How a Crane Fly on My Keyboard Led to an $8,000 Potain MDT 389 L16 Mistake

I've been an equipment coordinator handling parts orders for eight years. I've personally made (and documented) 14 significant mistakes, totaling roughly $23,000 in wasted budget. This is the story of the biggest one — and the checklist that finally ended my streak.

In July 2023, we were running a Potain MDT 389 L16 tower crane on a high-rise project in Salt Lake City. If you look at the Potain crane models Utah contractors commonly use, the MDT 389 L16 is one of the more popular luffing-jib units. It's a 17-ton luffing crane with a maximum load moment of 389 tonne-meters, which is why it's a workhorse on medium-rise residential jobs. We chose it over the MCT 205 because we needed the longer jib for the building's footprint. In Utah's wind, the luffing jib also gives better maneuverability than a hammerhead. We also had a trash compactor and a can crusher on site — the unsung workhorses of the recycling area. They're not glamorous, but they keep the site clean, and they'd soon become part of the lesson.

That morning, I needed to order a slewing ring seal for the crane. I was sure the part number was 9876-1A. I even had an email from Potain with the correct number, but I didn't bother opening it. I typed from memory. And then the crane fly showed up.

It was one of those big clumsy crane flies that buzzes in through an open window and makes you swat at it. It landed right on my keyboard, between the number keys. I swatted. Maybe I flinched. Either way, my finger hit the 0 key instead of the 1 key. The part number became 9876-0A.

I didn't notice. I hit send.

The Two-Week-Old Mistake

The replacement part arrived two weeks later. The box looked right. Our mechanic opened it, held up the seal, and frowned. He said this was for a 389 L10, not our L16. 'We don't have any L10s on this site,' he said.

We checked the purchase order. There it was: 9876-0A. We checked the supplier's confirmation email. Same. The typo had been sitting there, in both systems, for two weeks. If I'd spent five minutes checking the email instead of trusting my memory, I would have caught it. But I'd been in a hurry to get to the morning safety meeting, and I figured I knew the part number by heart.

The Price of Being Sure

Let me break down what that little mistake cost:

• $280 for the wrong seal, which was not returnable.
• $1,200 for the correct seal with overnight freight.
• $880 in overtime labor for the mechanic who had to do the job twice.
• $5,600 in downtime charges from the general contractor because the crane sat idle for three days.

That's $7,960, which I round up to $8,000 in my head because it's easier on my pride. (Ouch.)

While I was in damage-control mode, the trash compactor started jamming. The can crusher's motor was bogging down too. I hadn't scheduled their preventive maintenance because I was too busy staring at crane part numbers. It turned out the compactor's hydraulic filter was clogged and the crusher's auger was misaligned. Together, those repairs added another $2,300 and two more lost workdays.

The 12-Point Checklist

That was my wake-up call. The real problem wasn't the crane fly. It was the lack of a system. I was running equipment management on memory, and memory is exactly where costly mistakes go to hide.

So I built a verification checklist. Not just for the crane, but for everything that rolls, lifts, or crushes on our site. A few of the rules:

• Check the serial plate on the actual equipment before ordering any part.
• Type the part number into a fresh email, not from memory.
• Compare that number against the supplier's online catalog.
• Wait 60 seconds, then read the part number out loud.
• If the order is over $500, have a second person verify it.

The full checklist has 12 points and takes about 15 minutes to run through every device—including the Potain MDT 389 L16's wear parts, the trash compactor's hydraulic fluid levels, and the can crusher's belt tension. At first, my team made fun of it. 'You need a checklist to type a part number?' one operator joked. But after the third time we caught a wrong order before it shipped, the jokes stopped. By December 2024, the checklist was just part of our routine.

Since August 2023, we've caught 47 potential errors using this checklist. Some were small, like a wrong filter size. A few were substantial—like a cracked pin in the crane's luffing mechanism, which we found before it could cause real damage. I estimate we've saved at least $21,000 in avoided rework and downtime.

The Lesson I Keep Relearning

Everything I'd read about equipment management said to use checklists. I figured that advice was for people who didn't know their equipment. My experience suggests otherwise: overconfidence is exactly when you make the dumbest mistakes. It took me eight years and fourteen mistakes to understand that the best equipment managers are the ones who double-check everything.

And then there's the crane fly itself. They're harmless, you know. They don't bite. They just look like giant mosquitoes and startle people. The name is an assumption, too—they're not cranes, despite what the label suggests. That's what got me. I assumed the part number was correct. I assumed the seal would fit. I assumed I'd remember.

Now, whether I'm ordering a part for the Potain MDT 389 L16, scheduling maintenance for the trash compactor, or checking the can crusher's motor, I run the checklist. It's the cheapest insurance I've ever bought.

So if you're looking at Potain crane models Utah construction sites are using right now, and someone tells you the MDT 389 L16 is a good choice, they're not wrong. Just remember to double-check every part number before you hit send. A crane fly might be waiting to change your life.

Because five minutes of verification beats five days of correction. Every time.