J-Lay Pipe Loader and Offset Hoisting for Simultaneous Pipe Advancement
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Solution Overview
Problem
Existing marine J-lay pipelaying installations face inefficiencies due to sequential operations, requiring significant hoisting capacity and time-consuming lifting processes, especially in deep water depths, which hinder the simultaneous advancement and connection of new pipe sections.
Innovation Solution
The implementation of a laterally offset lifting path for the travelling head clamp and block, allowing for simultaneous overlap with pipe section advancement and connection, utilizing a lateral offsetting system and movable cable sheaves or U-shaped frames to divert cables, enabling the lifting of components along a path offset from the firing line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the head clamp and travelling block are lifted along the firing line, then the lifting path is simple and direct, but the pipe section loader system cannot advance new pipe sections simultaneously, causing sequential operations and time loss
Solution Approach 1:
The invention introduces a lateral dimension to the lifting path by providing offset lifting paths for the head clamp and travelling block that are laterally displaced from the firing line. This allows the head clamp and travelling block to be lifted along a path parallel to but offset from the firing line, enabling simultaneous advancement of pipe sections along the firing line without interference, thereby converting a sequential one-dimensional operation into a parallel two-dimensional operation.
2Ease of operation
If the head clamp is lifted back up along the firing line, then the hoisting device can be reused, but the pipe section loader system must wait, creating idle time and reducing productivity
Solution Approach 1:
The offset lifting paths allow the head clamp and travelling block to be lifted in a lateral dimension separate from the firing line, enabling the pipe section loader system to advance new pipe sections along the firing line simultaneously without waiting for the hoisting device to complete its cycle, thereby eliminating idle time and increasing pipeline laying speed while maintaining full hoisting device functionality.
3Productivity
If the lifting path is offset laterally from the firing line, then simultaneous operations are enabled, but the hoisting device and cable arrangement must be more complex
Solution Approach 1:
The invention introduces lateral offsetting systems as intermediary mechanisms that divert the hoisting cables from the firing line to offset lifting paths. These offsetting systems act as mediators between the simple vertical hoisting motion and the required lateral displacement, enabling simultaneous operations without requiring complete redesign of the hoisting device while managing cable complexity through dedicated offsetting mechanisms.
4Device complexity
If the head clamp and travelling block follow the same lifting path as the firing line, then the structure is simple, but new pipe sections cannot be advanced into position during lifting, causing operational delays
Solution Approach 1:
The invention provides offset lifting paths that are laterally displaced from the firing line, creating a separate dimensional space for lifting operations. This allows the head clamp and travelling block to be lifted without interfering with the advancement of pipe sections along the firing line, eliminating operational delays while maintaining relatively simple structural arrangements through parallel offset paths.
Data Source
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AI summary
Marine J-lay pipelaying installation comprising a tower having a firing line, a pipe section loader system adapted to advance a pipe section into a position in the firing line, and an upper work station mounted on the tower halfway between the uppermost level and the lowermost level. The pipe section loader system is provided with a pivotal loader boom, that is pivotal about a horizontal pivot axis between a horizontal loading position and a raised transfer position. The pivotal loader boom is provided with a lower and an upper set of pipe section grippers (110, 115),each adapted to grip a respective pipe section (8,9), and therefore allowing for at least two operational modes of the J-lay installation, i.e. a full vertical stroke mode and a half vertical stroke mode.