TOKYO >> An exhibition featuring heavy machinery used at construction sites is being held at Miraikan (National Museum of Emerging Science and Innovation) in the Odaiba area of Koto Ward, Tokyo.

On display are 10 heavy machines, ranging from the nation’s first domestically built hydraulic excavator to a state-of-the-art, robot-like concept machine with two arms. Visitors can even climb aboard a couple of the machines.

The special exhibition, titled “Kojichu! Tachiiri Kinshi!? Juki no Genba” (“Under Construction! Is It Safe to Enter!? Heavy Machinery in Use!”), is organized by The Yomiuri Shimbun and other groups.

Heavy machines show their abilities best at sites where uncultivated land is cleared and roads and buildings are built. The machines in the show are representative of such equipment.

These include a bulldozer used for leveling rough land. While the early 20th century saw the advent of the bulldozer in the United States, in Japan, the use of bulldozers became widespread after the end of World War II when they were a driving force for postwar reconstruction work.

The exhibition also includes the country’s first domestically built hydraulic excavator, which made its appearance in 1961. Such shovels were used in construction projects reflective of the nation’s high economic growth, such as those for expressways and Shinkansen lines.

In 2016, the National Museum of Nature and Science registered the machine under its “Essential Historical Materials for Science and Technology” system, commonly known as Mirai Technology Heritage, aimed at recording progress in scientific technology.

A hydraulic excavator is an expression of diversity. In addition to digging deep into the ground with a scoop-like bucket attached to the end of its arm, it can grab and cut by using other attachments. A Caterpillar Japan LLC employee praised hydraulic excavators as “all-round players at construction sites.”

Demolition work on old buildings, meanwhile, the start of urban redevelopment and housing reconstruction, requires other heavy machinery.

Overseas, the demolition of old buildings is often carried out with explosives. But that is difficult in urban areas of Japan, where buildings are close together. Instead, machines smash concrete and cut through steel frames. A huge, scissors-like attachment for the hydraulic excavator tackles such tasks. These monster scissors have an overwhelming presence at the exhibit, resembling a tyrannosaurus with jaws wide open. A video shows how the hydraulic scissors, with their huge magnets that separate iron scraps from other materials, can contribute to recycling materials from work sites.

Another heavy machine featured is a crane, outfitted with a spidery arm that can extend to a height of more than 28 feet, yet be folded up into a package just 27 inches wide. In this form, it can move through narrow spaces.

The exhibition also displays a pair of “visualization” goggles that enable users to see 3-D images of objects that are normally hidden from view, such as underground pipes, based on their design drawings. It is another example of cutting-edge technology adapted for construction work.

But what immediately catches visitors’ eyes is a machine with two arms and four legs that resembles a robot.

Hitachi Construction Machinery Co. built this heavy machine, fulfilling the wishes of young engineers at the firm who hoped to “create a robot-like heavy machine.”

Its four legs can move independently and stabilize the body even while standing on an inclined surface. It can also execute complicated movements, with one arm raising an object and the other cutting it.

With the 2020 Tokyo Olympics and Paralympics drawing near, there’s a lot of construction going on all around Tokyo but such sites are off-limits to the public. This ongoing exhibit allows visitors to get an up-close understanding of what goes on there.