Zusammenfassung der Ressource
Tug Use in Port - Cap 4
Tug Capabilities and
Limitations
- 4.1 -Introduction
- 4.2 - Basic priciples and definitions
- 4.2.1 - Pivot Pint
- 4.2.2 - Towing point,
pushing point and
lateral centre of
pressure. Direct Towing
and indirect towing.
Skegs
- The lateral centre of pressure
- The lateral centre of pressure
- Direct and indirect towing method
- Pushing point
- Skeg and their effect
- 4.2.3 Stability
- High GM and good dynamic stability
- Reducing transverse
resistance of the hull
- Reducing de height of
the towing point
- Reducing the height
of the pushing point
- A towline with good shock
absortion characteristics
- Tug freeboard being such that the deck edge is
not immersed at too small a heeling angle
- 4.3 - Capabilities and limitations
- 4.3.1 Capabilities and
limitations of the tug
- Tugs towing on a line
- forward tugs towing on a line
- Stern tugs towing on a line
- Tugs opeting at a ship`s side
- Pushing mode
- Pulling mode
- Stopping assistance
- Summary
- Conventional tugs
- Tractor and Reverse-tractor tugs
- ASD tugs
- 4.3.2 Effectiveness of tug types
- Performance diagrams
- Performance of a conventional and ASD-tug
when pushing at a ship underway at speed
- Performance of a ASD and VS
tug while towing on a line
- Speed control -
braking assistance
- 4.3.3 Effective tug position
- 4.3.4 Towing on a line compared with
operating at a ship`s side
- 4.4 - Operational limits
- 4.5 - Design consequences
- 4.6 - Conclusions regarding tug types
- 4.7 - Some other pratical aspects
- Coperation
- Communications between pilots and tug captains
- Tug use
- Speed
- Decreasing effectiveness of tugs when a ship gathers speed
- Ship´pulled or pushed around by a bow tug gathers speed