In large construction projects there are many factors that cause delays and unplanned expenses. Some are uncontrollable like weather. Other factors such as improper planning, lack of workers, or inadequate tooling are controllable.
Selecting an improper tool for one aspect of a project can cause delays, rework and costs increases. Worldwide, impact wrenches are a commonly used tool to fasten bolts because the initial purchase is inexpensive. But the impact wrench is like a small “time bomb” that will eventually lead to catastrophic or latent failures, which are costly.
Impact wrenches are destructive by nature with its “hammering” design. An impact wrench can easily damage parts and the threads of a fastener due to the lack of proper torque control. The wrench is not designed for toque control. The tool tends to under and over tighten the fastening application. An impact wrench is not ergonomically friendly to an operator and an impact wrench requires a high maintenance budget. The tool typically needs service multiple times each year.
During the maintenance of heavily operated railroads or laying down new railroad tracks, using an impact wrench for bolting applications is a costly decision. Lack of proper torque control requires an additional step in the fastening process. Either an additional torque tool is required for re-tightening the bolt or for applying the final torque to the bolt. Neither is an efficient process.
The construction group handling the project of laying down new railroad tracks in the Gotthard Base Tunnel construction project initially were using impact wrenches to fasten the bolts used with railroad ties. The project is railway tunnel that is currently being constructed beneath the Swiss Alps, which is expected to open in 2016. It will be the world’s longest rail tunnel, surpassing the Seikan Tunnel in Japan.
As time went on with the project, key obstacles started to arise with the use of the impact wrenches. Increasing costs, lack of torque control and other safety risk factors were becoming large issues for the construction group. After an internal evaluation of the fastening process and using impact wrenches, the construction group looked for an alternative solution. They decided to switch to electric torque multipliers for the bolting application.
The easy-to-operate electric torque multipliers are designed for precision tightening and loosening of all heavy duty fastening applications. Torque multipliers are ergonomically safer than the harmful hammering of impact wrenches and eliminates the frequently costly repairs of impact wrenches.
The construction group selected the EFCip electric torque multiplier for the railroad tie fastening application. The railroad ties used with the tracks are raised automatically and are affixed from below to the rails. Two bolts on the sides have to be loosened. Then, by hand, two clamps are placed over the rail base. Next, the torque multiplier securely fastens the bolts on both sides. In the past, an impact wrench was used for the process. The tool was inadequate as it didn’t fasten the bolts to the proper torque requirement. An additional tool was required to re-tightening many bolts after being inspected, which caused delays and increased costs.
The EFCip electric torque multiplier achieves precision torque in a quick, cost-efficient manner. The time-consuming and cost-intensive process that the impact wrenches caused were eliminated once the construction group changed over to torque multipliers. Designed to deliver smooth torque control, with “continuous” rotation, the torque multipliers automatically shut-off once the preset torque is achieved.
Using the proper torque tool for fastening the railroad ties, the construction group is reducing costs, saving time by eliminating unnecessary rework time and ensuring that the high safety standard requirement is met. Once the construction of the Gotthard Base Tunnel is completed, it’s estimated that nearly one million bolting connections will be made within this project.
Using a quality torque multiplier makes a safer world through accuracy and precision. Controlling torque is essential for companies to ensure their product’s quality, safety and reliability isn’t compromised. The failure of a five-dollar bolt that isn’t properly tightened can lead to catastrophic or latent failures. Fasteners that are insufficiently fastened can vibrate loose and excessive torque can strip threaded fasteners.