When the Spec Sheet Doesn't Match the Crane: A Potain Crane Quality Inspector's Tower Crane Specification Guide

I was about to close the monthly audit log when the email came in.

"Need a quick quote on a Potain MDT 178 with a bulk hoist. Also, can you send a tower crane specification guide? And what's your take on mobile crane private label?"

Three questions in one email, all from a rental company we'd been talking to for maybe a year. The first two were easy. The third one is the reason I put my mug down.

The afternoon that made me rethink how we quote cranes

I'm the quality and brand compliance manager at a Potain dealer in Utah. I've been in this role for about four years—maybe five if you count my previous job at a parts distributor. I review every crane and parts order before it goes out the door. That's 250 to 300 items a year, give or take. Potain cranes, especially the MDT line, have enough configuration options to fill a binder. Not a glamorous job. I check serial numbers, load charts, hydraulic leaks, paint touch-ups, and paperwork. The paperwork is usually the biggest problem.

In 2025, I rejected about 9% of first deliveries because the documentation didn't match the physical machine. That's not a brand ego thing. It's a "wait, this brake is rated for 8 tons, but the label says 10" thing. If you've ever had a load chart that says "similar to" instead of "equal to," you know exactly that feeling.

The rental company sent over their own spec sheet for a Potain MDT 178. It looked fine at first. Model, maximum radius, maximum load, free standing height. Then I checked the jib configuration. One cell said 56 meters. Another cell said 60. I asked which one. They said "the brochure shows both." That was the afternoon the project slipped sideways.

The two specs that didn't match

I said "I need the spec that matches the serial number." They heard "send whatever spec you can find." Result: we spent two days comparing a document that had been assembled from an old tender, a marketing page, and a generic brochure. We were using the same words—"tower crane specification"—but meaning very different things. The jib length mattered because it drives the foundation loads. The foundation loads drive the engineer's design. Get that wrong, and the crane gets delivered before the site pad does. That is not a date-list problem. That's a $22,000 stop-work problem.

The bulk hoist made it worse. The quote called for a "bulk hoist, 1.5-ton capacity." I asked for bucket size, material density, and lift height. The project manager replied, "It's a 1.5-ton hoist, that's enough." That's true until the bucket weighs 600 kilograms and you're lifting sand at 1.6 tons per cubic meter. A 0.6 cubic meter bucket, when loaded with sand, puts you at about 1,560 kilograms of material and bucket before you add rope. Now you're over the rated line—or you're eating your safety factor just to get to first speed. ANSI/ASSE A10.5, the standard for construction material hoists, requires the rated load to be marked and the operator to know the actual weight. In practice, nobody wants to do that math on site at 6 a.m.

Private label isn't the enemy—confusion is

The private label conversation threw me at first, because there's nothing inherently wrong with private label in construction equipment. I've seen good private-label machines. I've also seen private-label machines where the seller removed the OEM name and put a logo over the original load chart. That's where I draw a line.

If you put your company's name on a mobile crane, you're taking responsibility for the load chart. The load chart is not a branding exercise. It's a set of engineering promises. ASME B30.5, the standard for mobile cranes, doesn't care about the logo. The chart has to match the crane's actual configuration, counterweight, and outrigger setup. If it doesn't, the crane is a liability, not an asset.

The rental company was looking at a "mobile crane private label" option because it was almost $6,000 less than the Potain mobile crane in the original spec. I'd have to check the exact quote, but the difference was real. The problem: the private-label supplier intended to use a load chart from a different, heavier chassis. They thought we were saying that because we wanted the dealer margin. Honestly, we were saying it because their client's insurance company would eventually ask for the original spec—and there wouldn't be one.

Private label can work, but only if the original manufacturer provides serialized documentation, a matching load chart, and after-sale support. It's not automatically bad. But if you're buying private label to save money and the load chart says "refer to OEM," you're not saving $6,000. You're buying a $6,000 headache. The last time we saw a similar mismatch, the steel was fine, but the machine sat for two weeks while a regional dealer tried to reverse-engineer the configuration. That delay cost more than the discount ever saved.

What a tower crane specification guide actually needs

After that, the rental company did the right thing. They sent the official Potain documentation, and we put together a real tower crane specification guide for the MDT 178. Not a brochure summary. A guide tied to the serial number: jib length, mast section, free standing height, foundation loads, the bulk hoist rating, and the exact load chart. No "up to." No "approximately."

If you're putting together your own guide, this is what I check, in this order:

• Exact model and configuration—jib, mast, counter-jib. Not "up to."
• Load chart that matches the serial number, not the marketing page.
• Foundation and tie-in loads—engineers need these before they pour anything.
• Hoist and bulk hoist ratings, with bucket weight and material density.
• Certification and documentation—ASME B30.3 for tower cranes, A10.5 for material hoists, and OSHA 1926 Subpart CC for site compliance.

That last part is the part people skip. Under OSHA's crane rule, the operator has to have the load chart at the controls. If your spec is just a stack of glossy PDFs and a "trust us," that's not a spec. That's a hope.

The lesson I keep learning

About a week after the Potain crane arrived on site, the project manager called me. He said, "The client asked why our spec was so much clearer than the other quote. I told them: because we know what we're buying." I'm not saying that made our equipment better on paper. It made the customer more confident in the equipment. Quality perception isn't about paint and decals. It's about whether the person signing the check believes you know what you're selling.

It took me four years and more than a hundred spec reviews to understand something that sounds obvious: a crane is not a commodity. You can buy steel and wire rope as commodities. But when you buy a potain crane—or any crane under your own label—you're buying a set of promises that have to be verified. The promise is tested when an operator looks at the load chart and trusts it. If it says 5 tons at 20 meters, it has to be true at 20 meters. Not "basically true." Because somebody standing under the hook is betting their life on it.

That's why I review the spec before I review the paint. The paint needs to look right. But the spec is what makes the crane worth owning.