Buck Hoists
A rack-and-pinion powered personnel and material hoist — also called a construction elevator or man hoist — that carries workers and materials vertically in an enclosed or partially enclosed cage alongside a mast anchored to the building structure, providing fast, high-capacity vertical transport between ground level and multiple building floors throughout the construction period. Find buck hoist vendors near you through Scaffold Exchange.
What Is a Buck Hoist?
Definition: A buck hoist — also known as a construction hoist, man hoist, or rack-and-pinion elevator — is a motorized vertical transport system consisting of an enclosed or semi-enclosed personnel and material cage driven by an electric rack-and-pinion mechanism along a vertical mast anchored to the building structure at regular height intervals. The cage travels the full height of the mast under power, stopping at each floor level to allow workers and materials to board or exit through the cage gate and through a landing gate at the building floor opening. Buck hoists are rated for both personnel and material transport — most modern units carry a mix of workers and materials simultaneously — and are governed as personnel hoists under OSHA 29 CFR 1926.552(c), which imposes significantly more stringent design, inspection, and testing requirements than the general scaffold or material hoist standards that govern other temporary vertical access equipment.
The term "buck hoist" is the colloquial North American construction industry name for a rack-and-pinion construction hoist. The rack-and-pinion drive mechanism — in which a motor-driven pinion gear engages a rack welded to the mast — is what distinguishes a buck hoist from a wire rope hoist: the rack-and-pinion system provides positive mechanical engagement between the drive and the mast at all times, eliminating the reliance on wire rope integrity that governs the safety of suspended hoists and swing stages. The positive engagement also provides the platform with an inherently more controlled descent and a more precise floor-level stopping position than a wire rope drum system.
On major multi-story construction projects — high-rise residential and commercial towers, large hospital and institutional buildings, major renovation projects — the buck hoist is the primary means of vertical transport for workers and materials throughout the construction period, often operating from before the structural steel or concrete frame reaches its full height until the building's permanent elevators are commissioned and available for construction use. The throughput capacity of a single or twin buck hoist installation significantly affects overall project productivity: a hoist that is undersized for the worker population, too slow, or poorly positioned relative to the main worker access points is a bottleneck that compounds across every trade on the project. Through Scaffold Exchange, you can find vendors across the U.S. who supply and install buck hoists and compare their cage capacities, travel speeds, and availability for your project.
How a Buck Hoist Works
A buck hoist is installed, commissioned, and inspected as a complete engineered system before it is placed in service, and operates under strict daily and periodic inspection protocols for the full duration of its service on the project.
Install the Mast & Anchor to the Building
The rack-and-pinion mast is erected alongside the building structure from the hoist's concrete foundation pad, rising in mast section increments as the building advances in height. The mast is tied to the building structure at the required intervals using engineered tie brackets, transferring the lateral loads from the mast and cage into the floor slabs or structural frame. Mast ties must be installed at the intervals specified by the hoist manufacturer and verified by the project engineer before the hoist advances above each tie point.
Commission the Cage & Test Safety Devices
The hoist cage — fitted with the electric drive motor, rack-and-pinion pinion assembly, anti-fall safety device, overload sensor, limit switches, and control panel — is mounted on the mast and commissioned before workers are permitted to ride. The anti-fall safety device is tested under load to confirm it will engage and arrest the cage within the required stopping distance if the descent speed exceeds the rated limit. Limit switches at the top and bottom of travel are tested to confirm they prevent the cage from traveling beyond the mast's rated range. A commissioning certificate is issued before the hoist enters service.
Install Landing Gates & Floor Access Points
At each building floor level served by the hoist, a landing platform and a two-part interlocked landing gate system is installed — an outer gate at the building floor opening and an inner cage gate on the hoist cage itself. The interlock prevents the cage from moving when either gate is open, and prevents either gate from opening when the cage is not at that floor level. The interlocked gate system is the primary fall protection at each landing, preventing workers from stepping into the open shaft when the cage is not present at that level.
Operate Under Daily Inspection & Periodic Testing Protocols
The hoist is inspected before the first use of each working day by a competent person — confirming cage gate function, landing gate interlocks, limit switch operation, anti-fall device function, mast tie integrity, and drive system condition — and a daily inspection record is maintained. The anti-fall safety device is tested at the intervals required by OSHA 1926.552(c) and the manufacturer, and a periodic third-party inspection is performed at the intervals required by the applicable jurisdiction. The hoist is taken out of service immediately if any defect is found during inspection.
Key Components of a Buck Hoist
A buck hoist is an engineered mechanical system — not a scaffold component assembly — and its key components are purpose-built mechanical, electrical, and structural elements that work together as an integrated system.
Rack-and-Pinion Mast
The vertical structural mast along which the cage travels, fabricated from bolted lattice steel sections with a rack strip welded to one face that the drive pinion engages. Mast sections are added at the top as the building rises, and the mast is tied to the building structure at the required intervals to resist lateral deflection under cage and wind loads. The mast's rated height determines the maximum building height the hoist can serve without a mast extension agreement with the manufacturer.
Personnel & Material Cage
The enclosed or semi-enclosed platform on which workers and materials travel, typically fabricated from steel mesh or perforated steel panels with a solid roof, non-slip floor, and a vertically sliding or swinging access gate. Cage dimensions and rated load capacity vary by model — single-cage hoists typically carry 2,000 to 6,600 pounds; twin-cage configurations carry twice that — and the cage is sized to the worker population and material loads of the project it serves.
Electric Drive Motor & Pinion
The electric motor and gearbox driving the pinion gear that engages the mast rack, raising and lowering the cage at the rated travel speed. Drive motors are typically three-phase electric powered from a temporary electrical distribution panel at the hoist base. Variable-frequency drive (VFD) controllers on modern hoists provide smooth acceleration and deceleration and precise floor-level stopping without mechanical braking shock.
Anti-Fall Safety Device
A centrifugal governor device mounted on the cage that automatically engages and arrests the cage within a specified distance — typically 150 mm or less — if the cage descent speed exceeds the rated limit due to drive motor failure, gearbox failure, or power loss. The anti-fall device is the most safety-critical component on the hoist and must be tested before initial commissioning and at regular intervals throughout the hoist's service life. No hoist may be placed in service or returned to service after a safety device activation without the device being inspected and recertified by a qualified technician.
Interlocked Landing Gates
The two-part gate system at each served floor level — an outer landing gate at the building floor opening and an inner cage gate on the hoist cage — interconnected by an electrical or mechanical interlock that prevents cage movement when either gate is open and prevents gate opening when the cage is not present at that level. The interlock system is the primary fall protection at each landing point and must be tested daily as part of the pre-shift inspection.
Limit Switches & Overload Sensor
Electrical limit switches at the top and bottom of the mast travel range that cut drive power to prevent the cage from traveling beyond the mast's rated limits in either direction. An overload sensor prevents the cage from departing the landing if the total load exceeds the cage's rated capacity. Both devices are tested daily as part of the pre-shift inspection protocol required by OSHA 1926.552(c).
Common Applications & Job Site Uses
Buck hoists are used on any multi-story construction or major renovation project where the volume of workers and materials moving vertically throughout the workday exceeds what stair towers, scaffold hoists, or temporary elevators can efficiently handle.
High-rise residential and commercial tower construction where the hoist is the primary vertical transport from structural frame completion through interior fit-out
Large hospital, university, and institutional building construction where multi-trade worker populations require high-capacity vertical transport throughout the shift
Major building renovation projects where the permanent elevators are out of service or restricted from construction use during the project
Mixed-use developments where the hoist serves both the construction workforce and deliveries of finish materials — flooring, millwork, MEP equipment — to upper floors
Industrial plant and power station construction where large equipment components must be transported vertically to installation elevations
Bridge tower and infrastructure construction where workers must access elevated work areas repeatedly throughout the shift
Projects in dense urban sites where the building footprint and adjacent site constraints limit the number of stair tower locations available for worker access
Long-duration projects where the cumulative productivity loss from stair climbing across the full worker population justifies the hoist installation cost
Buck Hoists vs. Other Vertical Transport & Access Systems
Buck hoists provide the highest vertical transport throughput of any temporary access system — here is how they compare to the alternatives contractors evaluate for multi-story worker and material access.
Rack-and-pinion personnel & material hoist
- Highest throughput of any temporary vertical transport system
- Carries workers and heavy materials simultaneously in a single cycle
- Rack-and-pinion drive provides positive mechanical control at all speeds
- Governed by OSHA 1926.552(c) — most stringent temporary vertical transport standard
Material-only wire rope or rack-and-pinion hoist
- Carries materials only — workers not permitted in the cage or on the platform
- Lower cost and less stringent OSHA requirements than a personnel hoist
- Governed by OSHA 1926.552(a) and (b) rather than the personnel hoist standard
- Used alongside a personnel hoist or stair tower for worker access
Powered facade access work platform
- Large platform for facade work — workers perform tasks from the MCWP directly
- Not designed for vertical transport between floor levels in the way a buck hoist is
- Cannot carry the material loads or worker throughput of a full buck hoist installation
- Different application — facade access rather than floor-to-floor vertical transport
Fixed stair access between floor levels
- Required for emergency egress — buck hoist does not replace the stair as an egress route
- No energy cost or mechanical maintenance — workers climb under their own power
- Throughput limited by stair width and worker climbing speed and fatigue
- Used alongside a buck hoist — not as an alternative to it on tall buildings
Find Buck Hoist Vendors Near You
Use the Scaffold Exchange map to search by location, filter by equipment type, and connect directly with local suppliers who supply and install buck hoists for construction and renovation projects of all scales.
Compliance & Site Safety Considerations
Buck hoists used as personnel hoists in construction are governed by OSHA 29 CFR 1926.552(c), which imposes the most stringent requirements of any temporary vertical transport standard in the construction regulations. Key requirements include: the hoist must be designed by a registered professional engineer; the anti-fall safety device must be tested before initial use, after any activation, and at intervals not exceeding three months throughout the hoist's service life; the hoist must undergo a commissioning inspection and load test before workers are permitted to ride; landing gates at every served floor must be interlocked with the cage gate to prevent cage movement when any gate is open and to prevent gate opening when the cage is not at that floor; a hoist operator must be present whenever workers are riding the hoist; the rated load capacity must be posted in the cage and never exceeded; and the hoist must be inspected by a competent person before the first use of each working day. OSHA 1926.552(c) also requires that the hoist be equipped with upper and lower limit switches, an overload device, and a slack rope switch where applicable. Where the jurisdiction has adopted a state plan or local building code requirements for construction hoists that exceed the OSHA federal minimum, the more stringent local requirement governs. The hoist must be taken out of service immediately upon discovery of any defect in the cage, mast, drive, safety device, or interlock system, and must not be returned to service until the defect is corrected and the relevant component is re-inspected.
- Hoist designed by a registered professional engineer and commissioned with a load test before workers are permitted to ride
- Anti-fall safety device tested before initial commissioning and at intervals not exceeding three months throughout service
- Interlocked landing gates installed and tested at every served floor level before the hoist enters service
- Upper and lower limit switches and overload device tested as part of the daily pre-shift inspection
- Rated load capacity posted in the cage — never exceeded during worker or material transport cycles
- Competent person inspection completed and recorded before first use of each working day
- Qualified hoist operator present whenever workers are riding the hoist
- Hoist taken out of service immediately upon discovery of any defect — not returned to service until defect is corrected and re-inspected
1926.552(c)
Personnel Hoists & Employee Elevators
OSHA Interpretations & Rulings →