Of all the industries affected by the development and implementation of hydraulic power, it might be said that no industry has been affected quite as much as the construction industry. From the powerful excavators that are such a common sight at construction projects to compact equipment that is indispensable when building in crowded urban areas, hydraulics have left their mark on construction and have made possible feats of both engineering and architecture that would not have been feasible otherwise.
Steam Power, Cables, and Winches
Early construction equipment, including the steam shovels that proved invaluable to the railroad, mining, and construction industries, used complex mechanical systems to achieve the motion of a shovel or bucket. These systems were comprised of gears, linkage systems, ropes, and cables that were driven by powerful steam engines and later powerful diesel engines. They were miracles of technology in their time and made feats of engineering such as our first railroad systems, the Hoover Dam, and the Suez canal possible.
First Use of Hydraulics
History indicates that the first use of hydraulics in construction equipment occurred back in 1882. The machine was a hybrid hydraulic excavator, and while its appearance is far from what we connect with the word excavator today, it was truly a groundbreaking innovation for its time (pun intended). Its purpose was to aid in the construction of hull docks in England. You probably noticed the use of the word hybrid: fluid power (water, to be precise) was used to actuate hydraulic sheaves for multiplying power while the rest of the system was still using cables and winches. This design, however interesting and prophetic, did not turn out to be very effective.
First Hydraulic Excavator
In 1897, the world saw the first completely hydraulic excavator/shovel, built by the Kilgore Machine Company. One of the benefits touted by its designers was the fact that hydraulics allowed the motions to be cushioned, reducing the jar on the operator and the impact damage that the machine would inevitably experience over time. These machines, unlike the hybrid discussed earlier, were extremely effective. Now fluid power was used to dig, lift, hoist, and deposit instead of manpower, which assembled large teams of men working with hand tools trying to accomplish an almost inhuman task.
The Expansion of Hydraulics in Construction
It was not until the 1960s that the construction industry as a whole began to switch from cables and winches to hydraulics on machines like dozers, excavators, graders, and power shovels. Once manufacturers made that switch to hydraulic actuators and hydraulic control, they never looked back. While hydraulic systems are not as easy to repair (especially in the field), they proved to be more reliable and far more powerful.
And, as the technology continued to mature, hydraulics also made it possible to achieve far more precise motions (as evidenced by modern videos showing excavator teeth being used to remove the lid on a bottle). Such precision has allowed for more optimization of certain construction processes, such as grading roads and excavating construction sites.
Hydraulically Powered Machines
When it comes to the use of hydraulics in construction, we automatically think of big machines: excavators, shovels, bulldozers, backhoes, and massive cranes. However, those are not the only machines where hydraulic systems are crucial. There are scissor lifts, trenchers, concrete pumping systems, hydraulic support cylinders, and even brick molding machines that all depend on hydraulics for their operation.
Achieving Powerful Motion and Precise Control with Hydraulics
One of the key benefits of hydraulic machinery is the ability to achieve motion via hydraulic actuators such as cylinders and swing motors. Through the use of multiple actuators, extremely complex motions are made possible. And with hydraulics providing the power behind these motions, machines like excavators can dig deeply into the earth or front loaders can scoop, lift up, and deposit heavy loads of soil or rock. And hydraulics, coupled with a skilled operator, can achieve motion to an amazing degree of precision. Modern graders with hydraulic systems are capable of far greater accuracy than their cable, winch, and linkage operated ancestors. And when hydraulics are combined with modern technology such as grade control, laser positioning, and GPS, the potential seems almost endless. The United States has already seen self-operating compact track loaders made by Built Robotics at work on commercial work sites in California.
Moving Construction Machinery Using Hydraulic Motors
When you see a massive excavator lumbering slowly across a construction site or perhaps a small skid steer loader rolling quickly by with a load of damp sand in its bucket, you might be surprised to learn that they are both propelled by the same kind of power: hydraulic power. The vast majority of equipment found on construction sites across the world is propelled by hydraulic power.
That includes hydraulic final drive motors that convert hydraulic power to torque to enable track loaders, bulldozers, diggers, and backhoes to carry or push heavy loads. These motors, which are sometimes referred to as track motors, enable tracked excavators, bulldozers, and other tracked machines to keep moving across some of the most difficult surfaces imaginable. These hydraulic propelled motors rely on the machine’s hydraulic system to function correctly. Hydraulic wheel motors are also indispensable for wheeled machines, such as skid steer loaders, wheeled excavators, backhoes, and even forklifts.
Hydraulic Construction Attachments
If you have ever watched a hydraulic excavator utilize a set of hydraulically powered jaws to chew through scrap sheet metal or concrete, you understand the power and functionality that hydraulics has made available to attachments. And these powerful attachments are not just for massive excavators, but for small machines such as skid steer loaders and compact track loaders. These hydraulic attachments can perform an almost unimaginable assortment of tasks, including:
- Hydraulic hammer and breakers (one of the oldest types of attachments)
- Cable reelers
- Truss booms (for maneuvering and placing trusses)
- Compactors (ideal for areas where