Marine Engineering and Naval Architecture

Scantling Length (L) L is the distance in meters (feet) on the summer load line from the fore side of the stem to the centerline of the rudder stock. For use with the Rules, L is not to be less than 96% and need not be greater than 97% of the extreme length on the summer load line. The forward end of L is to coincide with the fore side of the stem on the waterline on which L is measured. Freeboard Length (Lf) Lf is the distance in meters (feet) on a waterline at 85% of the least molded depth measured from the top of the keel from the fore side of the stem to the centerline of the rudder stock or 96% of the length on that waterline, whichever is greater. Where the stem is a fair concave curve above the waterline at 85% of the least molded depth and where the aftermost point of the stem is above the waterline, the forward end of the length, Lf, is to be taken at the aftermost point of the stem above that waterline. In ships designed with a raked keel, the waterline on wh...

Before application of proof test load, the anchors are to be visually examined, and all defects are to be removed, and if necessary repaired by welding, prior to testing. Proof tests are to be carried out on all anchors after being temporarily assembled. The proof tests are to be in accordance with the values given in Table. The proof load in accordance with Table is to be applied on the fluke at a location one third of the distance from the tip of the fluke to the center of the crown as shown in Figure. In the case of stockless anchors, both arms are to be tested at the same time, first on one side of the shank, then reversed and tested on the other. After proof load testing the anchors are to be examined for cracks and other defects, and for excessive deformation due to seating. Upon completion of the proof load tests, anchors made in more than one piece are to be examined for free rotation of their heads over the complete angle. The anchor shackle that underwent proof load t...

After having found the equipment numeral from previous blog , the details regarding sizes and quality  may be obtained from the rigging tables provided in these regulations. From these table , we can find the following information The Equipment Letter Stockless bower anchors number of anchor Mass per anchor (kg) Stud-link chain cables for bower anchors Total length (m) Grade and Diameter (mm) of chain CC1———— low  strength. CC2———–medium strength. CC3———–high strength Towline Minimum length (m) Minimum breaking strength (KN) Mooring Lines Number Length of each mooring ropes (m) Minimum breaking strength (KN)

The equipment number, EN, on which the requirements of equipment ship anchor are based is to be calculated as follows :- EN = K * ENc where, ENc = Δ^2/3 + 2BH + 0.1A where, Δ = moulded displacement, [t], to the summer load water line. H = effective height, [m], from the summer load waterline to the top of the uppermost deck-house, to be measured as follows: H = a + Σhi a = distance [m] from summer load waterline amidships to the upper deck at side. hi = height [m] on the centreline of each tier of houses having a breadth greater than B/4. For lowest tier, hi is to be measured at centre line from the upper deck, or from the notional deck line where there is a local discontinuity in the uppers deck. A = area [m2] in profile view of the hull, superstructures and houses above the summer load waterline, which is within the Rule length of the vessel. Houses of breadth less than B/4 are to be disregarded. In the calculation of H and A, sheer and trim are to be ign...

The Volume of Displacement is the quantity of water required to fill the molded shape of the hole left by a ship, if she were lifted out of the medium in which sheep floats. It should be noted that the Ship’s Displacement maybe expressed in either terms of ton weight, or measured capacity in cubic foot. And it should be noted also that Salt and Fresh water are different to each other; and we can float more easily in Salt Water (sea, ocean) compare to Fresh Water (swimming pool, river). The Coefficient is expressed as a decimal and varies from about .5 in the case of five lined yachts, gradually increasing through .6 to .75 in the case of fast passenger steamers and to .85 for slow, bluff, cargo type of vessels. The Formulas to find Ship or Vessel Displacement in either Sea Water or Fresh Water: Sea Water Displacement Formula: Displacement (Tons) = L x B x D x C / 35 Displacement (Cubic Foot) = L x B x D x C / 0.9912 Fresh Water Displacement Displacement (Tons) =...

The American Bureau of Shipping is authorized to assign Load Lines to vessels registered in the United States and other countries. Requests for the assignment of Load Lines are to be made on forms which will be furnished by one of the offices of ABS. The center of the ring is to be placed on each side of the vessel at the middle of the length, as defined in the Load Line Regulations. The ring and lines are to be permanently marked, as by center punch, chisel cut or bead of weld. AB American Bureau of Shipping TF Tropical Fresh Water Allowance  F Fresh Water Allowance  T Load Line in Tropical Zones S Summer Load Line  W Winter Load Line  WNA Winter North Atlantic Load Line 

Ships come in various descriptions and have hundreds of thousands of components, but there are a few parts that are common to all ships. In this guide, you can learn about how the basic parts of ships have evolved over the centuries. From floating vessels made of wood to ultra-modern cruise ships, the evolution in design and architecture of ships have come a long way. However there are a few parts that are and will always be common to ships (or rather sailboats or floating vessels) from those that were built 4000 years ago to the newest cruise ships that are nothing less than floating cities. Parts of Ships Common to All Ships Body of the Ship or The Hull: The hull of a ship is responsible for the floatation property of the ship. Generally ships are single hulled (monohull design). It's only other vessels like catamarans (two hulls) and trimarans (three hulls) that have more than one hull to keep it afloat. It is the hull that houses the engines that to which the propel...

If you are going to work in the shipping sector or have a general interest in sailing the seas then you might want to know what different types of ships there are. You may come across a wide range of different vessels and it’s useful to be able to identify them when you are out at sea. It is also important to note that safety regulations vary a lot depending on what type of ship you are operating. Each type of vessel has its own strict regulations that must be followed. Working on each type of ship can also be completely different, so it’s definitely worth doing your research before you apply for a job. For example, working on a fishing vessel is a completely different experience to a cargo ship. Marine industry experts and experienced sailors will have a good idea of the different types of ship. If you are new to the industry then here are some of the main types of international ships that you will probably come across on your travels. 1. Cargo Ships Cargo ships are generall...

Although everyone knows the difference between a boat and a ship, there are quite a few person who often get confused between the two terms a boat and a ship. Technically, there is a very thin line between them and this often leads to a major confusion between them. While talking about difference between a ship and a boat, the first thing that comes to one’s mind is their sizes. Traditionally people consider a ship as a large ocean going vessel, whereas boats are comparatively quite smaller in size. To understand the differences between ships and boats, a number of aspects need to be taken into consideration. Mentioned below are seven main aspects which are taken into account to differentiate between a ship and a boat. 1. Size The most important aspect that is considered while stating the difference between a ship and a boat is the size. It is said that the best way to differentiate between a ship and a boat is to remember that “A ship can carry a boat, but a boat can...

A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying passengers or merchandise, or in support of specialized missions, like defense, research and fishing. traditionally, a "ship" was a sailing ship with a minimum of 3 square-rigged masts and a full bowsprit. Ships are usually distinguished from boats, based on size, shape, load capacity, and tradition. Ships are necessary contributors to human migration and commerce. they have supported the spread of colonization and also the slave trade, but have additionally served scientific, cultural, and humanitarian needs. after the fifteenth century, new crops that had come from and to the americas via the european seafarers considerably contributed to the planet population growth. Ship transport is responsible for the largest portion of world commerce. As of 2016, there have been more than 49,000 merchandiser ships, totaling nearly 1.8 billion dead weight tons. ...