Hoist & Crane Terms - CATET | Leading Crane Manufacturer & Heavy Lifting Solutions

Hoist & Crane Industry Glossary

Source: Crane Manufacturers Association of America (CMAA) – Key Terms & Definitions

Your Essential Guide to Hoist & Crane Terms, Standards & Safety

Table of Contents

1. Crane Types & Configurations

Term	Description
Automatic Crane	Crane that operates through pre-programmed cycles when activated.
Electric Top Running Crane	Electrically powered overhead crane with bridge traveling on elevated runway rails.
Floor-Operated Crane	Pendant-controlled crane operated from floor level.
Gantry Crane	Bridge supported by one or more legs running on fixed floor rails. → Single Leg: One end on leg, other on elevated rail. → Double Leg: Supported by two+ legs on floor rails. → Portable: Mobile via wheel base.
Indoor/Outdoor Use	Equipment weatherproofed and corrosion-resistant for external environments.
Industrial Duty Crane	CMAA Spec 70/73 service class for standard industrial applications.
Jib Crane	Rotating boom crane. → Floor Supported: 360° rotation, base-plated to floor. → Column Supported (Tie Rod): 180° rotation with tie rod support. → Full Cantilever: 180° rotation, no tie rod, max headroom.
Mill Duty Crane	AISE Standard No. 6 for heavy steel mill service.
Monorail	Single-beam material transport system. → Curved: Fixed curved path. → Switches: Branching paths via track switches.
Multiple Girder Crane	Two or more girders supporting live load.
Remote Operated Crane	Controlled via radio, infrared, or other non-pendant methods.
Top Running Crane	Bridge girder rides on top of runway beams. → Single Girder: 250 lbs – 15 tons. → Double Girder: 10 – 160 tons.
Under Running Crane	Bridge girder hangs below runway beams (ceiling-mounted). → Single Girder: ≤10 tons. → Double Girder: ≤25 tons (practical limit ~15 tons). → Patented Track: High-duty, precision applications (e.g., military).

2. Hoist Types

Type	Medium	Power	Typical Use
Air Chain Hoist	Chain	Pneumatic	Spark-safe explosive atmospheres
Air Wire Rope Hoist	Wire rope	Pneumatic	Spark-safe explosive atmospheres
Electric Chain Hoist	Chain	Electric motor	General industrial lifting
Electric Wire Rope Hoist	Wire rope	Electric motor	Heavy-duty, high-speed lifting
Hand Chain Hoist	Chain	Manual	Low-frequency, light loads
Ratchet Lever Hoist (Come-Along)	Chain	Manual lever	Lifting, pulling, tensioning

3. Structural Components

Component	Function
Auxiliary Girder (Outrigger)	Parallel girder supporting cab, controls, platform; reduces torsion on main girder.
Box Section	Fully enclosed rectangular girder/truck for maximum strength.
Bridge	Horizontal structure (girders + end trucks) carrying trolley parallel to runway.
Bridge Rail	Rail on bridge girders for trolley travel.
Camber	Upward curve in girders to offset deflection under load.
Diaphragm	Internal plate reinforcing girder webs.
Drive Girder	Girder mounting bridge drive machinery.
Drop Stops	Safety devices limiting bridge/trolley fall if wheel/axle fails.
End Tie	Connects girder ends to maintain bridge squareness.
End Truck	Wheel-mounted frame supporting bridge ends.
Girders	Primary horizontal beams supporting trolley.
Longitudinal Stiffeners	Horizontal web plates preventing buckling.
Torsion Box Girder	Trolley rail positioned over one web for torsional rigidity.
Web Plate	Vertical plate between girder flanges.

4. Motion & Control Systems

Term	Description
Brake	Device (friction/power) to stop/hold motion. → Holding Brake: Auto-engages when power off. → Mechanical Load Brake: Unidirectional; controls lowering, no extra lift load.
Counter-Torque Braking	Motor reversed to oppose motion.
Cushioned Start	Soft acceleration to reduce shock.
Dynamic Lowering	Motor acts as generator during overhauling (regenerative).
Eddy-Current Braking	Induction load brake for smooth speed control.
Electrical Braking System	Non-friction speed control in overhaaling condition.
Plugging	Braking by reversing motor polarity/phase.
Regenerative Braking	Energy fed back to power system.
Variable Frequency Drive (VFD)	Adjusts motor frequency for infinite speed control.
Stepless vs. Stepped Control	Infinite vs. fixed speed increments.

5. Electrical & Safety

Term	Function
Collectors	Sliding contacts transmitting power (runway → bridge → trolley).
Contactor, Magnetic	Electro-magnetic switch for power circuits.
Enclosed Conductor(s)	Insulated bus bars preventing accidental contact.
Fail-Safe	Auto-stop on malfunction (e.g., E-stop).
Limit Switch	Cuts power at travel limits.
Overload Limit Device	Prevents lifting beyond safe working load.
Overload Protection (Overcurrent)	Interrupts excessive current.
Undervoltage Protection	Cuts power on voltage drop/failure.
Explosion Proof	Contains sparks to prevent ignition in hazardous areas.
Spark Resistant	Operates safely in non-hazardous flammable environments.

6. Loads & Forces

Term	Definition
Capacity	Max rated load (tons).
Dead Load	Fixed structural weight (girders, walkway, etc.).
Live Load	Moving load (hook load).
Impact Allowance	Extra load factor for dynamic effects.
Mean Effective Load	Durability calculation load (between max/min).
Wheel Load (Bridge/Trolley)	Vertical force per wheel (excl. impact).
Lateral / Skewing / Torsional Forces	Horizontal, diagonal, or twisting forces on structure.

7. Dimensions & Clearances

Term	Measurement
Clearance	Min distance from crane extremity to obstruction.
End Approach	Min horizontal distance parallel to runway from crane end to hook centerline.
Headroom	Distance from track suspension to hook palm.
Hook Approach	Min horizontal distance from runway rail center to hook.
Lift	Max safe vertical hook travel.
Span	Center-to-center distance of runway rails.
Wheelbase	Center-to-center of outermost wheels.

8. Miscellaneous

Term	Meaning
BHN	Brinell Hardness Number.
Kip / KN / KSI	1,000 lbs
CMAA / CSA / NRTL/C	Industry standards & certifications.
Two Blocking	Load block jams against trolley — DANGEROUS.
Side Pull	Lifting outside vertical plane — PROHIBITED.