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Topic: Elco at flank speed |
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Phil
Full Member
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Posted on: Aug 12, 2021 - 9:02pm
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How long could an 80’ Elco run at flank speed before it had to be slowed down?
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Total Posts: 26 | Joined:
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Jerry Gilmartin |
TOP BOSS
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 Posted on: Aug 13, 2021 - 1:57am
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Hi Phil,
It was not a matter of having to slow down as much as the amount of gasoline they carried and how much they used at top speed. I have read that the top speed on 3 engines uses about 450 gallons per hour. The boats would carry 3000 gallons of gas on board. 3000 divided by 450 gallons per hour is around 6.5 hours max possible time at top speed.. But that will only get you around 280 miles if you are moving at 42knots. So the boats would go more economical speeds to get on station and then race back to port at the end of the patrol.
Jerry
Jerry Gilmartin
PT658 Crewman
Portland OR |
Total Posts: 1472 | Joined:
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Jerry Gilmartin |
TOP BOSS
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Posted on: Aug 13, 2021 - 2:15am
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Here is a chart from a Higgins that shows the principal. Also the High speed cruising test data where they ran PT625 for 1 hour at 2000 rpm on Port Forward tank used 390 gallons and then at 2400 rpm for one hour using gas from Stbd fwd tank (475 gallons used)
Graph shows number of engine in use, rpms vs speed in knots, note that the graph stops at 22 knots when on 2 engines only and 9.5 knots when running only 1 engine since the engine cannot physically move the boat any faster when all 3 not running.
High Speed run trials fuel tank soundings showing fuel usage
Jerry Gilmartin
PT658 Crewman
Portland OR |
Total Posts: 1472 | Joined:
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Phil
Full Member
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Posted on: Aug 16, 2021 - 4:36pm
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Thanks Jerry! You are the MAN! A guy on Facebook asked today if the prop shafts had joints for alignment on the Higgins?
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Total Posts: 26 | Joined:
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