When you think of a busy construction site, what comes to mind? For most people, it’s the heavy equipment: the bulldozer, the crane, the excavator. These great, noisy machines that help to create the buildings we work, eat, and live in take the forefront of the jobsite by virtue of their size and noise.
A Must-Have for Any Construction Equipment List
Unlike hand tools where the main force of the work performed is provided by the operator, heavy machine equipment takes the effort off of the human element and makes the job ahead easier, faster and more efficient. Moreover, these essential construction tools are capable of lifting or moving loads too heavy or large for a person to manage on their own. Here are a few different types of heavy machinery:
Although it is a common misconception, not all heavy machines on a jobsite are called a bulldozer. In fact, a true bulldozer is a tractor fitted with a large metal plate, called a blade, on the front. Some bulldozers are also equipped with a claw on the back, known as a ripper.
The purpose of the blade is to push large amounts of dirt, sediment or debris from one location to another. The blade itself can come in a few varieties: the straight or “S” blade, the universal or “U” blade, or a combination “S-U” blade. A tractor’s straight blade is short with very little curvature and no side wings. It is mainly used for fine grading and leveling. The universal blade is tall and widely curved with large side wings, and is used for carrying material. The combination blade is used as a compromise between the two, being capable of pushing large, heavy loads.
The ripper is a claw-like device attached to the back of a bulldozer. It can actually be a single, large shank ripper or a multi-ripper, although a single shank is the better of the two for a heavy ripping. The ripper does just what its name implies: it rips through earth, pavement, rock, whatever needs to be made smaller and removed from the jobsite. Another rear attachment that can be used in place of a ripper is the stumpbuster. This piece of equipment, although less common, has a single horizontal spike and is used for clearing stumps from the ground.
Bulldozers are very large, very powerful machines. Running on tracks instead of tires gives them better traction and stability even on muddy, uneven ground. These wide tracks also help to even out the impressive weight of the ‘dozer, helping to keep it from sinking in loose silt or soil. It’s because of their size and strength that bulldozers are put to work clearing ground, whether it be of dirt, ripped up pavement, or demolished buildings.
The excavator is a true marvel of modern technology. This machine is capable of demolition, of digging trenches for pipes and cables, of removing material; it can also mine and lift heavy objects and create a general grading for landscaping.
- The blade (if fitted,) which operates like a bulldozer blade,
- The tracks, as the excavator is a crawling machine, and as such rides on tracks as opposed to wheels,
- The track frame, upon which the tracks run, and
- The final drives, which have a hydraulic motor and provide the drive for the individual tracks.
- The operator cab, wherein the operator sits and controls the machine with pedals, switches and levers,
- The counterweight, a mass on the rear of the excavator that provides balance to the loads it may push, lift or carry,
- The engine, and
- The fuel and hydraulic tanks, which keep the machine running.
The house mounts onto the undercarriage by means of a single center pin. This arrangement allows the house of the excavator to pivot on a 360 degree swivel without needing to engage the tracks, which makes it possible to use this equipment even in smaller spaces. Attached to the house are the boom, stick and bucket. This is the part of the excavator that does the actual work.
The boom connects the stick to the house. There are a couple types of boom that are capable of moving laterally with the excavator or even independently of it, but those are mostly used on compact excavators. The most common boom, the mono boom, is only able to move up and down. The boom holds the stick, also known as a dipper arm. The stick provides the digging force, with its length being determined by the job to be performed, i.e. a longer stick is used when reach is a factor, and a shorter stick is employed when force is required.
On the other end of the stick is the bucket. There are two types of bucket used on an excavator, once again the type depends upon the task. The Mud bucket is a wider, large capacity bucket with a straight cutting edge. This bucket is used when the material to be lifted is soft, or when leveling or cleanup are needed. The general purpose bucket is smaller and stronger, with side cutters and teeth that are used for breaking through tough, hard surfaces.
Cranes are probably the most noticeable piece of heavy machinery you’ll see on a construction job. Their size alone makes cranes stand out, but their size is just what makes them so good at what they do. Although they vary in size from jib cranes, which are used indoors, to the soaring tower cranes that deliver necessary materials to different levels of buildings. In addition to raising loads to higher levels, cranes can also move its contents from one place to another laterally, such as a load from dockside to the decks of a ship. Cranes can also be fixed or mobile; here are a few examples of each:
- Truck-mounted cranes are mounted to trucks, thus able to be transported without requiring special equipment,
- Rough terrain crane, which is basically a crane mounted to a frame with 4 rubber tires for off-road use,
- Railroad cranes, used for maintenance on railway tracks, usually mounted on a flatcar,
- Aerial cranes are helicopters designed to lift and carry anything within their allowed weight restrictions, and are often used in disaster relief and med-evacs, and
- Floating cranes, used in bridge building, can be mounted on pontoon boats or specially designed barges.
- Tower cranes, which are used in construction of tall buildings because of their height and lifting capacity,
- Self-erecting cranes are usually a type of tower crane which can actually lift its own pieces into place,
- Jib crane, used in workshops and indoors, is a crane mounted to a jib from a wall or floor mounted pillar,
- Deck cranes are found on ships and boats, and are used for underway replenishments when unable to load onshore, and
- Stacker cranes, which are computer controlled cranes operating on tracks and used to automatically store or retrieve goods.
Mobile cranes, while certainly convenient, because of their nature cannot reach the stability and heights of their fixed counterparts. That is why tower cranes are so useful in construction work; their height makes them ideal for lifting heavy materials faster and more safely than other methods.