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SUBSTATIONS: 3 Common Steel Structures Found Inside

steel structures DIS-TRAN Steel standard shape steel structures switch stands substation dead-end structures H-Frame structures dead-end h-frame structures

Updated 9/1/2026

Before 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. 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.

What steel structures are commonly found inside a substation?

Three common steel structures found inside substations are:

1.) Dead-End Structures - Support conductors where a transmission line terminates or changes direction.

2.) Static Poles - Help protect substation equipment from lightning.

3.) Bus Supports/ Equipment Stands - Support rigid bus and electrical equipment throughout the substation.

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

Here is a closer look at the three main types of steel structures commonly found inside substations.

1. What is a dead-end structure in a substation?

Dead-end structures are steel structures used where a 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 structures
A-Frame structures

HFrame Substation Structure t&d_1-resized-600

Static pole steel structure inside an electrical substation

2. What is a static pole in a substation?

A static pole is a single, free-standing pole that creates a shield to help protect equipment inside a substation from lightning.

Static poles may or may not have overhead shield wires attached to enhance protection. The number of static poles needed depends on the size of the substation.

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

3. What are bus supports and equipment stands?

Bus Supports

Bus supports are among the most basic steel structures found inside a substation. Their main purpose is to support the rigid bus as it travels through the substation.

A rigid bus is stiff and will not move around during weather events. Unlike rigid bus, flexible bus is typically used in high-seismic areas so it can move and dampen the seismic forces that occur.

Equipment Stands

Electrical equipment can be of significant weight and must meet specific guidelines for structural loads, deflection limits, or clearance requirements.

Equipment stands are steel structures that support the actual electrical equipment inside a substation.

Examples of equipment stands include:

Potential Transformer (PT) stands
Current Transformer (CT) stands
Coupling Capacitor Voltage Transformer (CCVT) stands
Lightning Arresters (LA)
Switch stands

Quick Guide to Common Substation Steel Structures

Structure	Primary Purpose
Dead-End Structure	Supports conductors where a line ends or changes direction
Static Pole	Helps shield substation equipment from lightning
Bus Support	Supports rigid bus as it travels through the substation
Equipment Stand	Supports electrical equipment such as transformers, arresters, and switches

What type of steel is used for substation structures?

When it comes to which type of steel is used inside a substation — galvanized or weathering steel — weathering steel can be used, but it is very rare.

Weathering steel is used more often for transmission structures than substation structures.

One of the main reasons is aesthetics. Galvanized steel typically fits the appearance of a substation better. A substation is commonly surrounded by a fence and may include a metal building and white rock on the ground.

Weathering steel, which is usually dark brown, can aesthetically blend better with a transmission line running through wooded areas than with the typical environment inside a substation.

Substations are an essential part of powering our world. There are many pieces that work together to send power to our homes, workplaces, and other locations we visit that need electricity to function. If you want more information on Substation and Transmission Steel Structures, click the picture below: