Woodworking is not just for the boys anymore. I am all girl, but I love to play with hammers and saws. This blog is all about women in woodworking and how we can encourage young girls who are interested in building amazing products with their hands and some power tools, too! Browse through amazing project ideas like make-up tables and jewelry boxes, ideas specifically with girls in mind. Women of all ages will also learn how to make traditional furniture, puzzle boxes, and lamps as well as all kinds of decorative items. Girls and women can be incredible at woodworking. Stick with me to find out how.
If you already work in the container shipping industry, you've probably seen the gantry overhead bridge crane in action. The development of these cranes, along with the invention of the "stackable" shipping container, streamlined the industry. Early versions of the cranes were used in factories beginning in the late 1800s. The shipping containers were invented more than half a century later. The following is a brief history and description of how these two inventions work together.
The Gantry Crane
A gantry is a large, weight-supporting beam that sits at the top of a specially designed overhead bridge crane. While all cranes have some sort of weight support, those labeled "gantry cranes" have larger uprights helping to support that top beam. The uprights have wheels along the bottom end, allowing the crane to be moved along the dock to make the loading and unloading of goods easier.
The Shipping Container
Malcolm McLean developed the shipping container during the 1950s. He wanted a means of shipping items in bulk, and to easily transport those items to and from truck, railway car or ship without unpacking the goods. The government became interested in the project, but they wanted the containers standardized. The results were the 20-foot and 40-foot containers that we see today.
The Shipping Ports
In order to handle this sort of shipping, special container ports were built. The Port of Oakland and New Jersey's Port Elizabeth were two of the earliest sites. Each was equipped with plenty of parking, railway spurs and of course, gantry overhead cranes. Today, those cranes are found world-wide.
Putting It All Together
You could say that the gantry crane operator has a bird's eye view of his surroundings. He sits in a cab under the trolley, the part that swings out to transfer loads from ship to ground transportation. The crane hooks are lowered, picking up the container using locking points on the four top corners. The container is lifted, the crane swings around over the flatbed truck or rail-car, and the container is then lowered.
The procedure is reversed when going from ground transportation to ship, except that the containers must also be stacked on that ship. They are secured by built in twistlocks. The female parts of the lock, large oval holes on the bottom corners of the containers, are lined up with the pointed male sections on the top corners. Once in place, a deckhand turns the male portion to lock the two containers in place. The same system is used on inter-modal flatbed trailers, which have the male ends of the twistlocks welded on the bed. Talk to other crane experts like American Equipment Inc for more information.
26 January 2015