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Waterfronts for Ships

The shoreside infrastructure presents a wide variety of construction and design types to meet the requirements of tide, current, vessel use, and space limitations. They are built to match vessels of varied size, service and number, to fit varied sizes of available "watersheet" (area available for docks/piers and vessel maneuvering), and to function in a great spectrum of coastal and inland settings. The basic engineering and design types are limited, but, in arrangement and accommodation details, their diversity nearly matches that of the vessel population.

    Dock is usually interchangeable with the term wharf. Although the term dock may be used to signify an enclosed man-made basin which permits the entrance of a vessel for loading and unloading, the term is also used for a projected structure or structures built into the water to create an area for loading and unloading ships. A dock is a landing and moorage facility for watercraft. A dock gives access to the water, as does a boat ramp. A dock is essentially a bridge connected to land at only one end. Docks are constructed in both natural and artificial inlets where large and/or small ships can be received for mooring or harbor. They are typically perpendicular to shore, often having a "T" or "L" shape with a portion of the dock parallel to shore. Although docks can be made from a variety of materials including wood, metal, fiberglass, concrete, and plastic or wood/plastic composites, most tend to be supported by treated wooden pilings with decking material that is made of treated lumber. Docks can be dry docks, floating docks, or wet docks. Docks can be floating or stationery (i.e. not floating) and supported by various arrangements of piers, pilings and/or floats. Pile docks are very similar to traditional boardwalk structures. They rely on large wood, steel, or concrete piles to support them above the water. Pipe docks are similar to pile docks. However, the deck and frame rest on 1.5- to 3-inch-diameter metal pipes rather than on large piles. The metal pipes rest on supports placed on the bottom of the waterway. Many commercially produced floating docks are available. These products are easy to purchase and assemble and are usually less expensive than building a dock from scratch. A cantilever dock typically relies on the shoreline or on a shoreline structure for its entire anchorage. Some docks may have intermediate supports very close to the shoreline. The end of a cantilever dock juts out over the water, appearing to float on air. Cantilever docks are suitable for almost any type of environment and have a very small environmental footprint. The shoreline anchorage and framing must be strong enough to support the weight of the dock and its users. A crib is a framework of large timbers (made of a durable wood such as Douglas-fir, larch, or hemlock) filled with rocks. Timbers continually submerged in water can last 50 years or longer without treatment. A traditional crib dock extends from the shoreline out to a crib. Cribs can also be used for shoreline supports, anchorage, foundations, and landing platforms. Crib docks are not suitable for deep-water applications.

    A wharf is a structure, built of open rather than solid construction, along a shore or a bank that provides cargo-handling facilities. Wharf is probably the oldest of these terms, and it applies to any structure projecting from the shore that permits boats or ships to lie alongside for loading or unloading. A wharf is a landing place or platform built into the water or along the shore for the berthing of vessels. A wharf is a structure extending parallel with the shoreline, connecting to the shore at more than one point (usually with a continuous connection), and providing, in most cases, berthing at the outshore face of the structure only. A wharf is typically a structure of timber, masonry, concrete, earth, or other material built along or at an angle from the shore of navigable waters (as a harbor or river). Wharf can be made with a partially covered platform so that vessels may lie close alongside to receive and discharge cargo and passengers. A wharf may also be a structure of open rather than filled construction extending parallel to the shoreline. A similar facility of solid construction is called a quay.

    A quay is a solid wharf or reinforced bank where ships are loaded or unloaded. A quay is a marginal wharf with solid fill. A quay is an artificial wall or bank, usually of stone, made toward the sea or at the side of a harbor or river for convenience in loading and unloading vessels. A quay is a structure of solid construction along a shore or bank that provides berthing and generally provides cargo-handling facilities. A quay usually refers to an artificial embankment lying along or projecting from a shore and mainly used for loading and unloading. If there's an oil spill, operators deploy all means necessary to contain the spill. The top priority is containment, and operators can use an oil boom for containment. A boom is a long buoylike line that small boats release in the water and swing around to make a U or other shape that will collect contaminants in the water in one isolated area. There are other ways they can isolate a spill. Operators can use natural barriers - quay walls that the ships are moored up to. They pocket the oil, and once it's pocketed they can get a skimmer boat in and work it.The term normally applies to wharves or piers characteristic of small places. A similar facility of open construction is called a wharf.

    A pier is a structure extending outward at an angle from the shore into navigable waters and normally permitting the berthing of vessels on both sides along its entire length. A traditional definition of a pier is a raised walkway supported by pilings or pillars. Pier is sometimes interchangeable with the terms dock or wharf, especially a large pier extending out quite a distance into a body of water. A pier extends from a shore over water and supported by pillars. Fixed piers are attached to the shore and are supported by wooden pilings driven into the shoreland. A pier is used to secure, protect, and provide access to ships or boats. A pier is a structure, usually of open construction, extending out into the water from the shore, to serve as a landing place, recreational facility, etc., rather than to afford coastal protection. Concrete piers are hard to beat in terms of strength. However, the cost, complexity, esthetic considerations, and environmental footprint -- these are massive structures -- make them problematic. A pier when used plural can also mean the pilings used for intermediate support between adjacent ends bridge spans (as distinguished from abutment). A pier has also been used to mean a breakwater, groin or mole extending into navigable water for use as a landing place or promenade or to protect or form a harbor. Piers may be open, closed, partially open or partially closed.

While individual docks and wharves vary considerably in their design, dimensions, material and use they are typically attached to shore via fixed piers with walkways or gangways. Waterward sections of the structure are also attached to piers with the elevation of the walkways fixed in water bodies with little or no fluctuation in water level and floating in tidal waters. Floating docks are attached to the pilings by means of a movable wooden collar and/or chains and supported from underneath by buoyant floats. Commercial docks associated with terminals and industrial facilities are generally wider than recreational docks and capable of accommodating smaller vehicles and/or trucks that assist with loading and unloading operations.

    Anchorage means a designated and permitted area reserved for the anchoring of vessels. Anchoring means the holding of a vessel solely by means of an anchor which is dropped to underwater lands and which is carried aboard the vessel. An anchorage area is a customary, suitable, and generally designated area in which vessels may anchor.

    A berth is a space at a wharf for a ship to dock or anchor [the term also references a place to sleep on a ship]. A Berth is also known as a Slip. A berth is the location of ships and craft secured to a pier or otherwise made fast to an object for a relatively long period of time. The term Berth applies to the space between two piers or wharves which gives room for a ship when anchored or not in use.

    A dock is also the term used for the water area between parallel piers; also called a slip. A dock is the area between two piers or alongside a pier or wharf. A dock is a basin for the reception of vessels. Wet docks are utilized for the loading and unloading of ships. Dry docks are utilized for the construction or repair of ships.

    Moorage means a designated and permitted area reserved for the mooring of vessels. "Berthage" is tying up for a short time; "moorage" is tying up for a longer period, such as during the winter season. Mooring means the holding of a vessel by means of a mooring buoy or similar device which is fastened to a stationary underwater device that is not carried aboard the vessel as regular equipment. Most small craft commercial marinas provide both "permanent" moorage (vessels moored for a period in excess of 30 continuous days) and "guest" moorage (vessels moored for a period of 30 days or less).

    A slip is the open water area where an individual boat is moored and is normally bounded on one or more sides by uplands or structures (e.g., bulkheads, walkways, piers, piling, etc.). Slip is the more common for such a place construed for ferryboat landings or boardings. Slip also applies to a sloping ramp usually constructed or used where the shore is high and shore water shallow.

A fender pile can be utilized as part of a mooring structure in order to help dissipate the force of an impact of a vessel. A fender is a device of canvas, wood, line, cork, rubber, wicker, or plastic slung over the side of a boat/ship in position to absorb the shock of contact between vessels or between a vessel and pier. Pier fender systems such as fender piling must be designed to absorb the impact energy of berthing vessels to avoid damage to either the vessel or pier structure. Some energy is dissipated in the system during vessel impact. Energy dissipation has the effect of reducing the forces on the vessel and fender and therefore should be considered in design both to minimize overconservatism and to evaluate the relative performance of various types of fendering systems. Fender piles have the task of elastically absorbing the ramming impact of a ship during berthing and of protecting from damage the ship's hull on the one hand and the quays or other harbour structures on the other hand. It is therefore essential for a fender pile to be elastic on the one hand but to also have sufficiently high strength on the other hand in order to resist the ramming impact. Apart from the wooden or steel fender piles known from time immemorial, there are also concrete fender piles which are prestressed in their longitudinal direction with steel prestressing members. Although these concrete piles fulfill their purpose, they only have a low durability, since the prestressing members, in particular when the fender piles are used in sea ports, are subjected to very severe corrosion due to the effects of the atmosphere and sea water. Since the fender piles are intended to deform during the ramming impact, cracks inevitably occur in the concrete through which water and air and also aggressive gases present herein can reach the prestressing steel members and quickly destroy them. In addition, since the elasticity of the prestressing members made of high-strength steels is limited, the deformation of the pipes under the ramming impact is relatively slight so that the fender piles themselves must have a relatively high strength, in order to be able to absorb the ramming impacts acting on them.

A dolphin is a structure consisting of a number of piles driven into the seabed or river bed in a circular pattern and drawn together with wire rope. It may be used as part of a dock structure or a minor aid to navigation. A dolphin is commonly used when a single pile would not provide the desired strength. These may be either breasting dolphins or mooring dolphins. The breasting dolphins are used to carry the lateral load during vessel impact, transferred through an energy-absorbing fendering system. A breast line is a mooring or dock line extended laterally [ie, abreast] from a vessel to a pier or float, as distinguished from a spring line. A ship may be berthed along side a number of breasting dolphins or similar pier structures. Mooring or breasting structures are known in the maritime arts for guiding and securing vessels to a fixed location on a body of water for loading, unloading or storage. One particular type of mooring or breasting structure, known as a dolphin, consists of groups of elongate piles having a first end driven into the bed underlying the body of water and a second end extending above the body of water for contacting the vessel. Ideally, in order to avoid damage to either the vessel or the dolphin upon a vessel impacting the dolphin, the dolphin must possess considerable powers of resistance and also a high degree of elasticity. During berthing a ship can impact and severely damage the breasting dolphins or pier. Likewise, once berthed, the motion of waves can cause the ship to impact or at least cyclically bear against the breasting dolphins in a manner likely to cause damage. In order to minimize damage which might occur incident to the exertion of dynamic forces due to impacts or wave motion, it may be advantageous to provide docking fenders to dissipate the energy of the cyclic forces and thereby protect the breasting dolphins and the hull of a ship. Some form of fendering or protective bumper system has been utilized to dissipate kinetic energies imparted from a floating vessel into a relatively stationary mooring or berthing facility. Such devices may range from the expedient utilization of a worn out tire casing to elaborate elastomeric cellular fendering units of a variant and often intricate configuration. Ships may be moored during loading and unloading to mooring dolphins. These mooring dolphins consist essentially of large, slender towers extending from the floor of the body of water upwardly to protrude a desired distance above the water.

A wingwall is a side wall to the dock designed to assist in guiding a ship into the slip. Prior to the 1990s, terminals used creosote-treated wood for their pile-supported trestles, vehicle loading structures and offshore vessel berthing structures (called "wingwalls" and "dolphins"). For decades, marine piles and timbers were coated with creosote, a preservative that protects the wood from wood-boring organisms.

A bollard is a metal or wooden post on a dock, wharf, ship or tug to which mooring lines are fastened. A bollard is a post made of concrete, stainless steel, aluminum, cast iron, or other durable material. The term is nautical in origin, though bollards are sometimes used to direct traffic. The traditional anti-terrorist anti-ram solution for protecting buildings entails the use of bollards. These bollards are concrete-filled steel pipes that are placed every few feet along the curb of a sidewalk to prevent vehicle intrusion. In order for them to resist the impact of a vehicle, the bollard needs to be fully embedded into a concrete strip foundation that is several feet deep. "Bollard pull" is an industry standard used for rating tug capabilities and is the pulling force imparted by the tug to the towline. It means the power that an escort tug can apply to its working line(s) when operating in a direct mode. Direct Mode means a towing technique defined as a method of operation by which a towing vessel generates towline forces by thrust alone at an angle equal to or nearly equal to the towline, or thrust forces applied directly to the escorted vessel's hull. Indirect Mode means a towing technique defined as a method of operation by which an escorting towing vessel generates towline forces by a combination of thrust and hydrodynamic forces resulting from a presentation of the underwater body of the towing vessel at an oblique angle to the towline. This method increases the resultant bollard pull, thereby arresting and controlling the motion of an escorted vessel. California's bollard pull regulations within the state require escort tug's braking force be re-measured within three years of its last bollard pull test. Due to the limited number of facilities to conduct bollard pull testing, by 2004 some escort tug bollard pull certificates were being extended pass the three year cycle. In subsequent tests of a tug's bollard pull measurement it was demonstrated the tug's performance did not significantly change over a three year period, providing the tug is properly maintained. A security bollard is a post made of concrete, stainless steel, aluminum, cast iron, or other durable material, that creates an aboveground obstacle. At the high end, bollards are constructed to completely stop most vehicles. In place of jersey barriers, some secure facilities employ specially designed bollards, which may be retractable or removable. The retractable bollards allow authorized vehicles to access the site through frequently used gates, while the removable bollards will accommodate less frequently used gates. The bollards for free pedestrian movement, maintaining a visually open environment.

Pier / Wharf Facilities

Piers and wharves provide a transfer point for cargoes and passengers between land and water transportation carriers. The pier/wharf complex may provide the following facilities:

(1) Berth capacities of sufficient depths and widths to allow safe vessel approach and departure.

(2) Sufficient mooring devices to safely secure vessel.

(3) Access for railroad and highway facilities.

(4) Storage space for open or covered cargoes.

(5) Cargo handling equipment.

(6) Fender system.

(7) Administrative and maintenance facilities.

(8) Fire protection and fire fighting equipment.

The arrangement of berths should fit the proposed site without encroaching on pierhead or bulkhead lines, with consideration given to the depth contour below which the driving of piles is impractical. A Single-length berth dock length should equal the overall length of the largest vessel to be accommodated, plus an allowance of 75 feet at each end of the vessel. For preliminary design, the following approximate pier lengths may be used:

Lighters 150 ft.;

Submarines and destroyers 450

General cargo ships 600

Cruisers 750

Container ships 1,000 Dock length should equal the total overall length of the largest vessels simultaneously accommodated, plus allowances of 75 feet between the inshore end of inboard vessels and the bulkhead and 75 feet between the outboard end of outboard vessels and the end of the pier. Allow about 50 feet between vessels.

There are no definite width requirements, but sufficient area should be provided for storage and for truck and rail access. An apron should be provided along the outboard face. For general cargo wharves, the required width for aprons, shed, and upland facilities should be about 300 feet. The width may be increased for container wharves.

Clear distances between piers will be adequate for the safe berthing of the required maximum size vessels, plus clearances for the safe working of tugs and barges, lighters, and cranes operating between vessels. Where multiple berthing is provided, clearances shall be sufficient for dispatching the vessel at the inboard berth without moving the vessel at the outboard berth.

A ramp is a landing facility for watercraft. A ramp gives access to the water, as does a dock. A ramp is essentially a road connected to land at only one end. A boat ramp is a sloping incline or short roadway, and typically built abutting a road or parking area, extending beyond ordinary low water to provide for the loading or unloading of boats. Immediately waterward of the ramp is often an area that has been excavated (dredged) and a layer of soft sediment (e.g., sand) is occasionally placed in this area. Building a boat ramp is not just digging out a slanted entrance into the water. Creating fairly level parking and turn-around space, as well as an adequate access road, to accommodate heavy use by boaters is just as important as the ramp itself. All ramps have a top and a bottom and when the water drops below a certain point the ramp end is exposed. Many ramps are built in bays to provide some wind protection, with the ramp bottom and bay bottom at similar elevation.

A Gangway is a walking surface which spans any two marine facilities or vessels. Gangways are not fixed and their slope depends on the relative position of the facilities they are spanning.

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Page last modified: 05-07-2011 02:59:54 ZULU