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Triple expansion marine steam engine model
Triple expansion marine steam engine model

Triple expansion marine steam engine model

Datec 1895
Object number00029479
NameModel
MediumMetal, paint
DimensionsOverall: 49 × 48 × 23 mm, 45.5 kg
ClassificationsModels
Credit LineANMM Collection Purchased with USA Bicentennial Gift funds
DescriptionThis builder's model is a working vertical triple expansion marine steam engine. Triple expansion steam engines feature three cylinders of increasing size and decreasing pressures, making them unique from duel or single cylinder steam engines. They are able to capture more of the steam's energy, increasing efficiency and fuel economy. Triple expansion steam engines move with greater balance, and use a smaller flywheel.HistorySteam engines were successfully adapted to marine vessels as the primary method of propulsion in the early 19th century, after decades of experimental use throughout England and America. Steamboats were introduced to the Australian colonies in the early 1830s, however they were limited to calm river waters along short colonial trading routes. Steam engine technology continually developed, and by the 1870s steamships were well and truly seaworthy and could undertake extensive ocean voyages. Marine steam engines became progressively more complex and powerful in order to cope with the increase in size and weight of ships. By the 20th century, marine steam engines had developed from slow-working single cylinder engines, into high-speed multiple-cylinder compound engines and turbines. Marine steam engine models are important historical records of these industrial and engineering developments. Miniaturised replicas of industrial objects were of huge importance in the mid 19th century, long before model making became a hobby. They were used as sales samples and promotions, and played an important part in the training of young engineers. Early model making was exacting work, and was carried out by professionals or apprentices who could undertake the complex engineering. The high cost of materials along with the difficulty in obtaining engine plans or instructions ensured that model making was challenging for amateur enthusiasts. Toward the end of the 19th century the number of novice model makers increased, and by the early 20th century many became well known for their excellent craftsmanship. The increase in demand for model parts and materials was met by the establishment of new business who specialised in model making. SignificanceMarine steam engine models are important historical records of developments in steam engineering. This model represents the triple expansion steam engine which hastened the end of the age of sail in the last years of the 19th century. In 1875, the Union Steam Ship Company's ZEELANDIA was probably the first Australian ship to be fitted with a triple expansion steam engine.

The advantages of higher speeds and improved fuel economy over the earlier two cylinder compound steam engines was made possible through improvements in metallurgy and boiler design which allowed higher steam working pressures. This was one of the major developments in marine steam engines until turbines were introduced from 1897.