I. Engine Room Location and Dimensions
When determining the engine room location, it is necessary to comprehensively consider the ship’s compartment planning, ship balance requirements, and the operational characteristics and maintenance needs of the ship’s power plant. For ordinary merchant ships, the engine room is typically located at the stern or in the aft part of the ship.
The main advantages of placing the engine room near the ship’s midsection include: concentrated equipment weight amidships, making it easier to maintain fore and aft balance whether the ship is fully loaded or empty; the engine room space is spacious and flat, facilitating the arrangement of machinery and equipment; and the ship has better anti-sinking stability. However, its disadvantages are also evident: the ship’s propulsion shafting is longer, requiring the installation of a shaft tunnel; the aft hold capacity is reduced, and the tank top is uneven, making cargo handling inconvenient; the size and weight of the power plant increase, and power transmission efficiency decreases; long shafting is prone to vibration, increasing safety risks; simultaneously, the workload for personnel maintaining and managing the shafting also increases. The advantages and disadvantages of an aft engine room are precisely the opposite, and modern ships more commonly adopt the aft engine room. Especially for liquid cargo ships, an aft engine room is more advantageous, facilitating the routing of piping for loading and unloading liquid cargo, reducing the number of void spaces, increasing cargo hold capacity, and also aiding in leak prevention and safety.
A Merchant Vessel typically has one engine room per ship. The length of the engine room is mainly determined by the length and type of the main engine, generally decided by the length of the main engine unit (including transmission equipment) plus access passages and reserved maintenance margins. For an aft engine room, the distance required to withdraw the tail shaft from the compartment and the hull’s stern structure must also be considered. The width of the engine room is the width of the ship at the engine room’s location. The height of the engine room primarily depends on the main engine height and the height required for maintenance, with machinery and equipment usually installed below the main deck. The engine room space above the main deck is mainly used for host cylinder lifting and ventilation. Due to the numerous pieces of equipment in the engine room, a certain number of platforms are typically set up within the engine room for equipment installation. Sometimes, depending on the width of the ship’s stern, the aft engine room may be appropriately lengthened to install related equipment.
II. Principles for Engine Room Equipment Layout
1. Ensure the overall reliable operation of the ship’s power plant
During navigation, a ship will inevitably experience heeling and /rolling, requiring the entire power plant to operate reliably and normally under conditions of 15° heel, 22.5° rolling, as well as 5° trim and 7.5° pitching. Therefore, the positions of certain machinery and equipment must be properly arranged. Typically, seawater pumps (including main seawater pumps, auxiliary seawater pumps, fire pumps, ballast pumps, refrigeration system seawater pumps, etc.) should be located a certain distance below the minimum waterline to ensure sufficient suction head. Sea chests should be arranged on both port and starboard sides, with high and low positions, to ensure uninterrupted seawater intake. Various horizontal machinery should be arranged along the ship’s longitudinal direction to reduce the impact of ship rolling. The emergency power station should be located on the upper deck outside the engine room to ensure it can be activated promptly during an engine room emergency. If conditions permit, ship power generation equipment can be arranged above the engine room’s bottom level to ensure a certain power supply duration even if the engine room floods.
2. Ensure ship balance and stability
The engine room is an area of concentrated equipment, and its weight significantly impacts the ship’s balance and center of gravity height. Equipment in the engine room should strive for even weight distribution port and starboard, and the center of gravity of the equipment layout should be as low as possible. After the engine room layout design is completed, verification calculations should be performed based on the weight and installation positions of the machinery and equipment. The specific method is as follows: take the moment of weights aft of the midship section relative to the midship section as “+”, and those forward as “−”, as shown in Figure (a); if any machinery and equipment are located away from the centerline plane towards the starboard side, their distance to the bottom of the centerline plane is “+”, otherwise it is “−”, as shown in Figure (b); the moment of weights below the main waterline plane relative to the main waterline plane is “+”, and those above the waterline are “−”, as shown in Figure (c).
3. Convenient for Maintenance and Management
A reasonable layout of ship engine room equipment facilitates effective use, maintenance, management, and troubleshooting by engine room management personnel, ensuring the safe and reliable operation of the power plant. From a management perspective, the rationality of the layout can be assessed by the route length, time required, difficulty, and effort expended by engine room personnel to complete operational procedures. During the layout process, the routes taken by engine room personnel during standby, rounds of inspection, and securing operations should be minimized, ensuring clear passageways; frequently operated equipment and valves should be easily accessible and operable; space for equipment disassembly and inspection should be reserved; instruments should be clearly readable, and all markings should be clear; system-related equipment should be placed close together, avoiding overlapping pipelines; equipment with high noise and strong vibration should be kept away from the control room and operating console.
4. Easy Fireproofing and Drainage
To meet fire safety requirements, the following factors should be considered during engine room layout: keep areas requiring frequent hot work, high-temperature equipment, etc., away from fuel tanks, oil cabinets, oil pipelines, and /explosive materials; prohibit oil pipelines from passing above boilers, exhaust pipes, and switchboards; areas prone to generating large amounts of oil vapor must be well-ventilated and equipped with exhaust equipment; emergency shutdown switches for oil cabinet quick-closing valves, fans, etc., must be provided outside the engine room; pipeline layout should ensure that in the event of engine room flooding, large-capacity pumps like the main seawater pump, ballast pump, and fire pump can simultaneously discharge the accumulated water, safeguarding the ship’s anti-sinking capability; the emergency bilge valve should be prominently marked, easy to operate, with the /close direction indicated; the stern tube tunnel watertight door should be operable from both sides and equipped with an /close status indicator.
The layout design work for the engine room can be traced back to the initial stages of the ship’s overall design, but its specific implementation and actual arrangement is a task that runs through the entire shipbuilding process, from the initial planning and design phase all the way to the final completion of the construction work. Throughout this process, construction codes provide very clear and detailed regulations and requirements for the engine room layout, which serve as important basis for the engine room’s design and construction. Therefore, during the supervision process, engine room management personnel need to undertake the crucial responsibility of strict oversight, ensuring every环节 complies with relevant standards. Simultaneously, they also need to combine their rich experience in ship operation and management, proposing scientifically sound layout requirements and improvement suggestions from the perspectives of practical operation and long-term maintenance, thereby further optimizing the functionality and practicality of the engine room to meet the needs of long-term ship operation.
