MB shipbuilders & Engineering Works

02/04/2026

আলহামদুলিল্লাহ
লাহারহাট বরিশাল
Project all most done

06/11/2024

8 TYPES OF MARINE PROPELLERS.

1. FIXED PICTH PROPELLER (FPP)
Is the most common type of Propeller used and manufactured for many years in either mono-block or built-up form.
So that the position of the propeller and the propeller PICTH is fixed. There are 2 types of FPP, namely mono-block and built-up propellers.
Most ships that do not require the ability to move usually use this type of Propeller. The advantage of FPP is that its price is quite economical compared to other types of propellers and its maintenance is quite easy and does not pose an excessive risk.

2.CONTROLLABLE PICTH PROPELLER (CPP)
CPP can provide a level of freedom in its ability to change the PICTH Blade. CPP is a propeller that has a larger hub than the FPP propeller, because the hub must have room for a hydraulic mechanism to control the pitch. CPP is relatively more expensive
Up to 3-4X. Due to the relatively larger hub, the propeller efficiency is slightly lower. CPP is widely used on RORO ships, SHUTTLE TANKER, and similar ships that require high maneuverability, the advantage of CPP when compared to FPP is that this type of CPP can provide better acceleration, stopping and maneuvering. The speed of the ship can be varied without changing the RPM of the main engine, the speed can be controlled directly from the bridge.
However, there are drawbacks, namely the control mechanism
Very complex so it requires more maintenance compared to FPP propellers.

3. DUCTED PROPELLER
This type of propeller can be a fixed or controllable PICTH type. DUCTED PROPELLER has the advantage of increasing propulsor efficiency when high loads occur and has good course stability. DUCTED PROPELLER is commonly called kort nozzles due to the recognition of the initial patent kort porpolution company and found applications over the years where high thrust is required in low speed, DUCTED PROPELLER is commonly used on tug boats, towing tugs and trawlers. Ducting can generally contribute 50% of the total propulsor thrust at zero ship speed, the so-called bollard pull condition. However, the relative contribution of this duct will drop to a smaller amount with increasing ship speed and can also make a negative contribution to propulsive thrust at high forward speeds.

4. AZIMUTH PROPELLER
is a configuration of marine propellers housed in pods that can be rotated to any horizontal angle (azimuth), so that steering is no longer required. This system provides better maneuverability for the vessel than a fixed propeller and rudder system. Mechanical transmission, which connects the motor in the vessel to the outboard unit with gears. The motor can be either diesel or diesel-electric. Depending on the shaft arrangement, mechanical azimuth thrusters are divided into L drive and Z drive. L drive thrusters have a vertical input shaft and a horizontal output shaft with one right-angled gear. Z drive thrusters have a horizontal input shaft, a vertical shaft in a rotating column, and a horizontal output shaft, with two right-angled gears. The main advantages are better maneuverability, better use of ship space, and lower maintenance costs. The main disadvantage of azimuth drive systems is that ships with azimuth drives maneuver differently than ships with standard propeller and rudder configurations, thus requiring special pilot training.Another disadvantage is that they increase the draft of the ship.

5.CONTRA ROTATING PROPELLER (CRP)
Contra rotating is a type of ship propeller that consists of two propellers rotating in opposite directions. In this design, one propeller is mounted in front of the other and works by utilizing the opposite direction of rotation, allowing the vessel to generate greater thrust with high efficiency. As a result, the use of this type of propeller allows the vessel to achieve high speeds with optimal performance. By placing the second (rear) propeller on the same thrust shaft as the first (front) propeller it gains a number of additional advantages including that the second (rear) propeller can recover the slip stream rotation caused by the first (front) propeller.

6.OVERLAPPING PROPELLER
This type of propeller divides the load between two existing propellers where there are two propellers with their shafts placed at a horizontal distance less than the diameter of one propeller to another (not parallel).
This type of propeller is still largely limited to research and development and is rarely used in ship practice in the field. Overlapping propellers are considered to provide higher hull efficiency because they work in areas of high time. The drawback of overlapping propellers is that sometimes the interaction between propellers can produce more cavitation.

7.TANDEM PROPELLER
The tandem propeller has two propellers mounted on a single shaft rotating in the same direction. The main purpose of using this propeller is to ease the loading situation on the propeller.
Tandem propellers are installed to reduce the load on a single propeller as it can cause cavitation.
Here the thrust is shared between the two propellers. In normal loading, this is not much use but in moderately heavy loading, this propeller produces better loading than a single propeller. generally, the same size and number of blades.
The disadvantage of tandem propellers when compared to a single propeller is that the weight and axial distribution of the propeller creates a large bending moment that can give losses especially in the strean tube bearing. However, some azimuthing and pod propulsor arrangements use this arrangement by having propellers located at each end of the propulsion shaft, on either side of the pod body. In this way the load is shared by the tractor and pusher propellers and the moment of the shaft at the induced weight is controlled.

8.CYCLOIDAL PROPELLER (VOITH-SCHENIDER PROPELLERS) (VSP)
Basically it consists of a horizontal blade that rotates on a vertical axis. The obvious advantage of this type of propeller is that it can provide good maneuverability on the ship, this type of propeller consists of a circular blade with an arrangement of 5 foil-shaped vertical blades. The plate is attached to the bottom of the ship and rotates vertically. Internal gears change the angle of attack of the blades synchronously with the rotation of the plate, so that each blade can provide thrust in the same direction. VSP makes the ship highly maneuverable because the thrust can be adjusted arbitrarily in magnitude and direction without changing the engine RPM, almost instantaneously.

04/11/2024

Spherical tanks, called Moss-type tanks, are used on LNG (liquefied natural gas) carriers to store LNG at very cold temperatures, usually around -162°C.

These tanks were developed by Moss Maritime and have a round shape, which helps them stay strong by spreading stress evenly across their surface. This design also reduces heat transfer, helping to keep the LNG cold and minimizing the amount that turns back into gas.

The tanks are made from materials like aluminum or 9% nickel steel because these metals can handle extremely low temperatures.
Each tank can store tens of thousands of cubic meters of LNG, and most LNG carriers have four to six tanks, depending on the size of the ship.

The tanks are partly inside the ship, with the top part sticking out above the deck, which helps with stability and protection. Moss-type tanks are popular in the industry because they are efficient and safe to use.

30/10/2024

HOW SHIPS ACTIVITIES IMPACT THE ENVIRONMENT:

Ships are essential for global trade and travel, but they also have significant environmental impacts. Let’s break down the key systems on board and their effects on our oceans and air:

~Inputs to the Ship:

●Fuel Oil: Powers engines and generators.

●Lubricating Oil: Reduces wear in machinery.

●Air: Needed for engine combustion and ventilation.

●Sea Water: Used for cooling and ballast.

~Outputs from the Ship:

●NOx Emissions: Nitrogen oxides from combustion, a contributor to air pollution.

●SOx Emissions: Sulfur oxides, which contribute to acid rain.

●CO2 Emissions: Greenhouse gases that impact climate change.

Daily Consumption: Energy and resources used during operation.

~Discharges from the Ship:

●Sewage & Grey Water: Wastewater from toilets, sinks, and showers.

●Ballast Water: Taken in and discharged to maintain stability, potentially introducing invasive species.

●Garbage Disposal: Regulated to minimize ocean pollution.

~Hull Leaching: Substances from anti-fouling paint that can harm marine life.

●Regulations in Place:

Annex I: Limits oil discharge.

Annex IV: Controls sewage discharge.

Annex V: Regulates garbage disposal.

●Ballast Water Management Convention: Oversees ballast water exchanges.

●Anti-Fouling Systems Convention: Controls harmful substances leaching from hulls.

It’s essential to manage these inputs and outputs to protect our oceans and environm

29/10/2024

What is Bilge and Ballast Eductor On a Ship?

An eductor on a ship is a pump that moves liquids without mechanized parts, using Bernoulli's principle and the Venturi effect. It works by creating a pressure drop, causing one fluid to draw another into a chamber, mixing them before expelling the mixture. Eductors are used for tasks such as stripping cargo oil tanks, removing sludge, and dewatering. Careful operation is essential to avoid backflow or pressure issues, particularly when working with different fluids like oil and water.

Dagdag kaalaman sa mga tropa nating kubyerta boys..once na set up na yung Eductor OK na yung driving water at nagka suction na tpos nawala yung suction pag lipat nyo nang suction valve for other tanks..hindi yan sa makina yung problema..nasa kubyerta yan.

Minsan tawag kayo sa oiler para eh reset yung Eductor..wala nmn kming gina galaw doon sa makina kasi nga driving water yan..so double check nyo baka may bukas kayong valve sa ibang tangke nyo or cargo hold bilge.

Thank you po 😊😁

27/10/2024

The Types of Ship Motions at Sea and Their Effects

When cargo ships travel across the sea they are subjected to six types of ship motions due to wave action.

There are six general types of ship motions
The six types of wave action motion are constantly applied to the ship in varying degrees as it travels across the water. This complex interaction of motions is why sailors often find it difficult to walk on a deck.

Ship motions occur along the vertical, transverse or longitudinal axis, or around the center of gravity for the ship. They are made up of three lateral movements and three rotations. The six ship motions are:

Heaving: vertical movement
Swaying: transverse movement
Surging: longitudinal movement
Rolling: longitudinal rotation
Pitching: transverse rotation
Yawing: vertical rotation

26/10/2024

What is Tri-Fuel Propulsion, and why is LNG used in ships to reduce emissions?

Tri-fuel propulsion allows ships to burn three types of fuel: LNG , diesel, and heavy fuel oil. LNG is preferred because it burns cleaner, producing fewer emissions like sulfur oxides (SOx), nitrogen oxides (NOx), and carbon dioxide (CO2), which helps ships meet stricter environmental standards. Ships with tri-fuel engines can switch between fuels based on cost, availability, or environmental regulations.

Using LNG requires modifications to the ship’s fuel system, such as specialized tanks for its extremely low storage temperature (-162°C) and adjustments to the engine. Despite some challenges, like limited LNG refueling infrastructure and retrofitting costs, LNG reduces harmful emissions compared to diesel or heavy fuel oil.

Tri-fuel propulsion provides flexibility, enabling ships to reduce emissions by using LNG when available, while still having the option to use other fuels. As LNG infrastructure grows and environmental regulations tighten, tri-fuel engines are becoming a popular solution for greener shipping.

22/03/2018

Vacancy for Marine Diploma . Minimum Exp-03 years

13/10/2015

09/08/2015

i lost my mobile memory, plz give me ur phn number inbox or time line

22/12/2014

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