by William Lafferty » December 10, 2020, 3:15 pm
Studies done by the United States Shipping Board showed that on average a ton of oil takes up 5 cf less space than a ton of coal, while the heat conversion efficiency was 80% for oil and 65% for coal. This yielded a 40% savings in bunker space for an oil-fired steamship that could be applied to cargo carriage and a reduction in engine room crew, and (although not a factor on the Great Lakes) a cruising range extended two to three times over that of a coal-fired vessel, depending upon size and speed. I looked at anthracite and fuel oil prices 1949-1955 and they stayed fairly consistent, even while anthracite use in the transportation sector was nearly cut in half during that period, reflecting the Dieselization of the railroads and shipping as well as the conversion of vessels from coal- to oil-fired. Price differential seems not have been a concern, and would probably have been in favor of oil. Oil was clearly better, even though it generally had to be kept heated, but as I state below I think the wide availability of coal and perhaps for operators to gain discounts from suppliers (who were often their customers, too) led at some point to a cost-benefit analysis resulting in coal-firing. Or, it could be the Great Lakes maritime industry's innate technological conservatism. For example, without the need for boilers and a reduced bunker capacity and manning need, the Diesel-powered vessel was perfect for the Welland and St. Lawrence canals where prescribed vessel dimensions made the absence of boilers and coal bunkers (and the flexibility of an internal combustion power plant) made for increased cargo capacity within a given outboard parameter. Somewhere here I have a study made back when the first (and woefully underpowered) Diesel canallers came to the lakes from Europe, and the overall cost savings compared to a coal-fired steam canaller were truly significant. Despite great advancements in Diesel marine engineering after World War I, no Great Lakes operator (other than Ford) contemplated Diesels, save for the few but pioneering motor ships that exploited the New York State Barge Canal. As I recall, by any metric the Pargny's conversion to Diesel resulted in a more efficient and economical vessel compared to the Williams with its conversion to steam turbine and oil-fired boilers. Nevertheless, the next year USS built the Anderson, Callaway, and Clarke with steam turbines and water tube, oil-fired boilers.
Studies done by the United States Shipping Board showed that on average a ton of oil takes up 5 cf less space than a ton of coal, while the heat conversion efficiency was 80% for oil and 65% for coal. This yielded a 40% savings in bunker space for an oil-fired steamship that could be applied to cargo carriage and a reduction in engine room crew, and (although not a factor on the Great Lakes) a cruising range extended two to three times over that of a coal-fired vessel, depending upon size and speed. I looked at anthracite and fuel oil prices 1949-1955 and they stayed fairly consistent, even while anthracite use in the transportation sector was nearly cut in half during that period, reflecting the Dieselization of the railroads and shipping as well as the conversion of vessels from coal- to oil-fired. Price differential seems not have been a concern, and would probably have been in favor of oil. Oil was clearly better, even though it generally had to be kept heated, but as I state below I think the wide availability of coal and perhaps for operators to gain discounts from suppliers (who were often their customers, too) led at some point to a cost-benefit analysis resulting in coal-firing. Or, it could be the Great Lakes maritime industry's innate technological conservatism. For example, without the need for boilers and a reduced bunker capacity and manning need, the Diesel-powered vessel was perfect for the Welland and St. Lawrence canals where prescribed vessel dimensions made the absence of boilers and coal bunkers (and the flexibility of an internal combustion power plant) made for increased cargo capacity within a given outboard parameter. Somewhere here I have a study made back when the first (and woefully underpowered) Diesel canallers came to the lakes from Europe, and the overall cost savings compared to a coal-fired steam canaller were truly significant. Despite great advancements in Diesel marine engineering after World War I, no Great Lakes operator (other than Ford) contemplated Diesels, save for the few but pioneering motor ships that exploited the New York State Barge Canal. As I recall, by any metric the [i]Pargny[/i]'s conversion to Diesel resulted in a more efficient and economical vessel compared to the [i]Williams[/i] with its conversion to steam turbine and oil-fired boilers. Nevertheless, the next year USS built the [i]Anderson[/i], [i]Callaway[/i], and [i]Clarke[/i] with steam turbines and water tube, oil-fired boilers.