by Guest » May 7, 2010, 1:56 pm
Here is a cross-section of the James R. Barker / Mesabi Miner. American Spirit is similar except for having two conveyor belts instead of three. Paul R. Tregurtha is nearly identical to the Belle River class in cross-section.
Ever wonder why American Century, Indiana Harbor, Walter J. McCarthy can carry 71,300 net tons of coal, while the American Integrity and Burns Harbor can only carry 71,000 net tons of coal? It's because the American Integrity and Burns Harbor's hatch coamings are only 12 inches high, whereas American Century, Indiana Harbor and Walter J. McCarthy's hatch coamings are 24 inches high.
Getting back to the Edgar B. Speer vs Belle River class comparison. The cargo hold for the Speer can only handle 50,200 net tons of coal versus the Belle River class which can carry 71,300 or 71,000 net tons of coal. The reason is because Speer has less cubic feet in her cargo hold as compared to the Belle River class. That is why even though there hull shapes are exactly the same, there cargo-hold configuration is different, hence one is more efficient than the other in carrying coal. Since the Speer and her sister the Edwin H. Gott were designed to operate in a captive market - that is to carry iron ore exclusively for there owner's steel mills, it wasn't necessary to design them for maximum efficiency in carrying coal.
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Here is a cross-section of the James R. Barker / Mesabi Miner. American Spirit is similar except for having two conveyor belts instead of three. Paul R. Tregurtha is nearly identical to the Belle River class in cross-section.
Ever wonder why American Century, Indiana Harbor, Walter J. McCarthy can carry 71,300 net tons of coal, while the American Integrity and Burns Harbor can only carry 71,000 net tons of coal? It's because the American Integrity and Burns Harbor's hatch coamings are only 12 inches high, whereas American Century, Indiana Harbor and Walter J. McCarthy's hatch coamings are 24 inches high.
Getting back to the Edgar B. Speer vs Belle River class comparison. The cargo hold for the Speer can only handle 50,200 net tons of coal versus the Belle River class which can carry 71,300 or 71,000 net tons of coal. The reason is because Speer has less cubic feet in her cargo hold as compared to the Belle River class. That is why even though there hull shapes are exactly the same, there cargo-hold configuration is different, hence one is more efficient than the other in carrying coal. Since the Speer and her sister the Edwin H. Gott were designed to operate in a captive market - that is to carry iron ore exclusively for there owner's steel mills, it wasn't necessary to design them for maximum efficiency in carrying coal.