XMT® 456 Multi-Process Inverter Racks Eliminate Material Handling Time and Save Energy for Gunderson Marine

XMT® 456 Multi-Process Inverter Racks Eliminate Material Handling Time and Save Energy for Gunderson Marine

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Miller's XMT® 456 multi-process inverter racks simplify material handling and help Gunderson Marine achieve organizational goals – all while saving enough energy and providing enough benefits to pay for the entire system in just over three years.
Published: January 1, 2008
Updated: January 7, 2016

Executive Summary

  • Time saved in material handling and set-up, along with energy savings, will pay for 20 XMT racks and 80 wire feeders in just over three years.
  • XMT racks give fitters and welders all the tools they need – no waiting for a crane, no running to the tool crib, and no wasted set-up time.
  • With an energy efficiency of 85 percent, the XMT has lowered Gunderson’s utility bills.
  • Easy-to-understand controls simplify operator training.  

Gunderson Marine Cuts Fabrication Time After Switching to XMT 456 Inverter Racks

“Touch each piece of paper only once,” goes the old saying for paperwork efficiency. For barge manufacturer Gunderson Marine, welding efficiency means “position each welder only once.”

This strategy - possible after upgrading from old single-process welders to new multiprocess inverters from Miller Electric Mfg. Co. - will save handling time and contribute to organizational goals.

“We’re expanding and looking to increase throughput while continuing to meet our customers’ scheduling expectations,” says Ron Windes, Gunderson’s production manager. “We take a lot of pride on delivering products on time, and our new Miller equipment makes it easier to stay on schedule.”

The time-saving equipment includes 80 XMT(r) 456 multiprocess inverters paired with SuitCase(tm) X-TREME(tm) 12VS wire feeders in four-arc “rack” configurations. Through saved time, improved productivity and lower energy costs, the new equipment will easily pay for itself in a short time.

Big Launch

Located on the Willamette River in Portland, Ore., Gunderson Marine is a unit of The Greenbrier Companies (NYSE: GBX). The Gunderson yard is a deep-water facility, fully equipped for constructing all types of river and ocean-going barges. Since WWII, it has built more than 250 vessels, including double hull, conventional deck barges, dump scows, chemical barges and military vessels.

The Gunderson facility includes CNC plasma burning and flame cutting, 52-ft. forming capability, a complete panel line and over 56,000 square feet of platen build space supported by (2) 200 ton Clyde cranes.  It also has the largest side-launch ways on the West Coast (up to 700 ft. of capacity).

In the last two years, the company has renewed its production processes and dramatically increased capacity. Throughout this growth, Gunderson has maintained its high quality standards and emphasis on delivery schedules. However, to meet these aggressive goals while controlling costs required investing in new welding equipment.

No More Follow the Welder

Gunderson uses a modular construction process. Barges, typically 300 to 429 ft. long, are too big to in build single units. For easier handling, Gunderson fabricates smaller modules and then assembles the modules together on the launch ways.

The first step involves Stick welding for fit-up. Prior to using new technology, old Miller constant current (CC) welders followed the fitters as they moved from one module to the next. Then the flux cored welding crew would come in and weld shell plate (decks, hulls, bulkheads) using a constant voltage (CV) welder.

For flux cored welding, Gunderson moved in a mix of aging CV welders. However, because welding procedures require back gouging (“scarfing” using the air carbon arc gouging process) weld seams to ensure 100 percent penetration, flux cored welding locations also required a high-output CC welder.

“We had three types of equipment that we constantly moved all over the yard, typically with a crane,” says Windes. Fortunately, multiprocess inverters eliminate the need to constantly reposition welders.

The XMT 456 has an output range of 5 to 600 amps (450 amps at 100 percent duty cycle) for Stick, MIG/flux cored and DC TIG welding. Miller engineers also designed the unit with a volt/amp curve that provides excellent gouging capabilities with carbons up to 3/8-in. diameter.

Paired with a custom-design rack that has holders for SuitCase feeders, weld cables and electrode clamps, the XMT rack gives both fitters and welders all the tools they need; no waiting for a crane, no running to the tool crib and no wasted set-up time. For further convenience, the XMT rack requires a single 60-amp/three-phase/460 VAC primary power connection due to the XMTs low primary power requirements. This enables Gunderson to put more welders to work in a given area, as well as further reduce set-up time.

“With our new XMT racks, we can place four arcs next to a module station and leave it there,” says Windes. “We calculated that the XMT racks save time in material handling and set-up. That, along with their energy efficiency, will enable us to pay for 20 XMT racks and 80 feeders in a little over three years.”