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Span Guard

The Indoor/Outdoor Industrial Power Supply System for Cranes and Stationary Equipment

Plant managers, engineers, crane operators, and others with extensive crane experience know that electrical joints are the most common source of crane electrification problems. Among other things, electrical joints become loose over time, overheat, expand and contract, and can cause a loss of power.

Span-Guard was the first continuous, joint-free electric conductor bar introduced. Span-Guard is uniquely designed with no electric joints in the solid copper conductor. And the flexible fully-enclosed insulated cover provides the most reliable, highest quality conductor system on the market. This joint-less conductor is ideal for cranes, hoists, and moving equipment where problems and downtime cannot be tolerated.

Superior design means fewer parts to repair or replace, and minimal maintenance. The solid copper conductors and cover ship preassembled on a reel and come in 250 and 520 amp sizes. The spring-loaded collectors come in 100, 200, 300 and 400 amp sizes. Stainless steel is optional.

Capable of running joint-free at lengths up to 2,000 feet, Span-Guard eliminates the power loss and overheating associated with the unreliable electrical joints of other heavy industrial power systems.

Our spring-loaded collectors use a carbon-graphite shoe and are more reliable and less costly to maintain than wheel based trolley systems because fewer moving parts require less maintenance. The collectors automatically compensate for up-and-down, and side-to-side misalignment between the trolley electrification bars and the crane runway.

Unsurpassed Durability

The Span-Guard System’s heavy duty design and construction allows it to take abuses that other systems would not survive, making it the ideal choice for heavy duty, highly corrosive environments. Span-Guard systems can sustain high-wear applications, acid and corrosive fumes, moisture, and severe outdoor weather including temperatures from 5ºF (-15ºC) to 131ºF (55ºC).

Easy Installation and Maintenance

Span-Guard has fewer parts than other systems, allowing for faster installation up-front, and less maintenance in the future. The system is comprised of an electrical conductor such as hard drawn copper that is completely enclosed by a flexible insulating cover. Advanced manufacturing methods make it possible to ship the conductor and cover in coil form to your exact length requirements.


  • Superior design – continuous copper conductor and self-closing cover – NO ELECTRICAL JOINTS!
  • Used in the harshest environments: paper mills, steel mills, galvanizing, smelters, mining and more
  • Highest performing crane electrification system for indoor and outdoor applications
  • 15′ to 25′ hanger spacing, suitable for roof trusses for support
  • Installs faster – 50% less time than jointed conductor bar systems
  • Under tension – no expansion joints required
  • Handles large misalignment applications
  • Safe – no chance of accidental contact with conductors
  • Virtually maintenance free
  • Span-Guard can be cut to your specification and can accommodate all of your AC or DC crane electrification needs
  • Copper conductor and cover ships preassembled on a reel
  • Unsurpassed reliability is the primary reason Span-Guard Electrification has been on the market for more than 50 years


Paper Mill

International Paper

International Paper implemented the joint-free Span-Guard conductor bar system in the 1980s to power its paper machines.

In the paper mill industry, a paper machine being down for just one hour equates to approximately $100,000 lost in productivity. When it comes to powering this essential equipment, reliability is key. A jointed conductor bar system can mean a glitch in the power, production stopping, and having to call in maintenance to fix the problem. This is exactly why International Paper chose to rely on Span-Guard - the time-tested, continuous copper conductor bar - as its mobile power solution.

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Steel Mill

US Steel, Nucor

US Steel selected U-S Safety Trolley's Span-Guard to power up its equipment due to the system's dependability in harsh environments.

The process of manufacturing steel requires intense temperatures and an abundance of chemicals. These types of conditions can wreak havoc on a jointed conductor bar- meaning lots of maintenance issues to deal with and a loss in productivity due to power being down. US Steel took notice of the Span-Guard system due to its solid copper, joint-free design with a protective vinyl cover; creating the perfect combination of reliability and safety.

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Conowingo Dam - Route 1 in Maryland

Span-Guard was chosen to provide a 2700 foot long stretch of joint-free electric conductor bar across the center of the Conowingo Dam, a large hydroelectric dam located along Route 1 in Maryland.

The Conowingo Dam supports a 9,000 acre reservoir that covers the original town of Conowingo. The dam has 53 flood control gates, all of which are operated by three overhead cranes. To power these cranes, an extremely long stretch of electric conductor bar was needed. Span-Guard is capable of running joint-free at long lengths, and has a self-sealing vinyl cover to guarantee protection through any weather condition- making it the ideal crane electrification solution for the job.

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