Isolate multiple energy sources and repair a cooling tower fan gearbox

You are a Mechanical Fitter on the day crew at Newport West.

Simulated workplaceIntermediate missionCAQA Powergen Station

What is going on

The oil sample from cooling tower fan CT-3 shows elevated iron and copper and the gearbox has been noisy for a week. Permit PTW-26-1191 shows the motor control centre racked out and the fan blade restrained, and work order WO-26-5134 asks for an inspection and bearing replacement. The fan sits on top of the cooling tower cell, so the work involves working at height and the blade carries stored energy from wind. The condenser vacuum on the steam turbine depends on the tower, so the control room wants the fan back before the weekend. Mei Ling Chua is your leading hand and will check your alignment.

Anthony Duong, Mechanical Maintenance Manager
Subject: CT-3 cooling tower fan gearbox inspection

The oil sample from the CT-3 fan gearbox shows metal and the permit is already isolated. Please plan the inspection and bearing replacement under WO-26-5134, prepare the multiple energy source isolation list including the fan blade restraint, and make sure the alignment and clearance records go on the work order when the fan is reassembled. Mei Ling can talk you through the alignment tolerances. Keep the control room informed because summer condenser vacuum depends on that fan.

Your brief

Verify the isolation covers every energy source, complete the permit walk down, carry out the inspection and bearing replacement, record alignment and clearances on the work order, and restore the fan under the permit rules.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

Read the Procedure: Multiple Energy Source Isolation for Permit to Work and list every energy source on a cooling tower fan and gearbox, including wind on the blade and the gearbox oil.
Review permit PTW-26-1191 in the Permit and Isolation Register and record any energy source not covered by the isolation list, then update the permit notes with your walk down findings.
Complete the Permit to Work and Isolation Request for the work as you would submit it, including work at height and the number of workers.
Describe the inspection sequence for the gearbox, what you look for on the gear teeth and bearings, and how you decide whether to replace the bearings or the gearbox.
Record the bearing replacement, the shaft alignment readings and the gear backlash on WO-26-5134 in Maintenance Work Orders and Defects, and set the status to Complete.
Describe the restoration sequence and what you must confirm with the control room before the fan is released for a test run.
Raise a hazard in the HSE Incident Register for anything you found unsafe on the tower deck, such as damaged grating or a missing handrail.

My notes: what did I enjoy, and what surprised me?

What someone in this role would produce

Energy source list and permit walk down findings
Completed permit request
Work order with alignment and clearance records
Hazard report if applicable

Printing this is a record of what you explored. It is not a certificate or a qualification.