Just after 11am on Friday 4 June 2010, the demolition of the last two cranes at the Swan Hunter shipyard in Wallsend went ahead.
It took just 10 seconds for both cranes to fall to the ground.
The last evidence of the yard’s massive influence on Tyneside has now gone.
For every large construction projects, tower cranes are always used. Tower cranes are obviously designed to lift up the construction stuffs specially those heavy ones. Tower cranes can be used to transport objects from rise hundreds of feet in the air and can reach out just as far. Powerful tower cranes can rise up to 150 feet and can lift up to 19 tons. It can lift a wide variety of building materials like steel, concrete, and even big generators.
Tower cranes would not be able to do that kind of work without its important components. The most important part of the crane is its steel components because the tower crane uses this part of the machine to lift very heavy objects, it requires great strength.
Crane manufacturers use a variety of substances known as HSLA or High-Strength Low-Alloy steels. One of the basic parts of the Tower crane is the base which is bolted to a large concrete pad that supports the crane and connects to the mast or tower which gives the tower crane its height. The gear and motor that allows the Tower crane to rotate is the slewing unit which is attached to the top of the mast. The portion of the Crane that carries the load is the jib or working arm. The operators cab is the most important because it is like the brain of the Tower crane. With all these components working together, a tower crane would be fully functional and be used to lift heavy objects.
Though all of us have seen Tower Cranes before, few of us know their real capabilities and how much they can actually lift. The maximum load of that a usual Tower Crane can lift is 18 metric tons or equivalent of 39,690 pounds of weight. But if the load is positioned at the end of the jib or the working arm, the Tower Crane cannot lift that much weight because the closer the load is positioned to the mast or the tower, the more weight the Tower Crane can lift safely.
The Tower Crane has a specifications when it comes to maximum unsupported height which is 265 feet or equivalent to 80 meters, maximum reach which is 230 feet or 70 meters, maximum lifting power which is 19.8 tons and counterweights of 20 tons. The Tower Crane also uses two limit switches to make sure that the operator does not overload the Crane. These are the maximum load switch and the load moment switch. The maximum load switch monitors the pull on the cable and make sure that the load does not exceed 18 tonnes, while the load moment switch makes sure that the operator does not exceed the tonne-meter rating of the tower crane as the load moves out on the jib. That is why it is very critical to operate this massive machine. The Tower Crane operator has to be very skilled at what they does because there is a lot to risk when you are swinging 18 metric tons of load hundreds of feet above the ground.
Safety is the most important factor to be considered during a construction. The Tower crane seems quite unsafe to the naked eye because they have no support wires of any kind. But the Tower Cranes stability depends on certain elements. The first element is a large concrete pad that the construction company pours several weeks before the crane arrives. The concrete pad typically measures 30 feet by 30 feet by 4 feet and weighs 400,000 pounds or 182,000 kilogram. The Tower Cranes are essentially bolted to the ground to ensure their stability. Large anchor bolts are embedded deep into the pad support in the base of the Crane. But before that, Tower Cranes are delivered at the construction site on 10-20 tractor trailer rigs.
Mobile Crane is used to assemble the jib and the machinery section. The Mobile Crane then adds the counterweights. To rise to its maximum height, the Tower Crane grows itself one mast at a time. Special devices within the Tower Crane prevent the user from attempting to lift a weight heavier than allowed. Because the United States Government sets specific regulation through safety that limit the weight that a specific Crane is allowed to lift. A completed Crane is first tested without a weight to ensure that all of its components operate properly. It is then tested with a weight to ensure that the crane is able to lift heavy objects without loosing stability. Safety is ultimately depends on that proper use of the Crane.
Sany Crawler Crane
By the end of this year (2009), one of the leading manufacturers of cranes, Sany, would soon launch two new crawler cranes with 650 and 100 tonne capacity. The all-new 650 tonne SCC6500WE will be targeting the Chinese market and would be available for export in the next three years to come.
The model is primarily designed and construction for use for erection of 3 MW wind turbines, according to Sany’s Science and Technology International Sales Director- Zhu Wenkui. He also stated that the Sany 650 tonne SCC6500WE will be initially offered to the Chinese market. It would then go through a process of improvement and product/ technique testing and as soon as it is perfected, then the Sany crane would be open to the export market.
This new crane machine offers a maximum of primary boom of 84 meters with a fixed jib of 12 meters. Its 7 meters chassis is retractable with an engine that passes the high emission standards of Euro Stage III.
From the same manufacturer comes the 100 tonne capacity heavy duty SCC1000HD crawler crane that would be aimed for the international market as soon as production is completed. The markets would include South East Asia and Europe. The crane engine of this crawler is also up to the standards and passed the Euro Stage III emission laws. It has a maximum of 3 meters width and offers better transportation.
Tadano Faun Crane
Tadano Faun, one of the leading manufacturers of mobile crane, would be launching a new 5 axle crane in its line of products. The new machine would be a 130t all-terrain ATF, 130G5 truck-mounted crane. It has a very powerful chassis that’s available in 10×6x10. It has a strong wheeling power and there is no need to lift an axle to be able to use crab steering. The upper machine has a 60-meter long boom single that extends with a hydraulic cylinder. The hook can be extended to its longest position in minutes. In as fast as 400 seconds, the new Tadano Faun mobile crane can change position. The boom extension can be shortened in varied lengths of up to 10 mm. It can also extend up to 32 meters. It works in two types of anchors, either in mechanical versions or hydraulic.
The ATF 130-G5 crane can carry as much as 6t of counterweight. It also has a 10m extension, a 10t swivel hook and 63t hook block. It carries a 10×8x10 chassis along with big 16.00 R25 tyres with weight limits within 12t per axle. The prototype of this crane machine is being tested in one of Tadano Faun’s facility in Germany. It would soon be launched for the international market after its production in Japan.
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