Entire Bridge of the Royal Clipper (of Star Clippers Cruise Line) Sailing Yacht (above) – photo by Mimi Auchter
The bridge of any cruise ship is manned 24 hours per day, and is the operational center of the ship. It is manned by highly trained and qualified Deck Officers on a four hours on, eight hours off basis. The watches comprise two Deck Officers and two Able Seamen. The Officer of the Watch is responsible for maintaining continuous visual and audible lookout and taking the ships helm when required. During busy periods (i.e. arrival into port, bad weather or heavy traffic), the manning of the bridge is supplemented by the Captain and Staff Captain.
The bridge is the location of the navigational and primary safety systems on board the vessel. Here is an insight into the purpose of some of the equipment, the operation of the bridge and the work of the personnel who navigate your ship.
The fully integrated bridge system of a cruise ship comprises a series of sensors and items of equipment including: Gyro Compass, speed log, satellite navigation, radar, echo sounder and ECDIS (Electronic Chart Display and Information System). The information from these sources is all displayed on one user friendly console, allowing the Officer of the Watch immediate access to important information.
Second Officer on Extended Bridge Wing of Celebrity Summit – photo by Mimi Auchter
The ships compass is one of the most important pieces of navigational equipment on board. There are 2 types of compasses aboard most cruise ships, a Magnetic Compass and a Gyro Compass.
The Gyro Compass is an extremely sophisticated piece of equipment and consists of a spinning disc rotating in azimuth. It will always point to a point in space above the meridian of the earth which makes it extremely accurate and an error rarely exceeds 1 degree high or low. The Gyro is housed in a separate room, with repeaters on each bridge wing and on the center line. The Gyro Compass is the main aid to navigation. The Gyro Compass is used by the helmsman as a reference for steering the ship and the heading is also fed into the auto pilot system so that the ship may be steered automatically.
The Magnetic Compass is used as a back up and is susceptible to suffer variation and deviation. The compasses are frequently checked for errors by taking a bearing of celestial objects.
The Engine Room
The majority of large cruise ships (like Princess cruise line Grand class) operate using a diesel electric propulsion system – 4 large and 2 small diesel generators for electricity, which is in turn fed to electric propulsion motors which drive each propeller shaft. The diesel generators produce all the power required to run the ships’ facilities such as domestic power, A/C systems and the galleys. The engine room is manned 24 hours a day, just like the bridge, by dedicated engineer watch keepers. The senior engineer mans the control room, monitoring the plant on the control screens, while the junior Engineer will be down in the engine room.
Allure of the Seas Engine Room – Royal Caribbean International
The Chart Pilot
Many modern cruise ships operate on a fully ECDIS (Electronic Chart Display and Information System) compliant system. The Chart Pilot system allows for the ship to be navigated without the means of conventional paper charts and is part of the Integrated Bridge System which allows for the chart and radar to be monitored simultaneously.
Navigation System Chart of Celebrity Summit – photo by Mimi Auchter
NACOS Navigation System
The ship is steered from the bridge in either NACOS (Navigation and Command System) control, automatic or manual control modes. Repeaters from the gyro compass are located on the steering console, together with a magnetic compass read out situated above. The auto pilot is an adaptive unit; it is “intelligent” and learns about how the weather is affecting the ship. It is then able to use this intelligence to control the ships rudders to compensate for the effects of drift, caused by wind and currents. The auto pilot calculates the amount of rudder required for maintaining a set course. This signal is then fed to the ships steering motors which in turn operate the rudders. Rudder angle indicators are located on the steering console and also on both bridge wings, allowing the bridge team to see the required degrees of rudder to apply during a maneuver. A rate of turn indicator is also included on the steering console and is repeated on the bridge wings which allows the bridge team to monitor the rate at which the ships course is changing in degrees per minute.
The NACOS is made up of a group of integrated navigational systems which can automatically guide the ship, adapting to weather and current on preplanned courses and tracks. The track control takes into account wind, set and drift, ensuring the ship follows her set track, constantly correcting herself under the supervision of the Officer of the Watch. The system is also able to follow a detailed time table by controlling the propulsion system.
Underwater Depth and Seabed Chart of Celebrity Summit while in St. Thomas, USVI – photo by Mimi Auchter
Each cruise ship has several primary radars. In the case of Princess Grand class ships, there are 3 scanners mounted on the main navigation mast, one scanner mounted on her bow and one at her stern. These all have a function fitted known as ARPA – Automatic Radar Plotting Aid which allows the navigational officers to “acquire a target” and find out all the relevant information to avoid collision, including bearing, speed, course, CPA (closest point of approach) and time to CPA approach.
Thanks to Princess Cruises for the detailed information above.
See our website cruising page for information about cruise options available from Getaway Dreams Come True Travel Agency. To schedule your personalized Vacation Planning Session, please call 724.752.2655. You may wish to view our other blogs relating to cruising: