Cement Stone Blocks at Kopgalis in the Curonian Spit: Historical and Technological Context

摘要

The article discusses the circumstances and events accompanying the hoisting and usage of the cement stone blocks after the sinking of the motor sailing-boat Grisslan in the spring of 1924. They relate to navigation, hydro-technical construction and the Curion Spit bank reinforcement operations of that period. The article also reveals certain features of the work performed by Klaip?da port administration in relation to response to and registration of vessel sinking accidents. Customary and modernized (motor) sailing-boats dominated in the shipping of construction materials and other cargo from Sweden to Klaip?da port, whereas liner cargo shipping with Germany and Great Britain mainly employed motor vessels. Although the boat Grisslan had the displacement very similar to the displacement of most vessels arriving at Klaip?da port in the beginning of the 20th c., this type of vessels – motor sailing boats – was already outdated and did not comply with the requirements of modern cargo shipping. Therefore the reasons of this sailing boat sinking accident can be regarded as symptomatic. The described shipping accident can be related to obvious changes in two areas of technical development: more intensive development (modernization) of shipping vessels and technologies between the two wars, and the use of Portland cement and concrete in hydro-technical and urban constructions. Sparse archive material, mundane and laconic press reports of those days show that specific work of divers, application of underwater explosions and breakwater concrete work technologies in Klaip?da port were routine procedures in port operations. The decisions to use barrel-shape cement stone blocks for the reinforcement of the southern edge of Klaip?da port breakwater and Kopgalis dune ridge is interesting and uncommon in technical history; on the other hand, the decision was sound and realistic, as boulders suitable for hydro technical construction were short in supply and the use of cement stone blocks was a good money saving opportunity for the port administration. Then again, such a decision proves that at that time there were no doubts concerning the durability of Portland cement in seawater environment and other performance characteristics. Good present condition of the cement stone blocks at Kopgalis has proven that this decision was viable. Article in Lithuanian