Vessel Part Names
Created | Updated Aug 15, 2015
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Vessel-\ Types | Part Names | Hull Shapes | Navigation | Stationary /\ Propulsion | Hydrodynamics | Rigging | Foils | Sailing / |
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This is a general description of the parts of any vessel. Some vessels have these parts as recognisable ojects. In other vessels the name merely suggests about what location you are talking. Also several vessel related motions and dimensions are explained.
The hull, is the entire enclosure making a vessel watertight, including the deck. Most often made by large sheets of material and though contributing to the structure of the body not the most essential structural part.
The bow is the front part of the vessel. The part above the waterline is most often sharp and overhanging to deflect waves. On or below the water line modern sea freighters will have a bulb, this is to break waves and to increase the waterline length.
The stem is the sharp frontal edge, originally the beam connecting the hull plating.
The stern or aft is the rear part of the vessel.
The transom is the part of the hull at the stern this is often flat but it can be inward or outward rounded, spoonshaped or as sharp as the bow.
The stempole if present, is the central beam in the stern.
The keel is the central line from bow to stern most often a wooden or steel structural part of the vessel. On many vessels the stem and stempole are part of the keel. Sailing yachts have a keelfin protruding deep into the water.
The part of the keel under the stern is the skeg, most often the deepest part of the vessel and therefore strengtened by (replaceable) material the wormshoe. On single propeller driven vessels the skeg is most likely the support for the driveshaft and propeller.
The water depth required for a vessel to float is the draft or draught.
The bottom is edged with the bilges, this is where the hull curves from near flat to near vertical.
Starboard, right when facing the bow, is where the romans, vikings and many fishing vessel had their steering oar or sweep.
Port, left when facing the bow, is the entrance for pulling in the nets and the side to the quay when docking. For practical reasons many vessels have a preferred side to board and disembark, only on that side the vessel carries a gangway.
The sides or walls of the hull are the boards, known as port and starboard. The uppermost rim of the boards is the gunwale on the outside of the vessel. The inside of this rim is the inwale this is where many attachements can be made, rings for shrouds and sheets, vertical holes for oarlocks or stanchions.
The freeboard is the part of the boards above the waterline when loaded.
From the keel to the rim of the boards there are rib like structures, these are the trusses. Together, the keel and the trusses form the frame of the vessel.
The beam of a vessel is the widest part of the hull. The beam is also the direction perpendicular of the length of the vessel. As you have passed a reference point, it is abaft beam, it is behind the vessel.
The rudder is a blade only attached behind the stern. It is most often hinged above the waterline and on or very near the skeg on the stempole.
Although present on almost any vessel the rudder is not an essential part!
The tiller or helm1 is attached to the rudder. Perhaps the vessel will not tumble over if you give ninety degrees rudder, probably next to nothing happens, the blade will close to the stern and just a little extra drag is created. Consider using the rudder as using a brake on one side, use it with ease, the vessel will turn even if you give just a few degrees. The length of the tiller makes a lever so it is more easy to excert significant forces to the blade. This is often made more easy to control by a wheel, this is connected with chains or cables to an actual tiller somewhere in the stern. The advantage is mainly you now can use the deck at the stern for anything else but the tiller swiming over. The larger a vessel gets, the smaller is the actual control. Modern cargo, navy and passenger vessels only have a small computer interpreted joystick.
The deck is the flat surface, topping off the vessel, also any flat surface for cargo. Often carried by structural beams, also strengthening the boards. These act on larger vessels also as support for watertight walls.
If the deck is lower then the board there are often scuppers in the board to let water off. These will not be in the cargo holds as these decks are preferrably below the waterline.
The space below the deck in the cargo hold is called the bilge. If a vessel takes on water this space is emptied using the bilge pumps. The limber holes connect the compartiments between the trusses. On small vessels a bucket with a rope is used to scoop. A cloth is then used to dry and clean out the edges between the ribs. Aspirant sailors often get the command to dry out the daggerboard case.
Ballast is mainly used to stabylise a vessel, having a total low centre of gravity reduces rolling and enables sailing. The ballast is carried in tanks near the bilges or, in ancient times, just a load of rocks dumped over the keel.
On the forward deck and near the stern you may find cleats small, most often metal fittings with horns used for securing lines. Alternative on larger vessels you will find bitts or pairs of bollards also used to secure lines.
The hawsepipes are holes through the deck and hull enabling anchor chains or hawsers to run through. When the anchor is not in use that hawsepipe will be near covered with the flukes and filled with the shank.
A bunker is the tank used to store fuel oil aboard a vessel, original the bunker was to store coal, later liquid fuel tanks took over the name.
The galley is where the food comes from, the shipboard kitchen. Whether there is not much of an alternative or endless plates of the most luxurious delicacies.
The cockpit is the open wheelhouse from where the vessel is controlled. You will find a cockpit most likely on sailing vessels where a wheelhouse or bridge will be found on motorised vessels. Very large vessels will have brigde wings, spanning above the boards, from where they can see the quay or lock while handling the controls.
Fenders onboard may be small stretched ball shape balloons to keep the prestine white of a yacht really white. On larger vessels huge skippy balls may be used. On many commercial vessels old tyres are preferred, making several perforations in the sidewalls to enable running a rope through it and to enable water to run out. The old tyre is used to make the vessel bounce off of furniture fenders as near locks. Commercial rubber fenders are also available, they are mainly used when the esthetic impact is required. A wooden beam with two holes to run a rope is also often used, this is particular used between two hard flat surfaces, the board and the quay.
Keeping your fenders overboard during sailing is called showing the dirty laundry.
On yachts we wil see lifelines, these are steel lines running along the boards on the outside of the deck, creating a railing. The lines are attached to stanchions. On racing yachts there may be a life line midships, where the crew can attach a harness. On passenger vessels the lifeline is most often a railing made of metal tubing.
The pulpit is not unlike the crow's nest a lookout point. The pulpit is above the bow and was used by whalers to spot and harpoon the animals. The crow's nest is merely for beeing able to look over the horizon. At sea the horizon is about eight kilometres on one metre elevation, as the crow's nest is high up in the mast the horizon may be near 30 kilometres (about 55 nautical miles).
Not so much parts, as well as concepts regarding any vessel
A rolling motion is when the vessel moves one board up, the other down and then the other way. This is most often caused by waves from the side. This motion of swinging of the decks creates the infamous seasickness. The frequency of the swing and the vessel as well as the surrounding making these motions to create an error between your inner ear and your eyes. Try to look at some land or the horizon, this corrects the experienced defect between inner ear and eye.
A pitching motion is when the vessel is climbing over a wave and diving into the trough following the wave. Remember the rule: 'One hand for the ship and one hand for yourself.' or you will fall when you least expect it.
A yawing motion is a change in direction when hit by a wave from the stern. If the waves roll in faster then the vessel sails incoming waves from near abaft will set aside the stern where the following trough will drag the stern back.
Heeling is a static position due to bad loading, making a sharp curve or while sailing. List should be avoided as that is when the heeling is due to bad loading. Perhaps move the heavy load to a lower deck.
The lateral point is a virtual point on the horizontal plane of the vessel where all the underwater forces seem to gather. Applying a force to the lateral point will shift the vessel in the direction of the applied force. Applying a force just afront of it and the bow will turn in that direction. Applying a thrusting force at the stern will give accurate control of where the bow will go, though curves have to be planned and started before you actually make them.
The waterline length is a measure for the maximimum possible speed of most vessels.
Man overboard manoeuvre, is a drill every sailor should know by heart even before touching the rudder. Specially on small vessel leisure cruises it is of the highest importance everyone reacts instead of freezing.
One shouts 'SWIM!' to the drowning person and 'Man Overboard!' this should alert the rest of the crew.
One throws a survival ring, lifebuoy, life vest, something that floats to (not on) the drowning person.
One points to the drowning person from a location the helmsman can see.
The helmsman has made a short curve to enable getting the drowning man on the luff2 side of the vessel.
Essential parts
A radar reflector is a retroreflector, any ray coming in will be bounced back to where it came from. Something like cats-eyes in the road. This is an aluminium shape, three sheets of aluminium interlinked such they make eight threesided cavities. Each of these cavities has all right angles inside and will reflect any radar signal3.
A radio, not unlike a Citizen Band radio system, a free to air communication system with emergency4, official and free channels. The use of such systems requires permits and grades. The local official channel is often displayed at harbor ports, near bridges and locks.
Hawsers, lanyards, lines, ropes and cables for mooring and many other connecting purposes.