Grove's GMK8700 Luffing Jib: What a 351-Foot Reach Actually Buys a Bridge or High-Rise Contractor

Boom length is the number everyone quotes when they talk about a crane's reach, but boom length alone doesn't solve every lift. A straight boom extended to its full length still has to clear whatever's in its way, whether that's power lines, an existing structure, or a bridge deck already partway built. A luffing jib solves a different problem: it's a secondary boom section that angles independently from the main boom, letting the crane work up and over an obstruction the main boom alone can't clear. Grove's GMK8700 carries the most capable luffing jib system in its current all-terrain lineup, and it's worth understanding on its own terms before you decide whether to finance one.

Real Specs on the GMK8700's Luffing Jib System

Manitowoc's own published figures for the GMK8700's luffing jib system:

• Main boom options: 177 ft (54 m) or 263 ft (80 m), both MEGAFORM boom design

• Luffing jib, maximum extension: 351 ft (107 m)

• Jib design: single back mast configuration

• Crane rated capacity: 800 US tons (700 tonnes)

• Maximum counterweight: 385,000 lb

• Engine output: 644 hp

That 351-foot figure describes the jib itself, mounted on top of either the 177-foot or 263-foot main boom, not a combined tip height number. In practice, that means a GMK8700 configured with the longer boom and the jib fully extended is reaching well past 600 feet of combined structure, which puts it in genuinely rare territory for an all-terrain crane that can still drive to a jobsite on its own wheels rather than needing a crawler or tower crane erection.

What a Jib Actually Solves That a Longer Boom Doesn't

A straight boom has one working angle at a time. A luffing jib adds a second, independently adjustable angle on top of it, which is what lets a crane reach up and over something in the way, set a load at a steeper angle into a tight pick point, or work a lift where the load path has to clear an obstruction the main boom's angle alone can't get around. Bridge erection over an active roadway, high-rise steel sets where the building itself blocks a straight approach, and wind-turbine component sets at height are the classic use cases, and they're exactly why we covered the GMK8700 separately for bridge and heavy-highway contractors already. The jib is the piece of that story that makes those specific lifts possible, not just the raw tonnage number everyone leads with.

Should You Actually Finance the Jib, or Rent One When You Need It?

This is the honest question, and it doesn't have the same answer for every fleet. A luffing jib is a specialized accessory most crane owners don't need mounted for every lift; it comes out for the specific jobs that call for it and sits in storage the rest of the time. If your fleet only hits a jib-required lift a few times a year, renting the jib attachment for those specific jobs, if your dealer offers that option, can make more financial sense than financing one outright and paying to store and maintain a component you use occasionally.

Where owning the jib pencils out is when your bid mix regularly includes the kind of work that needs it: bridge and heavy-highway contractors with a steady pipeline of overhead-obstruction lifts, wind-energy installation crews, and high-rise steel erectors who'd otherwise be turning down jobs or subcontracting the jib-equipped lift to a competitor. If you're regularly declining bids because you can't clear an obstruction with the configuration you own, that's the signal the jib has moved from a nice-to-have to a real financing decision.

Crew Certification and Rigging-Plan Considerations

Running a jib-equipped configuration isn't just a hardware decision; it changes the rigging plan and the load chart your crew works from. NCCCO certification covers crane operation broadly, but your operators and lift directors still need to be genuinely fluent in reading a jib-configured load chart, which de-rates differently from a straight-boom chart depending on jib angle, length, and offset. If your current crew has never run a jib-equipped lift, budget for manufacturer or third-party jib-specific training before the equipment shows up on a jobsite, not as an afterthought once the financing is already signed. It's also worth having your insurance carrier confirm that your policy's rigging coverage extends to jib-configured lifts specifically, since some policies price and underwrite that work differently from standard boom-only lifts.

Financing the Jib as Its Own Line Item

A jib system can sometimes be ordered as part of a new crane's original package, or added later as a separate accessory purchase on a crane you already own. Either way, it's worth financing it as its own clearly identified line item rather than letting it disappear into the total crane price, since that makes the deal easier to evaluate, easier to insure correctly, and easier to resell separately down the line if your fleet's work mix changes. We finance jib systems and crane accessories nationwide, with the same credit-based down payment structure as any equipment deal: strong credit profiles can mean little to nothing down, while a newer business or thinner file typically lands in the 20 to 40 percent range. For the dealer-support side of owning a Grove crane and its accessories, see our breakdown of Manitowoc's Crane Care, EnCORE, and Elite Dealer programs.

Section 179 depreciation applies to a jib system the same way it applies to the crane itself: purchased and placed in service in the same tax year, it can often be expensed well beyond standard depreciation schedules. We're not tax professionals and this isn't tax advice, but it's worth a direct conversation with your accountant, particularly if you're timing the purchase to a specific bridge or high-rise contract that's already on your books.

What to Check on a Used Jib System

A jib is a load-bearing structural component, not an accessory in the casual sense, so a used one needs a real structural inspection before you finance it, not just a visual walk-around. Ask whether the specific unit has ever been through Manitowoc's CraneCheck structural inspection program, and if it hasn't, budget for a proper inspection as part of the purchase rather than skipping it to save time. Check the back mast and luffing cylinder pins closely for wear, and confirm the jib's rated capacity chart matches the specific main boom configuration you're pairing it with, since jib capacity de-rates depending on which boom length and counterweight setup it's mounted to.

Who This Actually Makes Sense For

Bridge and heavy-highway contractors, wind-energy installation crews, high-rise steel erectors, and crane rental fleets that regularly field requests for obstruction-clearing lifts are the realistic buyers for a jib system like this. If that's not a recurring part of your bid mix, renting the jib attachment for the occasional job that needs it is almost certainly the smarter financial move, and there's no shame in that calculation; not every piece of capability needs to live on your own balance sheet.

One more practical point worth weighing: a jib-equipped GMK8700 is a genuinely rare machine in most regional fleets, which can cut either way for an owner. On one hand, you're less likely to face direct competition for the specific jobs that need that reach, which supports stronger pricing on those bids. On the other hand, a highly specialized configuration can be a slower sale if you ever need to exit the equipment, since the pool of buyers who specifically need a jib-equipped unit is smaller than the pool of buyers for a standard-configuration crane. Factor that resale reality into your financing term, not just your bid pipeline, when you're deciding how long to finance the jib for.

Ready to finance a Grove GMK8700, a luffing jib system, or any other heavy-lift equipment? Visit our home page, start your application, browse our equipment for sale marketplace, or subscribe to our blog for more equipment spotlights like this one.