A ship loading terminal near Punta Arenas, the southernmost city of the world (53 ° -10'S, 70 ° -54'W) is described. Strong winds, choppy seas, frequent gales, rain and snow make it difficult to load ships at an offshore berth in this area. Detailed site investigations, including a wind recording program, supplied sufficient information for the analysis of operating conditions. The weather pattern of the entire region, including the predictability of gales, was utilized in the analysis. The results showed that a bulk loading terminal at this location is feasible, provided that the design takes into consideration the specific problems of the site. The final layout shows a terminal that can be approached from several different directions, depending on the direction of the wind. The mooring system-is arranged to allow alternative ways of attaching and casting off mooring lines and executing docking and departing maneuvers.
The berth is supported on piles and contains the minimum of structures, relying on a slewing ship loader to reach the ship in any position, with only limited fore and aft shifting of the vessel for loading the extreme hatches.
Results of wind recording, statistical analysis of wind and wave data, operating criteria and the results of berth availability analysis are included in the paper.
Construction of a terminal capable of loading 3 million tons of coal per year into 60,000 DWT bulk carriers was a basic condition for opening the Pecket mine near the southernmost city of the world, Punta Arenas, Chile (Lat. 53 ° -10' South, Long. 71° -54' West). The only location close enough to the mine to allow economical transportation is on the eastern shore of Otway Sound, a large body of water accessible from both the Pacific and Atlantic Oceans via the Strait of Magellan and the Geronimo Channel (Fig. 1). This area is exposed to prevailing onshore winds that often reach gale force, generating choppy seas and heavy surf. Summer rainstorms and winter snowshowers occur with considerable frequency.
Otway Sound (Fig. 2) covers 2,750 square kilometers (800 square nautical miles). The fetch of open water over which waves can be generated by the prevailing westerly winds is approximately 37 kilometers (20 nautical miles).
The weather pattern of the region is dominated by the large Pacific Ocean air masses whose eastward flow is obstructed by the Andes mountain range. Being forced south, these masses burst through the Strait of Magellan area with explosive force. As a rule, gale or near-gale force winds blow for several days, followed by a calmer period before the next gale. During the Southern Hemisphere summer the gales occur with greater frequency than during the winter. The arrival of these strong winds can usually be predicted several days in advance, from simultaneous readings of the atmospheric pressure at two or more meteorological stations located hundreds of miles apart.
