Potain Cranes, Tower Crane Specs & Hoist Buying: 8 Questions I Wish I'd Asked Sooner

I handle parts and equipment orders at a Potain dealer — eight years now, mostly tower cranes, some mobile and crawler work, and a steady stream of hoists and spare parts that nobody thinks about until something breaks. Over that stretch I've made mistakes that cost roughly $11,000 in wasted budget that wasn't mine. I keep a checklist now. This is that checklist, in the order I wish someone had handed it to me.

Eight questions. Skip to whichever one matches your problem.

• What should I check first on a tower crane specification sheet?
• Why do two cranes with the same model number have different specs?
• How do I read a load chart without getting burned?
• What's actually different about a Potain city crane job in Utah?
• What should I verify in a mobile crane catalog before I call anyone?
• Hoist distributor buying guide: what do buyers get wrong?
• New OEM, aftermarket, or used parts — how do you decide?
• When is a tower crane the wrong answer?

1. What should I check first on a tower crane specification sheet?

The load chart. Not the model number, not the max capacity line at the top of the brochure.

Potain's families — MDT, MCT, HDT, MD, MR, the Igo self-erectors — are frames. The same frame ships with different jib lengths, different counterweight and ballast packages, different tower combinations, and sometimes different reeving. Rated capacity at a given radius changes with every one of those choices. Two machines that both say "MDT 178" on the side can have genuinely different tip loads, and the number everyone remembers is the one at the top of the page, which is almost never the number the job needs.

In my first year — that was 2018 — I quoted an MCT 85 off a spec PDF I'd had sitting in a folder since 2016. Looked fine on my screen. It wasn't fine. The lift needed a radius that only worked on a longer jib with a heavier ballast package, which was a different machine at a different price. I found out when the customer's engineer sent the chart back with a red circle on it. We kept the order, but I burned a week of back-and-forth and a lot of credibility.

Since then I ask for the build sheet for the actual serial number. Brochures are for browsing.

2. Why do two cranes with the same model number have different specs?

Year of manufacture, retrofit history, and — on newer machines — software.

Here's the part that caught me off guard. Later MDT and MCT machines run Potain's CCS control system, and the load curve is programmed, not stamped. That's mostly a good thing: it means overload protection and zoning are set up for the actual configuration. It also means a machine can be quoted off a spec sheet that no longer matches what's loaded in the cab, especially after a jib change, a counterweight swap, or a control update.

I should add that this is exactly why used cranes are so hard to price from a listing. "MDT 178, 2020" is not a specification. It's a category. Ask three questions: what jib, what ballast, and does the load curve in the cab match the physical configuration. Get the answers in writing before money moves.

3. How do I read a load chart without getting burned?

Four things, in order:

Radius is slew center to hook. Not from the building, not from the edge of the slab. Measure from the mast.

Subtract everything below the hook. Hook block, rigging, spreader beams, hoist rings. The rated capacity is for the crane, not for your lift. A 4,000 lb chart number with 600 lb of rigging underneath is a 3,400 lb lift.

Check whether you're reading the in-service or out-of-service condition. The chart assumes something about wind. The park-position and out-of-service wind procedure lives in the operator's manual and it's a site decision, not something to leave to whoever's on the controls that day.

Read the manual for that machine. OSHA's Cranes and Derricks standard (29 CFR 1926 Subpart CC) is built around manufacturer procedures — 1926.1417 requires that equipment not be loaded beyond rated capacity and that operations comply with the manufacturer's instructions. The applicable load chart is the one on that specific crane. ASME B30.3 is the tower crane consensus standard and worth knowing by name.

4. What's actually different about a Potain city crane job in Utah?

First, an honest note on the phrase itself. "City crane" isn't a Potain model line. In the Utah market it usually means one of three things: a compact topkit machine, a topless unit for sites where the jib has to swing over adjacent property, or a self-erector like an Igo. You'll get better answers from a supplier if you describe the site instead of the label.

Now the Utah specifics, because they're real:

Elevation. Most of the Wasatch Front sits between roughly 4,200 and 6,000 feet. That barely matters for an electric tower crane and matters a lot for diesel mobile equipment — engine derating at altitude is in the manufacturer's charts. Ask for it.

Cold. Single digits and below zero are normal, not exceptional. Hydraulic warm-up cycles, slew bearing grease, and brake behavior at low temperature are all legitimate questions.

Wind. Canyon winds along the Wasatch are not gentle. In-service and out-of-service wind limits, plus park position, need to be decided before the crane goes up.

Paper. Foundation loads, seismic design, and geotech. Foundation design is per-lot. I've had a submittal kicked back because the geotech report was for the neighboring parcel, and it cost us a week. And if the jib swings anywhere near a flight path, that conversation starts early.

5. What should I verify in a mobile crane catalog before I call anyone?

A mobile crane catalog is a family of configurations, and the chart that matters is the one for the exact setup. Before you call, know this:

• Is the rated capacity off the main boom chart, or the boom-plus-jib chart? They are not the same document.
• What counterweight package, and what does each package weigh? That's a transport question and a permit question.
• Outrigger spread and ground bearing pressure. The soil is your problem, not the catalog's.
• Axle loads and road permits if the machine is moving between jobs.
• Altitude derating on diesel machines, per the manufacturer's data.

And the one people forget: a catalog is not inventory. Ask what's physically available, in what configuration, and what the setup time actually looks like. ASME B30.5 governs mobile and locomotive cranes; power line clearance rules are in OSHA Table A under 1926.1408, with a 10-foot minimum for lines up to 50 kV. That number is a floor, not a target.

6. Hoist distributor buying guide: what do buyers get wrong?

First, figure out which "hoist" you're actually buying. A base-mounted drum hoist (ASME B30.7), an overhead hoist (ASME B30.16), and the hoist winch on a tower crane are three different products with three different standards. A fair number of bad quotes start with two people using the same word for different machines.

Have these in writing before you talk to anyone: line pull, lift height, line speed, duty class, voltage/phase/hertz, drum capacity and rope size, brake type, and environment — indoor, outdoor, temperature range.

Voltage is where I got mine. Late 2020, I think — might have been early 2021 — we ordered a hoist on a 460V three-phase assumption for a shop that turned out to be 230V single-phase. We caught it at delivery, so it could have been worse. Freight both ways plus restock came to about $700 on a $3,800 unit, and the customer's schedule slipped a week. Voltage is now line one of our intake form.

Also ask the boring questions: is the rope a standard size, will brake parts still exist in five years, and who's doing the annual inspection. The frustrating part of this business is how often the same three issues come up — voltage, capacity, and who owns the inspection — despite everyone having written specs. Interpretation varies more than you'd think.

7. New OEM, aftermarket, or used parts — how do you decide?

Classify the part before you classify the source.

Load path — brakes, wire rope, sheaves, pins, slewing components, anything the load chart depends on. OEM, with documentation. This isn't a price conversation, it's a liability conversation.

Everything else — covers, limit switch housings, lighting, electrical components, cosmetics. Aftermarket is defensible if it's rated for the environment and the enclosure is right. To be fair, the aftermarket world has kept a lot of older Potain cranes working that would otherwise be parked. I'm not going to tell you it's all bad.

Used can work. What causes trouble is a used part with no history. Ask for the source machine's serial number, running hours, and why it came off.

One thing I should add: Potain has been a Manitowoc brand since 2001. If someone's selling you "Potain genuine," the paper trail should run through the Manitowoc/Potain network. Ask for the part number and the source. Verify current pricing in writing — I'd rather not quote part numbers from memory, because a stale number is worse than no number.

8. When is a tower crane the wrong answer?

More often than the industry likes to admit — including a Potain, and including a city crane.

A tower crane makes sense when you're moving a lot of material over a long duration on a site that has no room to drive a truck around. If your job is 40 picks over three weeks on a gravel pad with room for a rough-terrain machine, I'd push back before I'd quote you a tower.

The other disqualifiers: no room for a pad; a basement that's being dug later; electrical service and permitting you don't want to chase; or a jib that has to cross a property line you can't get an easement for. And if you need a luffing jib, that's a different family of machine entirely — check what's actually available rather than assuming a topkit will fit.

Here's how I'd frame the decision: the tiebreaker between a tower crane and a mobile crane is almost always duration, not capacity. Duration is the number nobody puts on a spreadsheet, which is why people get it wrong.