Ballast Water-Free Ship Stepped Bottom Shell Design
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Solution Overview
Problem
Existing ballast water-free ship designs face challenges in maintaining posture control, propeller immersion depth, resistance propulsion, bow slamming countermeasures, operability in conventional ports, easy technical implementation, and life cycle economic efficiency without the use of ballast water.
Innovation Solution
A ballast water-free ship design featuring a stepped portion in the bottom shell plate between the bow/stern and midship section, with a bilge keel or fin stabilizers on the midship section, allowing for differential drafts and using clean water as ballast during cargo operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If ballast water is used to maintain ship stability and control, then ship stability and posture control are improved, but ballast water operation complexity and environmental impact increase
Solution Approach 1:
The patent removes the ballast water system entirely from the ship design. Instead of using ballast water for stability and posture control, the invention uses a stepped bottom shell plate structure where the bow and stern portions extend lower than the midship section, creating permanent draft differences that eliminate the need for ballast water operations while maintaining ship stability.
Solution Approach 2:
The patent applies local quality by creating different bottom shell plate depths at different locations along the ship length. The bow and stern portions have greater depth than the midship section, producing localized draft differences that provide stability and posture control functions without requiring ballast water.
2Ease of manufacture
If uniform bottom shell plate depth is used, then ship construction is simplified, but propeller immersion depth and resistance propulsion performance cannot be optimized
Solution Approach 1:
The patent applies local quality by creating different bottom shell plate depths at different locations along the ship length. The bow and stern portions have greater depth than the midship section, producing localized draft differences that provide stability and posture control functions without requiring ballast water.
3Ease of operation
If stepped bottom shell plate is formed between bow/stern and midship section, then ballast water operation is eliminated and cargo loading/unloading is simplified, but ship structure complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the bottom shell plate into distinct segments with different depths: a first bottom shell plate portion at the bow, a second bottom shell plate portion at the stern, and a third bottom shell plate portion at the midship section. This segmentation creates the stepped configuration that enables ballast water-free operation while maintaining structural integrity.
4Object-affected harmful factors
If deeper draft is used at bow and stern, then bow slamming is reduced and propeller immersion is improved, but wetted surface area increases and resistance increases
Solution Approach 1:
The patent applies local quality by creating different bottom shell plate depths at different locations along the ship length. The bow and stern portions have greater depth than the midship section, producing localized draft differences that provide stability and posture control functions without requiring ballast water.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration maintains proper propeller immersion, reduces resistance, counteracts bow slamming, ensures operability in conventional ports, simplifies technical implementation, and enhances life cycle economic efficiency by eliminating the need for ballast water and associated certifications.
Implementation Method 1
a stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section
Implementation Method 2
posture control of the ship in a body of water is enabled in a ballast water-free condition, using a difference in depth of the bottom shell plate between either the bow or the stern and the midship section
Implementation Method 3
a bilge keel provided on a bottom of the bottom shell plate in the midship section
Data Source
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AI summary
A ballast water-free ship using a difference in the depth of the bottom shell plate between the bow/stern and the midship section and a construction method thereof. A stepped portion is formed between either the bow or the stern and the midship section, such that the depth of the bottom shell plate of either the bow or the stern differs from the depth of the bottom shell plate of the cargo containment in the midship section, so that cargo can be loaded and unloaded without ballast water operation.