Tower cranes are a common sight at any major construction location, and typically rise hundreds of feet into the air (usually reaching out just as far). They are used to life large tools (like generators and acetylene torches), concrete, steel, and other heavy building materials. They are usually fixed to the ground on a concrete slab, but can sometimes be attached to the sides of structures or buildings. In order to attach and detach loads, the crane operator works together with a signaller on the ground.
Terex is one of the most well-known tower crane manufacturers in the world. They have four different types of tower cranes: luffing jib, hammerhead, self-erecting, and flat top tower cranes. The self-erecting model is particularly interesting; it is erected quickly but a simple automated system. They are suited for construction sites which are of short duration, requiring the crane to be frequently transported, set up, and dismantled.
All tower cranes consist of multiple parts, including the base, the mast, the slewing unit, the jab, the machinery arm, and the operator’s cab. The average tower crane can reach around 230 feet and lift a maximum of 19.8 tonnes. Tower cranes use two limit switches to ensure that an operator does not accidentally overload the crane, which could cause serious damage or injury. The load moment switch ensures that the operator does not exceed the tonne-meter rating of the crane, while the maximum load switch monitors the pull on the cable and makes sure that the load does not go over 18 tonnes.
Safety Features & Guidelines
Before a tower crane can be erected at a construction site, several structural elements and components must be inspected, and several safety guidelines need to be followed. For starters, it is important to make sure that everyone working on the job site with the crane has been trained properly. This includes an authorized crane operator. There also need to be rescue procedures in place in case something goes wrong. Before operating the crane, operators should check to make sure each button and accessory is working properly, and that the chain and other parts of the crane are in good working order. While operating, it is of vital importance to have clear and precise communication with someone on the ground. They can direct you to where to drop the load, and if you are in danger of coming into contact with a building or other obstacle.
Pros & Cons
Tower cranes have helped solve a lot of inner city construction problems. They can reach so high up that they can lift materials and help repairs tall skyscrapers in busy metropolitan areas.
Self-erecting tower cranes are especially useful for smaller job sites, or sites that require cranes to be transported frequently. These types of cranes can easily place materials exactly where the workers require them, which makes it much easier for them to do their job. They can also be manoeuvred into tight areas, and are much quieter than other types of crane, which means they do not disturb nearby workers or home owners.