关于郑和宝船船型的探讨

INVESTIGATION INTO THE TYPE OF ZHENG HE'S TREASURE SHIPS

该文系定量研究郑和宝船的初步尝试。关于郑和宝船的船型,历来有两种不同的意见:一种认为是沙船型,一种认为是福船型。该文根据我国古代木帆船的营造法式,复原了沙船型宝船和福船型宝船的主体尺度,并运用现代船舶理论,研究了两种船型的摇荡性能。结果表明,福船型宝船的横摇周期接近于现代船舶的横摇周期,而沙船型宝船的横摇周期则太小,摇荡太剧烈。从抗风浪性和舒适性考虑,笔者认为郑和宝船为福船型。该文考察了宝船航行海域的气候条件、风浪状况和海流流向后,进一步计算了福船型宝船的航行阻力,推算出宝船的帆面积和摇橹水手人数,并据此印证了宝船为福船型结论的合理性。

The authors try to do some research on the type of Zheng He's treasure ships. Zheng He of the Ming Dynasty headed an impressive fleet on seven voyages to the South Seas. The ships of the fleet were classified into many types according to their size, capacity, number of sweeps and purpose, as well as the place where they were built. The largest ships of the fleet are called treasure ships. Most of them were built in the Nanjing Treasure Yard or in the coastal regions of Fujian Province which were also important shipbuilding bases. According to archives recording Zheng's voyages to Southeast Asia and Africa, his treasure ships were committed to the flames, so we could not know their type, and historians have been arguing about this for many years. Some people hold that Zheng's treasure ships are of the sha-type (with flat bottom), and others think they are Fu ships (with sharp bottom, deep draft and broad beam, and this type of ships are used as seagoing ships in Fujian Province). Considering the huge treasure ships were requisite for the Ming government's 'demonstration of military force' in politics and 'showing off power' in economy, they must be designed safe and comfortable. The authors calculated the rolling period of two types, i. e. , Fu and sha treasure ships. The conclusion based on the principle of modern ships and the calculation result both show that the rolling period of the Fu-type is almost equal to that of modern ships, while the rolling period of the sha-type is too short as compared with that of modern ships. The ships with such short rolling period are dangerous and uncomfortable. So, Zheng He's treasure ships must be of the Fu-type. Furthermore, by estimating the resistance of Zheng He's Fu-type treasure ship and the style of its sail canvas, the authors conclude that the Fu-type is reasonable.