Ships husbandry

Last updated
A diver at work on hull maintenance Working Diver 02.jpg
A diver at work on hull maintenance

Ships husbandry or ship husbandry is all aspects of maintenance, cleaning, [1] and general upkeep of the hull, rigging, and equipment of a ship. It may also be used to refer to aspects of maintenance which are not specifically covered by the technical departments. [2] The term is used in both naval and merchant shipping, [3] but naval vessel husbandry may also be used for specific reference to naval vessels. [4]

Contents

Etymology

Ships husbandry diving

Underwater ships husbandry can be financially advantageous when it eliminates the need for dry-dock repairs or extends the interval between dry-dockings, and reduces the time a ship is required to stay in dry-dock. [5]

Underwater ship husbandry includes the following operations, usually done by commercial divers, though some can be done by ROVs or robotic machinery:

Environmental impact

Several of the operations classified as ship husbandry will release some quantity of harmful material into the water, particularly hull cleaning operations which will release antifouling toxins. [6] Underwater ship husbandry can cause an adverse environmental effect as significant amounts of copper and zinc are released by underwater hull scrubbing. Alien biofouling organisms may also be released during this process. [6] :15

Diving under the hull

The underside of the hull is an overhead environment with no direct vertical access to the surface. As such it constitutes an entrapment hazard, particularly under large vessels where it may be too dark due to low natural light or turbid water to see the way to the side of the hull. The bottom of the largest ships is mostly flat and featureless, exacerbating the problem. Only surface-supplied diving is authorised for this work in most jurisdictions, as this not only secures the diver's breathing gas supply, but also provides a guideline to the exit point. The use of mechanised bottom scrubbing devices which are steered along the hull surface by a diver and scrub it with rotary brushes has been linked with high release of environmental toxins. [6] There is also a hazard of crushing if the clearance is small and the tide range is large.

Related Research Articles

<span class="mw-page-title-main">Diving activities</span> Things people do while diving underwater

Diving activities are the things people do while diving underwater. People may dive for various reasons, both personal and professional. While a newly qualified recreational diver may dive purely for the experience of diving, most divers have some additional reason for being underwater. Recreational diving is purely for enjoyment and has several specialisations and technical disciplines to provide more scope for varied activities for which specialist training can be offered, such as cave diving, wreck diving, ice diving and deep diving. Several underwater sports are available for exercise and competition.

<span class="mw-page-title-main">Professional diving</span> Underwater diving where divers are paid for their work

Professional diving is underwater diving where the divers are paid for their work. Occupational diving has a similar meaning and applications. The procedures are often regulated by legislation and codes of practice as it is an inherently hazardous occupation and the diver works as a member of a team. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated.

<span class="mw-page-title-main">Commercial diving</span> Professional diving on industrial projects

Commercial diving may be considered an application of professional diving where the diver engages in underwater work for industrial, construction, engineering, maintenance or other commercial purposes which are similar to work done out of the water, and where the diving is usually secondary to the work.

Underwater divers may be employed in any branch of an armed force, including the navy, army, marines, air force and coast guard. Scope of operations includes: search and recovery, search and rescue, hydrographic survey, explosive ordnance disposal, demolition, underwater engineering, salvage, ships husbandry, reconnaissance, infiltration, sabotage, counterifiltration, underwater combat and security.

<span class="mw-page-title-main">Diving support vessel</span> Ship used as a floating base for professional diving projects

A diving support vessel is a ship that is used as a floating base for professional diving projects. Basic requirements are the ability to keep station accurately and reliably throughout a diving operation, often in close proximity to drilling or production platforms, for positioning to degrade slowly enough in deteriorating conditions to recover divers without excessive risk, and to carry the necessary support equipment for the mode of diving to be used.

<span class="mw-page-title-main">Cofferdam</span> Barrier allowing liquid to be pumped out of an enclosed area

A cofferdam is an enclosure built within a body of water to allow the enclosed area to be pumped out or drained. This pumping creates a dry working environment so that the work can be carried out safely. Cofferdams are commonly used for construction or repair of permanent dams, oil platforms, bridge piers, etc., built within water.

<span class="mw-page-title-main">Careening</span> Method of grounding of a sailing vessel to expose its hull

Careening is a method of gaining access to the hull of a sailing vessel without the use of a dry dock. It is used for cleaning or repairing the hull. Before ship's hulls were protected from marine growth by fastening copper sheets over the surface of the hull, fouling by this growth would seriously affect the sailing qualities of a ship, causing a large amount of drag.

<span class="mw-page-title-main">Navy diver (United States Navy)</span> US Navy personnel qualified in underwater diving and salvage

A United States Navy diver may be a restricted fleet line officer, Civil Engineer Corps (CEC) officer, Medical Corps officer, an Unrestricted Line Officer who is qualified in Explosive Ordnance Disposal (EOD) Warfare (1140) or an enlisted who is qualified in underwater diving and salvage. Navy divers serve with fleet diving detachments and in research and development. Some of the mission areas of the Navy diver include: marine salvage, harbor clearance, underwater ship husbandry and repair, submarine rescue, saturation diving, experimental diving, underwater construction and welding, as well as serving as technical experts to the Navy SEALs, Marine Corps, and Navy EOD diving commands.

<span class="mw-page-title-main">Patent slip</span> Mechanism for hauling ships out of water

A patent slip or marine railway is an inclined plane extending from shoreline into water, featuring a "cradle" onto which a ship is first floated, and a mechanism to haul the ship, attached to the cradle, out of the water onto a slip. The marine railway was invented by a Scot, Thomas Morton, in the early 19th century, as a cheaper alternative to dry docks for marine vessel repairs, in particular below waterline. Larger modern marine railways can handle vessels of thousands of tons.

<span class="mw-page-title-main">Hyperbaric welding</span> Welding metal at elevated pressure

Hyperbaric welding is the process of extreme welding at elevated pressures, normally underwater. Hyperbaric welding can either take place wet in the water itself or dry inside a specially constructed positive pressure enclosure and hence a dry environment. It is predominantly referred to as "hyperbaric welding" when used in a dry environment, and "underwater welding" when in a wet environment. The applications of hyperbaric welding are diverse—it is often used to repair ships, offshore oil platforms, and pipelines. Steel is the most common material welded.

<span class="mw-page-title-main">Salvage diving</span> Diving work associated with the recovery of vehicles, cargo and structures

Salvage diving is the diving work associated with the recovery of all or part of ships, their cargoes, aircraft, and other vehicles and structures which have sunk or fallen into water. In the case of ships it may also refer to repair work done to make an abandoned or distressed but still floating vessel more suitable for towing or propulsion under its own power. The recreational/technical activity known as wreck diving is generally not considered salvage work, though some recovery of artifacts may be done by recreational divers.

<span class="mw-page-title-main">Diving equipment</span> Equipment used to facilitate underwater diving

Diving equipment, or underwater diving equipment, is equipment used by underwater divers to make diving activities possible, easier, safer and/or more comfortable. This may be equipment primarily intended for this purpose, or equipment intended for other purposes which is found to be suitable for diving use.

<span class="mw-page-title-main">Commercial offshore diving</span> Professional diving in support of the oil and gas industry

Commercial offshore diving, sometimes shortened to just offshore diving, generally refers to the branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States, the North Sea in the United Kingdom and Norway, and along the coast of Brazil. The work in this area of the industry includes maintenance of oil platforms and the building of underwater structures. In this context "offshore" implies that the diving work is done outside of national boundaries. Technically it also refers to any diving done in the international offshore waters outside of the territorial waters of a state, where national legislation does not apply. Most commercial offshore diving is in the Exclusive Economic Zone of a state, and much of it is outside the territorial waters. Offshore diving beyond the EEZ does also occur, and is often for scientific purposes.

<span class="mw-page-title-main">Army engineer diver</span> Armed forces occupation

Army engineer divers are members of national armies who are trained to undertake tasks underwater, including reconnaissance, demolition, and salvage. These divers have similar skills and qualifications as professional divers. Army divers use both surface supplied "Hard hat" and SCUBA to perform their missions. In the United States Army, they are members of the Corps of Engineers. In the British Army, they may be Royal Engineer Divers or Commando Engineer Divers.

Underwater work is work done underwater, generally by divers during diving operations, but includes work done underwater by remotely operated vehicles and crewed submersibles.

In-water cleaning, also known as in-water surface cleaning, is a collection of methods for removing unwanted material in-situ from the underwater surface of a structure. This often refers to removing marine fouling growth from ship hulls, but also has applications on civil engineering structures, pipeline intakes and similar components which are impossible or inconvenient to remove from the water for maintenance. It does not generally refer to cleaning the inside of underwater or other pipelines, a process known as pigging. Many applications require the intervention of a diver, either to provide the power, or to direct a powered tool.

Underwater construction is industrial construction in an underwater environment. It is a part of the marine construction industry. It can involve the use of a variety of building materials, mainly concrete and steel. There is often, but not necessarily, a significant component of commercial diving involved. Some underwater work can be done by divers, but they are limited by depth and site conditions, and it is hazardous work, with expensive risk reduction and mitigation, and a limited range of suitable equipment. Remotely operated underwater vehicles are an alternative for some classes of work, but are also limited and expensive. When reasonably practicable, the bulk of the work is done out of the water, with underwater work restricted to installation, modification and repair, and inspection.

<span class="mw-page-title-main">Underwater survey</span> Inspection or measurement in or of an underwater environment

An underwater survey is a survey performed in an underwater environment or conducted remotely on an underwater object or region. Survey can have several meanings. The word originates in Medieval Latin with meanings of looking over and detailed study of a subject. One meaning is the accurate measurement of a geographical region, usually with the intention of plotting the positions of features as a scale map of the region. This meaning is often used in scientific contexts, and also in civil engineering and mineral extraction. Another meaning, often used in a civil, structural, or marine engineering context, is the inspection of a structure or vessel to compare actual condition with the specified nominal condition, usually with the purpose of reporting on the actual condition and compliance with, or deviations from, the nominal condition, for quality control, damage assessment, valuation, insurance, maintenance, and similar purposes. In other contexts it can mean inspection of a region to establish presence and distribution of specified content, such as living organisms, either to establish a baseline, or to compare with a baseline.

<span class="mw-page-title-main">Underwater cutting and welding</span> Metalworking techniques used by underwater divers

Underwater cutting and welding are metalworking techniques used by underwater divers in underwater construction, marine salvage and clearance diving applications. Most underwater welding is direct current wet stick welding, and most underwater metal cutting is immersed oxygen-arc and shielded metal-arc cutting, though other technologies are available and sometimes used. These processes are mostly applied to steel structures as that is the most common arc-weldable material used in the underwater environment.

References

  1. Nelson, Mark. "Ship's Husbandry". Jackspeak of the Royal Canadian Navy. ReadyAyeReady.com. Retrieved 19 March 2017.
  2. Staff. "1: Hull Maintenance". Ship Husbandry (PDF). Royal Australian Navy Apprentice Training Establishment.
  3. Jensen, Milinda D. (3 March 2004). "Underwater Ship Husbandry Combines Navy, Civilian Divers into Successful Team". Story Number: NNS040303-02. Naval Sea Systems Command Public Affairs. Retrieved 19 March 2017.
  4. Staff (2014). "Naval Vessel Husbandry". Strategy Logistics. Retrieved 19 March 2017.
  5. Staff. "Underwater Ship Husbandry". SUPSALV. Washington, DC: Naval Sea Systems Command. Retrieved 17 March 2017.
  6. 1 2 3 4 5 6 7 8 9 "Underwater Ship Husbandry: Nature of Discharge (EPA-842-R-99-001.)" (PDF). Phase I Final Rule and Technical Development Document of Uniform National Discharge Standards. United States Environmental Protection Agency. April 1999. Retrieved 19 March 2017.