R A Rohan Rihat

R A Rohan Rihat Learn Maritime science, Sea life easily.

09/01/2025

I gained 273 followers, created 91 posts and received 11,011 reactions in the past 90 days! Thank you all for your continued support. I could not have done it without you. 🙏🤗🎉

Understanding Common Ship Stresses Ever wondered what kinds of stresses a ship faces while out at sea? Here's a breakdow...
03/01/2025

Understanding Common Ship Stresses

Ever wondered what kinds of stresses a ship faces while out at sea? Here's a breakdown of some key types of structural stress that can impact a vessel’s safety and performance:

1. Sagging: When a ship is loaded more heavily in the middle, it bends downward in the center with elevated ends. This happens when cargo is concentrated amidships.

2. Hogging: The opposite of sagging. The ship bends upward in the middle when loaded more heavily at the bow and stern, causing the ends to sag.

3. Racking: This occurs due to transverse distortion from rolling, leading the ship’s structure to twist about its longitudinal axis. Racking can be particularly challenging in rough seas.

4. Pounding: Common in rough waters, pounding happens when the ship’s bow rises above the water and slams down forcefully. This can cause significant stress to the ship’s hull.

5. Torsion: A twisting motion where the ends of the ship rotate in opposite directions. This can result from uneven loading or waves hitting the ship at an angle.

6. Panting: The hull flexes in and out due to pressure changes as the ship moves through waves. This causes the hull plates to bulge, putting stress on the structure.

Understanding these stresses is key for safe ship design and smooth sailing! Proper distribution of cargo and robust engineering help ensure vessels remain safe even in tough conditions.

Understanding Relative Bearing Relative bearings indicate the direction of an object (in this case, another ship) relati...
28/12/2024

Understanding Relative Bearing
Relative bearings indicate the direction of an object (in this case, another ship) relative to your own ship's heading.
Key Points:
Reference Point: The center of the diagram represents your own ship.
Cardinal Points: The four main directions (North, South, East, West) are not explicitly marked but are implied by the arrangement of the bearing sectors.
Bearing Sectors: The diagram is divided into 32 sectors, each representing a 11.25-degree increment of bearing.
Bearing Labels: Each sector is labeled with a bearing range, such as "On the Port Bow" or "Broad on the Starboard Quarter."
Bearing Reporting: The "Report the Ship" section at the top provides a template for reporting the bearing of another vessel.
How to Interpret the Diagram:
Determine Your Ship's Heading: Imagine your ship's heading is pointing towards the top of the diagram (North).
Locate the Other Ship: Imagine the other ship is located somewhere within the diagram.
Determine the Bearing Sector: Identify the sector in which the other ship is located. This will give you the relative bearing of the other ship.

Example:
If the other ship is located in the sector labeled "On the Starboard Bow," you would report its bearing as "On the Starboard Bow."

Additional Notes:
Abbreviations: The diagram uses abbreviations such as "Stbd" for Starboard and "Fwd" for Forward.
Accuracy: While the diagram provides a general understanding of relative bearings, precise navigation requires more accurate instruments and calculations.
Real-World Application: This concept is crucial for collision avoidance and safe navigation at sea.
Remember: Always refer to official navigation charts and regulations for precise and safe navigation practices.

18/12/2024

Another day at deep ocean.

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The CMA CGM Bougainville is a large container ship built in 2015 by Samsung Heavy Industries. It measures 398 meters in ...
18/12/2024

The CMA CGM Bougainville is a large container ship built in 2015 by Samsung Heavy Industries. It measures 398 meters in length and 54 meters in width, with a deadweight of 185,000 tons. The ship has a capacity of 18,000 TEU (Twenty-foot Equivalent Units) and is powered by an engine that allows it to reach a cruising speed of around 22 knots.

One of the notable features of CMA CGM Bougainville is its use of TRAXENS technology, making it the first container ship in the world to be equipped with this system, which transforms containers into smart, connected objects. This technology allows for real-time tracking and monitoring of cargo, enhancing the efficiency and safety of operations.

The ship operates under the French flag and is part of the CMA CGM fleet, serving on key global trade routes, including those connecting Europe and Asia.

BASIC THINGS TO KNOW🛳🛳🛳Fet.: Main Engine Wartsila 5RT Flex50-B and its parts⚓🛑🚨Disclaimer: The content used in this vide...
30/11/2024

BASIC THINGS TO KNOW🛳🛳🛳

Fet.: Main Engine Wartsila 5RT Flex50-B and its parts⚓🛑🚨

Disclaimer: The content used in this video is intended for educational purposes only.All rights to the images music ,clips and other materials used belong to their respective owners.I do not claim owbership over any other third party content used.

゚viral

Internet on ships navigating the open seas relies on satellite communication technology. Here’s a simple breakdown: 1. S...
28/11/2024

Internet on ships navigating the open seas relies on satellite communication technology. Here’s a simple breakdown:
1. Satellites in Orbit: Ships connect to satellites orbiting the Earth, typically geostationary or low Earth orbit (LEO) satellites. These act as intermediaries between the ship and ground-based internet infrastructure.
2. VSAT (Very Small Aperture Terminal): Most ships are equipped with a VSAT antenna that maintains a connection with the satellite, even as the vessel moves.
3. Signal Transmission: Data from the ship is sent via the antenna to the satellite, which then beams it to a ground station. From there, it connects to the broader internet.
4. Challenges: Satellite internet at sea tends to be slower and more expensive compared to land-based systems due to limited bandwidth, latency, and environmental factors like weather or the ship’s location.
5. Advances: Newer technologies, like LEO satellite constellations (e.g., Starlink or OneWeb), are revolutionizing maritime internet by offering faster speeds, lower latency, and better global coverage.


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Laser Rudder and Tiller Assembly: A detailed schematic of the rudder and tiller mechanism for a Laser sailboat, showing ...
27/11/2024

Laser Rudder and Tiller Assembly: A detailed schematic of the rudder and tiller mechanism for a Laser sailboat, showing the components and their interactions.

Parts of a Sailboat: A labeled diagram of a sailboat's components, useful for educational purposes or novice sailors lea...
26/11/2024

Parts of a Sailboat: A labeled diagram of a sailboat's components, useful for educational purposes or novice sailors learning the terminology.

Why are ballasting and de-ballasting operations important for ships?Ballasting involves taking in seawater into a ship's...
24/11/2024

Why are ballasting and de-ballasting operations important for ships?

Ballasting involves taking in seawater into a ship's ballast tanks to maintain stability, balance, and proper trim, especially when the ship is not carrying cargo. De-ballasting is the reverse process, where water is discharged to adjust the ship’s weight and draft as necessary. These operations are crucial for safe navigation, especially when ships are in ports, during cargo operations, or in rough weather conditions. Ballasting helps to stabilize the ship, keeping it upright and ensuring proper maneuverability.

For example, when a ship unloads cargo, it becomes lighter and more prone to instability. Ballasting compensates for the lost weight by adding water to maintain balance and prevent excessive rolling. Similarly, de-ballasting is necessary when a ship loads cargo to avoid overloading and sinking too deep into the water.

Moreover, proper ballasting and de-ballasting are required when entering shallow ports, navigating canals, or handling adverse weather. Mismanagement of ballast operations can cause a ship to list dangerously or even capsize. Additionally, ballast water can pose environmental threats as it may introduce invasive marine species from one region to another, which is why international regulations like the Ballast Water Management Convention require careful management of ballast operations.

What Prevents Ship from Overloading : THE LOAD LINE MARKINGSThe main components of the load line markings are:Deck Line:...
22/11/2024

What Prevents Ship from Overloading :
THE LOAD LINE MARKINGS
The main components of the load line markings are:

Deck Line: A horizontal line 300 mm long and 25 mm wide, marking the upper edge of the uppermost continuous watertight deck.

Load Line Disc (Plimsoll Mark): A circle 300 mm in diameter intersected by a horizontal line. The center of this circle aligns with the Summer Load Line, and the letters beside the circle indicate the classification society that certified the load line.

Load Lines:

TF (Tropical Freshwater): Indicates the maximum load line in tropical freshwater.

F (Freshwater): Indicates the maximum load line in freshwater.

T (Tropical): Indicates the maximum load line in tropical seawater.

S (Summer): This line passes through the center of the load line disc and indicates the maximum load line in summer seawater.

W (Winter): Indicates the maximum load line in winter seawater.

WNA (Winter North Atlantic): Positioned 50 mm below the Winter load line, it applies to voyages in the North Atlantic during winter months.

These load lines are essential for adjusting the vessel's load based on the density of the water (freshwater or seawater) and the geographical location (tropical, summer, winter, or winter North Atlantic zones). For example, a ship loaded to the Freshwater mark will automatically adjust to the Summer mark when it moves to seawater due to the difference in water density.

The load line marks ensure that the vessel has sufficient freeboard (the height of the ship's side between the waterline and the deck) and reserve buoyancy, which is critical for safe navigation through various sea conditions

What is a controllable pitch propeller?A controllable pitch propeller (CPP) allows for the adjustment of the blade angle...
22/11/2024

What is a controllable pitch propeller?
A controllable pitch propeller (CPP) allows for the adjustment of the blade angle to optimize performance under various conditions, improving efficiency at different speeds and loads. Wärtsilä’s CPP system, for example, enhances propulsion efficiency, reducing fuel consumption and improving maneuverability. It includes features like an eco-mode engine and a battery pack for load variations. CPPs are especially beneficial in eco-sensitive zones, reducing emissions and meeting stringent environmental norms. They also provide flexibility in power usage, crucial for operations in challenging conditions like icy waters.

20/11/2024

Shout out to my newest followers! Excited to have you onboard! Theo Enna Mertens, Анатолий Сытник, Wal Yip, Sanni Kaseem, Gangan Payyanur Madathil, ہندوستانی افسر پٹھان, Konvict Ajith Sujeevan, Zulkarnain Amit, Robi Kumarroy, Rudi Anto, Sahirus De La Nero X

19/11/2024

Propeller of a giant ship in shipyard

The color coding of piping systems onboard ships is crucial for safety and quick identification of different types of fl...
18/11/2024

The color coding of piping systems onboard ships is crucial for safety and quick identification of different types of fluids or gases. Each type of pipe is painted a specific color to indicate its contents, helping crew members understand potential hazards and manage the systems safely. Here’s a general guide based on typical maritime standards:
1. Fuel Oil (FO) - Brown
• Used for pipes carrying fuel oil, such as heavy fuel oil, diesel, and other types of fuel.
• Often marked with black bands or a black stripe.
2. Lubricating Oil (LO) - Yellow
• For pipes carrying lubricating oil used in engines and machinery.
• Marked with black or brown bands for easy distinction.
3. Fresh Water (FW) - Green
• This color is designated for fresh water lines, including potable water and domestic water.
• Sometimes marked with white or blue bands.
4. Sea Water (SW) - Green with Black Bands
• Sea water used for cooling and firefighting is represented with a green base and black bands.
• This helps distinguish it from fresh water.
5. Steam - White
• Steam pipes, often used in older systems or engine rooms, are painted white.
• Easily identifiable to avoid accidental contact.
6. Compressed Air (CA) - Light Blue
• For compressed air used in various ship systems, including starting air for engines.
• May have different bands or labels to indicate high or low pressure.
7. Firefighting Systems - Red
• Firefighting or emergency water systems are marked in red.
• This includes fire main, hydrants, and emergency water supplies.
8. Bilge Water - Black
• Bilge water pipes, which handle oily water, are generally painted black.
• Prevents mixing with other water systems on board.
9. Hydraulic Oil (HO) - Orange
• Used for hydraulic systems on the ship.
• Marked with black or white bands to indicate oil type and avoid confusion.
10. Sewage (Sanitary Systems) - Grey
• Sewage or waste water pipes are marked grey.
• This coloring alerts personnel to potential hazards.
11. Refrigerant - Purple
• For refrigeration systems, typically painted purple.
• Ensures clear differentiation from other fluids.
12. Inert Gas (IG) - Buff/Light Brown
• Inert gases used for cargo tanks or ballast are painted buff.
• Commonly found on tankers and gas carriers.
13. Acid and Caustic Solutions - Yellow/Orange with Stripes
• Hazardous chemical pipelines are marked with yellow or orange and specific stripe patterns for warning.
Labeling and Safety
In addition to color coding, ship piping systems often have labels or tags that display the pipe’s content and flow direction. This enhances safety by providing clear information, especially in emergencies.
While these colors are generally used internationally, variations may exist depending on regional standards or vessel types.



A **Container Identification System (CIS)** is a method or technology used to uniquely identify, track, and manage conta...
18/11/2024

A **Container Identification System (CIS)** is a method or technology used to uniquely identify, track, and manage containers in logistics, supply chain, and shipping operations. These containers can be of various types, such as shipping containers, storage containers, or intermodal units. The purpose of the CIS is to improve efficiency, reduce errors, and enhance security and transparency in container handling and movement.

Here are key components and technologies used in a Container Identification System:

# # # 1. **Container Numbering**
- **Unique Identifier:** Each container is assigned a unique number, typically using an alphanumeric system, such as the **ISO 6346** standard. This identifier often includes:
- **Owner code:** 3-letter code for the container owner.
- **Equipment category identifier:** Indicates whether the container is standard, refrigerated, or specialized.
- **Serial number:** A unique sequence assigned to the container.
- **Check digit:** A single-digit used for error detection in the ID.

# # # 2. **Barcodes and QR Codes**
- Barcodes and QR codes can be placed on containers to facilitate quick scanning and tracking.
- These codes link to databases that store information about the container, such as its contents, location, and destination.

# # # 3. **RFID (Radio Frequency Identification)**
- **Active or Passive RFID Tags:** These tags are attached to the containers and use radio frequency to communicate with scanners.
- RFID systems enable real-time tracking of containers, providing automatic updates on their status and location, which is especially useful in large-scale operations.

# # # 4. **GPS and IoT**
- Many modern containers are equipped with **GPS trackers** and other **Internet of Things (IoT)** devices that provide real-time location data.
- These systems can also monitor container conditions (e.g., temperature, humidity) for sensitive cargo, ensuring that the containers remain within optimal parameters.

# # # 5. **Container Management Software**
- **Cloud-based platforms** allow logistics companies to manage large fleets of containers.
- These systems track containers from departure to delivery, including details such as container condition, handling, and customs information.

# # # 6. **Cameras and Computer Vision**
- Advanced **image recognition** and **computer vision** technology can automate container identification, particularly at ports and terminals. Cameras and AI algorithms can recognize container numbers, inspect containers for damage, and ensure proper handling.

# # # 7. **Blockchain for Security and Transparency**
- Some systems incorporate **blockchain technology** to provide a secure, tamper-proof ledger of container movements and status updates.
- Blockchain can enhance supply chain transparency and reduce the risk of fraud or theft.

# # # Benefits of a Container Identification System:
- **Improved Efficiency:** Automation of tracking and data collection reduces human error and improves speed.
- **Better Visibility:** Real-time tracking and monitoring provide visibility across the supply chain.
- **Security:** Unique identification, combined with RFID, GPS, and blockchain, enhances security by preventing fraud, theft, and loss.
- **Cost Reduction:** Automation and streamlined operations reduce operational costs and delays.

In summary, a Container Identification System helps streamline the global movement of goods by leveraging various technologies to track and manage containers efficiently and securely.








Fuel dribble (dripping) after injection This occurs when the fuel supply is not precisely cutoff at the end of fuel inje...
16/11/2024

Fuel dribble (dripping) after injection

This occurs when the fuel supply is not precisely cutoff at the end of fuel injection and fuel particles are accumulated on the tip of the nozzle. If fuel dribble occurs after fuel injection, the fuel in the cylinder will not burn completely. This will result in the emission of black or white smoke being exhausted. To prevent fuel dribble, the relief valve of the delivery valve is designed to draw back any fuel that may drip out of the nozzle after injection. Fuel dribble occurs if there is any failure in the delivery valve or injection nozzle, as the residual pressure remains in the injection pipe after fuel injection.

Diesel EngineBleeding Air for the Fuel System

1. Bleeding the air between the fuel tank and the injection pump (low pressure side)

(1) Repeatedly push down and release the pump handle.

(2) Gradually the pump handle resistance will become higher, and the pump will seize to operate. Then the air flows with the fuel into the fuel tank via the return pipe.

(3) Bleeding the air is completed when the pump handle becomes hard to operate.

SERVICE HINT:

In following cases, bleed the air between the injection pump and injection nozzle (high pressure side).

When the engine does not operate properly after the engine is warmed up

When a part on the high pressure side of the fuel system are replaced

2. Bleeding the air between the injection pump and the injection nozzle (high pressure side)

(1) Loosen all injection pipe union nuts on the nozzle holder side.

(2) Crank the engine to force the fuel out of the injection pipe and bleed the air.

(3) Tighten the injection pipe union nuts.

NOTICE:

In the case of the common-rail type, use the hand-held tester and operate the injector to bleed the air. Do not bleed the air with the injection pipe union nuts loosened.

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