UNIT FOUR TEXTS, TASKS AND PROJECT NAVIGATION - Navigation - Anchoring, Berthing, Leaving berth and Underway - Buoyage - Loading, Discharging & Trim - Project: Pilot Reading Glossary and Practice
Navigation Introduction By navigation is understood any act or procedure that will ensure the safety of passengers and crew, vessel and cargo during a voyage from a point of departure to a destination. This safety is greatly determined by good seamanship. And since good seamanship refers to The Human Factor (HF), it is obvious that the influence on safety on board vessels is largely determined by acts of the seafarers on board. Therefore the manning of a vessel must be planned very accurately, and because most vessels are manned with multi-lingual crews, special attention should be paid to the internationally standardized form of maritime communication, both intership and intra-ship. Manning All vessels have one thing in common: they must be manned by qualified crews. On board vessels the two main departments are the deck department and the engine room department. The radio department is often integrated in the deck department. The head of the deck department is the first mate - or Chief Officer. The Chief Engineer is the head of the engine room department. Officers are assisted by ordinary seamen and able (bodied) seamen (OS and ABS). An "able seaman" is an experienced seafarer. He or she will often act as man-at-the-wheel (helmsman), or lookout. The boatswain, or bosun, is the head of the ratings (OS and ABS). Apprentice officers are officers in training. Nowadays many vessels are manned with General Purpose Officers - or Multi- Purpose Officers - who have been trained to perform the duties of the mate, engineer and radio operator together. Duties Of course the main responsibility of all the deck officers on merchant vessels is navigation, i.e. getting the vessel safely to her destination. There are many other duties to be performed in the deck department. The first mate is responsible for making up the stowage plan, supervision of loading and discharging of the cargo and general ship's maintenance. The second mate is responsible for the navigational equipment. The third mate will often act as safety-office. He or she is responsible for the maintenance of all the safety equipment on board. The main duties of the Engineering-Officers in the engine-room department are the maintenance and overhauling of the main engine and the auxiliary-engines.. The captain, or master, is ultimately responsible for all that goes on aboard the vessel. Usually he has not been integrated in the watch-keeping system on the bridge. If he thinks it necessary to appear on the bridge and interfere with the work of the officer of the watch (OOW), or if the master is called to the bridge by the OOW, he must clearly indicate that he will become the conning officer by saying: "I now have the watch". To confirm this, the OOW will then answer: "You now have the watch". The tasks of the radio operator are to contact shore based stations and other vessels in cases of distress, to transmit urgency messages, safety messages when there are imminent dangers to navigation, to listen to Notices to Mariners, weather reports and navigational warnings and to maintain contact with other ships for a safe and efficient voyage.
Watchkeeping The 24-hour-period on board the vessel is divided into 6 shifts, or watches, as they are called. Each watch lasts 4 hours. The watches are: First watch (2000 hrs-2400 hrs) Middle watch (0000 hrs - 0400 hrs) Morning watch (0400 hrs-0800 hrs) Forenoon watch (0800 hrs - 1200 hrs) Afternoon watch (1200 hrs - 1600 hrs) Evening watch (1600 hrs - 2000 hrs). The evening watch is often divided into two watches of 2 hours each to allow everyone to enjoy the evening meal. These two watches are called the first- and second dogwatch. The Radio-operator keeps watch four periods of two hours a day. One of the watchkeeping-systems that is used in the deck department aboard sea-going vessels is the "4-12-8" system, whereby the first mate stands all four-o'clock watches, the second mate stands the twelve-o'clock watches and the third mate stands the eight-o'clock watches. The captain will often join the third mate, since the third mate is usually the least experienced officer. Heading, course, track and drift By heading is understood the direction in which the vessel is pointing. It is the angle between the fore-and-aft line of the vessel and True North, expressed in degrees. Heading constantly changes due to sea and wind influences and steering errors. By course is understood the intended sailing direction of the vessel. In other words: it is the direction in which the vessel is steered in order to reach her destination (B). It is expressed in degrees. A track consists of one, or a number of course lines along which the navigator intends to proceed for a safe passage, e.g. when clearing a danger. A great circle course will form the shortest connection between two places on the earth. A Rhumb Line, or loxodrome, will form a line whereby all the angles made by the course line and the meridians are equal. This implies that in (Mercator) sea charts the earth is not a sphere, but a square. Composite sailing combines the advantages of the great circle and the rhumb line: it will offer the shortest route, while the vessel can keep constant true directions. Due to the influences of wind and current the vessel's destination will not be reached with out any alterations of course. If the influences of wind and current are not taken info consideration she will not reach her destination (8), but will follow a line (A - C) called course over ground. If allowances are made for the effects that are caused by wind and sea, the vessel will follow a line called course made good.
Position The vessel's position can be determined in a number of ways, for example by means of pilotage (coastal navigation), cross bearings, a cocked hat, a running fix, dead reckoning, astronomical navigation or satellite. The vessel's position may be indicated by a latitude/longitude-reference, or as a bearing and distance from a fixed point. In VHFcommunication and written reports the latter position-indication must always be preceded by the word "bearing". Positions are expressed in degrees and minutes. Distances are indicated by nautical miles (1852 metres) and cables (one tenth of a nautical mile - 185.2 metres). Pilotage (coastal navigation) When sailing along the coast, compass bearings of conspicuous objects are taken at regular intervals. A conspicuous object (conspic) is an object on land or at sea that is mentioned and described in the pilot book. Cross bearings form an intersection of two bearing lines that have been taken of two conspicuous objects. If a third conspic is available, a third bearing ("check line") can be taken. Because the vessel is proceeding, the two bearing lines and the check line will form a triangle, called a cocked hat. The ship's position is in or at the cocked hat. Running fix A "running fix" is made when there is only one conspicuous object available. It is dane by taking two bearings of the same conspic at interval. (The angle between the two bearing lines must be > than 30 degrees). Example The first bearing is taken at 16.50 hrs. Log-reading: distance travelled = 380 nautical miles. The second bearing is taken at 16.55 hrs. Log-reading: distance travelled = 381 nautical miles. The difference between the first log-reading and second log-reading is 1 mile. Now, with the aid of chart dividers, "1" is measured from the chart scale at the side of the nautical chart and transferred to the course line. The position of the ship is at the intersection of the second bearing line with the line that runs parallel to the first bearing line.
Dead Reckoning "Dead Reckoning" is determining (reckoning) one's position by deduction. In other words: finding one's position by taking into consideration a number of standard data: - last known position and time - course and speed - sea and weather conditions. The expression "dead reckoning" is not spelt correctly. "Dead" should actually be spelt "ded" as an abbreviation of deduced. Astronomical Navigation With astronomical navigation, or celestial navigation, observations are taken of celestial bodies (the sun, the moon or the stars). With a sextant the angle between a celestial body and the horizon is measured. Now with the aid of the chronometer and the tables in the nautical almanac the ship's position can be determined. (This way of fixing a position is quite obsolete. However, it comes with good seamanship and should never be deleted from maritime studies). Satellite Navigation & Radio Navigation. In the (Differentia~ Global Positioning System a signal is transmitted from the satellite. Within the shortest possible time the ship's position is determined by data received from the satellite, and shown on the GPS- display on the bridge. Depth The depth of the water must always be determined accurately. In areas where shoaling has been reported, in restricted- and inshore waterways, in harbours and ports, and in areas of which the navigator does not have any local knowledge, the risk of going aground is always imminent for deep draft vessels and very often shallow draft vessels, too. Furthermore the navigator should always be aware of the fact that charted depths may sometimes be unreliable and must be increased or decreased due to sea states, swells and winds. Therefore Notices to Mariners should be studied carefully and regularly to avoid grounding due to insufficient depths of water or an unexpected tide below prediction. Places where depths are maintained by regular dredging-operations are indicated as areas with controlling depths. These depths are always very reliable. The old-fashioned way of sounding (determining depth of water) is by means of the handlead. Nowadays the most common way to determine depth is with the aid of the echo sounder, whereby a signal is transmitted to the seabed. This signal "bounces" back and is received again by the echo sounder. From the time elapsed between transmission and reception of the signal, the depth of the water can be determined. Protruding obstacles on the seabed, such as wrecks and rocks, are not easily detected by the sound signals. Therefore the depth over a protruding obstacle is obtained by wire sweeping, whereby a cable is swept over the seabed between two survey vessels. This routine is continued until the wire will experience no resistance from any obstacle. Now the depth of the specific position can be determined and recorded.
Directions The terms that are used to indicate directions of proceeding are: starboard, port, ahead and astern. These terms are used in helmorders and engineroom orders to indicate in which direction the vessel must be steered. Helmorders ("Starboard 5!", "Port 10!", "Midships!", "Steady!" etc.) and engineroom orders ("Full ahead!", "Dead slow astern", etc.) are given by the mate to the helmsman and must be repeated by the lafter before they are actually executed. To indicate directions towards the vessel, e.g. when a pilot, gale or Tsunami is approaching the vessel, the terms "on", "before" and "abaft" are used, followed by the appropriate section of the vessel. Like so: on the stem/stern, on the starboard bow, on the port quarter, before the starboard beam, abaft the port beam, etc. Directions that indicate the position of other vessels, objects or dangers with respect to our own vessel are indicated by the words starboard, port, ahead and astern. ("I will overtake you on your starboard / port side" / "wreck ahead of you" / etc.). However, due to technical restrictions of the radar, a VTS-operator will not always be able to determine a vessel's heading and course exactly. The exact positions of two vessels with respect to one another are even more difficult to assess. Therefore the use of the terms "starboard / port / ahead / astern" must be avoided. In stead, VTS-operators must use "cardinals "and "half-cardinals" to indicate positions and directions. Like so: "Shallow waters to the North of you"; "Vessel overtaking to the Southeast of you"; "Uncharted shoal to the West of you"; "Obstruction to the Northwest of you.
Navigation: tasks 1) Idioms The italicized words in the text are given below in alphabetical order. Find out what they mean as they appear in the text and learn them by heart.
Notes:
2) Manning, duties and watchkeeping ("4, 12, 8 system") Match the descriptions, duties and watches with the officers and crew by filling in one letter (A, B, C, etc).
3) Heading, course and track: Fill in...
4) Position Oral practice: - every number must be pronounced separately. - "point" is pronounced as "decimal" (2.5 = two - decimal - five) - be fluent in your pronunciation; every mistake, however little, must be corrected by the phrase "mistake correction", followed by the correct position. 51 DEGR. 29 MIN. N / 047 DEGR. 53 MIN. E. 134 DEGR. FROM BUOY NHR-SE, DISTANCE 0.6 MILES. 159 DEGR. FROM FALLS LIGHT, DISTANCE 2.4 MILES. 49 DEGR. 8 MIN. N / 013 DEGR. 5 MIN. W 178 DEGR. FROM ROYAL SOVEREIGN LIGHTHOUSE, DISTANCE 4.1 MILES. 250 DEGR. FROM BUOY CA 4, DISTANCE 1.2 MILE. 68 DEGR. 27 MIN. N / 039 DEGR.53 MIN. E. 025 DEGR. FROM ALlCE BUOY, DISTANCE 2.5 MILES. 46 DEGR. 29 MIN. S / 018 DEGR. 53 MIN. E. 158 DEGR. FROM THE BASSURELLE, DISTANCE 1.5 MILE.
5) Position Cross bearings and coocked hat - Fill in:... X =... a =... b =... c =... d =... - Finish the sentence A "conspic" is... The ship's position is... A triangle of 2 bearing-lines and 1 check line is formed, because... Running Fix - Fill in:... X =... a =... b =... c =... d =... A running fix is made when there is only one... The second bearing is taken at 16.52 hrs.;... is 847 miles. The difference between the first and the second bearing is 2 miles. This distance is... to the course line with the aid of... The position of the ship is at the... of the line that runs parallel to the... and the second bearing line.
6) Order of events ("Running Fix") Indicate the order of events by filling in A, B, C, etc. A - Measure mileage by means of log-reading. B - Determine the position of the Conspic. C - Proceed on ground course. D - Take first bearing. E - Take second bearing. F - Determine the intersection (ship's posn.) of the parallelline with the 2nd bearing line. G - Transfer mileage to course line. H - Determine the angle between the two bearing lines (> 30 degr.). I - Draw a line parallel with the 1 st bearing line through transfer-point. 7) Directions Match the numbers ("expressions") with the letters ("directions")
8) Depth and Draft: matching Match the reports on groundings with the causes by filling in A, B, C, etc.
9) CD-ROM Tests: Navigation Test 1: Fill in the missing word(s) 1-2 - 3-4 - 5-6 - 7-8 - 9-10 - _ 11 - _ 12 - _ 13 - _