Cliffs Natural Resources – Tilden Mining Co. – Ishpeming, MI

Outage Work

Copyright 2011 Cliffs Natural Resources Inc.

This outage consisted of a plant wide 24 hour water down, plant wide power down affecting about 50% of our work areas that lasted for 3 Days and an equipment down that lasted for 3 Days in the concentrator and 6 Days in the pellet plant. All of these outages started at the same time and all of the work was completed at once.

We performed over 11,500 man hours of work without a single incident or injury to the equipment or personnel. We were able to maintain a very aggressive schedule that was set by the customer and completed 100% of the work assigned to our company and also an extra 5,000+ hours that other contractors could not man. Extreme care was taken performing all hot work due to lack of fire water. Temporary lighting was required due to no power in sections of the building. Temperatures and humidity during this outage were both very high, extreme care was taken to prevent any heat stroke or exhaustion to personnel.

Tasks Completed:

  • Completed work in over 20 confined spaces.
  • Completed (5) rock barn feeder insert replacements (this was 2 more than what was scheduled).
  • Completed repairs to 12 apron feeders below rock barn this included structural steel repair and 100+ wear plate replacement.
  • Replaced valves (manual and air actuated) and piping throughout the entire concentrator varying in size from 3/4” to 24” in diameter.
  • Performed conveyor repairs throughout the plant that varied from roller replacement, head, bend, take up and tail pulley replacement, structural steel replacement, belt replacement and alignment, skirting replacement and adjustment and bearing replacements.
  • Made structural iron repairs throughout concentrator and (1) dust collector.
  • Inspected and replaced grate return shaft bearings on one of the units.
  • Installed new dead beds in the cooler to help with dust control and make the equipment more efficient.
  • Replaced / leveled 1/3 of the cooler dump rail and leveled the remaining 2/3 of rail on one of the units.
  • Performed misc. preventative maintenance work to the cooler on one of the units.
  • Repaired all of the leaks on the water jacket on one of the coolers.
  • Inspected and made the necessary repairs to the grate dust valves on one of the units.
  • Installed ports in the precipitator stacks for EPA testing devices.
  • Installed Refractory clips in duct work throughout the plant and on the underside of the stack cap.


Mailing Address:

PO Box 369
Wells, MI 49894

Physical Address:
1920 20th Ave North
Escanaba, MI 49829
Phone & Fax:
Phone: (906) 789-9021
Fax: (906) 789-9129