Geovisualizing the sail-to-steam transition through vessel movement data

Abstract

Despite the crucial importance of maritime transport for world trade and economic development, dedicated tools to map the evolution of vessel movements remain lacking.Such movements, especially those recorded by the maritime insurance company Lloyd's List, represent the only available information documenting the changing spatial distribution of the world's shipping routes in the last century or so. This chapter tackles the lacuna head on by discussing how this particular type of shipping data can be accurately represented on a map (see Chapter 1 for a review of the field). Such an exercise poses specific issues in terms of geovisualization, as it necessitates, among other developments, the creation of a virtual maritime grid to which port nodes and their mutual vessel flows are assigned. Beyond geomatics, this research is also an opportunity to shed new light on a vibrant research question in maritime history, namely how steam has replaced sail shipping in space and time.We extracted snapshots of global maritime flows every five years from the Lloyd's Shipping Index between 1890 and 1925 in order to test the capacity of the geoportal to visualize such flows, and at the same time verify the spatio-temporal evolution of a bi-layered maritime network. The remainder of this chapter is organized as follows: the next section discusses the scarcity of maritime data cartography until recent years in the light of general knowledge on flow mapping in geography and elsewhere. It is followed by a description of how vessel movement data had been incorporated into a dedicated visualization system. Lastly, it provides the first-ever cartographies of such movements while discussing the gaps between our results and the existing literature on the transition from sail to steam shipping.Conclusions point to a number of ways how the visualization system may be improved in the future, and how it can contribute toward addressing numerous other issues in global transport studies in general.

Maritime Network Analysis: Connectivity and Spatial Distribution

“…As already demonstrated for airline networks (Guimera et al, 2005) and for liner shipping networks (Ducruet, 2017), there is a high statistical significance between node degree or weight and the distance to/from of its adjacent neighbors. Nautical distance was calculated using GeoSeastems, a Geographical Information System (GIS) dedicated to maritime flows (see Bunel et al, 2017). Our results do not show, however, significant correlation between traffic size and average length of links, which stands in contrast with existing research.…”

“…Assortativity relates to the above formula: (5) Where j i , k i are the degrees of the vertices at the ends of the ith edge, with I = 1... M (M edges). And the average neighbor degree: (6) Another possibility to test the hierarchical dimension of the network is to look at the latter's degree distribution (Figure 4a). We then plot the degree centrality of nodes (x axis) against the cumulated number of nodes (y axis) in a log-log diagram and insert a power-law function to obtain the slope exponent of the line.…”

Disruptions in Spatial Networks: a Comparative Study of Major Shocks Affecting Ports and Shipping Patterns

“…, Asian crisis 1997(e.g. -1998, dockworkers strikes, other natural disasters, and technological change like canal creation or closure (Suez, Panama) but also transitions in the shipping world like propulsion technology (see Bunel et al, 2017 for the case of sail to steam). Other metrics than vessel traffic could be integrated, such as vessel turnaround time (intra-port), vessel voyage duration and connectivity distance (inter-port) to verify ports' ability to reinsert international trade after the shock, and intermodal centrality measures such as land-sea (Berli et al, 2018).…”

The geography of maritime networks: A critical review

“…Political factors influencing maritime connectivity thus need a thinner quantitative resolution, as in the case of Taiwan/China cross-border shipping (Wang et al, 2019b). Progress was made however to catch the effects of technological change on maritime network structure and port connectivity in the past decades, especially with regards to containerization, but also earlier such as from sail to steam (Bunel et al, 2017). Research on maritime networks as integral parts of territorial structures will remain relatively difficult until more precise data shall become available on the true origins and destinations of maritime flows.…”