Steel Tower and Steel Structure Business

We, as a leading manufacturer of steel towers such as power transmission towers, telecommunication towers, etc., have made a contribution to the establishment, maintenance, and development of energy and data communication networks of all areas in Japan through design, manufacture, erection, inspection, and maintenance of these towers along with research and development of these in-house processes and products.

In addition, we have done business that suits the current needs such as developments of steel-made supports for facilities of solar/wind power renewable energies, access transmission towers between their energy sources and main transmission networks, etc.

Electric Transmission Line Towers
Telecommunication Towers
Renewable Energy Facilities
Landscape and Design Oriented
DC Standard Products
Tower Maintenance

We provide design, manufacture, inspection, maintenance, etc., of following towers.

Electric Transmission Line Towers 

Transmisson towers and steel structures, trestles, etc., for electric power plants and substations for Japan’s nationwide electric power suppliers.

Examples of electric transmission line tower

Examples of outdoor steel structure


Telecommunication Towers

Steel towers to establish stable telecommunication and broadcasting networks for Japan’s government/municipal offices and common carriers such as mobile phone companies, electric power companies, broadcasting companies, JR group companies, etc.

Renewable Energy Facilities

Wind power generation steel towers, trestles of solar panels, and access transmission towers connecting renewable energy sources and main transmission lines of electric power companies.

Landscape-Harmonic and Design-Oriented Towers

Consulting services, landscape-harmonizing simulation, design, manufacture, etc. for steel towers giving priority to landscape-harmony and designability including functionality.

DC Standard Products

The following original products called “DC standard products”, which stands for Denro Corporation standard products, as auxiliary products of steel towers can be provided.

Anti-Climbing Devices

Anti-Climbing Devices are tower accessories that prevent unauthorized personnel from climbing steel towers. We have a wide assortment of shapes and functions of our anti-climbing devices to fit various attached locations and steel materials such as main posts, braces, full-plane blocking, etc. Our devices for main posts can be opened horizontally to accept authorized personnel’s climbing towers.

“Noncladd” (Foldable Ladders)

Our foldable ladders called Noncladd are normally folded, stored and locked to prevent unauthorized personnel from climbing towers so that they will be unfolded and used only for authorized personnel. By use of our wall-mount Noncladd for station buildings, you don’t need to prepare any temporary ladders to climb up to their rooftops. We have many kinds of Noncladd for a wide variety of applications such as utility poles, angle steel towers, tubular ones, station building walls, and custom-made ones are also available.


“MyWay” (Site-Assembled Small Bridges), “MyStep” (Site-Assembled Stairs)

MyWay and MyStep are our standard products to enable safer passage at various sites; MyWay are site-assembled small bridges installed over logging roads and creeks, and MyStep are site-assembled stairs installed over steep slopes. And these products are knockdown-packed for easy transportation and installation. Furthermore, these are hot-dip galvanized steel products insuring long-life and maintenance-free service.



Tower Anchor Setting Devices

Our tower anchor setting devices are installed under bottom-ends of tower main posts to facilitate vertical, horizontal and tilt-angle adjustments, thereby to realize easier installation of tower foundations. By use of these devices, such dimensioning work can be performed safely, surely, and efficiently at tower erection sites.

Other Tower Accessories

We provide other various tower accessories as follows:
Toris-Top to prevent birds from nesting by being physically installed at tower top portions and crossarms

KANTAN-Check to prevent birds from nesting by being physically installed at tubular steel ends

Round Fastening Nut to prevent stealing tower bolts

Toris Top


Round Fastening Nut

Tower Maintenance

Tower-shaped steel structures are recognized as the important infrastructure and thus their surfaces are usually hot-dip galvanized for excellent rust prevention. However, depending on site conditions, their galvanized surfaces could be worn by aging deterioration within comparatively short periods. As a result, enormous costs may be required for painting or replacing tower members due to insufficient rust-proofing performance.

We satisfy every customer’s needs by means of the following maintenance technologies. Please feel free to inquire anything about the tower maintenance.

・Lifetime diagnosis including image analysis of galvanized surfaces

・Inner surface inspection and repair work for tubular steel members by using robots

・”Countermeasures against Uneven Displacement” such as correction of towers inclined due to earthquakes.

・Tower height raising work to secure minimum separation distances between lowest conductors and structures/trees

・Strength calculation, investigation, test/inspection, maintenance, etc. when changing strung wiring and installed antennas


We have a full-scale tower loading test station and various testing facilities for researches commissioned by customers, collaborating researches with universities and other academic research institutes, our own researches, developments of new products/methods, validation test of reliability/workability, etc. Through these R&D activities, we have obtained patents and made technical presentations at domestic/foreign conferences and academies like CIGRE (International Council on Large Electric Systems).

Also, twice a year continuously since 1983, we have kept issuing Denro Technical Report, in which our technical papers and products have been presented.