Friday, August 27, 2010

Liebherr Overhead Cranes

The Liebherr Group is a German corporation that manufactures a wide variety of equipment including quite a few cranes. Liebherr makes construction cranes, maritime cranes, shipboard cranes, construction cranes, mobile cranes, mobile construction cranes and port equipment. Some of this equipment includes Liebherr overhead cranes.

Liebherr overhead cranes for industrial uses come in all shapes and sizes. Most of Liebherr’s cranes are self propelled so they can be used indoors and out doors. Port and cargo handling cranes are a specialty of Liebherr’s.

Liebherr Cargo Handling Cranes

The Reachstacker is a small but very powerful wheeled crane with an extendable jib that is ideal for stacking cargo containers. A special mechanism on the end of the jib allows the Reachstacker to actually pick up and stack cargo containers the way a child stacks blocks.

The Reachstacker can actually stack cargo containers up to six high yet it is quite small. The Reachstacker is small enough to be used on a ship or inside a warehouse but it can also be used outside in the yard as well. The Reachstacker is one of the smallest and most versatile cargo handling solutions available.

One of Liebherr’s specialties is cranes designed to move cargo containers from ship to port and back again. Liebherr overhead cranes designed for moving containers include rubber wheeled gantry cranes.

Liebherr’s rubber tired gantry cranes are mobile gantry self propelled gantry cranes that can stack several containers at once. These are ideal for moving containers around in a yard or loading them onto railcars or trucks.

A larger solution intended for moving a much higher volume of cargo containers is rail mounted stacking cranes. These Liebherr overhead cranes are designed to move containers from one side of the yard to another. They would be ideal for loading a train or ship or stacking containers for storage.

Ship to shore container cranes are Liebherr overhead cranes specifically designed for loading and unloading ships. These cranes enable crews to stack containers right on the ship for easy transport.

Electric Excavators

A specialized crane manufactured by the Liebherr group is the electric excavator. This is a smaller crane that looks like the excavators and cranes used in construction and similar work. The difference is that it sits in one place and it is electrically powered.

Electric excavators are used for lifting odd sized materials such as scrap metal or garbage. They are often equipped with grapplers or magnets to increase their lifting capacity.

Mobile Harbor Cranes

Another specialty of Liebherr’s is mobile harbor cranes. These are large mobile cranes intended to move around a port facility on their own power. These cranes can lift cargo containers and other large objects on and off of ships. They are also often used for moving bulk cargos.

Liebherr overhead cranes include a number of cranes specifically designed for use on shipboard. These include materials handling cranes, cranes for moving cargo containers and hose handling cranes. Liebherr also manufacturers gantry cranes specifically designed to move cargo containers on shipboard.

Thursday, August 26, 2010

Jib & Gantry Cranes

Jib & gantry cranes are two popular varieties of freestanding cranes often found in environments such as factory floors. These are usually lighter and smaller cranes used right at work stations or by workers engaged in specific tasks.

Jib Cranes

A jib crane is a free standing crane that looks a bit like the cranes used on construction sites. It usually consists of an arm mounted on a small tower with a winch or hoist at one end. A wire rope or other lifting mechanism runs up the arm from the hoist providing the lifting power.

Jib cranes have the advantage of being free structures that can be easily moved. They are usually only useful for lifting unless they are mounted on some sort of wheeled carriage or rail system for movement.

It is not uncommon for jib cranes to be mounted directly upon walls and other structures. Jib cranes are often used outside because they are not overhead cranes.

Gantry Cranes

The difference between jib & gantry cranes is that a gantry crane is an overhead crane or bridge crane. It usually consists of a crane mounted upon a girder or girders or span held up by supports similar to a bridge.

The difference between a gantry crane and a traditional bridge crane is that a gantry crane is usually mobile. In many cases the gantry crane is mounted on rails or wheels so that it can be moved. In other cases it can be easily broken down for easy movement.

A popular trend in gantry cranes is smaller gantry cranes designed for home and small business uses. A popular brand of smaller gantry crane is the Snaptrac which is small enough for use in home garages and mom and pop shops.

Giant gantry cranes are often used in outdoor industrial facilities such as lumberyards and intermodal shipping yards. In these facilities huge gantry cranes are used to move large objects such as cargo containers.

In some cases the gantry crane will be mounted upon wheels or rails and motorized so it can be moved around. Outdoor gantry cranes maybe moved around a yard for easy lifting.

Gantry cranes usually have a much heavier load capacity than jib cranes and have the advantage of sometimes being traveling cranes. A drawback to gantry cranes is that they take up quite a bit of space on the floor.

Advantages to Jib & Gantry Cranes

The biggest advantage to jib & gantry cranes is that they are free standing structures. This means that their installation involves no construction or engineering work on the building. Since they are not attached to the building, jib & gantry cranes can be used in older structures and larger structures where traditional overhead cranes can’t be used.

Another advantage to jib & gantry cranes is that they can be quickly installed and set up. This makes them ideal for situations when a lifting solution is needed fast.

A disadvantage to jib & gantry cranes is that they can take up quite a bit of space on the floor. This can get in the way of work and manufacturing processes.

Wednesday, August 25, 2010

Design Guide for Overhead Crane

The basic design for an overhead crane is pretty simple, a hoist mechanism is suspended or mounted upon a guide way running between two supports. A design guide for overhead cranes is needed because of all of the features being added to them.

In the United States a wide variety of safety features and mechanisms are mandated on overhead cranes by the Occupational Health and Safety Administration (OSHA). OSHA is the federal agency charged with overseeing workplace safety which includes overhead cranes.

Any overhead crane installed in the United States will have to comply with OSHA regulations and standards. This means that OSHA regulations and standards will have to be part of any design guide for overhead cranes in the United States.

All overhead cranes in the United States also have to pass an OSHA mandated inspection every two years. Cranes that don’t can not be legally operated in the US. This means the design guide should take this inspection into account as well.

Increasing Complexity of Overhead Cranes

The main reason for the design guide for overhead cranes is the increasing complexity of overhead cranes. A wide variety of features and accessories are being added to overhead cranes as more and more uses are found for these useful devices.

The design guide will have to take the use for which the crane is intended into consideration. One of the main considerations is the load capacity or the amount that the crane will be designed to lift. The heavier the load capacity the stronger the hoist and the more substantial the crane support structure that will be needed.

Another consideration is the way in which the crane will be used. Will it be used primarily as a lifting mechanism or a transportation system? If the crane is to be used as a transportation system, it will have to be a traveling crane which will require more engineering.

The degree of automation required will also have to be considered in the design guide for overhead cranes. Completely automated cranes will require more electronic controls and different safety features.

The degree of operator control will have to be considered as well. Will there be one crane operator or several? Some organizations require special training for crane operators, while others let anybody use the crane.

Crane Location

The location of the crane determines the type of crane to be used and the requirements of the design guide for overhead cranes. Cranes that will be used outside will have to be bridge or gantry cranes. Cranes used inside can be monorail and other cranes that can be mounted on the ceiling.

When a crane is to be mounted on the ceiling or directly to a building the load capacity of the building has to be taken into account. The building must be capable of supporting the loads lifted by the crane. The crane must also be able to operate safely without interfering with the work done on the factory floor.

There maybe separate design guides for different types of overhead cranes. Cranes inside buildings can be part of integrated materials handling systems or production process. This requires an entirely different design guide for overhead cranes.

Tuesday, August 24, 2010

Bridge Cranes Michigan

The state of Michigan is one of the centers of American industry, not surprisingly Michigan is also a center of the bridge crane industry. A number of different companies manufacture bridge cranes Michigan and several excellent crane service companies also operate in the state.

Versa Handling Systems

Versa Handling Systems in Detroit specializes in providing complete handling systems including bridge cranes Michigan. Versa can put in almost any crane system from a basic traveling bridge crane to a complete automated materials handling system.

Versa can install both single and double girder bridge cranes throughout Michigan. Versa can also put in monorails, jib cranes, gantry cranes and a wide variety of other overhead crane systems.

A specialty crane that Versa can install for manufacturing is enclosed track cranes or ergonomic cranes also known as tool rail. These low capacity Bridge cranes Michigan are completely enclosed crane systems. This means they are safe and ideal for industrial purposes such as workstation cranes and personal lifting systems. Custom cranes and a complete line of under the hook components are also available.

Unified Industries Inc

United Industries Inc in Howell, Michigan, can provide complete bridge crane solutions. Its specialty is turnkey systems with manipulators and articulated arms. Unified Industries third runway rail systems can increase load capacities by up to 35% without undue amounts of construction and installation. This reduces costs and makes the system more efficient.

Another specialty at Unified Industries is telescoping extensions for bridge cranes Michigan these can extend the length of bridge cranes without undue expense. These allow for ergonomic interfaces that increase productivity without driving up costs.

United Industries specializes in create bridge crane solutions for industries including the automobile industry. Unified’s trolleys and traveling cranes have an excellent reputation.

Unified can fabricate a wide variety of components for bridge cranes including carriers, trolleys and rails. This can enable the expansion and extension of existing bridge cranes without disrupting production.

Crane Technologies Group Inc

Crane Technologies Group in Rochester Hills, Michigan, manufactures a wide variety of cranes including bridge cranes. Crane Technologies builds the well regarded Michigan Crane line of traveling bridge cranes.

Michigan Cranes are built with anti friction bearings in order to reduce wear and tear and lower maintenance costs. Motor driven bridges and totally enclosed gear reducers also reduce maintenance costs. Fitted bolts and drilled and reamed holes make for a seamless fit and smother running on these bridge cranes Michigan.

Crane Technologies builds a wide variety of bridge cranes including single girder bridge cranes. The single girder bridge cranes are custom engineered for use in a wide variety of industrial applications.

Double girder bridge cranes Michigan are also available. These are heavy use cranes designed for many different applications and industrial processes. Many special features including cab control, tandem hoists and auxiliary hoists are available. The standard top running double girder system can accommodate up to 150 tons on 125 foot spans. The standard under hung double girder system can carry up to 15 tons on 60 foot spans.

For extremely heavy load capacities, open barrel bridge cranes are available. These bridge cranes Michigan can carry almost load required.

Monday, August 23, 2010

Automated Bridge Cranes

The fastest growing use for bridge cranes is certainly automation. Automated bridge cranes are now being used for a wide variety of applications in many different industries. The growing use of robotics in industry has led to many new uses for automated bridge cranes.

Automated bridge cranes are now used on everything from wood products to the space shuttle. Many modern automated cranes are now so specialized and sophisticated that many people may not recognize them as cranes. This is certainly the case when robotic arms are added to automated cranes. Gantry robots are robots designed to operate from bridge cranes and other cranes. These robots are often used to automate production processes in hazardous environments and clean rooms.

Automated Bridge Cranes in Clean Rooms and Hazardous Environments

Modern industry, especially high tech industries increasingly does its production in clean rooms, environments where there can be no contamination. Not surprisingly human workers are often unable to enter such environments so automated bridge cranes are often used to move materials in and out.

In hazardous environments, automated bridge cranes with robotic controls and gantry robots are often used in places that would be unsafe for human workers. An example of such a use would be to move barrels or other containers filled with radioactive or poisonous liquids.

Telescopic tube systems enable robots mounted on automated bridge cranes to reach almost any work area. Such tube systems greatly extend the reach of both robotic arms and gantry robots. Automated bridge cranes with robotic arms and gantries are now regularly being used in the chemical, explosives and munitions industry. One use for these cranes is the decommissioning or disarming of old weapons systems including nuclear weapons.

Food Processing and Robotic Packaging

A growing area for the use of automated bridge cranes is the food processing industry. The use of automated bridge cranes enables manufacturers to move food without the dangers of spillage and contamination.

Automated bridge cranes may be used in conjunction with robotic packaging machines. These robots pack food without damaging or contaminating it. The robots can be mounted on the bridge crane to enable them to reach the food. Robotic tray systems combined with automatic bridge cranes can greatly increase the speed and efficiency of food processing operations.

Precision Industries

Some of the most advanced and sophisticated automated bridge cranes are used in the aerospace industry. Airplane manufacturing often requires precision drilling and trimming that can’t be done by human workers. Automated bridge cranes are used to bring the components to these processes and to move machinery into place.

Other industries that require precision machining such as the medical device industry often make use of automated bridge cranes. In industries that require a high degree of precision integration and program management is required.

An example of an integrated system would robotic drills mounted upon automated bridge cranes. Another would be a system would in which components were delivered to a milling machine by an automatic bridge crane then moved to the final assembly area by another automatic bridge crane.

The use of automatic bridge cranes will only increase in the future because such cranes are among the most versatile devices in the modern factory.

Saturday, August 21, 2010

Automated Gantry Cranes

As the volumes of trade between countries increase due to globalization, the volume of container movements received at main port terminals in most countries has increased also. Thus, the need for a highly effective mode of executing receipts and transfer of containers from ships, trucks and trains becomes expedient. Coupled with the safety concerns around human traffic within container handling cranes, design and manufacture of automated gantry cranes came into force.

Advantages Of Automated Gantry Cranes

Automated gantry cranes are the newest and unmanned versions of gantry cranes which can be controlled remotely, thus eliminating some hours of downtime associated with increased human interaction with the container handling system. They are very large versions of rail container gantry cranes, and are employed to increase operational efficiency and reduce operational costs. Automated gantry cranes have the capability to perform container movements at higher speeds, based on operator programming.

Though automated gantry cranes are mostly used for container handling, a good number of them can also be found in manufacturing industries where an automated warehousing system is employed. Here, they are referred to as “Stackers” and the crane moves on a track (similar to the gantry rail or tyre) along an aisle within the warehouse. Its hoist is similar to the fork in a forklift and can be raised or lowered to retrieve or place a large item on the stacks.

It is very advantageous for use in cold-room industries and oil and gas drilling in sub-zero regions, as it prevents the operator from constantly working in freezing temperatures. This would be carried out from a console in a warm room, thus reducing risks associated with workman’s compensations.

Automated gantry cranes are better suited for loading and offloading multiple containers at a time. They are also equipped with anti-collision systems which are employed to prevent all sorts of collisions, be it other cranes or otherwise. They also have very large spans and heights, to maximize value for the large investment it requires. Automated gantry cranes have been touted as the safest way to handle containers by most manufacturers, because of the limited interaction within the system by humans.

In terms of cost and manufacturing lead time, automated gantry cranes are guzzlers. Some of them can take up to two years from request to delivery, because they are usually manufactured of request due to high costs involved. A full unit can cost as much as US$15 million, before cost and time overruns. Major manufacturers of these crane types include Mitsubishi Heavy Industries, Kone Cranes, Samsung Heavy Industries, and Kalmar Industries among others.

Finally, it must be noted that in general terms, an automated gantry crane can refer to any of the gantry crane types which required very little human manipulation to function. They should also not be confused for other crane types which are automated, but not in the gantry family of cranes. I would also like to state that the automated gantry crane is the shipping industry’s response to general safety during container handling operations, improved efficiency and profitability, including cost and time minimization.

Mobile Gantry Cranes

Mobile gantry cranes are about the smallest variants of gantry cranes available. They can hoist loads and be moved from one location to another, where the load will be dropped. Mobile gantry cranes can either be self-propelled or manually moved around. Some mobile gantry cranes can also be dismantled, transported across distant locations and re-assembled for use at the new location, with height adjustable features. Mobile gantry cranes can satisfy both indoor and outdoor use. Indoors, they are mostly found in fabrication workshops, car shops, and in semi-heavy industries application.

Advantages Of Mobile Gantry Cranes

Mobile gantry cranes are about the most flexible among the gantry cranes family. From the point of ordering to final installation, they can be customized, set to adjustable heights, dismantled and assembled as the operation demands. They can also be transported across different locations for use, thus reducing operational costs. In terms of energy consumption, theirs is the lowest of all gantry cranes, with the only disadvantage, being the limit of loads they can hoist.

Mobile gantry cranes can be used in many applications, on ships, fishing trawlers, oil processing vessels, car workshops, manufacturing industries etc. Thy can serve as a cost saving option, instead of a conveyor, in situations where the loads being moved are not of high volume.

Operation

Depending on the industry in which it is applied and the specific company, mobile gantry cranes can serve numerous intended functions. As earlier noted, they can be self propelled or manually propelled, if need be. But, power for hoisting is mostly via electrical Direct Current, or general Alternating Current used by the facility. Lighter duty mobile gantry cranes move loads only in the vertical direction, which is, lifting only, while higher duty types can both lift and move loads. Here, the load can be traversed across the width of the crane.

Also, some mobile gantry cranes can be used in conjunction with other crane types because of their higher mobility level, thus leading to increased operational efficiency. They can be used both indoors and outdoors within a facility. Even if a company is moving shop, all that needs to be done is to dismantle the mobile crane and re-assemble at the new location. This is less expensive than other crane types where you have to call in experts to un-install the large crane, incur transportation costs and also pay for re-installation at the new location.

There are several manufacturers of mobile gantry cranes world over, and they are constantly in competition to provide clients with innovative mobile gantry cranes, more so, since they can be highly customized. This has driven down the cost of the cranes relatively, when compared to other gantry crane types. You can even have your company name embossed on the mobile gantry crane during manufacture. Test runs are much more possible before purchase and they can be easily bought off the counter.

To get the best out of your investment in a mobile gantry crane, you need to incorporate all your lifting needs, send it out to the manufacturing companies and get the best technical bid for your needs. You can even consider using your mobile gantry as a mini-conveyor.

Friday, August 20, 2010

Rail Container Gantry Cranes

Rail container gantry cranes are a form of gantry cranes mounted on rails to aid movement while hoisting heavy items from one position to another. The other form of movement can be on rubber tyres. The first design of a rail container gantry crane appeared in the year 1960. It was designed by Paceco Corporation and referred to as a “Portainer”, coined from the words “port” and “container”. The major loads hoisted by this type of cranes are cargo containers, usually from ship to shore or vice-versa. Thus, they are also referred to as ship to shore cranes.

Operation Of Rail Container Gantry Cranes

Using either electrical AC or diesel engine powered DC as the power source, the trolley in rail container gantry cranes run along rails wile hoisting loads. These rails are located on the top of the boom and girder or at their sides and serve as the support end for moving the hoisted load.

Rail container gantry cranes are best suited for inter-modal container terminals where multiple containers need to be moved from one holding area to another. This can include ship to shore, truck to train, ship to truck, ship to train and vice versa. For these operations, the most important consideration is movement of the container to its desired location effectively and not the speed at which it is moved. One big advantage of rail container gantry cranes is that it allows for better land usage at a shipyard or port and also reduces possibility of ground accidents. This is so since movements by multiple mobile cranes has been eliminated. Also, it increases available stacking area for containers. When offloading containers from ships, the rail container gantry cranes usually straddle the ship, allowing for lifting and moving massive objects over the ship without problems.

For maximum effectiveness at a container terminal, rail container gantry cranes are built with a supporting framework that can manoeuvre across the length of the quay. This framework supports a platform, also known as a “spreader”, allowing the spreader to be lowered to latch onto a container and move it to and from a specific location at the quay. Containers are usually picked one at a time, but some newer rail container gantry cranes have the capacity to pick up four (4) containers at a go.

Two major types of rail container gantry cranes in operation today are the high profile and low profile variants. The low profile variants are most suitable for use when container terminals are situated close to airports, where the high profile type may obstruct the flight path of a plane. In terms of size, rail container gantry cranes are rated with reference to the Panama Canal, especially when the cranes are welded on to and travel with the ship.

We can have a “Panamax”, “Post Panamax” and “Super Post Panamax”. In this light, a “Panamax” crane is one capable of fully loading and off-loading a container ship that can pass through the Panama Canal, while the “Post Panamax” does same for ships too wide to pass through the Panama Canal. The largest, which is the “Super Post Panamax”, is about twice the size and weight of the “Post Panamax.”

Wednesday, August 18, 2010

How Do Gantry Cranes Work?

In its simplest form, a gantry crane is a member of the fixed family of cranes, with the other main family being the mobile variant. Similar crane types which are members of the fixed family include the overhead crane, jib crane, loader crane etc. A gantry crane, also called a portal crane is a type of crane that has a vertical support on one end, and moves horizontally at the other end, either on rail tracks or on rubber tyres. Usually, gantry cranes lift large or small objects by the means of a hoist which is fitted in a trolley and allowed to move horizontally across an area over which it picks and drops items. Gantry cranes are found in most port locations around the world, as they are used for lifting heavy objects around ships, which is a major advantage for gantry cranes in the shipping and heavy duty industries.

The major types of gantry cranes in use today include the container gantry crane, rail mounted or Electrical Overhead Travelling (EOT) gantry crane and the workstation gantry crane, mobile gantry crane.

Applications Of The Gantry Crane

As earlier noted, gantry cranes are utilized mainly in heavy industries, with its largest types being found in ship-building and port locations around the world. This is because they are specifically designed for lifting very large and heavy objects. At their prime locations, these objects include containers and ship-engines. Smaller gantry cranes can be found in car workshops and are used for lifting engines and their components in and out of cars. These variants are usually mobile units or free standing gantry cranes.

Power for operation of gantry cranes is usually derived from two main sources via diesel engine power generators and electrical power. The diesel powered generators can be found at the top of the crane and emits Direct Current (DC) while the electrical power source is usually located at the dock. This is also referred to as shore power and emits Alternating Current (AC).

Gantry cranes can be classified either based on their operational capability and size or physical mode of operation. The most advanced of the pack is the automated gantry crane, also referred to as the Stacker. It is usually unmanned and controlled from a remote operations center. This is used when volumes of large loads, especially containers are to be moved between two holding bays, e.g. from ship to train or truck to ship and vice versa. In terms of size, the rail container gantry cranes are the largest available anywhere in the world. Two famous gantry cranes nicknamed Samson and Goliath, built in 1974 and 1969 respectively are one of the largest in the world today. In combination, they have a lifting capacity of over 1,600 tonnes at heights up to 70metres. They currently reside and execute lifting assignments in the largest dry dock in the world at Belfast.

The hoist, that is, load lifter on gantry cranes can either be located in a fixed machinery enclosure or on a trolley. Trolley hoist systems usually run horizontally along rails and can be fitted either on a single beam or on two beams, that is, a mono girder and twin girder respectively. When gantry cranes run on rubber tyres, there is no need for a rail system, thus reducing cost and earth impact.