The Romans had them; so did the Greeks. But these ancient cranes were operated using pure muscle, either human or animal. Nor were they mobile. Each time you wanted to move the crane it would be manually torn down and then rebuilt. Today's cranes are power driven, usually using a combination of engine power, levers and hydraulics. The mobile varieties conveniently move from place to place under their own steam or by using flatbed trucks. The following is a list of the four most common mobile cranes. Perhaps, if you learn more, it will help you pick out the right one for your project. None of these cranes are meant to be driven by amateurs.
The Compact Carry Deck Crane
Carry deck cranes are the compacts of the mobile crane line. They are nimble and drive more like a regular truck. These machines are able to swing the boom, which is the part that does all the lifting, in a complete circle. This allows your to pick up and drop off objects without doing so much back and forth adjusting of your position. A small deck, usually in front of the driver's compartment, allows you to put an object on the crane and then transport it for longer distances. Carry deck cranes have two axles and either four or six tires. These are great for building sites where you don't have a lot of elbow room, like downtown job sites that are already surrounded by buildings.
The Extra Large Hydraulic Truck Crane
A hydraulic truck crane is one of the largest mobiles. The hydraulic system, a mechanism that uses special fluid to increase power, allows these cranes to lift thousands of pounds. These are the heavy lifters used to build bridges, airports and skyscrapers. Because of their long reach, hydraulic truck cranes are brought in for changing signs or even installing extra large HVAC systems on existing structures. Outriggers, special foot-like mechanisms that pull out from the crane's truck bed, provide balance and help distribute the weight. If you ever watch one of these cranes in action, take a look at the outriggers. When the crane is lifting, it's not uncommon to see the outriggers dig into the ground to help lighten the load. If you have a large project in a city, urban or rural environment this might be your best bet. You will need lots of maneuvering space, both to park the rig and to use it.
The "Go Anywhere" All Terrain Crane
All terrain cranes, sometimes called the "go anywhere" cranes, are nearly as powerful as their hydraulic cousins. The all terrain's big advantage is that the rig can be driven on paved roadways, on gravel and in certain off-road areas. These all-wheel-drive cranes usually have 3 or 4 axles, but tend to have shorter wheelbases than the hydraulic variety. The shorter length makes the crane more maneuverable, especially in off-road situations. All terrain cranes are often used in the oil and natural gas industry, either during the initial exploration or when creating the infrastructure needed when a site is developed.
The Tank-Like Crawler Crane
Instead of wheels, crawler cranes have a tread-track system, similar to that on a tank. Once on the job site, they are self-propelled but because of the tracks, they must be transported to the site using oversized flatbed trucks, usually with a pilot car to deal with traffic issues. The track system also allows these cranes to operate without outriggers. The weight of the tread-track system is heavy enough to act as counterweight. Crawler cranes are often used at energy exploration sites, highway development sites and when new ground is being broken for neighborhood property developments.Share
26 January 2015
Welcome to my site, my name is Hugo Ciela. I'd like to talk to you about hand tools used by contractors of all kinds. Although air and power tools frequently make jobs easier, and sometimes even more enjoyable, hand tools have not lost their place in this industry. Many jobs cannot be completed without a hand tool or two due to their versatility and precision. Contractors of all types, ranging from roofers to foundation specialists, keep a plethora of hand tools in their worksite kit. I will discuss the types of hand tools you might see in those kits. I will also explore all of the different ways they can be used. Please stick around to learn more information about contractor's hand tools.