Estimating ship's powering 

L.K. Kupras' method 

At the initial stage of a ship's design a propulsion power estimation is to be done to ascertain that the vessel can sail at the specified speed. As the ship design development progresses, models tests are usually performed in a hydrodynamics tank, which serve to optimize the hull form, adjust the propeller(s) design and ensure the speed/power prediction for a proper choice of the propelling engine(s).

¿ How much does a ship weigh ?

Archimedes' principle

This question is deliberately ambiguous and what intends to ask is how can you get the weight of a ship, referring, of course, to a large ship, that can not be placed on a balance. It also refers to the weight of a real floating ship  already built and it is not considering here the weight estimation during the ship's design phase.

Safe Return to Port

Jaime Oliver's lecture in RINA

At the end of last February an international conference entitled "Design and operation of passenger ships" was held in London, at the RINA's headquarters (Royal Institution of Naval Architects), whose 52 lecturers from 10 countries developed, in 14 papers, a series of new ideas and thoughts on the development of ships technology. 

Ballast-free ships

In the realm of ships, ballast is a fixed or transitory weight that must be placed on board to solve or alleviate what I name " ballast-related problems" (BRPs), what means those problems that can fixed by using ballast. For example, BRPs are a poor ship's stability, insufficient or inadequate drafts, propeller(s) incomplete immersion, excessive ship movements at sea, etc.

Triality: An innovative project of VLCC tanker 
 Accomplished by Det Norske Veritas (DNV)

In early December Classification Society DNV published a preliminary information on his new project, named Triality,  a VLCC size tanker (aprx. 300.000 TPM) embodying a number of features that show it as an innovative oil tanker, emphasizing its ecological character, non-polluting the environment, sea and air, all at a lower operating cost than a conventional tanker of same capacity.

Lloyd's Register's 250th anniversary

Lloyd's Register is a ships classification society widely known in all marine shipping areas, which this year is celebrating its 250th anniversary, so I join the chorus of congratulations from the whole maritime family with my wishes they continue working for many years in their usual fields, and in those that technological progress will gradually be opening.

 

 

"Oliver Design" at Basque Television (Euskal Telebista)

Euskal Telebista (ETB), the Basque TV society, has issued on July 31 and August 1, within his channels ETB1 and ETB2, in Euskera and Spanish respectively, as a part of his Kresala program, a report about the ship design firm  "Oliver Design", of my friend and colleague Jaime Oliver.

Ships to install offshore wind generators

The European Union has plans to expand electric production by wind turbines up to 20 percent of total production in 2020, Spain being one of the leading countries in installed capacity of such generators located onshore.

Recently they have begun to install wind turbines at sea in areas up to 200 miles offshore and at not excessive depths, outstanding this kind of parks in North Sea countries. These "off-shore" generators solve some of the problems arising onshore, as noise, visual aesthetics, environmental opposition, and they get too a better use of wind power, which is greater at sea than onshore, and also allow for larger power / sizes, with better economic performance.

Merchant ships preliminary dimensioning

In the form that appears below the user indicates the type and size of a merchant ship whose main features wants to know and getting in response, a preliminary approximation of the same.

This estimate is based on statistical analysis and regressions (Ref.1) of ships dimensions, being actual ships or  designed projects, linking each of the characteristics of the ship with a single parameter describing her size ( deadweight, cargo volume, number of containers etc.). The resulting characteristics should therefore be considered as a first approximation only, which will give an idea of the characteristics of the new project or will serve as an initial basis for a more detailed definition by usual design procedures (Ref.2).

Estimating Ship's Gross Tonnage

On a past post I explained a simplified method to do an aproximate estimation of a ship's gross tonnage and an exact calculation of the compensated gross tonnage. Herein I enclose a simple input form to enter ship's main dimensions that produce results as explained in the mentioned past post.

Gross Tonnage GT, Compensated Gross Tonnage CGT

 

If you know the actual gross tonnage just input its value in the text box (cyan color), and click button "Calculate". If you don't know the actual gross tonnage, input ship's dimensions and click "Calculate"

Ship type  Bulk carrierOil tankerChemical tankerProduct tanker General cargo Coaster ReeferLPG carrier Container carrier

Gross Tonnage GT:
Length PP (m):
Breadth (m):
Depth (m):
Block coefficient:

Result GT

Result CGT

Naval Architects from Basque Country inaugurate a new managing board

On First day of December, on proceeded to confirm the appointment of the new members of the managing board of the COIN  Delegation in the Basque Country, for a further period of four years, in a simple ceremony held at hotel Igeretxe, Getxo, with an associates assistance  rather large for what is usual in such a kind of event.

Panama Canal enlargement

It has recently been published some news about the approval by the Government of Panama of an enlargement of its maritime Canal between the Atlantic and Pacific oceans. This project has had several years of preparation and the final approval required a referendum from the citizens of Panama, as stated by its Constitution. The completion of the works is planned for late 2014, one hundred years after the opening of the Canal, whose project was initiated by the French engineer and diplomat Ferdinand Marie de Lesseps.

The enlargement includes several types of performances but the most visible from the naval engineering point of view is the building of new locks at both ends of the Canal, of greater length and breadth than the current ones, to allow an increase of the maximum length and breadth of vessels which can enter these locks, that are currently 294,10 m and 32,20 m respectively. The maximum ship breadth allowable in the enlarged locks, will be ab. 53,50 m, which will increase the size of ships able to transit through the Canal. Details of the award of this locks enlargement work can be read in Ref. (1), where it is reported that the Consortium winning the competition open to select a contractor, presented an offer of 3.220 million USD.

Ship tonnage: Its use and  an aproximate calculation method.

DEFINITIONS


The concept of ship tonnage is related to her size or volume, but it is not a physical particular than can be expressed in any measurement unit, but it is the result of some calculations performed with the ship's dimensions by applying a set of agreed rules.


Until recent times the words ship tonnage were suggesting that they referred to a weight when actually it is a volumetric concept. Ship tonnage nowadays is adimensional.


There are three tonnage classes: Gross, Net and Compensated gross