Loading dock

Last updated
Modern loading bay with overhead door, dock leveller and dock shelter. Modern loading dock.jpg
Modern loading bay with overhead door, dock leveller and dock shelter.

A loading dock or loading bay is an area of a building where goods vehicles (usually road or rail) are loaded and unloaded. They are commonly found on commercial and industrial buildings, and warehouses in particular. Loading docks are part of a facility's service or utility infrastructure, typically providing direct access to staging areas, storage rooms, and freight elevators. [1]

Contents

Loading docks may be exterior, flush with the building envelope, or fully enclosed. They are part of a facility's service or utility infrastructure, typically providing direct access to staging areas, storage rooms, and freight elevators. [1]

Basics

Truck loading dock with overhead door, dock leveler, dock seals, canopy, indicator lights, and truck restraint system. Loading dock.jpg
Truck loading dock with overhead door, dock leveler, dock seals, canopy, indicator lights, and truck restraint system.

In order to facilitate material handling, loading docks may be equipped with the following: [1]

Warehouses that handle palletized freight use a dock leveler, so items can be easily loaded and unloaded using power moving equipment (e.g. a forklift). When a truck backs into such a loading dock, the bumpers on the loading dock and the bumpers on the trailer come into contact but may leave a gap; also, the warehouse floor and the trailer deck may not be horizontally aligned. In North America, the most common dock height is 48–52 inches (120–130 cm), though heights of up to 55 inches (140 cm) occur as well. [1] A dock leveler bridges the gap between a truck and a warehouse to safely accommodate a forklift.

Where it is not practical to install permanent concrete loading docks, or for temporary situations, then it is common to use a mobile version of the loading dock, often called a yard ramp.

Dangers

There can be very serious accidents on loading bays. One example is trailer creep (also known as trailer walk, or dock walk), which occurs when the lateral and vertical forces exerted each time a forklift truck enters and exits the trailer cause the trailer to slowly move away from the dock, resulting in separation from the dock leveler. Factors that affect trailer creep are the weight and speed of the lift truck and load, the gradient of the ground the trailer is parked on, the condition of the suspension, tire air pressures, the type of transition being used (dock levelers, dock boards), and whether the trailer has been disconnected or if it is still connected to the tractor. Trailer creep is often prevented by a vehicle restraint system.

Separation of a vehicle from the loading dock also occurs when a driver prematurely pulls away while the truck is still being loaded/unloaded. This issue is usually caused through a driver not correctly observing traffic lighting signals on a loading bay which prohibit the movement of the trailer. It is also important to ensure that drivers are adequately trained on the safe system of work they are expected to follow.

Loading zone

In different parts of the world, a section of a public or private road may be allocated for loading goods or persons, at specific or at all times. There are parking signs and/or road markings to warn motorists of parking regulations. These areas are known as loading zones or loading bays in many jurisdictions. They are generally monitored by parking inspectors, and vehicles found to be violating the rules can be towed or fined. [2] [3]

Safety

There are many ways to prevent an accident at a loading dock. Different forms of safety preparation include dock lights, back-up lights, trailer restraints, wheel chocks, heavy duty rising roller barrier, safety gates and safety netting. There are many online courses for safety training, and it is very important to regularly audit equipment, making sure that it is correctly assembled and in good working order.

Components of Loading Docks

A loading dock leveler is a piece of equipment which is typically mounted to the exterior dock face or recessed into a pit at a loading dock. Commonly referred to as “bridging the gap”, a dock leveler allows for the movement of industrial vehicles (e.g. forklifts, pallet jacks) between a building and a transport vehicle. Because of the different heights and sizes of many freight and semi-trucks, a dock leveler is an all-encompassing fixed solution[ buzzword ] to fit varying transports, capacities and budgets.

Although there are many different types of dock levelers [4] many share common components:

A flexible, less-expensive alternative to a loading dock leveler is a dock plate or dock board. Often more portable and not fixed to a dock or transport vehicle, dock plates and dock boards and metal ramps which help bridge the gap between dock and truck. Dock plates are commonly made out of aluminum and suited for lighter loads, such as handcars or dollies. Dock boards are generally made out of steel and suited for heavier loads such as motorized equipment or electric pallet jacks.

Related Research Articles

Forklift Powered industrial machine

A forklift is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th century by various companies, including Clark, which made transmissions, and Yale & Towne Manufacturing, which made hoists. Since World War II, the use and development of the forklift truck have greatly expanded worldwide. Forklifts have become an indispensable piece of equipment in manufacturing and warehousing. In 2013, the top 20 manufacturers worldwide posted sales of $30.4 billion, with 944,405 machines sold.

Crane (machine) Type of machine

A crane is a type of machine, generally equipped with a hoist rope, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy things and transporting them to other places. The device uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment.

Intermodal freight transport Cargo transport using multiple types of vehicles

Intermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation, without any handling of the freight itself when changing modes. The method reduces cargo handling, and so improves security, reduces damage and loss, and allows freight to be transported faster. Reduced costs over road trucking is the key benefit for inter-continental use. This may be offset by reduced timings for road transport over shorter distances.

Warehouse Building for storing goods and giving services

A warehouse is a building for storing goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial parks on the outskirts of cities, towns, or villages.

Sidelifter

A sidelifter is a specialised vehicle or semi-trailer used to hoist and transport ISO standard intermodal containers over longer distances.

Trailer (vehicle) Towed cargo vehicle

A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials.

Dump truck Truck which can tip its bed, dumping its contents

A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.

Distribution center Warehouse or other specialized building, often with refrigeration or air conditioning

A distribution center for a set of products is a warehouse or other specialized building, often with refrigeration or air conditioning, which is stocked with products (goods) to be redistributed to retailers, to wholesalers, or directly to consumers. A distribution center is a principal part, the order processing element, of the entire order fulfillment process. Distribution centers are usually thought of as being demand driven. A distribution center can also be called a warehouse, a DC, a fulfillment center, a cross-dock facility, a bulk break center, and a package handling center. The name by which the distribution center is known is commonly based on the purpose of the operation. For example, a "retail distribution center" normally distributes goods to retail stores, an "order fulfillment center" commonly distributes goods directly to consumers, and a cross-dock facility stores little or no product but distributes goods to other destinations.

Dock plate

In a loading dock, one problem to overcome is the problem of bridging the gap between a truck and the dock or warehouse floor. Not all trucks are the same height, and the height of the trailer floor within a truck can vary according to how heavily the truck is laden. Thus there is not only a gap to bridge but a height difference to overcome. Various devices are employed in order to achieve this: dock plates, dock levelers, dock boards, and various forms of lift. These devices vary in construction, suitability to dock conditions, cost of installation, and loading capacity.

Automated guided vehicle Type of portable robot

An automated guided vehicle or automatic guided vehicle (AGV), also called autonomous mobile robot (AMR), is a portable robot that follows along marked long lines or wires on the floor, or uses radio waves, vision cameras, magnets, or lasers for navigation. They are most often used in industrial applications to transport heavy materials around a large industrial building, such as a factory or warehouse. Application of the automatic guided vehicle broadened during the late 20th century.

Pallet jack Industrial machine

A pallet jack, also known as a pallet truck, pallet pump, pump truck, hand truck, scooter, dog, or jigger is a tool used to lift and move pallets. Pallet jacks are the most basic form of a forklift and are intended to move pallets within a warehouse.

Semi-trailer Trailer vehicle without a front axle

A semi-trailer is a trailer without a front axle. In the United States, the term is also used to refer to the combination of a truck and a semi-trailer; a tractor-trailer.

Automated Truck Loading Systems - ATLS has been commonly used in the material handling industry to refer to the automation of loading or unloading trucks and trailers with product either on or without pallets, slip sheets, racks, containers, using several different types of automated guided vehicle systems (AGV) or engineered conveyor belt systems that are integrated into vehicles, automating the shipping / receiving and logistics operations.

Straddle carrier

A straddle carrier or straddle truck is a freight-carrying vehicle that carries its load underneath by "straddling" it, rather than carrying it on top like a conventional truck. The advantage of the straddle carrier is its ability to load and unload without the assistance of cranes or forklifts. The lifting apparatus under the carrier is operated by the driver without any outside assistance and without leaving the driver's seat.

Moving floor


A moving floor is a hydraulically-driven moving-floor conveyance system for moving bulk material or palletized products, which can be used in a warehouse, loading dock or semi-trailer. It automates and facilitates loading and unloading of palletized goods by eliminating the need for a forklift to enter the trailer. In a truck-based application, the system can quickly unload loose material without having to tip the trailer or tilt the floor as with other dumping systems. In a bulk material application such as a waste facility, these systems can reduce double handling by allowing any vehicle to deliver material to the conveying floor and move heavy bulk materials to subsequent stages of a process. For bagged waste, the system can also be combined with bag openers.

Flatbed truck Type of truck

A flatbed truck is a type of truck which can be either articulated or rigid. As the name suggests, its bodywork is just an entirely flat, level 'bed' with no sides or roof. This allows for quick and easy loading of goods, and consequently they are used to transport heavy loads that are not delicate or vulnerable to rain, and also for abnormal loads that require more space than is available on a closed body.

Pallet racking Material handling storage aid system designed to store materials on pallets

Pallet rack is a material handling storage aid system designed to store materials on pallets. Although there are many varieties of pallet racking, all types allow for the storage of palletized materials in horizontal rows with multiple levels. Forklift trucks are usually required to place the loaded pallets onto the racks for storage. Since the Second World War, pallet racks have become a ubiquitous element of most modern warehouses, manufacturing facilities, retail centers, and other storage and distribution facilities. All types of pallet racking increase storage density of the stored goods. Costs associated with the racking increases with increasing storage density.

Material-handling equipment

Material handling equipment (MHE) is mechanical equipment used for the movement, storage, control, and protection of materials, goods and products throughout the process of manufacturing, distribution, consumption, and disposal. The different types of equipment can be classified into four major categories: transport equipment, positioning equipment, unit load formation equipment, and storage equipment.

A specialized set of jargon describe the tools, equipment, and employment sectors used in the trucking industry in the United States. Some terms may be used within other English-speaking countries, or within the freight industry in general. For example, shore power is a term borrowed from shipping terminology, in which electrical power is transferred from shore to ship, instead of the ship relying upon idling its engines. Drawing power from land lines is more efficient than engine idling and eliminates localized air pollution. Another borrowed term is "landing gear", which refers to the legs which support the front end of a semi-trailer when it is not connected to a semi-truck. Some nicknames are obvious wordplay, such as "portable parking lot", in reference to a truck that carries automobiles.

Blue Giant Equipment Corporation is a loading dock equipment manufacturer with corporate headquarters in Toronto, Ontario, Canada.

References

  1. 1 2 3 4 Sophia Greenbaum. "Whole Building Design Guide: Loading Dock". National Institute of Building Sciences . Retrieved 2008-02-26.
  2. Archived November 11, 2013, at the Wayback Machine
  3. Archived February 28, 2014, at the Wayback Machine
  4. various applications