For boats equipped with a hydraulic steering, it will be necessary to determine:
– The volume of the steering cylinder (take the biggest volume in case of a single rod cylinder)
– Available voltage on board (12 VDC, 24 VDC, etc.)
For planing or semi-planing hulls, the power pack will be selected in function of its flow rate so that the steering cylinder will run its complete stroke within 10 to 12 seconds. | |
For displacement hulls, the power pack flow rate must enable the steering cylinder to run its complete stroke within 15 to 17 seconds. | |
Examples | |
Speed boat, planing hull with a 239 cc cylinder – Available voltage 12 VDC | |
60 seconds (1 minute) ---------------------------- 12 seconds (required time) |
x 0.239 litre (239 cc) = 1.195 litre / minute |
The flow rate of the required power pack will be 1.19 litre / minute, therefore we will select a reversible power pack with adjustable flow rate type RV2 (12 V) | |
Fishing or work boat, displacement hull with a 2,307 cc cylinder – Available voltage 24 VDC | |
60 seconds (1 minute) ---------------------------- 15 seconds (required time) |
x 2.307 litre (2307 cc) = 9.228 litre / minute |
The flow rate of the required power pack will be around 9 litres / minute, therefore we will select a power pack type HF 1.5 – 9 (24 V) | |
For boats equipped with a mechanical steering (wire ropes, cables, rack and pinion), it will be necessary to determine:
– The rudder(s) torque
– The available voltage on board (12 VDC, 24 VDC, etc.)
Torque Calculation: For boats fitted with a rudder with speed not exceeding 25 knots, the torque (C) of the rudder or rudders will be calculated according to the formula and correction coefficients below: C = S x [ (0.4 Lg) – Lc ] x V² x K
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