Over-the-Stern Deep Digging Trenching Plow with Instrumentation for Assessing the Protective Capabilities of a Seabed Trench

• US 20160376766A1
• Filed: 06/24/2015
• Published: 12/29/2016
• Est. Priority Date: 06/24/2015
• Status: Active Grant

• Current Assignee: Oceaneering International Services Limited (Oceaneering International Incorporated)
• Original Assignee: Ecosse Subsea Systems Limited (Oceaneering International Incorporated)
• Inventors: Wilson, Michael W. N.
• Granted Patent: US 9,657,455 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B63B 2027/165 Deployment or recovery of underwater vehicles using lifts or hoists
• CPC Class Codes: B63B 35/00 Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
• CPC Class Codes: E02D 1/00 Investigation of foundation soil in situ investigation involving boring or specially adapted to earth drilling E21B25/00, E21B49/00; investigating or analysing materials by determining their chemical or physical properties, in general G01N, e.g. sampling G01N1/00
• CPC Class Codes: E02F 3/907 Measuring or control devices, e.g. control units, detection means or sensors E02F3/902 takes precedence
• CPC Class Codes: E02F 5/006 adapted for working ground under water not otherwise provided for E02F3/081, E02F3/4131, E02F3/8833, E02F5/104, E02F5/125, E02F7/005, E02F7/023, E02F7/065, E02F9/026, E02F9/045, E02F9/06 take precedence
• CPC Class Codes: E02F 5/027 with coulters, ploughs, scraper plates, or the like E02F5/102, E02F5/103, E02F5/106 take precedence
• CPC Class Codes: E02F 5/106 using ploughs, coulters, rippers
• CPC Class Codes: E02F 5/14 Component parts for trench excavators, e.g. indicating devices travelling gear chassis, supports, skids
• CPC Class Codes: E02F 5/145 control and indicating devices
• CPC Class Codes: F16L 1/16 on the bottom
• CPC Class Codes: H02G 1/10 in or under water

Abstract

A seabed trenching plow has a chassis, a sled and a towing assembly. The towing assembly has a pair of wings extending laterally from each side of the chassis. The wings are aligned on an axis transverse to the chassis and adapted for connection to a towing line. The transverse axis is forward of the center of gravity of the plow and rearward of the sled, affording an over the stern releasable and retrievable trenching plow of sufficient weight and strength to excavate a three meter trench in a single pass. To assess the protective capabilities of the trench, a threshold signal indicative of a desired composition of seabed-trench soil is compared with a real-time data signal indicative of the actual to produce an alarm signal when the real-time data signal is not protective-capability compliant with the threshold signal.

Claims

1. A seabed trenching plow comprising:

a chassis,

a sled connected to a forward end of the chassis by uprights;

a towing assembly comprising a pair of wings, one extending laterally from each side of the chassis, said pair of wings being aligned on an axis transverse to the chassis and adapted for connection to a towing line, said axis being forward of a center of gravity of the plow and rearward of a connection point of said sled uprights to said chassis.

2. A method of releasing a seabed plow from a deck of a vessel having a stern roller, the plow having a chassis and a sled connected to a forward end of the chassis by uprights, the method comprising the steps of:

connecting the plow to a towing line at a point forward of a center of gravity of the plow and rearward of the sled uprights;

causing the plow to traverse along the deck and over the stern roller; and

allowing the plow to rotate by gravitation about the stern roller until the plow is suspended by the towing line from the vessel aft of the stern roller.

3. A method of retrieving a seabed plow from a deck of a vessel having a stern roller, the plow having a chassis and a sled connected to a forward end of the chassis by uprights, the method comprising the steps of:

raising the plow from the seabed to the stern roller at the end of a towing line connected to the plow at a point forward of a center of gravity of the plow and rearward of the sled uprights; and

pulling the chassis to traverse against and rotate about the stern roller until the plow is resting on the deck of the vessel.

4. For use in assessing the protective capabilities of a seabed trench, a method comprising the steps of:

generating a threshold signal indicative of a desired composition of seabed-trench soil for a specific application;

pulling a trenching plow having a plow share with a soil-analyzing tip along an intended trench path in the seabed;

generating a real-time data signal in response to the composition of the soil analyzed by the soil-analyzing tip along the intended trench path; and

comparing the real-time data signal to the threshold signal to produce an alarm signal when the real-time data signal is not compliant with the threshold signal.

5. A method according to claim 4, said step of generating a real-time data signal comprising the sub-steps of:

measuring the force required to pull the soil-analyzing plow tip through the soil, the sleeve friction of the soil, the pore pressure of the soil and the total pull force applied by the pulling mechanism to the plow; and

combining the measured data according to an algorithm predetermined to produce a signal indicative of the composition of the soil being analyzed by the soil-analyzing plow tip.

6. A method according to claim 5, said sub-step of measuring further comprising measuring the depth of the soil-analyzing plow tip.