Navigation and Control on a Cruise Ship

SUN PRINCESS - A VISIT TO THE BRIDGE

 

The Bridge of the Sun Princess exploits the latest technology in marine electronics. This brief summary will give you a small insight into life on the Bridge on a state-of-the-art Cruise Liner.

Watches

The Bridge of the Sun Princess is manned 24 hours a day, 7 days a week by a team of highly trained Officers and Crew. The watch system is split into three watches at the following times, 12 until 4, 4 until 8 and 8 until 12, both night and day, meaning that each watch team works for four hours and then has a period of eight hours rest.

Each watch is manned by four members of the ship's company.

First of all is the Senior Officer of the Watch who has overall responsibility for the watch, the First Officer holding the 8 -12 watch, the Second Officer the 12 - 4 watch and the Navigator the 4 - 8 watch. Second on watch is one of the Ship's three Third Officers, who work alongside the Senior Officer of the watch. These two Officers on each watch form the Bridge's navigating and conning team.

To assist the Officers on watch the team is supplemented by two Able Seamen. Their position on the Bridge is to maintain a continuous lookout, which we are required to do by law, and to manually steer the ship when the need arises.

On Port approaches, in areas of confined navigation or high traffic density, this team is supplemented by additional Officers, and the Captain and / or Staff Captain. The Bridge of the Sun Princess is split into three separate sections comprising the Main Bridge or conning position, a Chart Room and the ship's Safety Centre.

 

THE BRIDGE AND ITS EQUIPMENT

The Bridge equipment onboard the Sun Princess is of the new generation of Integrated Bridge Systems. This in short means that all of the equipment is integrated together enabling individual pieces of equipment to 'talk' to one another.

The Ship's Wheel is no longer a large traditional wooden spoked helm, but is now smaller than that found in a modern sports car. With her twin rudder and twin propeller configuration, Sun Princess is highly maneuverable and only small amounts of rudder are required when at sea to maintain the required course.

Also located on the centre console is a repeater from our two gyro compasses. The gyro compass is a high precision instrument which unlike it's Magnetic counterpart does not suffer from the errors of Variation and Deviation. These are our two main steering compasses. Situated directly above the helm position is the periscope to our Magnetic Compass which is positioned on the Monkey Island above the Bridge. This compass is positioned high up in the ship in an attempt to reduce the errors induced by the electromagnetic field of the ship's steel structure. If the gyro compasses were to fail then this compass would be used as a backup.

We still have to plot our position on the paper charts. The new electronic charts onboard the Sun Princess have the main benefit of being connected into the Integrated Bridge System which means that we can superimpose the radar picture onto the chart. This can be very useful for helping us to identify points of land for navigational purposes.

In the centre between the two radar displays is our Conning Pilot Console (3). This is another visual display which can provide us with various pieces of information about the status of the ship and the weather. It can give us information on the status of the Main Engines, the vessels speed both fore and aft or sideways, the thruster status, way point information, and more. It is also possible for the Navigator to enter information pages for ports of call.

The Conning Pilot display is also repeated on the Bridge wings. In addition to these displays we have a repeater which is interchangeable between the port radar and the Conning Pilot, at the front of the Bridge for the Captain's or pilot's use, when conning the ship from this position.

Also located in the main console are the telegraphs, (4) which are used to control the speed of the engines and therefore the thrust provided by the propellers. Sun Princess' motive power comes from her diesel electric power plant Sun Princess has four diesel generators which provide the electricity to drive her two main electric propulsion engines. In addition to the telegraph levers, are the telegraph buttons (4a), an emergency backup for the levers.

 Just aft of the telegraphs between the emergency buttons are the control levers for the bow and stern thrusters (5).

Sun Princess has two bow thrusters and two stern thrusters to assist with manoeuvering the vessel. These are large pitch propellers housed in transverse tunnels beneath the waterline. They are fitted to reduce the need for tugs thus reducing operating costs and also to provide us with the extra maneuverability required by a vessel such as this in areas where no tugs are available.

Both the telegraph and thruster controls are repeated on the Bridge wings, in order to enable the Captain to manoeuvre the ship alongside the berth whilst monitoring the ship's side.

The automatic steering onboard Sun Princess is different from that used on many other ships. Onboard Sun Princess we use a system known as the NACOS system. This is the main part of the Integrated Bridge System. The NACOS (Navigation and Command System) was designed, built and fitted by Atlas Electronik in Bremen, Germany. This system is connected into the GPS satellite navigation system and also the steering and speed management systems.

At the start of a voyage we program the intended passage into the NACOS computer in the Chartroom along with our ETA at our destination. The system will then steer the ship along the intended track with an accuracy of around 100 meters, adjusting the vessel's course accordingly to maintain this track. Whenever the computer recognizes that it is time to alter course, an alarm will sound at which point we press the "Execute" button on the console, enabling the computer to steer the ship around the corner. However the computers have no collision avoidance capabilities, so we have to take manual control and steer the vessel clear of such dangers. dangers.

If we were to enter an anticipated time of arrival at the next port, the computer will tell us what speed we require to make that arrival and if we are going fast enough. Then if we enable a function known as the Speed Pilot, the computer will adjust the vessel's speed accordingly to ensure that we arrive at that port on schedule.

To starboard of the conning position is the chart table. Despite the modern technology of electronic charts the ship's position must still be plotted on a paper chart, as this particular piece of equipment is still in the development stages. It is the job of the Junior Officer of the Watch to plot the ship's position.

Above the chart table are our three (7) Differential Global Positioning System (DGPS) satellite receivers Leica Mx412 (7).

Above the navigation console and chart table are readouts of the engine revolutions and power outputs, along with depth, course speed readouts and a CCTV monitor.

Moving further to starboard we have our Atlas Echograph echo sounder (8). This tells us only the depth directly beneath the keel and has no forward or sideways projection.

At the front of the Bridge, in the centre, is yet another manoeuvring console. This console houses the LIPS joystick (9). The LIPS is a Single joystick arrangement from which all of the manoeuvring machinery can be controlled with one easy movement. The joystick is linked into a computer which determines which machinery to use, so as to manoeuvre the ship as required in the best and most economical manner possible. This utilizes the bow and stern thrusters, the main engines and also the rudders which can be used individually from one another so as to make the vessel still more manoeuverable.

On the port side of the port side console is the Bridge GMDSS equipment. This is the Global Maritime Distress and Safety System, or communications equipment. In these modern times Safety Of Life At Sea is paramount and all Princess ship's are fitted with the latest in communications equipment. We have everything from VHF radio equipment and HF (10) radio equipment to state of the art satellite communications apparatus (Ll ). This enables us to communicate with any other vessel in the vicinity using our radio equipment, or any satellite earth station anywhere else in the world in the instance of distress.

Located around the Bridge are several other VHF radio transceivers for the normal everyday working of the ship. To starboard of this equipment is the navigation, Signalling and deck light control panel. Sun Princess has specific lights which by law must be exhibited during the hours of darkness. Just by simply glancing at a vessel's navigation and signal lights, a Mariner can determine what type of vessel it is, and in what direction it is travelling.

Moving to starboard again, the next panel is probably the most important from our passengers point of view - the stabilizer fin control panel! Sun Princess has two Stabilizer fins. These fins are retractable and are situated at approximately midships. They work on a similar principle to that of an airplane wing and utilize a gyroscope to detect the rolling motion of the ship. They are approximately ten feet in length and fifteen feet below the waterline.

When an announcement is made from the Bridge on the public address system this is done from the panel to starboard of the stabilizer panel.

Adjacent to the port side radar is the last piece of equipment that we come to on the Bridge. This is our machinery equipment and alarm readout display. From here we can observe the status of the electric generators, the main engines, bow thrusters and most of the other mainstream equipment onboard. We can also trim the ship, that is fine tune the angle of list or heel, from this position, as well as observing the volumes of liquids in all of our tanks, i.e. fresh water, fuel oil etc.  

Command and Control Centre

THE CHARTROOM

The chartroom onboard the Sun Princess is where the planning of our future voyages and the upkeep of our extensive chart folio takes place.

The navigational charts held onboard Sun Princess, along with all of our navigational publications, are updated weekly by our Second Officer. This ensures that we have the latest and most up to date navigational information at our fingertips. Each cruise undertaken by Sun Princess requires a vast amount of navigational planning. This not only involves drawing the track lines on the charts for us to follow, but also finding out the relevant information about a port such as pilotage requirements and tugboat availability, calculating tidal data, calculating the speeds we require to maintain our schedule and briefing the Officers and crew involved in the operation to name only a few jobs. This is all the responsibility of the ship'S Navigator, and the main function of the Chartroom.

THE SAFETY CENTRE

Located just aft of the Bridge is the vessel's Safety Centre. As indicated by the name the sole function of this centre is to monitor the safety systems onboard and it is the place where most onboard emergencies are controlled and dealt from.

Probably the most important piece of monitoring equipment in the safety centre is the fire alarm system.

Onboard the Sun Princess, every space is fitted with a smoke, heat or flame detector, and most spaces including all passenger and accommodation spaces are fitted with water sprinklers. If any of the above are activated, this is indicated on the display giving the exact location of the alarm both on a plan of the area and as a written text address. If an alarm is activated we can then investigate and if necessary deal with the problem if one exists.

In the event of a fire onboard we can also slow down it's advance and reduce the spread of smoke from the safety centre. This can be done by closing down a section of fire retardant doors which will not only slow the spread of fire but reduce the spread of smoke. We can also close down and isolate sections of ventilation thus further reducing the spread of smoke and fire. These systems are both controlled and monitored from the Safety Centre on our VDU screens, computers and control panels. Also indicated on the fire door mimic are the ship's side doors. This means that at all times we can determine at a single glance which of the shell side doors are open at anyone time.

Another display and control panel in the Safety Centre is the ship's watertight door control panel and computer mimic display. The ship is, for stability and damage control purposes, segregated into 19 watertight compartments below the deck 4 level. In order to make the normal operation of the ship practical, the watertight bulkheads are fitted with large sliding steel doors. When closed they form a watertight seal in the bulkhead but can easily be opened to allow people to pass through them.

In the event that these doors may be open if an emergency was to occur, they can all be closed from the Bridge in less than a minute. These doors are designed to close under all circumstances even if an object was to block their path by simply cutting through it. As a precaution if the vessel is in a potentially dangerous area or conditions, such as a port approach, in fog or in high concentrations of other vessels, then the doors are all closed and passage through them is restricted.

In the event of the vessel being damaged, we may also want to discharge as much top weight as possible, as quickly as possible. The first option is to empty the swimming pools which contain a vast amount of water very up high in the vessel. This can be done at the flick of a switch from the Safety Centre. From here we can also shutdown the main engines, isolate fuel lines, switch off fuel pumps and so on.

Also from the Safety Centre we can monitor key areas of the ship on our close circuit television system. These areas include the gangway doors, main alleyways mooring decks and the stern of the ship. Another piece of particularly important equipment in the Safety Centre is of course the Public Address system. This enables safety related broadcasts to be made from the location of the emergency command centre.