As a used tower crane supplier who’s been in this game for over a decade, I’ve seen more than my fair share of inspectors walk away from a potential deal with their heads in their hands—either because they missed a small, costly issue or because they got spooked by a cosmetic flaw that meant nothing. Tower cranes aren’t just big metal toys; they’re life-critical pieces of equipment that construction teams rely on to lift hundreds of tons of materials high into the sky day in and day out. When a contractor comes to us looking for a used unit, my team and I treat every inspection like it’s the first one we ever did—no shortcuts, no assumptions, no cutting corners. Today, I’m pulling back the curtain on exactly how we vet every used tower crane that comes through our yard, so you know what to ask for when you’re shopping too. Used Tower Crane
First things first: start at the bottom, not the top. It’s easy to get caught up in the shiny cab or the smooth jib end, but the foundation of a tower crane is where most hidden problems live. I once had a client who skipped the base inspection on a used 2018 Potain I go 50 and ended up with a $12,000 repair bill three months later when we found corroded anchor bolts in the base frame. The base sits directly on the building’s anchor points or a temporary concrete pad, so you need to check two key areas here: the base frame itself and the anchor bolts. Look for pitting, deep rust, or cracks on the steel base plate—even minor surface rust that’s flaking off into powder is a red flag, because that means the steel’s losing structural integrity. Then, grab a magnet (or a cheap bolt tester from a hardware store) and run it over every visible anchor bolt. Wait for it to stick? That’s great—regular carbon steel bolts are standard, and if they’re still full and intact, you’re in good shape. If the magnet doesn’t stick, that means those bolts are stainless steel replacements, which could mean the original ones snapped or corroded away at some point. And don’t forget to count them: if there are fewer anchor bolts than the crane’s manual specifies, that’s a huge risk. A missing bolt here can throw off the entire load distribution, leading to a potential collapse mid-lift.
Next, work your way up the tower sections. The tower is the spine of the crane, so every single section needs a once-over, and then some. Most used cranes have multiple bolted tower sections, stacked on top of each other, so you’ll want to inspect every flange joint and the vertical mast itself. First, check for alignment: take a long straightedge (we use a 10-foot steel ruler) and hold it against the mast. If there’s a gap of more than 1/8 of an inch between the ruler and the steel, that means the mast is bent or twisted from overloading or being moved incorrectly. Bent masts aren’t impossible to fix, but they add extra stress on the hoist and slewing mechanisms, so you’ll want to budget for that repair or negotiate the price accordingly. Then, check all the bolts on the tower flanges. A lot of cheap suppliers will use cheap lock washers that pop off over time, so look for missing bolts or loose ones. We use a torque wrench for every bolted joint on a crane, and we document every torque value—because a bolt that’s even 20 foot-pounds loose can cause a flange to separate under heavy load. Also, watch for welds on the tower sections. Some older cranes have welded sections, and any crack in a weld here is a critical failure point. If you see a crack, even a tiny hairline one, have a certified welder inspect it—don’t just grind it smooth and call it good. We once had a used crane come in from a construction site where a welder had ground down a 2-inch weld crack, and it only lasted three lifts before the tower split. It’s not worth the risk.
Once you’ve checked the tower, move to the slewing section— that’s the part that lets the crane rotate 360 degrees. This is where a lot of the moving parts live, so noise here isn’t normal wear and tear, it’s a warning sign. First, test the slewing motor: turn it on and let it make a full rotation. Listen for grinding, squealing, or uneven movement. If it jerks or lurches mid-rotation, that could mean the slewing gearbox is failing, or the slew ring (the big circular gear that the upper crane sits on) has broken teeth or is corroded. The slew ring is a $15,000 to $20,000 part, so replacing it on a used crane is a major expense. To check the slew ring, shine a flashlight under it and look for missing teeth, gouges, or excessive grease leakage. A little grease is normal, but if it’s dripping out in thick globs, that means the ring’s seals are shot. Also, check the slew limit switch—this is a safety feature that stops the crane from rotating too far and crashing into the building or other equipment. Test it by trying to turn the crane past its maximum rotation point; if it doesn’t cut power, that switch could be bypassed, which is a huge safety hazard. We always confirm that all safety interlocks on a used crane are functional before we even consider listing it for sale.
Now, the jib—this is the part that extends out over the jobsite, holding the hoist cable and hook. The jib takes the brunt of every lift, so it’s where most visible wear shows up, but don’t let cosmetic dents fool you. First, walk the entire length of the jib, checking every truss section. Look for bent chords (the top and bottom edges of the truss), broken welds, or cracked bolt holes. A small dent on the edge of a jib chord is fine, but a dent that’s more than 2 inches deep or affects more than one truss section is a problem. That dent could weaken the entire jib, especially under full load. Then, check the jib tip and the counter-jib. The counter-jib is the shorter section on the opposite end of the jib, and it’s weighted to balance the load. Make sure all the counterweights are in place and secured—missing even one counterweight throws off the center of gravity, which is a disaster when lifting heavy materials. We once had a customer who tried to sell a used crane with three missing counterweights, and we had to turn him away immediately—we couldn’t in good conscience sell a crane that posed a risk to his crew. Also, check the jib walkway and safety railings. These are easy to overlook, but if the walkway is rotting or the railings are bent, that’s a hazard for the maintenance workers who have to climb the jib to grease the cables or fix components.
Next, the hoist mechanism and cable—this is where the load actually moves, so it’s one of the most critical inspection points. The hoist drum, cable, and hook all get constant stress, so skip this part at your peril. First, inspect the hoist cable. Run your hands along the entire length of the cable (wear gloves—cable ends are sharp) and look for broken strands, kinks, or fraying. A small kink can be cut out, but if more than 5% of the cable’s strands are broken, or if there’s a major kink, the entire cable needs to be replaced. New crane cable costs around $2 per foot, so for a 200-foot jib, that’s a $400 expense, but it’s way better than a cable breaking mid-lift. Then, check the hook. Look for cracks in the hook’s safety latch, and make sure the latch closes properly—this prevents the load from slipping off the hook. Also, check the hook’s twist: if you spin it and it doesn’t straighten out, that means it’s been twisted under load, which weakens it. We always test the hook by lifting a test weight with a small crane before we hand over a used unit—if the hook twists or feels unstable, we replace it before delivery. Finally, test the hoist motor. Lift a moderate load (50% of the crane’s maximum capacity) a few feet off the ground, then lower it smoothly. If the motor stutters or makes unusual noises, that could mean the windings are failing, or the brake is worn out. Hoist motors aren’t cheap, so factor that into your inspection.
After the moving parts, check the cab and control systems—this is where the operator spends their time, and it’s where safety is controlled. First, look at the control levers and joysticks. Are they loose, sticky, or don’t return to neutral? That’s a sign of worn-out hydraulic valves or electrical connections. Test all the functions: lift, lower, rotate, extend the jib, retract the trolley. Make sure every control responds smoothly. Then, check the display panel. Are all the lights working? Does it show the correct load capacity, wind speed, and angle? The load moment indicator (LMI) is a non-negotiable safety feature—it stops the crane from lifting more than its maximum capacity. If the LMI isn’t working, that’s a big problem. We calibrate the LMI on every used crane we sell, and we provide a certificate of calibration with every unit. Also, check the emergency stop button—this should be red, prominent, and work instantly. If the emergency stop is sticky or doesn’t cut power, that’s a dealbreaker. Don’t forget to check the seat and safety belts, too—if the operator’s seat is worn or the belt is cracked, that’s another safety hazard waiting to happen.
Last but not least, electrical and hydraulic systems. These are the unsung heroes of a tower crane, and small issues here can turn into costly repairs fast. For electrical systems, check all the wiring for fraying, exposed wires, or water damage. Cranes work in all weather, so moisture can get into the wiring and cause short circuits. Also, test all the lights: cab lights, jib lights, beacon lights, and floodlights for the jobsite. A broken beacon light is a safety hazard for night operations, so make sure that’s fully functional. For hydraulic systems, check all hoses for leaks, cracks, or bulges. A leaking hydraulic hose can cause pressure to drop suddenly, leading to a loss of control. Most cranes have a hydraulic fluid reservoir—check the fluid level and color. If the fluid is cloudy or has metal shavings in it, that means the pumps or valves are wearing out. We always do a full fluid flush on used cranes before we deliver them, so our customers never have to deal with that headache.
Now, let’s talk about the stuff that’s not on the crane itself: documentation. You can do a perfect inspection, but if the crane doesn’t have the right paperwork, it’s not legal to use. Ask for the original operation and maintenance manual, the load chart, and the inspection records from the previous owner. Most countries require annual crane inspections by a certified professional, so if the previous owner skipped inspections, that’s a red flag. We keep all inspection and maintenance records for every crane we sell, so our customers know exactly what’s been done and when. Also, check the serial number and model—make sure it matches the paperwork. A lot of used crane scams involve selling mismatched parts or cranes, so confirm that every serial number on the base, tower, and jib matches the documentation.
At the end of the day, inspecting a used tower crane isn’t about finding perfect units—there’s no such thing as a “like new” used crane, unless it’s barely been used. It’s about finding a unit that’s been well-maintained, has no critical defects, and fits your jobsite needs. Over the years, I’ve built my business on honesty, and I tell every client the same thing: if you show up to inspect a used crane and the seller tries to rush you, or won’t let you do a full inspection, walk away. Good suppliers will encourage you to take your time, bring your own certified inspector, and even run a load test to confirm the crane’s capacity.
If you’re in the market for a used tower crane and don’t want to deal with hidden costs or safety risks, we’re here to help. We’ve got a full yard of inspected, serviced used tower cranes from top manufacturers, and our team will walk you through every step of the process, from inspection to delivery. Whether you need a small jib crane for a residential project or a large flat-top crane for a high-rise, we’ve got options that fit your budget and your needs. Don’t take chances with your crew’s safety or your project’s timeline—reach out to us to discuss your requirements and schedule an inspection.
Used Construction Hoist References
- Potain Crane Technical Manual, Manitowoc Company Inc.
- OSHA Standard 1926.550: Cranes and Derricks in Construction, Occupational Safety and Health Administration.
- Tower Crane Inspection Guidelines, National Association of Tower Erectors.
- Load Moment Indicator Calibration Procedure, Crane Manufacturers Association of America.
Tianjin Huizhi Import and Export Trading Co., Ltd.
We’re well-known as one of the leading used tower crane manufacturers and suppliers in China, specialized in providing high quality customized service. Please feel free to buy cheap used tower crane for sale here from our factory. Contact us for more details.
Address: Room 4175, Building D2, Zone D, Airport International Headquarters Base, Guangxuan Road, Dongli District, Tianjin, China
E-mail: admin@hugecrane.com
WebSite: https://www.hugecrane.com/
