Headroom can make or break your lift—literally. Whether you’re working indoors with a gantry or executing a heavy lift using a crane and spreader beams, understanding how much vertical space your equipment will occupy is essential for planning and safety. In this guide, we’ll walk through how to calculate headroom for lifting operations across two common scenarios:
Outdoor crane lifts using spreader beams
By the end, you’ll be better equipped to choose the right rigging tools and avoid common planning oversights.
A properly used gantry crane.
Let’s say you’re lifting a steam boiler indoors using two 5-ton steel gantries set to their max height of 15’10” under the beam. The boiler weighs 12,400 lbs and measures 13 feet tall. That gives you 34 inches of vertical space for your rigging configuration.
Here’s how headroom adds up for common hoist options, starting from the beam down:
1. Beam Clamps
• Load per clamp: 3,100 lbs
• Riley 2-ton Superclamp (model S1A) eats up 10 inches
• Remaining headroom: 24 inches
• Coffing 2-ton model
• Headroom usage: 15 inches
• Remaining: 9 inches of lift space
• Pros: portable, efficient in tight spaces
• Cons: labor-intensive
• Harrington SNER020L
• Headroom usage: 22.6 inches
• Remaining: 1.5 inches
• Faster and less labor but tighter on space
• JDN Profi 2TI
• Headroom usage: 19.6 inches
• Remaining: 4.4 inches
5. Low-Headroom or Ultra-Low Headroom Hoists
• Integrated trolley + hoist
• Low-headroom model: 16.5 inches used, leaves 17.5 inches
• Ultra-low model: 6.5 inches used, leaves 27.5 inches
• Note: weight of ultra-low hoist (395 lbs) may limit use
Pro Tip: If the lift requires precision but minimal lift height, consider a jack and slide system, air skate system, or a mechanical skate system instead, especially if the boiler doesn’t need to clear obstacles.
Headroom calculations get more technical with outdoor lifts, especially when cranes and multiple spreader beams are involved. Let’s use a recent customer lift as an example. The goal: lift a 90-ton load with four pick points under a top beam.
Modulift modular spreader bars lifting a bridge section.
• Modulift MOD110 at 45’ span
• Rated for 105 tons at 70° sling angle
• Sling length: 65 ft
• Half the span (base of triangle): 22.5 ft
• a² = c² – b² → a² = 65² – 22.5²
• a² = 4,225 – 506.25 = 3,718.75
• a = √3,718.75 ≈ 61 feet headroom
• Two MOD50 beams at 12’ span
• Sling length: 10 ft, half-span: 6 ft
• a² = 100 – 36 = 64
• a = √64 = 8 feet headroom
61 ft (top beam) + 8 ft (lower beams) = 69 ft
This does not include shackles or hardware, so the final figure will be higher.
If available headroom is tight, you may need to:
• Shorten sling length (which increases sling angle/load)
• Swap to higher-capacity beams that reduce vertical span
• Reconfigure the lift with different rigging geometry
From gantry lifts to multi-beam crane picks, factoring in headroom isn’t optional—it’s essential. Miscalculations can delay the project, damage equipment, or worse, create unsafe lifting conditions.
Not sure which hoist or beam setup is right for your space? Our team can help. We’ll walk you through gear selection, rigging geometry, and required headroom to ensure your lift is safe and successful.
Contact LGH or call 800-878-7305 to speak with a rental expert today.
LGH is North America’s largest single organization devoted exclusively to the provision of lifting and moving equipment for rent. LGH holds the most comprehensive inventory for hoisting, rigging, jacking, pulling, material handling, and safety equipment. With over 90,000 pieces, discover your next project solution at RentLGH.com.
