MANOEUVRING AND CONTROL CHARACTERISTICS OF SPECIAL-TYPE SHIPS SERIES
In this series of two videos the special-type ship chosen is a Pure Car Carrier (PCC).
The series uses this ship type to show the theory and the practice of ship handling.
Many of the common problems of ship handling apply in the extreme to the PCC so
its choice for use as an example in this series helps in the understanding of basic
principles. The two videos discuss from first principles some of the forces,
coefficients and equations which determine the handling of ships. The two features
of ship handling described in these videos are:
Manoeuvring Characteristics of Special Car Carriers - In Harbour Ship Handling of PCC
Code No 696
Time: 29 Mins
This video looks at the difficulties of handling a pure car carrier (PCC) in port
approaches and berthing due to the profile of these ships. Typically berthing and
unberthing tends to be difficult and complicated. Pre-planning and knowledge of
how the ship will behave are vital to ensure successful manoeuvres.
The effect of the high-sided hull is explained. Particular difficulties can be
encountered when handling anchors, picking up the pilot, maintaining course in
narrow channels and berthing and unberthing.
The forward position of the bridge also contributes to the difficulties of handling
PCCs. This arrangement means that it is difficult to verify beam and stern clearance.
There are also difficulties in observing tug operations and in identifying the ship’s
fore and aft line.
The video gives detailed explanations about the forces acting on a PCC, particularly
the wind forces. An understanding of this will help practical manoeuvring and course
keeping.
Shallow water effects can greatly influence the course keeping and turning abilities
of a PCC. There are explained in detail. Tugs are frequently used to assist PCCs in
harbours. The special precautions that apply to handling tugs are also explained
together with precautions when using bow-thrusters.
Finally the video shows the example of a PCC entering Bremerhaven to illustrate
many of the points explained earlier.
Tractor tugs provide enhanced manoeuvring and towing performance when
compared with conventional tugs. This performance is due to the underwater design
of the vessel’s hull and the use of twin controllable-pitch 360 degree azimuthal
thruster units. This video shows clearly the advantages of using tractor tugs by
showing two separate berthing exercises.
In the first exercise two tractor tugs meet a car carrier as she approaches the Port of
Gothenburg. We follow the progress as they navigate the channel and berths. In the
second exercise we see a car carrier berthing with a combination of conventional and
tractor tugs, the manoeuvre being complicated by the windage on the car carrier.
This instructive/informative film shows how both single and twin unit tractor tugs
(SUTTS and TUTTS) differ in their handling and application from conventional screw
tugs and from each other.
The Voith Schneider tractor propulsion system with which a range of tugs is fitted is
now well established as an alternative to conventional screws. Nevertheless, for
those who know only larger ships and tugs fitted with screws, the Voith Schneider
tractor unit will be something of a novelty and for that reason the mechanics are
explained at the outset. A knowledge of what is happening underwater is essential to
the understanding of the controls and the consequent behaviour of the ship.
The normal practices of ship husbandry apply to both SUTTS and TUTTS but, where
the propulsion units demand special maintenance procedures, these are covered.
Through extensive use of scale models in ship testing tanks the scientists were able
to document the phenomenon called interaction. They discovered that when two
vessels approached, the sudden pressure effects which build up are sometimes
greater than can be counteracted by rudder and engine. Interaction effects are most
pronounced in shallow water and at speed.
The film is an aid to practising ship handlers. It shows case studies and some of the
test results, thereby raising awareness of the subject and offers advice on how to
accommodate the sometimes unavoidable effects.
Safe anchoring is one of the most critical skills of good seamanship. It is also one of
the most basic. Worldwide though, the past twenty years have witnessed over a
thousand sometimes fatal, always costly anchor related incidents at sea. In
particular, this relates to large vessels and VLCCs.
Anchors have been let go in the wrong place, at the wrong time and in the wrong way.
Windlasses have been shattered. Anchors and cable have been lost. Vessels have
been stranded, beached and run aground. Lives have been lost. These examples
raise the question of whether the design limits, and the proper maintenance and use
of both windlass and associated anchoring equipment, are sometimes
misunderstood by those responsible for their ship’s safety.
In this package, which consists of a video and support book or CD-ROM, archive
images dramatically illustrate the consequences of such misunderstanding.
Against this background, the package highlights and explains in turn the proper
function and design limits of windlass, anchor and cable aboard vessels of all sizes
as well as demonstrating their correct use and maintenance.
Further sections of particular importance cover the identification of a dragging
anchor and how to cope with it, the importance of close anchor watches and
oversights to avoid when weighing anchor.
The bulk of the package is taken up by a step-by-step study of the careful onboard
preparations for, and textbook execution of, two anchoring operations. The first by
the most commonly practised 'fore and aft' method and, the second, by the less
common 'sideways' alternative – aboard a bulk carrier on route between Holland
and Canada.
This programme provides an introduction to the key issues surrounding towage in harbour and at sea. By raising awareness of the challenges faced by crews both on tugs and towed vessels, it aims to help vessel owners get better value from towage services and reduce risk for everyone involved.
The need for planning and risk assessment of towage operations is covered in depth. These include formal procedures established by port authorities and Pilots, as well as informal procedures agreed between Pilot, Master and Tugmasters during operations.
The programme highlights best practice while identifying some common errors which reduce the effectiveness of towage operations and increase risk. Throughout, the emphasis is on good communication. This is covered in some detail between Pilot and Master, Pilot and Tugmaster and between deck crews on both vessels.
Code No 9985
Time: 30 Mins
Code No 13
Code No 928
Time: 23 Mins