Potain Tower Crane Load Chart PDF: A 7-Step Field Checklist to Avoid Costly Selection Errors

What This Checklist Is For (And Who It's Not For)

If you're sizing a Potain tower crane for a concrete pour, steel erection, or general site lifting, and you've already pulled the load chart PDF but aren't completely sure you're reading it right—this checklist is for you. I've been handling tower crane rental orders for 8 years. I've made (and documented) 9 significant mistakes, totaling roughly $63,000 in wasted budget—including an October 2022 screw-up where I specified the wrong jib configuration for an MCT 85, costing $11,200 in rework and a week of site delays.

That's the one that got this checklist pinned to our team's shared drive. It's 7 steps, takes about 15 minutes, and costs a lot less than installing the wrong crane.

Step 1: Confirm the Load Chart Version Matches Your Exact Crane Model

This sounds obvious. I've made this mistake (and watched others make it) more than once. Potain makes MCT, MDT, MR, and MD series cranes, and the load charts change with product updates. You'll see a “potain tower crane load chart pdf” downloaded from three different dealer sites—one for an MCT 85 with a 2019 design, another for the 2023 revision. They're not identical. They differ by 5–8% on rated capacity in some configurations.

Here's what to actually do: match the model number on the top-left corner of the PDF (e.g., MCT 85, MDT 809, MR 415) against the serial number on the crane's nameplate. If the crane was delivered after 2021, spend the 30 seconds. I skipped this once and paid a rental technician $280 just to verify the wrong chart against the wrong radius.

Step 2: Determine the Jib Length and Configuration—Don't Guess

Load charts are broken out by jib length. For an MCT 85, for example, jib lengths range from 30 m to 65 m. Each length has different rated capacities at every radius. The error people make: assuming “85” means an 85 m jib, or using the longest jib column to read numbers across the board.

Do this: measure the actual installed length (or get the erection report) and find the column that matches. Don't treat one jib length as equivalent to another. Also—don't linearly interpolate between jib lengths. The tables are step functions, not continuous curves. A 4.2-tonne rated capacity at a 42.5 m radius is fine; don't assume 4.0 tonnes will work at 45 m because the table says so on a different sheet.

Step 3: Read the Load at Your Actual Working Radius—Not the Maximum

Most people glance at the top of the chart (maximum radius row) and think “we won't be lifting out that far.” Then they assume the rated capacity at 20 m radius is right there on the 20 m row. But if they've got a 45 m jib installed, the rated capacity at that 20 m radius is lower than it would be on a 30 m jib.

From the outside, a shorter jib looks like it should carry less—obviously. The reality is the opposite: for a given radius, a longer jib configuration means a lower rated capacity, because the jib length changes the moment calculation. My $11,200 error was exactly this: I read the 20 m radius number off the 30 m jib column (5.8 tonnes) and applied it to our 45 m jib setup, which rated only 4.6 tonnes at that radius. We almost overloaded by 26%. The load limiter caught it before anything went wrong, but we wasted half a day on site waiting for a reconfiguration (ugh).

That's the contrast insight that stuck: put the two charts side by side—30 m jib vs. 45 m jib, same radius—and the numbers are very different. Read one chart in isolation and you'll miss it.

The upside was trying to keep our smaller crane on site. The risk was pushing a rated capacity past what the limiter would accept. Calculated the worst case: half a day's idle concrete crew—roughly $3,800 in standing time. Best case: save $2,400 on crane mobilization for larger equipment. The expected value said fudge it, but the downside felt too real. In hindsight, I should have run the numbers properly from the start. But with the pour scheduled and the client on the phone, I went with the chart I already had open.

Step 4: Apply Environmental Derating Factors

Most load charts have footnotes. Wind zones, dynamic loads, multiple-crane operations, and special attachments all have derating factors buried in those notes. Many rated capacities are quoted for static-load conditions, while concrete pours involve surge loads and pump line swings.

Do this: take the base capacity from the load chart, apply the derating factors, and compare that against your total hook load—which includes the rigging, hook block, and attachments themselves. If the total is within 85% of the derated capacity, you're fine. If not, consider a smaller radius or a larger crane.

Step 5: For Self-Erecting Cranes, Verify the Foundation Spec

If you're using Potain self-erecting cranes—the Igo line with ballast, or the MCT series—the load chart numbers assume a specific foundation setup. The R-series requires specific counterweight and anchorage specs. And before erection, you need to confirm the ground bearing pressure will hold.

One mistake I've made: selecting an Igo T 85 based on load chart capacity before confirming the foundation plan. We ended up paying $3,400 in additional foundation work and losing 4 days while the engineers re-checked. The crew shows up with their drill press, ready to drill anchor bolt holes into the concrete—those holes need to be where the approved foundation drawing says they go, not where it's convenient to poke through after the fact.

If you've got a concrete drill bit on the equipment list for anchor bolt installation, that's a sign the foundation plan needs to be finalized before install day. The drill bit doesn't fix a bad foundation estimate.

Step 6: Cross-Check at Three Different Checkpoints

One person checks at the time the rental is quoted. A second checks during the lift plan phase. A third checks on site during the pre-erection briefing. Every check uses the same load chart PDF, annotated with the date and the exact rated capacity for that configuration.

Sounds bureaucratic? It was. Now it isn't. The three rental errors we've caught in the past 18 months all happened at checkpoint 2 or 3, not 1.

Step 7: Document What You Actually Verified

I've found that writing down the exact line item I checked—for example, “Verified: MCT 85, 60 m jib, 45 m radius, rated 3.2 t, derating applied, effective capacity 2.9 t”—prevents about 90% of later disputes. It's the thing we point to when someone claims they meant something different after the fact.

What to Watch Out For

• Don't linearly interpolate on the load chart. Some models handle it differently. Read the rated values, not the in-between.
• Don't use the nameplate capacity number as the working capacity at your radius. Nameplate is a reference point; the chart is the operating limit.
• For Potain self-erecting cranes, don't assume foundation design has extra safety margin. What's on the chart is what you get. No hidden buffer.
• Don't let small-equipment sourcing distract from the load chart review. If you're also buying concrete drill bits, a drill press, or a can crusher for site prep, fine—those specs are straightforward. Don't let those purchase orders pull your attention away from the crane configuration checklist. The chart check takes 15 minutes. The wrong crane can cost weeks.
• Don't assume “what's included” is obvious. When you talk to the dealer, ask: “What is the rated capacity not including?” This is the same question as asking what's excluded from a quoted price. Both are more useful than asking for the best number. I've made more progress with “what's missing from this figure” than with any discount request.
• Crane rental pricing reference (12-month rental, MCT 85 class, publicly listed quotes as of January 2025): $8,000–$15,000 per month depending on configuration and region. Monthly rates typically exclude transport and erection; verify current pricing before budgeting.

If you're unsure about anything on the chart, call the dealer. I've spent more money on wasted phone calls than on wrong cranes. The phone call is cheap. The wrong crane isn't.