Trim and Stability Update
Before you cut steel and start modifying your vessel, consider ship stability. If you forget about stability, modifications may make your ship unsafe for sea.
I have seen owners completely repower their vessels and ignore stability. Afterwards, they discovered that the vessel could not pass inspection, all due to ship stability. Don’t get caught by surprise. Plan for ship stability and control the changes.
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After every major vessel modification, you generally need to update the vessel’s stability documentation. With only a 2% change in light ship weight, a stability test may become necessary. For many vessels regulated by the US Coast Guard, it becomes required. (See MTN 04-95.)
After the stability test, you need a new stability analysis and an updated trim and stability booklet. Our services include many different forms of stability analysis.
- Intact stability
- Passenger vessel stability
- Subdivision draft / Load line calculation
- Damage stability
- Probabilistic damage stability
- Longitudinal strength
- Stability improvements
We provide stability analysis that clearly identifies the chain of applicable regulations and outlines your requirements. Critical points are identified, and we provide recommendations for any small changes that may improve vessel stability.
FREE Loading Condition Spreadsheet
DMS also cares about delivering practical utility to the vessel crew. Ultimately, stability analysis should be a tool for the vessel master to ensure safe operation. The best tools are easy to use and convenient. Along with the trim and stability update, we also provide a free loading condition spreadsheet. This incorporates your custom tank properties and MaxVCG curves. It allows you to easily develop custom loading conditions for yourself.
Plan your own burn-ballast sequence for each voyage. Safely check transfers between tanks. Other firms may charge you tens of thousands for a fancy program that achieves the same functionality. But at DMS, we think the knowledge is more important than the appearance. That is why we automatically include the loading condition spreadsheet when developing a trim and stability booklet. Want to learn more about your free loading condition spreadsheet? We’re happy to talk.
The fine print:
- Loading condition spreadsheet is NOT a substitute for a class approved loading computer. It is only a convenient tool for the vessel master.
- Stability update requires a full trim and stability booklet to provide a free loading condition spreadsheet. Stability letters and stability assessments do not receive a free loading condition spreadsheet.
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Relevant Ship Science Articles
Practical Stability Test: Naval Architect’s Guide
Every naval architect learns the theory of how to perform a stability test. But a well executed stability test employs very little theory, and a great deal of practical experience. This guide imparts some of that hard earned experience to make your next stability test go well.
Stability Test Theory
What science could possibly link moving a few weights on deck with calculating the light ship weight? Armed with knowledge, we carefully exploit physics to achieve high quality science without the fancy equipment. Today I explain some of the theory behind the stability test.
Practical Stability Test: Chief Engineer’s Guide
A stability test requires extensive work to prepare the vessel. Where do you go to find that work list? This guide should give you some advanced warning of what to expect. It covers all the practical matters for a Chief Engineer to prepare for their next stability test.
Practical Stability Test: Master’s Guide
Smooth stability tests require planning, and practicality. As the vessel Master, you want to prepare for this thing that completely disrupts vessel operations. But you are a busy person, and engineers are very long winded. Instead, this guide provides a brief overview, focusing on the major elements that concern you with a stability test.
Practical Stability Test: Owner’s Guide
What are the practical steps necessary to execute a stability test? How to avoid the pitfalls? Who do you call to arrange everything? This guide gives advice to the vessel owner on how to prepare for a stability test, from start to finish. Instead of theory, we focus on the logistics and coordination.