Inverted Chine Hull Transition for Stationary Stability

Solution Overview

Problem

Planing hulls with a deep-vee design face challenges in stability, particularly when stationary or below planing speeds, due to their V-shaped cross section, which results in reduced righting moment compared to hulls with flat bottoms or multihulls. Additionally, hybrid designs like cathedral/trihull compromise on comfort and seaworthiness.

Innovation Solution

A watercraft hull design that seamlessly transitions from a V-shaped cross section to an M-shaped cross section, with the aft sections resembling a cathedral/trihull and the forward sections maintaining positive deadrise, thereby enhancing stability and dynamic seaworthiness while minimizing disadvantages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a deep-vee V-shaped cross section is used, then dynamic seaworthiness and comfort are improved, but stability when stationary or below planing speeds deteriorates

Engineering Contradiction:

Improvedynamic seaworthinessVSAvoidstability when stationary

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The hull is divided into multiple cross-sectional sections along its length, with each section having a different deadrise angle. The forward sections have higher deadrise angles for dynamic seaworthiness, while aft sections have lower or negative deadrise angles for stationary stability, creating a segmented approach to the hull form.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the hull are given different geometric properties - the forward sections maintain positive deadrise for comfort and seaworthiness, while the aft sections feature inverted chine with negative deadrise for enhanced stationary stability, allowing each local region to optimize for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If a flat bottom or low deadrise angle is used, then stability when stationary is improved, but dynamic seaworthiness and comfort deteriorate

Engineering Contradiction:

Improvestability when stationaryVSAvoiddynamic seaworthiness

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The hull is divided into multiple cross-sectional sections along its length, with each section having a different deadrise angle. The forward sections have higher deadrise angles for dynamic seaworthiness, while aft sections have lower or negative deadrise angles for stationary stability, creating a segmented approach to the hull form.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the hull are given different geometric properties - the forward sections maintain positive deadrise for comfort and seaworthiness, while the aft sections feature inverted chine with negative deadrise for enhanced stationary stability, allowing each local region to optimize for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If hybrid cathedral/trihull designs are used, then stability is improved, but comfort and seaworthiness are compromised

Engineering Contradiction:

ImprovestabilityVSAvoidseaworthiness

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

Different portions of the hull are given different geometric properties - the forward sections maintain positive deadrise for comfort and seaworthiness, while the aft sections feature inverted chine with negative deadrise for enhanced stationary stability, allowing each local region to optimize for its specific functional requirement.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The hull design incorporates dynamic characteristics of deep-vee planing hulls in the forward sections while adding static stability through inverted chine in the aft sections, creating a hybrid form that adapts its stability characteristics based on operational state.

Inventive Principle:

Principle #15Dynamics

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

The hybrid deep-vee planing hull design achieves improved stability and dynamic handling characteristics, maintaining the comfort and seaworthiness benefits of deep-vee designs while addressing stability issues, particularly in smaller vessels.

Implementation Method 1

many are designed to primarily utilize the effects of hydrodynamic lift generated by the hull's geometry at speed to support the vessel's weight

Methodology Applied

Scientific EffectHydrodynamic lift:

Implementation Method 2

This induces a dampening effect that mitigates pitching and rapid vertical deceleration (commonly referred to as 'slamming')

Methodology Applied

Scientific EffectDampening effect: Damping

Data Source

PatentUS20250074545A1Watercraft planing hull with inverted chine

Publication Date: 2025.03.06 MCDONALD CHRISTIAN A

AI summary

Provided is watercraft hull system, including a hull having a fore end, an aft end, and a longitudinal axis extending between the fore end and the aft end; a substantially V-shaped portion extending from the fore end toward the aft end along a portion of the longitudinal axis; and a substantially M-shaped portion extending from the V-shaped portion toward the aft end, wherein the V-shaped portion gradually transitions to the M-shaped portion.