DIS-TRAN Steel Blog

What kind of Steel Structures Does Your Utility Project Need?

Posted by DIS-TRAN Steel on Sep 8, 2016 10:00:00 AM

Anyone in the utility industry today knows the importance of high-quality products so preparing for any kind of project can be stressful. Structures, whether substation or transmission need to stand up to unpredictable weather and heavy wear and tear. We like to be nimble, adaptable, and fast when we design and fabricate new structures for our customers. Our engineers always design structures for customers with economics in mind, to ensure not just functionality but affordability. They will choose and combine standard shape steel structures and tapered tubular steel structures as they make the most sense for the project at hand.

So, let's break down these two types of structures into why and when they make the most sense and examples of steel structures for each.


Standard Shape Steel Structures
At DIS-TRAN Steel, our in-house engineering and project management expertise and resources are vast. Using a mix of standard shape material we can exceed your expectations.

Best/Most economically used when:

  1. Low profile
  2. Light loads
  3. Low voltage compact design
  4. Compact design with potential future additions
  5. Shorter leadtime


  1. Equipment Pedestals
  2. Box Bay
  3. Bus supports
  4. Switch stand
  5. Substation riser
  6. Low voltage distribution sub


Tapered Tubular Steel Structures
Right now, fabricated tubular steel poles form about 80% of non-wood electric transmission structures in the United States.

Best/Most economically used when:

  1. High profile
  2. Heavy loads
  3. Higher voltage
  4. Aesthetic effects
  5. High-tension pull-offs
  6. Deflection concerns


  1. Transmission Towers
  2. Distribution Poles
  3. Standard Class Poles
  4. Substation Deadends
  5. Static Pole
  6. High Voltage Equipment Pedestal
  7. High Voltage Bus Support
  8. High Voltage Switch Stand

The Engineering/Sales office and plant facilities are only 15 minutes apart in Pineville, Louisiana, creating synergy across the design, detail and production processes from start to finish. Sitting on 50 acres with over 260,000 square feet of production space, our plant is organized for execution and volume. Whether you need pre-engineered poles, transmission poles, or substation structures, DIS-TRAN Steel can fabricate them to fit your exact needs and specifications. We’re here to make it happen quickly, effectively, and economically every time.

Learn more about our flexible engineering capabilities and collaborative project process by visiting us online at www.distransteel.com today!

Substation&Transmission Steel Structures eBook

Tags: steel structures, tapered tubular steel poles, standard shape steel structures

How Do Electrical Transmission and Distribution Systems Work? Find Out.

Posted by Brooke Barone on Aug 9, 2013 8:52:00 AM

A Transmission and Distribution (T&D) System, has a notorious job of delivering electricity to consumers 24/7, 365 days a year.

But before the electricity can travel into your home, it must pass through a substation first. A substation is an assemblage of equipment where electrical energy is passed in order to be stepped up or stepped down.

Transformers inside a substation change the voltage levels between high transmission voltages and lower distribution voltages. The high transmission voltages are used to carry electricity longer distances, like across the country, whereas lower distribution voltages travel to industrial, commercial or residential consumers.

In a T&D system, the major components typically consist of transmission lines, distribution lines, substations and switchyards.

Inside a substation is like its own unique “power world” where every pole, bolt, stand, surge arrestor or structure plays its own individual role.

The three main types of structures found inside a substation include:

1.)    Dead-End Structures

2.)    Static Poles

3.)    Bus Supports/ Equipment Stands

Dead-end Structures are where the line ends or angles off. They are typically constructed with heavier steel in case they are needed to carry heavier tension. The two most common dead-end structures are H-Frame and A-Frame structures.

H-Frame Structure

A-Frame Structure

The second structure, a Static Pole, is a single, free-standing pole that creates a shield to protect all of the equipment inside a substation from lightning. Static poles may or may not have overhead shield wires attached to enhance protection. It depends on the size of the substation as to how many static poles are needed.             

NOTE: Tapered tubular design is typically efficient and economical in dead-end and static pole situations when compared to AISC standard shape structures.

Bus Supports are the most basic structure found inside a substation. Its main purpose is to provide support for rigid bus as it travels though the substation. Rigid bus is stiff and will not move around during weather events. Unlike rigid, flexible bus is typically used in high seismic areas in order to be able to move and dampen the seismic forces that occur. 

Electrical equipment can be of significant weight and must meet specific guidelines for structural loads, deflection limits or clearance requirements.Equipment Stands are the structures that the actual equipment sit on.

Examples of some equipment stands include:

  • Potential Transformers (PT) Stands
  • Current Transformers (CT) Stands
  • Coupling Capacitor Voltage Transformer (CCVT ) Stands
  • Lightning Arresters (LA)
  • Switch Stands

 So, although the concept seems quick and simple like flipping a light switch, much more is going on behind the scenes.  

Transmission lines act as the utility interstate system where electricity is transmitted at high voltages in order to reduce the energy lost in long-distance transmission.

Although it’s hard to quantify structure types since there are always exceptions to the rules and never-ending configurations, transmission structures can be considered dead-end, strain or suspension.

dead-end structure is where conductors and ground wires are pulled only on one side, unless it is a double dead-end structure, and are used where:

•    Line ends
•    Line turns at a large angle
•    At major crossings like highways or rivers
•    Divide line into segments

For strain structures, the conductors are directly attached through in-line insulators through or around the tower. In suspension transmission structures, the conductor phases pass through the structure, and are suspended from the insulator.

Each structure type can either be classified as tangentwith no line angle, or anglewhen there is a line angle.

Steel transmission structures can be designed with tapered tubular poles, which are hollow, can be multi-sided and have a large base that tapers down, typically in the range of .18 to .45” per foot.

And to dig a little deeper, all of these structures can either be guyed or unguyed. A guyed structure provides extra support by fastening a wire from the structure to the ground or another structure, whereas an unguyed structure is self-supporting.

Transmission Structures

When deciding which type of structure is most economical, as well as best suited for varying conditions, there are many considerations that can influence which to select, such as:

•    Terrain type 
•    Erection techniques
•    Electrical constraints
•    Access & transport situation
•    Procurement & easements
•    Structural loading

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Tags: steel structures, tapered tubular steel poles, transmission structures, substation structures, tangent, switchyards, dead-end structures, electrical transmission and distribution

Behind the scenes look at Substations and Transmissions

Posted by Brooke Barone on Oct 26, 2012 10:29:00 AM

Turning on a light happens within a blink of an eye. But it’s a little more complicated than just flipping a switch. P1020296 resized 600

Transmission and substations work coinciding with one another in order to bring the electricity from the distribution station, into your home.

Transmission lines move high voltage power across the country, while substations basically take the higher voltage down to lower voltages.  Let’s say a 230kV line comes into a substation, the power is then transformed into a lower voltage, or multiple lower voltages, and then carried out by distribution lines into your home or business.

A good way to remember the difference between the two is to think of transmission lines as interstates or freeways, and distribution lines as smaller state or county highways.

There are three components that make up a transmission line:

  • Conductors
  • Insulators
  • Transmission Structures

Transmission structures are typically taller than substation structures because they carry a higher voltage and require a greater phase separation. Transmission structures can be made with either wood, concrete or steel. Lower transmission voltages are more commonly constructed with wood or concrete, while steel is used for higher voltage structures.

Transmission structures are built in a number of different designs, but the two most common that you will see are tapered tubular poles or lattice structures.  Other transmission structure types include:

  • Dead-end                           
  • Embedded
  • Base-plate
  • Tangent
  • Guyed
  • Unguyed

The transmission lines deliver power to transformers, which are located inside the substation. The substation is where the voltage is either increased or decreased. The power is then carried out by either overhead lines or underground potheads. (A device that connects overhead conductors to underground)

The main structures found in a substation are:

  • Dead-Ends
  • Static Poles
  • Equipment/Bus Supports

The circuits are connected by buses, which connects different  circuits within a substation, providing flexibility.  Buses can be made with either aluminum tubing, copper or other materials.

All electricity travels in three phases, or three separate lines, to make up one circuit. It depends on the voltage as to how far apart each line should be spaced. The higher the voltage, the further apart they should be in order to avoid arcing. If the wires get too close to the metal or any object, it will arc, finding the path of least resistance. This is vital with both transmission and substations.

For FREE Steel Sturcture Design Templates, click on the link below!

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Tags: substations, transmission, tapered tubular steel poles, transmission structures, substation structures, distribution line, high voltage, transmissions

More than just Standard Steel Poles...

Posted by Brooke Barone on Sep 20, 2012 9:07:00 AM

Aerial view of our plant in Pineville, LAIt’s always hard when you’re first starting out and trying to establish yourself and your company, but with perseverance and an appetite for success, growth is inevitable.

In the beginning, DIS-TRAN only manufactured standard shape steel structures; however, we were always in need of steel poles. We established a great relationship with a company here in Louisiana who we purchased our steel poles from until a larger company came in and bought them out and shut their plant down. This forced us to reach out to other companies across the country.

Right around this time, in the late 90’s, cell phones were rapidly catching on and cellular towers were going up everywhere. Contractors were purchasing tons of steel pole capacities, so it became very hard for us to get service. One of the problems that we ran into was that we would ship the structural steel out to a site, but then have to wait a month or so for the steel poles to arrive. We all know how that story ended-with unhappy customers.

So, in 1995, DIS-TRAN decided to open up its own steel pole shop and dabble into the market. With only 12 employees in the beginning, it was a huge learning curve, but as the industry grew and became more advanced, so did DIS-TRAN.

DIS-TRAN Steel Pole and DIS-TRAN Steel Fabrication were two separate companies at first, but after we realized we were doubling our internal workload, we decided to merge the two in 2010 to become what is now DIS-TRAN Steel, LLC. In 2006, DIS-TRAN Steel Pole and DIS-TRAN Steel Fab had 149 employees total, and now, six years later, DIS-TRAN Steel has more than doubled that number to 321.

Over the years, we’ve realized that there are some misconceptions about the capabilities of DIS-TRAN Steel since we initially started off just manufacturing steel structures. But we can also design, detail, fabricate and deliver tapered tubular steel structures for the utility industry. 

Our engineering and detailing capabilities allow DIS-TRAN Steel to pursue and be involved in highly technical design projects. With 18 in-house detailers and 10 engineers, including 4 Licensed Professional Engineers (P.E.), we can design any steel structure for the utility industry, whereas some of our competitors require shop-ready drawings.

Whether they are pre-engineered poles, engineered transmission poles or taper tubular substation structures, DIS-TRAN Steel can fabricate it. As one of our guys says, we can design steel structures with as little information as a stick figure on a napkin to fully-detailed drawings because of our in-house expertise and resources.

The investment we have made in our employees goes hand-in-hand with the investment that we have made at our plant, with 4 expansions in 16 years. Customers are always surprised when they tour our plant in Pineville, LA because of how large and advanced it really is. It’s not just this little fabrication shop tucked away in the swamps.

Our state-of-the-art facility is just as large as any other steel fabricating facility in the U.S., sitting on about 60 acres with 300,000 square feet under roof manufacturing space. Some of our most prized possessions at our plant include a fully automated 2500 ton, 60 foot Press Brake with a one-of-a-kind automation software package that our plant operators actually helped design. We also have in-house high definition plasma cutters, robotic welding systems, CNC controlled seam welders and CNC punches for standard shapes.

Something that also surprises many is that we can also supply wood transmission arm assemblies and distribution crossarms through our sister company DIS-TRAN Wood Products, LLC. DIS-TRAN Wood Products has two fabricating facilities, one in Pineville and the other in Vancouver, WA.

Throughout the years, DIS-TRAN has made the investment to meet the demands of the growing industry, and has made sure to keep up as the elite supplier, consistently providing the highest quality products.

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Tags: steel structures, utility industry, wood transmission assemblies, DIS-TRAN Steel, tapered tubular steel poles, DIS-TRAN Wood Products, wood distribution poles, pre-engineered poles, transmission poles, standard shape steel structures

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