Characterizing the sealing materials of the merchant ship Nanhai I of the Southern Song Dynasty

Abstract

Nanhai I is a highly valuable shipwreck of the Southern Song Dynasty for studying various topics, including the shipbuilding techniques. The sealing materials are of significant importance to ensure the ship’s reliability during the voyage across the ocean and they were rarely analyzed. Therefore, the sealing materials of this ship were analyzed by several analytical approaches. The sealing materials included two types, i.e., gap filler with jute fibers and surface coating without any oakum. The main components of both types of putty are calcite with minor Tung oil. The weight ratio of Ca(OH)2/Tung oil range from 4.3:1 to 7.9:1 for surface coating samples and the weight ratio of Ca(OH)2/organics is 3.1:1 for the gap filler sample. Additionally, we first find that the surface coating has a layered structure, where outer layers contain more Tung oil than inner layers. The innermost layer of the surface coating sample might be altered by organic acids from wood deterioration, causing its loose structure and grey color. The composite layers with different formula might be a result of balancing the costs and performances of the putty.

Characterization of archaeological lime mortars in a Ming dynasty tomb: A multi‐analytical approach

“…Interestingly, calcium soaps—that is, calcium stearate/palmitates—were identified in sample S‐6. Calcium carboxylates such as calcium stearates/palmitates have occasionally been detected in oil paintings (Ferreira et al, 2011; Helwig et al, 2019; Henderson et al, 2019; Salvadó et al, 2011), wall paintings (Sotiropoulou et al, 2018), historic leather (Vichi et al, 2018), Chu‐num putties (a mixture of tung oil, lime and fibers) for sealing ships (S. Fang et al, 2013; Gong et al, 2019; Y. Zhou et al, 2021). Calcium soaps such as calcium palmitate/stearate are formed between saturated fatty acids such as palmitic acid or stearic acid present in the oil and the calcium ions present in the lime.…”

Millennial-scale societal shifts drive the widespread loss of a marine ecosystem

“…At least 16 native reef-building species can be found in the region (within the genera Magallana and Tallonostrea) (Sigwart et al 2021), with the oyster harvesting and aquaculture industry dating back at least 800 years in countries throughout temperate and tropical Asia (e.g., Japan (Smith et al, 2018), China (Lam & Morton, 2003;Liu et al, 2021), Thailand (Chalermwat et al, 2003), Korea (Choi, 2008)). Archaeological records also highlight the widespread presence of middens with oyster shells (An & Lee, 2014;Engelhardt & Rogers, 1998;Hung & Zhang, 2019;Lee et al, 2017) and oyster-related cultural artefacts (Hung, 2019) throughout Asia, as well as the incorporation of oysters in architecture and ship construction materials in China and southeast Asia (Luengo, 2017(Luengo, , 2023Yihang et al, 2021;Z.-J. Zhang et al, 2019).…”