Managing a summer outage at Millmerran

It is essential that maintenance outages for power stations are carefully planned and expertly executed.

At Millmerran Power Station, Howden provides a tailored service that supports their needs of the plant while working right alongside the users, to prepare the plant for their upcoming major outage.

Ready to schedule an outage planning meeting? Contact us today

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My name's Bruce Pennell from Howden Australia, currently working on the Millmerran project up in Queensland. My role here is site manager / site safety Manager. We're up here for what's called a mini shutdown which consists of seven days to scope up work for a major outage next year. We have three work fronts going on at the moment: first one air preheater, second one is bag house, third one is all the fans associated with the boiler, so that would be the ID fan, the FD fans and the PA fans. Any emergent work that won't last gets done now, other than that it's all scoped up ready for next year.

We've developed a great working relationship with Howden and I'd certainly recommend anybody to use them. From a safety point of view, I'm very happy with Howden and the way they operate on-site, for this outage and previous outages. A pleasant and professional company to work with.

On the three works fronts we have a leading supervisor for each one. Adam Goodchild will be leading the team on the air preheater repairs, Sean Porter will be leading the team on the bag house and Dong Yue will be leading the team on the fans. In all we have a crew size of 49 personnel on site at the moment. Basically called the summer ready outage it has two outcomes, one is just to fix up any major problems to get us through the summer period which is a peak electricity demand we want to be up and running the full time through this period and the other one is just to go through lots of areas and scope it up for our big outage which is a three weeker which is every two years. Meaning that it's such a short outage it's critical that I'm on site to manage the change in the scope and where there's a variation order to cover the change in scope, it needs to be dealt with promptly we don't have the luxury of time to negotiate back and forth. 

At the moment in Queensland, and possibly all of Australia, there's a bit of a shortage of power through our summer with peak demand with the air conditioners it's extremely important that we are on producing the whole time. To try and help with the maintenance we've now issued Howden with a five-year contract. The contractor we had didn't have access to the information that Howden had. We started off getting an engineer in from Howden to help us with some of the technical issues from that it developed a good relationship and therefore we looked at Howden as our workforce and as our major contractor.

They welcome us back every year because they know they're going to get the job done and the jobs going to be done right. Through the last seven years there was one year that we missed out on the contract and they were more than happy to get a straight back after that experience with another contractor. We've built a really good relationship with Millmerran operating company over the years.

My team we work in the air heater we're likely to be doing internal works to the sector plates also doing some inspections on the inner rotor to scope up for next year, oil replacements on the bearings also doing some ductwork stiffeners as well. This is our access door to the bottom of the incline duct, that is where the hot gases come out of the air heater through the baskets and they shoot up the incline duct into the bag house for filtering. A lot of erosion repairs in there because it cops the brunt, We've got turning vanes in there they always need replacing on the major outages but for now they'll just patch up that'll get them through till next year.

Okay we're standing here now at the bottom bearing section of the air heater they're draining the oil they're doing an oil change on the bottom bearing we do both top and bottom bearings on every outage, not just the major. This door here is the axial door, that door is to go in and inspect the axial sill plates and the axial seals and on the major outages we'll replace all those so they won't be getting replaced on this outage but they do get replaced on the major.

We're up here in the secondary hot end of the air heater. At the moment our boiler makers are replacing the static plates that we removed at the beginning of the job, to enable us to get in and look for any emergent work on the top of the sector plates and also to vacuum all the ash out which was a result of some erosion holes that we found in the hub they're basically just replacing now we're putting it back together.

Okay we're up at the gearbox drive end of the air heater the task we're doing here is replacing the gearbox clutch assembly and electric motor, the old one had a leak which was becoming unsafe dripping oil down on top of the air heater, so they've asked us kindly to replace the gearbox and the electric motor put the new clutch in we'll be good to go.

The biggest challenge that the last couple of days with this project we've been working on is some of the equipment supplied to us wasn't exactly the same as the equipment that was coming out to be replaced.

So we're now halfway through the outage and things have more or less gone to plan we've had some slight hiccoughs that we've worked through quite well, such as the replacement of the gearbox that was actually not part of the original scope of work, worked with the client and accommodated that we've worked through and we've managed to sort that out.

Our role here this time is carry out repairs for the bag house, got some riggers, boilermakers, some fitting work to do, we need to identify all the problems and rectify the main issues. Here we have the bag house entry/exit door. A lot of erosion repairs in here this is the final section that the gas flue comes through with the fly ash before it enters the bag system so we cop a lot of wear in here, we need to do a lot of work in here on the major outage this outage is just planned to scope up.

We separate to three little groups one working on the PA Fans, one working on the FD and one working on the ID fans. Here we have the PA fans the primary air fans they feed the coal mills. The coal mills crush the coal to a fine powder, these fans blow it up into the boiler. What they're doing in here now is they're just doing inspections on the impellers and the other casings again just very similar to the FD fans. On a mini outage we don't do much work on the fans it's more inspections, lube change, lube change-outs etc etc unless of course they find something that will not make it through to the major outage next year and they'll fix it on the spot.

We found some cracks in from MPA inspections which requires I come here, to have a look at them physically and then make decision, not only for this time, but also for next time see how much work to do next time.

Kris is the safety advisor for Millmerran power station at the moment we're currently conducting a walk around just to check all our work fronts here baghouse, fans and air heater. We've just come down to the FD fans now to make sure the scaffolding is in good condition, housekeeping is good, we've been working with Bruce on this site for 4.5 years and every outage we've had with Bruce and the Howden guys has been professional approachable basically nothing's too much to ask. If you want them to change something they will do it I couldn't have asked for a better contractor to work with.

It's the end of the outage and things have gone fantastically I think in terms of safety we've outdone ourselves once again. I couldn't be more proud of the guys for the way they work.

We've completed everything in the work scope as well as additional extras.


Millmerran Power Station, Australia supplies enough electricity to power approximately 1.1 million homes.

Peak demand in air conditioners through the summer months means it is vital that Millmerran continue producing at a high level throughout this period.


However with a shortage of power in Queensland, and possibly all of Australia, there is a concern that an unplanned outage could cause havoc on production – resulting in loss of overall plant revenue.


Howden will conduct a mini summer outage shutdown across 7 days to scope up work for Millmerran’s major outage next year and address any current issues needed to keep them running through their peak period.

A crew of 49 personnel on site, with leading supervisors across three work fronts, Howden will address any emergent issues that need handling now, and ultimately make sure things are in place for the following major outage next year to ensure it happens efficiently and safely with no surprises.

The previous contractor lacked in information where Howden does not.

Starting off with a Howden engineer helping with some technical issues, a strong relationship developed and resulted in Howden becoming Millmerran’s major contractor with a current five-year contract.

They welcome us back every year because they know they're going to get the job done and the jobs going to be done right. Through the last seven years, there was one year that we missed out on the contract and they were more than happy to get a straight back after that experience with another contractor. We've built a really good relationship with Millmerran operating company over the years. - Bruce Pennel

Read more about our Outage Management Process


Millmerran Mini Outage

The team at Howden conduct a mini-shutdown giving them seven days to scope up work for Millmerran’s major outage next year. It also aims to discover and address any emergent work that won’t last until the following year’s outage during this time.

Follow Bruce Pennel as he takes you through the Millmerran plant and the work that Howden are doing.


Howden engineers working inside heater at Millmerran

Case Study

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