Today in Science and Technology History | 2023·7·17 The first domestically-made large cruise ship successfully completed its maiden voyage

Large cruise ships are known as the "pearl" in the crown of the shipbuilding industry. They are a large system project that integrates and intensively builds modern industry and modern cities, and directly reflects a country's comprehensive scientific and technological level and manufacturing strength. my country's first domestically-made large cruise ship, "Aida Magic City", was untied from the dock on the morning of July 17, 2023, and began its first sea trial. The arrival of domestically-made large cruise ships means that China has become the sixth country capable of building large cruise ships after Germany, France and other countries.

From the launch of the domestic large cruise ship project in October 2013 to the completion of the first voyage of the domestic large cruise ship in July 2023, in 10 years, numerous engineers and workers used 2.3 million design hours and 18 million construction hours to create this "mobile sea city" with 25 million parts.

The difficulty of solving the problem: an almost impossible task

The shipbuilding industry is the epitome of modern industry and is known as the "crown of comprehensive industries", demonstrating a country's comprehensive industrial strength. Among them, large cruise ships are known as the "pearl" in the crown of the shipbuilding industry.

When you first see the "Aida Modu", it's hard not to feel the insignificance of an individual. If the cruise ship is placed vertically on the ground, it is 3 meters higher than the Burj Al Arab in Dubai. This 323.6-meter-long and 77.8-meter-high white ship has a hull painted with Dunhuang flying ribbons and is full of densely stacked cabins and portholes. Walking into the hull, in the living and entertainment area of ​​more than 40,000 square meters and a total of 16 floors, the layout of entertainment venues such as theaters, swimming pools, and gyms is complex and exquisite, which makes people marvel.

This is also the feeling of Chen Gang, general manager of Waigaoqiao Shipyard and on-site commander of the large cruise project, when he visited the European cruise shipyard. One month after participating in the preparations for the large cruise project, Chen Gang and his colleagues went to Europe for an inspection. When he saw the construction process of the cruise ship, he was "dazed" and felt that "this is an almost impossible task. Putting aside the equipment and technology, the project has exceeded our project management capabilities at the time." After returning to China, everyone was busy looking up information, doing feasibility analysis, exploring and upgrading the digital shipbuilding design system... In the following years, solid preparations were carried out in an orderly manner.

The number of people in the development and design team quickly expanded from three or four to more than 100. Concept design, basic design, detailed design, construction design, process design... The team worked closely with the engineering team of the Italian shipyard and carried out five rounds of design work, with a total of more than 2.3 million design hours. In comparison, the design hours for a 300,000-ton ultra-large oil tanker are only 100,000. "One ship is equivalent to 23 ships." A designer in the team who is about to retire in 2024 said that he has been engaged in the development and design of ship air-conditioning systems for most of his life. After reading the drawings that year, he found that the workload of all the air-conditioning system designs he had participated in before was less than half of that of this large cruise ship.

By digesting, absorbing, and constantly revising in practice, the team gradually formed new specifications and drawings. With the steady progress of the design work, on October 18, 2019, the first domestically-made large cruise ship officially started steel plate cutting and entered the substantive construction stage.

Complex system: Building a large cruise ship like building a city

25 million parts, equivalent to 5 times the number of C919 large aircraft and 13 times the number of "Fuxing" high-speed trains; the total cable layout length is 4,200 kilometers, equivalent to the distance from Shanghai to Lhasa. While ensuring living and entertainment space, many equipment and pipelines related to electricity, water and gas must be integrated into one ship, and the complexity of outfitting work such as hull equipment installation, cable and pipeline laying, etc. has reached a new level.

"That's why many people compare large cruise ships to 'mobile cities on the sea.'" As a veteran employee who has been engaged in outfitting work for more than 22 years, Cao Zhengwei, deputy director of the Second General Assembly Department of Waigaoqiao Shipyard, believes that the biggest feature of large cruise ship outfitting work is to incorporate municipal service and support work into ship construction, "building large cruise ships like building cities."

"For example, the total power of the five generators on board is 62.4 megawatts. If they are fully loaded, the power generated every day can meet the electricity needs of about 5,000 households for a month." Cao Zhengwei said that although large cruise ships rarely generate power at full capacity during voyages, the workload of laying pipelines and cables has not decreased at all. In addition, the equipment groups can serve as backup for each other to ensure the continuous operation of the equipment and the safety and reliability of the cruise ship's voyage.

The huge workload is just the beginning. How to reasonably distribute the pipelines in a small space and connect various systems is even more difficult. On the lower deck where equipment is densely packed, there are often five or six layers of pipelines and cables arranged up and down in the same area. Even on the upper deck where passengers live, there are at least three layers of pipelines hidden in the ceiling of the room.

"Not only are there many layers of pipelines and various types, but also their relative positions up and down need to be considered. Pipes that need to be repaired should be located relatively low. Pipes that need insulation and heat insulation need to be wrapped with insulating cotton. Places where pipes are densely laid are often so narrow that even hands cannot be inserted." Cao Zhengwei introduced that if the overall planning is not considered in place in advance, if a problem occurs in one link during the construction process, the pipelines and cables on other layers may have to be removed and re-laid. Therefore, at the beginning of the design, a full lightweight model check of the pipeline and cable layout must be carried out to ensure that the project ultimately meets the expected quality and requirements.

Excellent facilities: moving luxury hotels onto ships

Different from cargo ships and ordinary passenger ships, large cruise ships have the crossover and customized product attributes of "ship + hotel + entertainment". Providing passengers with multiple choices and good experience is the value and competitiveness of large cruise ships. "Move the luxury hotel on board." This is the idea of ​​Wu Xiaoyuan, production director and director of the interior engineering department of Waigaoqiao Shipyard.

Reducing noise is the first step. For cruise ships, noise control is as important as weight control. "We have set up more than 1,400 monitoring points throughout the ship to ensure that no obvious noise pollution occurs." Wu Xiaoyuan said that as ships are sailing on the sea, wind and waves are inevitable, so it is necessary to ensure that no additional noise is generated during the shaking of the hull. "For example, an elastic base is installed at the connection between the structural parts of the wall panels and ceilings and the steel structure enclosure, and the screws are used for buffering, which can reduce the noise generated by the friction between the metals."

Improving passenger comfort is the second step. For the "Aida·Modu" with more than 2,000 rooms, controlling air conditioning and air supply is a big problem. "First of all, we need to solve the layout and installation of pipelines." said Xue Yabin, deputy director of the second general assembly department of Waigaoqiao Shipyard. Due to the long transmission distance and too many rooms in use, there will be problems such as insufficient room temperature control capacity and insufficient air circulation at the end of the pipeline. To this end, the commissioning team coordinated nearly 6,000 air volume balancing valves and more than 1,000 water volume balancing valves on the ship to ensure consistent air conditioning effect and comfort in each room.

Enriching the passenger experience is the last link. If it is just eating, staying and watching the sea, some people may be willing to experience it once, but they will not go a second time. For large cruise ships, attracting and retaining passengers is the way to marketization. From the passenger ladder to the 10th deck, the SPA room is undergoing the final decoration; towards the bow, the gym is just waiting for the equipment to arrive; teppanyaki, hot pot, Western food, there are many types of restaurants with different styles; in the duty-free shop, all kinds of exquisite goods will be displayed in the future...

Comprehensive from People's Daily, Guangming Online