A bulldozer is a large and powerfully tracked engineering vehicle that has incredible ground hold, making it mobile on rough types of terrain. A bulldozer has wide tracks that assist it to distribute its weight as it travels over large areas; the wide tracks also help prevent the bulldozer from sinking into the softer terrains like sandy or muddy grounds.

Bulldozers are known for their strong ground hold and having a torque divider, which is designed with the ability to convert the engines power into a dragging ability. This allows the bulldozer to use its own weight in order to push objects and remove objects from the ground. An example of this ability can be seen with the Caterpillar D9, when it easily tows a tank that weighs more than 70 tons. It is these attributes that make the bulldozer a key construction and excavation vehicle, as it is extremely instrumental in clearing heavy obstacles, debris, shrubbery and remnants from building structures.

The Blade of a Bulldozer

The bulldozer blade is constructed from a heavy and durable piece of metal plate, which is then installed and attached on to the front of the bulldozer. It has to be heavy and durable because the blade is used to push heavy objects around. The bulldozer blade is available in three different varieties: a straight blade, a universal blade and a combination blade.

The bulldozer straight blade is designed short with no lateral curve. This variety has no side wings, making it only useful for fine grading.

Universal bulldozer blades, which are also known as the U-blade, are designed to be tall and very curved. The universal blade has large side wings that help it to carry more material.

The third type is a combination blade, or S-U blade, and this blade is designed to be shorter, but has less curvature. The side wings of the combination blade are small.

Typical Modifications

The newer models of bulldozers have come along way from their distant past relatives, and have evolved with modern improvements that make them more efficient. One only has to look at the loader tractor for an example of modifications, which were accomplished by removing the blade and replacing it with a large volume bucket. This bucket is attached to hydraulic arms that will assist in raising and lowering the bucket, making it very useful for scooping up mounds of dirt and debris, and then loading it into trucks for removal or transport.

Another obvious modification has to do with the size of the bulldozer. The original bulldozer was larger than the ones today, and this compact version makes it easier to operate and maneuver in small work areas that might be restrictive to the larger models. This comes in handy when mining caves and tunnels. There are even very small bulldozers that are called calfdozers.

The History of the Bulldozer

With one look at a bulldozer, it is obvious that the origins were adapted from farm tractors that were used to plough farm fields. When it was necessary to dig ditches or canals, raise earth damns or move earth, the earlier tractors were fitted with thick metal plates in the front of the tractor. Eventually, the thick metal plate became known as the blade.

It is the progressive modifications of the bulldozer blade, which peels at layers of soil, that led to the useful advancements of this tractor. More to the point, the blade is the essential part of the bulldozer, making it extremely useful in excavation type projects. As time passed, engineers were able to use technology and toy with the modifications of the bulldozer. This need for modification developed out of the need for construction equipment to complete larger scaled jobs. It was companies such as CAT, Komatsu, John Deere, Case and JCB that pushed forward with efforts to manufacture large tracked earth-moving vehicles. These larger models were very loud and very powerful, which helped it earn the name “bulldozer”.

Still, time kept progressing and the need for more powerful and sophisticated bulldozers became essential, and so the bulldozer got larger. The new modifications included improved and better engines, reliable drive trains, improved tracks, and precision hydraulic arms that allowed for improved manipulation of the blades as well as automated controls. Another additive for the bulldozer is it can come equipped with the option of a rear-ripping claw, which breaks up rock, concrete and pavement.

The most common and well-known manufacturer in the bulldozer industry is CAT, which is a reputable name when considering tough, durable and reliable machinery. Though the bulldozer was born out of the classic farm tractor, it has become a useful piece of machinery for companies that deal with excavating and construction.

It has been said that the backhoe loader was possibly invented in the year 1957 in Burlington in the state of Iowa. However, it should also be noted that a man named Joseph Cyril Bamford, the founder of JCB, might have developed a similar construction vehicle in 1953 in the United Kingdom. The backhoe loader is considered a spin-off or variation of the farm tractor. Its name, the backhoe loader, does well in describing what this vehicle is — a loader bucket on the front, and a backhoe attached to the back of the vehicle.

When the loader and the backhoe are permanently affixed to the vehicle, it is not referred to as a tractor, it will not be used for towing, and most often will not have a PTO. The permanently attached models normally will have a seat that will swivel, so that the vehicle operator can swivel the seat to face to the rear in order to operate the backhoe controls. Backhoe loaders that have removable backhoe attachments have a separate seat found on the attachment itself.

The backhoe loader is a versatile vehicle, and, because of this, it can be utilized in a variety of different tasks like construction, transporting material, minor demolition, powering certain building equipment, digging and excavating, breaking up asphalt and paving roads.

Backhoe loaders that have detachable buckets can allow the operator to replace the bucket with other types of tools such as breakers, which are used to break up and smash concrete and rock. Some backhoe loader models are equipped with a loader bucket that has a retractable bottom. This allows it to empty a load more quickly, lending to a more efficient job that can be carried out in less time.

Models that have the retractable bottom loader buckets can be used in jobs that require grading and scratching off sand. Again, the front assembly on a backhoe loader can be either permanently mounted or removable. If the bucket is removable, it can often be replaced with other tools and devices used in construction. Before mounting different attachments, the operator must make sure the loader is equipped with a tool coupler, which is made up of two hydraulic cylinders that are found at the end of the arm assembly. The hydraulic cylinders will allow for expanding and retracting, and this enables the different tools to be attached.

When shopping for backhoe loaders, there are several brands, including New Holland, John Deer and Case, which are all reputable brands. There are also a variety of different backhoe loader models with some that have cabs, and others that do not. The newest models of backhoe loaders have numerous luxury accessories like air conditioning and radios, which help go a long way to making the work experience more positive.

The backhoe loader is commonly associated with jobs dealing with excavation; however, the backhoe loader can carry out many different tasks. It is often used on construction sites to haul equipment and supplies within the loader bucket. The backhoe loader can also be used to fill in trench lines or covering up newly put in pipes by shoveling in dirt. Also, the backhoe rear attachment is perfect for digging areas for placement of water pipes and sewer pipes.

The functionality and usefulness of the backhoe loader makes it very appealing for the engineering, construction and excavation industry. It is very easy to operate and can perform a variety of projects. The operator does not need to be a rocket scientist, but the operator should have some training and instruction on proper usage.

Then there are other types of machinery that fall somewhere between articulated trucks, wheel and track tractors and scrapers. It all boils down to the motor grades, which make the machinery capable of light duty types of excavation, making them typically used to level lots and grade roadways.

When researching heavy equipment, you go to the manufacturing source, and todays leading companies like Caterpillar, Komatsu, or Case will all agree that the most important change and advancement over the years has come from the ability to increase productivity. After that, they will all claim greater comfort and safety features as the next biggest changes and advancements.

The increase in productivity can be contributed to the different advancements implemented by each manufacturing company. Caterpillar has introduced more powerful engines that have faster rise in torque, allowing their machines to respond quicker, increasing the power demands. Even with the added power, the newer models are also made to reduce the impact on the environment, making them energy efficient.

Changes and Advancement in Electronics

Many of the new models are fitted with electronically controlled systems, which go a long way to optimizing the engine, the transmission performance, fuel consumption and the hydraulics system.

Again, look at the mid-sized G series wheel-loaders manufactured by Caterpillar. They feature electronically controlled power-shift transmission, which offers an auto-shifting capability that eases the pressure on the operator. Also, the electronic clutch pressure controls a smoother shift of the gears, making them last longer.

Changes in Comfort

In todays industry, there is a concern for the operators, and there is a willingness to go the extra mile to keep them happy. One way to keep the operator happy is to consider the comfort of the machinery they have to work with each day. Manufacturers are now hard-pressed to produce a model that is not just productive, but also comfortable and convenient for the operator. After all, keeping the operator happy will also lead to better productivity.

The newer models are being designed with cabs that do offer better visibility. There has been a reduction is noise and vibration, and all this goes into improving the comfort. The new innovative control systems are easy to operate and with less effort, all while it improves the overall operation of the machinery. It is easy to use by both the experienced and novice operator.

Maintenance Made Easy

A wonderful perk with the new machinery is the electronic monitoring system that has been implemented to provide a constant analysis of information on the health of the machine. This information is provided to the technicians, and allows them the ease of diagnosing problems and fixing them more quickly. The monitoring system takes the guessing out of troubleshooting.

The machines of today are designed specifically to make maintenance quick and easy. For example, Caterpillars wheel loaders have service points that are easy to access, with site gauges that make it easy to check fluid levels in the radiator, hydraulics and transmission, and no longer require the use of a dipstick.

The Best Changes

When comparing todays excavation equipment with those of the past, the beneficial changes and advancements are easily noticed. The machines from the past really relied heavily on the skills of the operator, since very few of them had the electronic features that have been implemented today.

The electronic features in todays machinery have really been a plus for the industry. They have made the operators job more efficient, yet easier to carry out. It is no longer necessary to physically get out of the machine to check fluid levels, since they have installed easy to read instrument panels, and this really does save a lot of time.

The manufactures know, the industries know and the operators know that the machines of the past cannot even begin to compete with the newer more efficient models of today. Technology has become more innovative and there is no telling what the future will bring to the heavy machine industry. As the years go by, changes and advances will continue to modify heavy machinery and the new improvements will, no doubt, continue to make the life of the operator easier and increase productivity.

After World War II, innovative experimentations were made in regards to the backhoe, and with that, digging trenches as a profession faded away. The year 1950 brought with it the hydraulically actuated backhoe, which made it very possible to dig deep trenches in minimal amounts of time. With the backhoe on the scene, there was no need for workers to be inside of the trenches during digging, and therefore, there was no longer a need to shore or support the walls.

When you think of trenches, all trenches have something known as “stand up time”. Stand up time is the amount of time that elapsed from the time it was dug until it collapsed. This calculated time depends on certain factors, such as soil type, how much water is in the soil, the depth of the actual trench, weather condition and the condition of the soil.

The calculated stand up time could be as little as zero seconds or as broad as several months, and often it is difficult to even predict. Prior to digging a trench, a sample of the soil should be taken to calculate and estimate its stand up time. Remember, soil conditions are varied from area to area; so, it may be different in the area that is only a short distance away from where a sample was taken.

Once a trench has been successfully dug out, the team of workers goes into the trench and carry out whatever work they needed to do, such as laying pipes, placing telephone or cable lines, welding pipes or maybe installing valves. It is important to realize that if the walls of the trench are not supported, there is always a chance for a collapse, and this is extremely dangerous. On average, it has been recorded that 100 to 300 people in the United States alone have been killed in trench collapses.

With this type of work, the public can become aware of industrial progress, and this may lead to negative side effects. Engineers have a responsibility to protect the public from certain types of side effects, which is a very controversial topic. This is why using a trench box on the job site helps ease the debate.

The trench box is also referred to as the trench shield, and it is placed within the trench in order to help prevent safety failures from injuring workers. A trench box consists of two large steel plates that run parallel to the wall of the trench, as well as horizontal, which keeps the two plates apart.

The lower edges of the trench box are set upon the bottom of the trench and the top edges extend above the top of the trench. The way it works is that the workers will stay between the plates of the trench box. This way if there happens to be a collapse of the trench, the workers will be in the trench box, and the collapsed dirt will be stopped by the outside of the trench box. The trench box is pulled along inside of the trench using a backhoe or other strong machine.

Sometimes certain projects will need a large excavation, such as when digging the foundation for very tall buildings. Often, the support structure for the walls is specified in the plans. However, there is a problem, more often than not, of trench boxes not being utilized in cities. The problem can arise when water or sewer lines have to be installed or fixed, and there has been no specification for a trench box. It is often left up to the discretion of the contractor, and unfortunately, if a trench box is not used and an accident occurs, it could be dangerous.

Remember, if you happen to be digging trenches or find yourself working in one, you should use your common sense and take your time. Trenches are not always a safe place to work. If an accident occurs, it could be a deadly one, especially when a trench box is not utilized. If at all possible, you should not be in the trench, and let the machines do all that type of work.

Normally, the skid loader is a four-wheel drive vehicle with left side drive wheels that are independent of the right side drive wheels. Since each side is independent of the other, wheel speed and rotation direction determine the direction the loader turns in.

A beneficial trait of the skid loader is its ability to turn in its own tracks. This makes the skid loader a very maneuverable vehicle. It will also make the skid loader more valuable on jobs that need a compact and agile loader.

The skid loader differs from the conventional loader in that the lift arms sit beside the driver and the main pivot points are found behind the shoulders of the operator. The earlier models of skid loaders were not as safe as the front loader because the operator was too close to the moving booms and buckets. This was extremely unsafe especially during entering and exiting.

However, today, the skid loader has been remodeled and upgraded with safety features that aim to protect the operator from safety related injuries. The skid-steer is also able to scrape material from one area to another area, it can carry material in the bucket, and it can load material onto a truck or even onto a trailer.

Operating a Skid Loader

Because of the size, the skid loader can be utilized in the place of a large excavator when digging a hole outwards from the inner side. In this situation, the skid loader has to dig a ramp that leads to the very edge of the hole. It will be this ramp that the skid loader is able to use to remove the material and debris from within the hole.

As the excavation becomes deeper, the skid loader will reconstruct the ramp and make it longer and steeper. This method is very convenient in situations where you need to dig under an overhead type structure, and the overhead does not have enough clearance for bigger excavation machinery. The skid loader would be put to good use when digging a basement underneath a house.

A notable feature of the skid loader is that the buckets on most models can be replaced with other specialized buckets and attachments. Many of the attachments utilize power generated by a hydraulic system.

The History of the Skid Loader

The history of the three-wheeled front-end skid loader takes you back to 1957, when two brothers by the name of Cyril and Louis Keller invented it in their machinist shop in Minnesota. The Keller Brothers were able to build the loader, which went on to help a local farmer clean out the turkey manure from the inside of his two-story barn. Their light and compact skid loader had rear caster wheels and it was able to maneuver around within the length of itself, while it was doing the same tasks the conventional front-end loaders carry out.

Eventually, in 1958, the right to the loader that was invented by the Keller Brothers was purchased by the Melroe Manufacturing Company, which was based in Gwinner, North Dakota. The Melroe Company even hired the Keller Brothers to continue working on their invention. They were able to improve upon the original loader they invented and they developed the M-200 at the end of 1958, which was a self-propelled loader.

This new loader featured two totally independent front drive wheels as well as a rear caster wheel. It also contained a 12.9 engine and a lift capacity that was about 750 pounds. Then only two years later, they upgraded even more and replaced the caster wheels with a rear axle. It was known as the M-400, the first and only four-wheel skid-steer loader.

In 1962, the name Bobcat was introduced and added to help describe the main features of this new machinery. The new model was tough, agile and speedy. A 15.5 HP engine powered it and it had an 1100 pound rated operations capacity. With a little more time, the skid-steer loader was upgraded to the M600 loader. As the years passed, the Bobcat skid-steer loader underwent many changes and upgrades. It incorporated a hydrostatic drive system, received an enforced cab structure, there are radius and vertical lift arms, innovative instrumentation, and a heating and air conditioning feature.

There have been so many advancements made with the skid loader over the years. Today, the rubber tire skid loader is just one type. Now, there is also the compact track loader and an all-wheel steer loader. The new compact track loaders create less ground disturbance and generally have better traction ability on terrains that are soft, muddy, slick and sandy.