Some of the most challenging industrial lifts happen where forklifts, mobile cranes, and standard material-handling equipment cannot safely reach the load.
Equipment installed inside tanks, pits, wet wells, vaults, basins, and other floor openings often needs to be lifted vertically before it can be moved anywhere else. Pumps, motors, mixers, valves, screens, and other components may be positioned several feet below the surrounding work surface with limited access from the sides.
In these situations, a portable aluminum gantry crane can provide an overhead lifting point directly above the equipment.
However, lifting over an opening requires careful planning. The weight of the equipment is only one consideration. Operators also need to account for the opening dimensions, surrounding structure, available floor space, lifting height, crane placement, rigging, surface conditions, and what will happen to the equipment after it clears the opening.
Why Is Lifting Equipment From a Pit So Difficult?
A piece of machinery sitting on an open warehouse floor may be accessible from several directions. Equipment installed below grade is different.
The surrounding structure can prevent a forklift from approaching the load, while the depth of the opening may prevent conventional lifting equipment from reaching it.
Common examples include:
- Industrial pumps inside wet wells
- Pumps located below floor level
- Motors and gearboxes inside pits
- Mixers used in treatment tanks
- Valves and piping components
- Equipment inside utility vaults
- Components within wastewater treatment basins
- Machinery positioned inside containment areas
- Equipment below elevated platforms
Before any of this equipment can be transported, it generally has to be raised high enough to completely clear the surrounding structure.
That creates a vertical lifting problem that is well suited to an appropriately designed overhead lifting system.
Creating an Overhead Lifting Point With a Gantry Crane
A portable gantry crane creates an independent overhead structure from which a hoist and trolley can be suspended.
Unlike a permanent overhead crane, the gantry can be brought to the equipment and positioned specifically for the lift.
This can be particularly useful when there is no approved structural lifting point above the pit or tank.
EC&MW manufactures portable aluminum gantry cranes in numerous configurations for industrial maintenance, machinery handling, pump removal, utilities, power generation, wastewater facilities, and other specialized applications.
Never Assume the Building Is a Lifting Point
When equipment is located below a floor opening, workers may be tempted to attach a hoist to a nearby roof truss, structural beam, pipe support, railing, or other overhead structure.
Unless that structure has been specifically evaluated and approved for the intended lift, it should not be assumed to be capable of supporting the load.
A gantry crane provides a dedicated lifting structure with a defined rated capacity when properly configured and used according to the manufacturer’s requirements.
This is one of the biggest advantages of portable gantries in facilities that were not originally designed with permanent lifting equipment above every pump, tank, or maintenance area.
Industrial Pumps Are a Common Application
Pumps are among the most common pieces of heavy equipment located below grade.
Water treatment plants, wastewater facilities, pump stations, lift stations, power plants, industrial facilities, and municipal utilities may have pumps installed inside wet wells or below the surrounding operating floor.
When the pump requires maintenance, it needs to be lifted vertically until the entire assembly clears the opening.
The pump can then be transferred to an appropriate work surface or transportation system.
EC&MW manufactures T-Frame aluminum gantry cranes that are frequently used for applications involving pumps, motors, gearboxes, tanks, wet wells, lift stations, and similar equipment.
Why a T-Frame Gantry Can Be Useful Around Tanks and Pits
A traditional A-Frame gantry generally requires enough room to position a leg assembly on each side of the load.
That isn’t always possible around a tank, pit, basin, or opening.
There may be a wall on one side, piping around the perimeter, a railing surrounding the opening, or simply insufficient floor space for a conventional base configuration.
A T-Frame gantry can provide another option because its cantilevered beam configuration can extend the lifting point beyond the supporting structure.
This can allow the hoist to be positioned over equipment without requiring the crane base to completely straddle the opening.
The correct configuration depends on the load, required reach, operating surface, and dimensions of the work area.
Lifting Pumps From Wet Wells
Wet wells create a particularly challenging maintenance environment.
Submersible pumps may operate below the water level and remain in service for extended periods before requiring inspection, repair, or replacement.
When maintenance is required, the pump may need to travel vertically through the entire wet well before reaching the operating floor.
The lifting system therefore needs sufficient Height Under Beam to raise the pump completely clear of the opening.
EC&MW discusses these applications further in its guide to portable gantry cranes for water and wastewater treatment plants.
Height Under Beam Is Critical
One of the easiest mistakes to make when planning a lift from a pit is focusing only on the crane’s rated capacity.
Capacity tells you how much the gantry can safely support within its rated configuration. It does not tell you whether there is enough vertical space to remove the equipment.
Consider a pump that is eight feet tall and installed several feet below the operating floor.
The gantry must provide enough usable lifting height for the hoist, rigging, pump, and required clearance above the opening.
When determining the required Height Under Beam, consider:
- Equipment height
- Depth below the operating surface
- Hoist dimensions
- Trolley dimensions
- Rigging length
- Required clearance above the opening
- How the equipment will be transferred after lifting
A crane with adequate lifting capacity can still be unusable if it does not provide enough vertical clearance.
Span and Opening Width Matter Too
The dimensions of the opening also need to be measured carefully.
If an A-Frame gantry will straddle a pit, the beam must provide sufficient usable span while allowing the legs and casters to remain on appropriate supporting surfaces.
Do not assume that the concrete immediately surrounding an opening can safely support the crane simply because it appears solid.
Floor loading, structural capacity, underground vault construction, drainage channels, curbs, and other conditions may affect where the crane can safely be positioned.
The facility’s engineering team or other qualified personnel should evaluate structural conditions when required.
What If the Floor Around the Opening Is Uneven?
Pits, tanks, wet wells, and industrial process areas frequently have less-than-perfect operating surfaces.
There may be:
- Floor drains
- Sloped concrete
- Curbs
- Channels
- Gravel
- Outdoor terrain
- Changes in elevation
A conventional caster gantry requires an appropriate operating surface.
For applications involving more challenging terrain, EC&MW manufactures All-Terrain aluminum gantry cranes.
These cranes use adjustable support legs and leveling pads that can accommodate many uneven surfaces when properly configured.
EC&MW also offers air pneumatic tire gantries for certain applications where larger tires provide improved mobility over less-than-perfect surfaces.
Plan What Happens After the Equipment Clears the Opening
Successfully lifting equipment out of a pit is only half the job.
Once the pump, motor, mixer, or other component reaches floor level, where does it go?
This should be determined before the lift begins.
Depending on the application, the equipment may need to be lowered onto:
- Machinery skates
- A maintenance cart
- A transport dolly
- A pallet
- A trailer
- A work platform
- Another engineered support system
The work area needs sufficient space to safely transition the equipment from a suspended load to its next support or transportation method.
Can You Move the Gantry While the Equipment Is Suspended?
This depends on the specific crane.
Never assume that a portable crane is automatically designed to roll while supporting a suspended load.
Some EC&MW gantry configurations can be designed for movement under specific loaded conditions, while others have different operating requirements.
The crane model, load, caster configuration, surface, height, and other factors all affect whether loaded movement is permitted.
Always follow the operating instructions for the specific gantry and lifting system being used.
Tank Maintenance Can Require Specialized Lifting Equipment
Industrial tanks present many of the same access challenges as pits and wet wells.
Equipment associated with tanks may include mixers, agitators, motors, gearboxes, pumps, valves, and other mechanical components.
Some components are mounted on top of the tank. Others extend into the vessel and must be raised vertically before they can be removed.
The tank itself may prevent a conventional crane from getting close enough to the lifting point.
In these applications, a T-Frame or custom aluminum gantry crane may provide the geometry needed to position the hoist over the equipment while keeping the crane supports on an appropriate surface.
Replacing Mixers and Agitators
Industrial mixers and agitators can be particularly difficult to remove because the equipment may extend several feet into a tank.
The motor and gearbox may be located above the vessel while the shaft and mixing components extend downward.
Removing the assembly can require substantial vertical clearance.
Before selecting a gantry, determine the complete length of the equipment that must clear the tank—not simply the dimensions of the motor visible above it.
This is another application where Height Under Beam can be just as important as lifting capacity.
Equipment Removal From Industrial Pits
Industrial manufacturing plants may contain pits for machinery, pumps, hydraulic equipment, conveyors, processing systems, and other components.
These pits are often surrounded by active production equipment, making mobile crane or forklift access extremely difficult.
A portable aluminum gantry can be transported into the facility and assembled around the opening.
This makes gantries particularly useful during:
- Plant shutdowns
- Scheduled maintenance
- Equipment replacement
- Production line modifications
- Facility upgrades
- Emergency repairs
Don’t Forget the Center of Gravity
Equipment removed from tanks and pits may not have an obvious center of gravity.
Pumps, motors, mixers, gearboxes, and other assemblies can be top-heavy or asymmetrical.
The load may also change orientation as it clears the opening.
Qualified personnel should determine the appropriate lifting points, rigging arrangement, and load control method before lifting begins.
Manufacturer-specified lifting points should be used when provided.
Custom Gantry Cranes for Difficult Openings
Some facilities simply don’t provide enough room for a standard gantry crane.
The opening may be too close to a wall. Electrical cabinets may prevent normal leg placement. The required lifting height may exceed a standard configuration. A railing, pipe, tank, or structural component may interfere with the crane.
That’s when custom engineering becomes valuable.
EC&MW has manufactured custom aluminum gantry cranes for industrial facilities where floor drains, electrical panels, walls, restricted access, unusual lifting heights, and other obstacles prevented the use of conventional lifting equipment.
Rather than modifying the facility around a standard crane, the gantry can often be designed around the actual work environment.
What Information Do You Need Before Selecting a Gantry?
If you need to lift equipment from a tank, pit, wet well, or other opening, gather as much information about the application as possible.
Important details include:
- Total equipment weight
- Equipment dimensions
- Opening dimensions
- Depth of the equipment below floor level
- Required lifting height
- Required Height Under Beam
- Available crane span
- Available floor space around the opening
- Floor and ground conditions
- Nearby walls, railings, pipes, and electrical equipment
- Doorway or access dimensions
- Hoist and trolley requirements
- Rigging requirements
- Where the equipment will go after removal
Providing these measurements to the gantry manufacturer can help determine whether a standard crane will work or whether the project requires a specialized configuration.
Bring the Lifting Point to the Equipment
Tanks, pits, wet wells, vaults, and floor openings create lifting problems because the equipment cannot simply be approached from every direction.
When a forklift can’t get underneath the load and a mobile crane can’t access the work area, a portable gantry crane can provide an overhead lifting point directly where it is needed.
EC&MW manufactures aluminum gantry cranes for pump maintenance, wastewater treatment, power generation, industrial manufacturing, utilities, tank maintenance, machinery moving, and other specialized lifting applications.
With A-Frame, T-Frame, All-Terrain, pneumatic-tire, removable-leg, and custom configurations available, the lifting system can be selected around the actual environment rather than simply the weight of the load.
If you need to lift a pump, motor, mixer, gearbox, valve, or other piece of heavy equipment from a difficult opening, view EC&MW’s custom gantry projects or contact EC&MW with the load weight, opening dimensions, required lifting height, available floor space, and operating conditions.
