The Energy of Innovation

National and Homeland Security

Transmission Line Security Monitor

Continued next page

High-voltage transmission lines strung 

from support towers 

sprawl for thousands of miles 

across the United States and 

form the backbone of the 

nation’s electric power grid. 

The grid carries power from 

generating sources to industrial complexes, urban areas 

and rural communities across 

America. On its march from 

power generators to consumers much of the high-voltage 

transmission corridor passes 

through remote areas where 

security is scant or not available. Authorities recognize 

that our power grid is vulnerable to terrorist attacks, vanThe INL-developed 

Transmission Line Security 

Monitor can remotely 

detect abnormal vibrations 

and faults on high-voltage 

transmission lines.

dalism and extreme natural 

conditions including weather, 

fire and seismic activity. 

These conditions can bring 

lines and towers down and 

disrupt service to wide areas 

of the country. Until recently, 

there was no cost-effective 

way to comprehensively 

monitor the grid, optimize 

performance and protect it 

from catastrophic failures.

Engineers at Idaho National 

Laboratory are working on 

an advanced transmission 

monitoring systems that is 

providing an effective and 

inexpensive way to monitor 

the physical security of towers 

and transmission lines. The 

Transmission Line Security 

monitor senses and identifies threats, then alerts power 

system operators to protect 

these valuable assets and take 

action to prevent damage. The 

TLS monitors mount directly 

on high-voltage lines ranging 

from 230 kV to 500 kV near 

each support tower. Using 

wireless communications to 

monitor and relay real-time 

threat information from tower 

to tower, these advanced 

sensors can detect tampering 

from sources such as unbolting tower support structures, 

08-GA50011-10a

08-GA50011-10b
National and Homeland Security

Continued from previous page

08-GA50011-10

the use of cutting torches and 

saws, shooting of conductors 

and insulators and explosive 

blast events. The sensors 

also monitor for operational 

problems such as excessive 

sagging of the conductor and 

galloping conductors. 

The TLS monitor is housed 

in a small, weatherproof and 

corona-resistant enclosure that 

clamps on to the transmission 

line conductor. Placement on 

energized high-voltage lines 

can be accomplished by using 

a specially designed tool. The 

TLS monitor requires no batteries – it derives power from 

the magnetic field generated 

by the flow of current through 

the conductor. If there is a loss 

of transmission line power, 

the TLS monitor will continue 

to operate for several minutes 

to provide post-interruption 

information. 

The principal innovations 

that make the TLS monitor 

possible are the development 

of custom software signal processing algorithms and secure 

packaging to integrate an 

array of advanced sensors and 

communications technologies. On-board processing 

and analysis identify sensor 

inputs as threats which require 

immediate attention, or as 

natural non-threats which 

are receive a lower response 

priority. These advances give 

the TLS monitor the ability 

to detect and characterize 

transmission tower vibrations, 

detect infrared heat at the 

base of the tower, conductor 

conditions and pinpoint the 

location and nature of potential problems. This type of 

on-scene, real-time information has the potential to thwart 

costly and disruptive terrorist, 

vandalism or weather events, 

and help utilities maximize 

power transmission efficiency 

and performance.

The TLS monitor was conceptualized and developed 

in 2005, and licensed to 

California-based Lindsey Engineering the following year. 

Current enhancements to the 

technology are being funding from the Department of 

Defense’s Technical Support 

Working Group. Additional 

power line testing is scheduled to occur this year.

Technical Contacts

John Svoboda

(208) 526-0857

John.Svoboda@inl.gov

Robert Polk

(208) 526-0850

Robert.Polk@inl.gov

Licensee Contact

Phil Spillane

Lindsey Manufacturing Co.

(626) 969-3471, Ext 148

pspillane@lindsey-usa.com

Technology Transfer

Contact

Lisa Nate

(208) 526-2426

Lisa.Nate@inl.gov

A U.S. Department of Energy

National Laboratory

For more information

The Transmission Line Security Monitor uses wireless communication to relay the status of high-voltage 

transmission lines to command and control centers.

08-GA50011-10c