The Admiralty Coefficient (C) is a method for estimating the propulsion power needed for a newly built ship. It's considered relatively constant for a given ship design. The formula is:
$$C=\frac{\Delta^{2/3}\times V^3}{BP}$$
Where:
- C = Admiralty Coefficient
- Δ = Displacement in tonnes (weight of the ship when fully loaded)
- V = Speed in knots
- BP = Brake power in kilowatts (power delivered by the ship's engine)
A higher Admiralty Coefficient indicates a more efficient ship design, meaning it requires less power to achieve a given speed. Values typically range from 350 to 600.
Fuel Coefficient:
The Fuel Coefficient (F.C.) is used to calculate a ship's daily fuel oil consumption. The formula is:
$$Daily\:fuel\:oil\:consumption\:=\:\frac{\Delta^{2/3}\times V^3}{FC}$$
Where:
- F.C. = Fuel Coefficient
- Δ = Displacement in tonnes
- V = Speed in knots
The Fuel Coefficient can vary significantly, with typical values ranging from 40,000 to 120,000. A higher Fuel Coefficient implies greater fuel efficiency (lower daily fuel consumption) for a given speed and displacement.
$$admiraty\:coefficient\:\left(C\right)=\:\frac{\Delta^{2/3}V^3}{Shaft\:power}=\frac{\Delta^{\frac23}\times V^3}{SP}$$
$$\frac{SP_1}{SP_2}=\frac{V_1^3}{V_2^3}$$
$$\frac{4460}{4120}=\frac{14.55^3}{V_2^3}$$
$$V_2=14.17kntos$$
$$Fuel\:consumption\:per\:hour=541\operatorname{\mathrm{\:kg}}\:per\:hour$$
$$Fuel\:consumption\:per\:day\:=\:541\times24=12.98t\:per\:day$$
$$Fuel\:coefficient=\frac{\Delta^{\frac23}\times V_2^3}{Fuel\:consumption\:per\:day}$$
$$=\:\frac{14900^{\frac23}\times14.17^3}{12.98}$$
$$=132726.9$$