What is a Draft Survey and Why Does It Matter in Shipping ?

In shipping, a draft survey is an important method used to measure the weight of cargo loaded or unloaded from a vessel. This process helps ensure the safety and efficiency of the ship's operations by calculating how much weight is on board.

The draft of a ship refers to how deep the ship sits in the water. As cargo is loaded, the ship sinks deeper. By measuring how much deeper the ship is submerged after loading, the weight of the cargo can be calculated.

The draft survey process begins with taking measurements of the ship's draft at various points. Crew members also consider factors such as ballast water and onboard fuel, which affect the draft. By comparing the draft before (Initial) and after cargo operations (Final), the weight of the cargo can be accurately determined.

Draft surveys are crucial for preventing overloading, which can lead to dangerous situations. One such example occurred in 2004 with the bulk carrier MV Rocknes, which tragically capsized due to overloading. The incorrect draft survey led to miscalculations in the ship's stability, and it was not able to handle the load it was carrying. As a result, the vessel overturned in calm waters, leading to the loss of 18 crew members. The investigation revealed that errors in draft calculations and cargo mismanagement were major factors in the accident.

This incident highlights the critical importance of conducting accurate draft surveys. Overloading or incorrect cargo distribution can seriously compromise a ship's stability, putting the vessel and crew at significant risk.

How Does iStow Draft Survey Make It Easier?

Traditionally, draft surveys involved manual measurements and calculations. With iStow Draft, the process is streamlined, though it still requires crew input. The crew manually enters the draft measurements into the iStow system.

Once the data is entered, iStow simulates the draft in a 2D format, providing a clear and accurate visual representation of the ship’s draft and cargo load. The system processes the inputs to calculate the cargo weight, allowing the crew to monitor and manage the ship’s stability and operations more effectively.

iStow also simplifies adjustments by accounting for factors such as ballast water and fuel, which impact the draft. This ensures that all relevant variables are considered, leading to a more precise calculation.

At the end of the draft survey, iStow generates a comprehensive report that can be shared with port authorities, cargo owners, or other relevant stakeholders, streamlining communication and documentation.

With iStow Draft Survey, the draft survey process becomes faster and more efficient, while still allowing for manual data entry by the crew. The system’s ability to simulate draft measurements in a 2D format makes it easy to visualize and understand the ship’s loading condition. This not only reduces the chance for error but also saves time.

By simplifying the reporting process and ensuring all factors are taken into account, iStow Draft enhances the accuracy and safety of maritime operations.

Moreover, with an accurate and quick reporting system, iStow Draft ensures that all factors are considered, making maritime operations safer and more efficient. Incidents like the MV Rocknes serve as stark reminders of the consequences of incorrect draft surveys and poor cargo management, underscoring the importance of reliable tools like iStow Draft.