The propeller on your vessel has a pitch of 22.8 feet. From 0800H 18 April, to 1020H 19 April, you steamed an observed distance of 403.6 miles. If your average RPM was 74, what was the slip?
Solution:
1. We have to calculate for the speed of the engine. This is the formula for the engine speed:
Engine speed = RPM x P x 60
6080
= 74 x 22.8 x 60
6080
= 101232
6080
Engine Speed = 16.65 knots
2. Solving for the Observed Speed. But we have to solve first for the steaming time.
19 April 1020 H
- 18 April 0800 H
1 day 0220 H (20min x 1 hr = 20 hr = 0.33 hr)
x 24 hr 60min 60
24 hr + 2.33 hr = 26.33 hrs is the steaming time
Observed Speed = Distance
Time
= 403.6 miles
26.33 hrs
= 15.33 knots
3. We can now solve for the slip of the propeller. This the formula for the slip.
Slip = (Engine Speed - Observed Speed) x 100
Engine Speed
= (16.65 kts - 15.33 kts) x 100
16.65 kts
= 1.32 kts x 100
16.65kts
Slip = +8
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Solution:
1. We have to calculate for the speed of the engine. This is the formula for the engine speed:
Engine speed = RPM x P x 60
6080
= 74 x 22.8 x 60
6080
= 101232
6080
Engine Speed = 16.65 knots
2. Solving for the Observed Speed. But we have to solve first for the steaming time.
19 April 1020 H
- 18 April 0800 H
1 day 0220 H (20
x 24 hr 60
24 hr + 2.33 hr = 26.33 hrs is the steaming time
Observed Speed = Distance
Time
= 403.6 miles
26.33 hrs
= 15.33 knots
3. We can now solve for the slip of the propeller. This the formula for the slip.
Slip = (Engine Speed - Observed Speed) x 100
Engine Speed
= (16.65 kts - 15.33 kts) x 100
16.65 kts
= 1.32
16.65
Slip = +8
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how did you get the positive?
ReplyDeleteDivide 1.32 by 16.65; and then multiply the answer by 100.
DeleteTop 6 daw ang Synergy? naniniwala kayo?
ReplyDeleteThis comment has been removed by a blog administrator.
ReplyDelete6080 i dont understand where it came from
ReplyDeleteMiles is different from nautical miles
Delete1 knot is 1.15 miles per hour
ReplyDeletewhat is 6080?
ReplyDelete