Friday, August 27, 2010

Rubber Tyred Gantry Cranes for Container Terminals

RTG, the rubber tyred cranesare mobile cranes employed for lifting, moving and for staking thestandard containers in stacking terminals in the specified stakingareas. These cranes serve to stake many rows of containers in thesecontainer yards for rail or road, for achieving the maximum soragedensity because of limited space in container terminals

chinaboy亚洲soloNormally, a container loading crane moves on rails rather than rubber tyres. A RTG and a straddle carrrier are almost similar in appearance when viewed from the side. RTG has a moveable crane on its top. RTG,rubber tyred gantry cranes are especially used equipemt at thecontainer yards for handling the normal 20 and 40 feet containers. Thesecranes are used almost all over the world at different largestcontainer terminals for performing this specific job of handling themillions of containers annually. RTGs serve inmost econoimical manner for straddiling of multi lane containers atrail or a road yard to get the maximum sorage density.

One example of well designed and successfully used RTG cranesis Konecranes which has been innovated very intelligently by itsdesigners. The machine employs the components which have proven theirperformance and require the least amount of maintenance with utmostdependability. These cranes provide the performance consistent to thecustomers’ expectations.

Konecranes RTG cranes have many additionalfeatures over and above the standard specifications of these gantrycranes. These additioanl features add to the performance substantiallyand help to considerably reduce the maintenance costs and down time ofthis equipemtn


  1. The crane has its exclusively designed sway prevention system thatprevents the sway of spreader rather than only dampening the sway.
  2. The spreader has a horizontal fine positioning that enables tomove it 300 mm without movement of trolley in the direction of trolleymovement.
  3. Spreader trim along with its hoist mechanisam eliminates the need of an additional trim mechanism.
  4. This gantry crane has sixteen wheels and reduces the cost of civilworks in container yards by causing minimum damages in the area ofoperation.
  5. Gantry drive is direct and there is no chain or wheels withsprokets. This feature imparts smooth movement to gantry and even themaintancne is lowest.
  6. It does not have any hydraulic mechanism for even wheel steering or for micromotion of antisway spreader. These RTG machine mostly work in marine environment, they perform most reliably owing to this feature with least maintenance cost.

Thursday, August 26, 2010

Construction and use of traveling gantry cranes

Gantry cranes are the most commonly used for lifting, raising,lowering down and shifting of heavy loads in industry or shipyards fromdifferent locations. The gantry cranes have steel fabricated structuresin their main parts.


Gantry cranes lift a load with the help of a hoist.The hoist is fixed to a movable trolley, which moves horizontally onrails fitted to a beam on the wheels under it. The crane has uprightssupports and can move on the wheels. These cranes are more suitable forhandling heavy loads. Huge gantry cranes are used in various industrieslike shipbuilding or for moving heavy loads in other industries. Thegantry crane with tires or caster wheels is used in many industries.These movable gantry cranes are named workstation gantry cranes used formoving the materials, parts, and products between differentworkstations. These cranes may have I-beam, tracks or other extrudedmetal sections in their mechanism for lifting of loads. Many cranes donot move when lifting the loads. They move only in unloaded condition.The load capacity of a gantry crane is dependent on design and structureof the cranes.

Use of travelling gantry cranes:

Very common use of the travelling gantry cranes are there in railyards, shipping docks and industries for loading, unloading and movementcontainers and of loads. In industry, they are employed for moving theitems from floor to floor for production and assembly operations ofproducts. In production and assembly operations, the material, parts,sub assemblies, or assemblies need to be frequently moved from oneworkstation to another. The loads are so heavy that it is impossible tohandle them manually without the aid of material handling equipment. Thegantry cranes help in the mobility efficiently. Final products are muchheavier than the parts and require lifting and transferring them withthe help of gantry cranes.

Parts of a mobile gantry crane.

Let us discuss about the various parts of a gantry crane.Two steel structured vertical columns support a horizontal beam at itsends. The beam carries a moveable lifting hanging mechanism called aspreader on it. The lifting mechanism can travel along the horizontalbeam. The lifting mechanism is employed for lifting the load. The gantrycranes are mounted on four wheels at the corners for movement of crane.Two wheels are used for steering the crane while other two are drivenby motor for movement over the floor. These wheels may be lined withrubber on the rim. The operator can move the crane to proper position,lift and raise the load and move the load to another location. It isdifficult to control the movement of load due to swing resulting fromthe crane mechanism. It becomes more difficult, if the floor is filledwith many machines and items and crane cannot move easily because of theobstructions to move it.

Wednesday, August 25, 2010

How useful are small gantry cranes

Gantry cranes are overhead cranes with a bridge and a trolleyattached to a hoist. The load is lifted with the overhead hoistconnected to the crossbeam. Crossbeam is mounted on rails or on wheels.In small gantry cranes, wheels are more preferred. After lifting theload, it is possible to move the load from one station to another in afactory or shipping yard.

The load can be moved along the rails or wheels as well as acrossthe crossbeam. The gantry cranes are produced in many sizes- one smallfor normal use in a warehouse and to that huge size used in a dock toload ships. In industry, for example, a typical use can be lifting anautomobile engine with a gantry crane. More powerful and larger cranesare used in many other industries for handling variety of products andmaterials.

Two largest gantry cranes are located in Belfast in Northern Irelandin a dry dock. These mark the history of largest cranes named Goliathmanufactured in 1969. Samson had erected it in 1974. These exemplify thepower and versatility of gantry cranes.

In fact, gantry cranes are smaller than Samson and Goliath cranes.Most of these cranes are portable cranes, which are not mounted onrails. In industry, mostly cost effective medium or small gantry cranesare used. The uprights are fixed on polyurethane caster wheels formaximum maneuverability and the cranes can handle up to 5-ton loadeasily.

Gorbal is a good quality portable gantry crane traded by ErgonomicPartners. It is provided with bolted attachment between uprights andcross beams for maximum safety. The Gorbal cranes are either operatedwith an electric or manually operated hoist. Other manufacturers alsobuild similar cranes that can be operated either way. If you need tolift heavy loads less frequently or lift heavy loads more frequently atdifferent locations, portable gantry cranes are more useful for theirinherent flexibility for use.

Portable small gantry cranes:

Generally, portable gantry cranes are built with a load capacitybetween 1 and 5 tons and crossbeam span of 30 feet. The design may varywith end use and some of the cranes may not need a full runway. ASCE rail can be successfully use on portable gantry cranes. ASCErail is just like steel rail and it can be installed on floor formoving the crane. In case the crone is to be frequently used at variousplaces within the industry, a portable gantry crane without tracks isideal alternative. The crane can move on tires or on caster wheel thatare lockable.

Portable gantry cranes are more safe and cost effective compared toforklift trucks. They are more powerful and versatile. Gorbal is thepioneer for manufacturing of portable gantry cranes renowned for theirstrength, durability, and safety. Gorbal has facilities to manufacturesmall portable cranes in Alabama and Network, USA.There is option to buy the cranes with fixed or adjustable widths andheights as guaranteed reliable products guaranteed for five years.

Tuesday, August 24, 2010

Types and Advantages of Steel Portable Gantry Cranes

Advantages of Steel Portable Gantry Cranes:

You may need a variety of equipment with different load capacitiesand range for lifting and handling different heavy loads and materialsfor different jobs in your factory. It will require a battery of steelportable gantry cranes readily available inside the factory or warehouseso that your trained staff can carry out the work efficiently inminimum time with the most suitable equipment.

You have several benefits from steel portablegantry cranes rather than using only fixed type expensive cranes. Theportable cranes are suitable for almost all sizes of the business andcan be very useful for hauling the material, if you are searching for aright solution. The fixed type of lifting equipment is able to move thematerial from one location to another easily. It has high initial costand there are a number of restrictions to its use. It cannot serve youbeyond a particular area in its range. For other locations you needsteel portable gantry cranes.

However, there is limit of the load lifting capacity for a portablecrane is lower than fixed cranes. Nevertheless, these cranes can beutilized to move the materials any one location to another locationsuccessfully. The workers will feel that it is the most convenientsolution for them in most of the material lifting and movement withinthe workstations.

Types of steel portable gantry cranes:

You can get several types of portable gantry cranes. The cranes aredesigned to work in normal working surroundings. The major task involvesthe lifting of materials and heavy components from floor level todifferent workbenches and back. These cranes are designed to operate inthe minimum possible area and at the same time, they should reach thenormal workbenches. The base size of crane is 68 inches and can easilywork in most of the small units.

For every user the important factors are the weight lifting capacityand the range to operate in a particular environment most economicallyto meet his requirements. There are many models and some of them aremost commonly used. Lightest steel gantry crane weighs 228 lbs and canlift almost same amount of load i.e. 300 lbs due to its lightweightstructure. This crane is most suitable for small workshops. You shouldinvest in a stronger crane to lift heavier loads, if you can accommodatethat in your workshop. You may be surprised to know that the mostpowerful portable gantry crane weighs only 300 lbs while it can lift aload of 2000 pounds. The crane can be easily handled and can lift a widerange of loads making it most convenient for the people to get to itand use immediately.

Safety is the most crucial factor in using any type of crane. Thegolden rule is that “never lift a load beyond the capacity of a craneand follow safety instructions” to avoid any accident.

Monday, August 23, 2010

Different Types of Gantry Mounted Cranes

Gantry mounted cranes are most useful for handling of containers in container yards. A rail mounted gantry craneis moves on the rails to lift and stack the 20 and 40 feet containerswith the help of a spreader or a twin lift spreader. The cranes areavailable in diverse models with different size of overhangs and spans.The gantry-mounted cranes are expressively designed for specificstacking and handling containers in docks as well as other containeryards.

RMG cranes have additional benefits as compared RTGcranes. These are powerful driven with electricity, higher haulagecapacity clean operation, and higher speed to travel with load. The RMGcranes are most productive for the shipment of containers by road andrail and transfer heavy loads. These applications of the crane requirespeedy movement in both longitudinally and crossways. Moreover, thesecranes have additional feature of automatic self-positioning for theirefficient performance.

Examples of gantry mounted cranes:

Terex stacking cranes can handle exhaustive container stacking atlocal as well as international docks and other points with maximumproductivity. Terex RMG cranes boast to haul containers and swap bodies on container terminals for stacking and railways.

Features of RMG:

The main features of gantry-mounted cranes are:

  • Anti-sway system
  • Approved weighing system incorporated with crane
  • System for crane management and data transfer
  • A piggyback

Examples of other gantry mounted cranes:

Another type of RMG crane is LPMCwhi9ch is especially designed for container yards. It works on electricpower available in yard and can lift, move and stack containers using20 and 40 feet telescopic types of spreaders or with the help oftwin-lift spreaders.

Features of LPMC gantry mounted cranes:

LPMC is specially meant for the container handling in yards and is most productive in comparison to RTG crane that is mounted on tires. LPMCis powered with electricity to lift heavier loads at higher speeds. Itcomprises different mechanisms for lifting, trolley transferring,gantry, and dampening sway. These mechanisms mostly operate with thehelp of a control system that works on Ac frequency conversion. Thesemachines work smoothly usually employing a single drum for liftingoperation. Double drum types of cranes are also used. There are a coupleof options available for these cranes and the user can select themaccording to his requirements: Trolley slewing mechanism permits slewingbetween -10 and +190. You can use continuous slewing also. Overhaulingbeam RMG gantry crane can reach beyond rail travel. The other choices are RMGfor different rail gauge, with generator power and twin-directionanti-sway mechanism. The quayside container crane, portal cranes, shiploaders, and RTG are the different gantry mounted cranes.

Overhead Industrial Cranes

Overhead industrial cranesare among the most versatile and cost effective mechanisms that can beinstalled in a factory or other facility. Such cranes can help anorganization maximize the use of its space, speed up production andreduce costs.

The main advantage to overhead industrial cranes is obvious: theyprovide a transportation system and a lifting mechanism that doesn’t putany more machinery on the floor. This can obviously save space whichcan be used to add workers and machinery to the floor. It can giveworkers more room to do their jobs and even increase safety.

Get Vehicles off the Floor

A big benefit of overhead industrial cranes is that they getvehicles like forklifts off the floor. This can make the workplace saferbecause vehicles won’t be driving around the floor. Obviously movingvehicles on the floor can lead to accidents which can cause injuries ordamage to machinery.

Moving vehicles on the floor can also interfere with work. Workersmay have to interrupt what they are doing to move out of the way as avehicle passes. A worker could also have to stop his work to go and get avehicle to move something or lift something.

An overhead crane enables workers to lift loads and move loadsaround the work area without vehicles. This lowers the possibility ofaccidents and the amount of interruptions to the work.

Increase Efficiency

A system of traveling overhead cranes such as a materials handling systemcan smoothly move loads around the facility. This could enable workersto stay in one place and do their job rather than move around as loadsmove.

Overhead industrial cranes can be used to bring supplies andequipment right to workers on the floor. This can reduce the amount oftime spent away from the work area fetching supplies or equipment. Itcan also limit the amount of equipment and items on the floor freeing upspace for work.

There are other ways that overhead industrial cranes can increaseefficiency. Such cranes can be used to load trucks or trains fromoverhead which is faster than using a forklift. They can also be used tomove bulk loads very quickly and to pick up large items on the shop.

Installing Overhead Industrial Cranes

The variety of overhead industrial cranes available today isincredible. There are dozens of kinds of overhead cranes with all mannerof capabilities. This means that a company could have a very hard timedeciding which crane to buy and install.

The best way to evaluate overhead crane needs is to hire aprofessional crane company. Professional crane companies have staffs ofexperts including crane technicians and crane engineers that canevaluate your needs and tell you which crane you should purchase.

Such companies can even design, build and install custom cranes andcrane systems for very specific needs. Overhead cranes can eliminate theneed for workers to handle potentially hazardous or dangerous materialssuch chemicals. Overhead cranes can even be used in clean rooms andother environments where people can’t go.

There are now overhead industrial cranes to meet virtually everyneed. A professional crane company should be able to help a company findthe crane or crane system that will meet its needs.

Saturday, August 21, 2010

Hand Signals for Overhead Bridge Cranes

There are quite a few hand singles for overhead bridge cranes. These signals are used for both safety and day to day work purposes.
It is vital that a workplace that uses an overhead bridge cranedevelop and adopt a uniform set of hand signals for overhead bridgecranes. These signals let the overhead bridge crane operator know whatis going which ensures safety in the workplace. Such signals enableworkers to communicate effectively and safely with the bridge craneoperator.
If an effective set of hand signals for overhead bridge cranes isnot adopted and implemented. Workers and the bridge crane operator maynot be able to understand each other. This can lead to some very tragicconsequences including accidents, injuries and even deaths.

The Signaler

The best way to ensure safety is to have only one person in the work area make signals to the operator at once. There should only be one signaler in the work area to prevent mixed signals and confusion.
Having one signaler enables the crane operator to know who to payattention to and who to ignore. It also ensures that only individualswho know what they are doing will be sending signals to the overheadcrane operator. One way to make sure that the crane operator knows whothe signaler is to have the signaler always wear a specific piece ofclothing such as an orange vest.
Signalers should also be as familiar with the operation of the craneas possible. The best way to ensure familiarity with the crane is tohave the signaler operate the crane. Having the signaler and the craneoperator trade places occasionally will make sure that both the signalerand the crane operator are familiar with each other’s jobs.
Designating a few signalers who are familiar with crane operationand hand signals for overhead cranes is the first step in crane safety.The next step is to never allow anybody but the signalers to signal thecrane.

Hand Signals for Overhead Cranes

The hand signals for overhead cranes are pretty simple and verybasic. Generally pointing a finger up indicates that they want to movesomething up. Pointing down means that the workers want somethinglowered. Two raised fingers will usually indicate a need for multiplecrane trolleys.
Other common signals include pointing the thumb up for bridge traveland making the hitchhiker’s signal for trolley travel. A flatoutstretched arm usually indicates stop. Moving a flat outstretched armback and forth usually indicates emergency stop. Holding hands togetheron the front of the chest indicates that an operator should “dog”everything while both arms outstretched means the magnet is disconnectedor turned off.
Even though hand signals for overhead cranes can be a very effectivemeans of communication they do have their limits. It is always a verygood idea to have another means of direct communication between anoverhead crane operator and the workers on the floor available. Radiotelephones and walky talkies are ideal for this purpose. Headsets thatworkers can put under their helmets and wear at all times will makecommunication even easier.