Ship Hull Tenon-Mortise Joint for Fast Crash Box Replacement
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Solution Overview
Problem
The process of replacing a collision box on a ship hull is lengthy and requires the ship to be taken out of the water, which is disadvantageous for specialized marine applications, as it involves repainting and specialized workforce, and is time-consuming.
Innovation Solution
A connecting device comprising a first and second frame with a tenon and mortise system, and a pin mechanism that allows easy installation and removal, utilizing a non-orthogonal pin insertion to maintain the frames together, with a ramp effect for clamping control, and screwing for secure fastening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the crash box is permanently incorporated into the hull with fastening means covered by coating, then the structural integrity and hydrodynamic performance are maintained, but the replacement process becomes lengthy and requires ship immobilization
Solution Approach 1:
The connection system is divided into separable components: a tenon integrated with the crash box and a mortise integrated with the hull. This segmentation allows the crash box to be permanently secured during normal operation while enabling rapid removal and replacement when damaged, eliminating the need for lengthy repainting and reconstruction processes.
2Reliability
If the fastening means are covered with coating to maintain continuity, then the hydrodynamic performance is preserved, but the ease of repair deteriorates as access to fastening means is lost
Solution Approach 1:
The fastening function is extracted from conventional covered fasteners and implemented through the tenon-mortise mechanical interlocking system. The tenon protrudes from the crash box and inserts into the mortise in the hull, providing accessible fastening that does not require coating coverage, thereby maintaining both hydrodynamic performance and ease of repair.
3Ease of operation
If a conventional cam mechanism is used for pin insertion, then the clamping control is achieved, but the sensitivity and reliability of adjustment are insufficient
Solution Approach 1:
The pin mechanism incorporates a cam surface that transforms rotational motion of the pin into translational clamping motion of the frames. This dynamic mechanism provides sensitive and reliable adjustment of the clamping force, allowing precise control of the connection between the crash box and hull while maintaining structural integrity.
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
Enables quick and reliable attachment and detachment of hull parts, maintaining hydrodynamic performance without hindering shock absorption, reducing downtime and maintenance complexity.
Implementation Method 1
the pin and the tenon hole are arranged in such a way as to create a ramp effect causing a clamping of the two frames towards each other in the longitudinal direction as a result of a transverse effort of insertion of the pin into said transverse through-hole
Data Source
AI summary
Disclosed is a device for connecting two parts of a ship hull, including: a first frame intended to be integral with a first part of the hull; a second frame intended to be integral with a second part of the hull; a tenon integral with the first frame; a mortise arranged in the second frame and able to receive the tenon as a result of a relative translation of the two frames towards each other in a longitudinal direction of insertion; and a pin which is able to be engaged, on the one hand, into a transverse housing provided in the second frame and opening into the mortise and, on the other hand, into a transverse through-hole provided in the tenon, so as to hold the tenon in the mortise. Also disclosed is a hull of a ship including such a device.