Tugboat Stopping Characteristics During Navigation
Due to their specialized propulsion system, tugboats can rapidly reduce speed even at full ahead. If operators (Captain, Chief Officer) do not properly understand this characteristic, the vessel will stop before reaching the intended position.
8~9
Max Speed (Knots)
200~250
Stopping Distance (m)
4
Stopping Phases
0m
50m
100m
150m
200m+
⚠ HIGH PROPULSION BRAKING ⚠
8.5
KNOTS
Current Phase
Full Ahead
P&S RPM 700
P: AH 90 | S: AH 90 | H: 0°
Stopping Sequence — 4 Phases
PHASE 1Full Ahead — High Propulsion
Port LeverAH 90
Stbd LeverAH 90
Steering Angle0°
RPM700
Speed8~9 Kts
PropulsionHIGH
Both engines full ahead. Maximum speed. Thrust jets discharge strongly aft from stern propellers.
PHASE 2Deceleration — Low Propulsion
Port Lever0
Stbd Lever0
Steering Angle0°
RPM500
Speed6 Kts
PropulsionLOW
Levers to neutral, steering angle 0°. Thrust direction shifts sideways — port prop discharges to port side, stbd prop discharges to stbd side. Low RPM produces small lateral wash.
PHASE 3High Propulsion Braking
Port Lever0
Stbd Lever0
Steering Angle0°
RPM700
Speed2 Kts
PropulsionHIGH — BRAKE
RPM increased to 700! With steering at 0°, massive lateral thrust creates powerful BRAKING action. Very large wash discharged sideways from both propellers.
PHASE 4Full Stop
Port Lever0
Stbd Lever0
Steering Angle0°
RPM400
Speed0 Kts
PropulsionSTOP
RPM 400, speed zero. Vessel fully stopped within approx. 200~250m.
⚓ Key Operational Characteristic
When a tugboat's propellers generate strong thrust during the stopping sequence, it produces a BRAKING effect. Stopping from 8~9 Knots using this method achieves full stop within 200~250m forward distance.