GB/T 31051.1-2014 serves as the base general standard within the crane terminology and classification series, providing unified specifications for crane term definitions and classification systems. The standard covers crane definitions, basic types, and classification methods, making it a cornerstone document for the entire crane industry. This article provides a systematic review of the standard's core content.

Standard Positioning and Classification Framework

GB/T 31051.1-2014 is Part 1 of the GB/T 31051 "Cranes — Terminology and Classification" series and a key component of the fundamental crane standards system. Unlike the GB/T 6974 series, which focuses on type-specific terminology, GB/T 31051.1 addresses crane classification from multiple dimensions. By structural type, cranes fall into three main categories: overhead type cranes (bridge, gantry, semi-gantry), jib type cranes (tower, mobile, portal, mast, floating, etc.), and cable type cranes (cable cranes). By mobility, cranes are classified as fixed base, mobile, or self-propelled. By hoisting mechanism, they are grouped into wire rope type, hydraulic cylinder type, and electric hoist type cranes.

Crane Classification Dimensions

The standard classifies cranes along the following dimensions: By bridge girder configuration — single-girder bridge cranes, double-girder bridge cranes (further divided into box girder, truss girder, etc.), single-girder gantry cranes, and twin-girder gantry cranes. By boom structure — trolley-luffing tower cranes, luffing-jib tower cranes, truck cranes, crawler cranes, all-terrain cranes, rough-terrain cranes (single cab, 4WD, pick-and-carry), portal cranes, mast cranes, floating cranes, railway cranes, deck cranes, and cantilever cranes. By load-handling device — hook cranes, grab cranes (clamshell cranes), electromagnetic cranes (lifting electromagnets), combination hook-grab cranes, and metallurgical specialty cranes (for ladles, clamps, charging, casting, etc.). By work duty — Class A1 through A8 cranes. The standard also categorizes cranes by application environment, including workshop cranes, warehouse cranes, yard cranes, shipyard cranes, harbor cranes, and construction tower cranes.

General Term Definitions

The standard provides precise definitions for general crane terminology: Rated lifting capacity — the maximum load a crane is permitted to lift, including the weight of the load-handling device. Span — the horizontal distance between the centerlines of the bridge runway rails of an overhead type crane. Working radius — the horizontal distance from the slewing centerline of a jib type crane to the vertical line of the load-handling device. Load moment — the product of the lifting capacity and the corresponding working radius, serving as a comprehensive indicator of a jib type crane's lifting capability. Work duty — a combined classification indicator reflecting both the degree of full-load usage and the frequency of operation, determined by the combination of utilization class (U0–U9) and load spectrum (Q1–Q4). Lifting height — the vertical distance from the ground to the highest position of the hook. Load-lowering height — the vertical distance from the ground to the lowest position of the hook, applicable to cranes serving below-grade areas. Hook pulley ratio — the number of hoisting rope parts wound on the movable pulley block; a higher ratio increases the rated lifting capacity but reduces the lifting speed.

Relationship Within the Terminology Standard System

GB/T 31051.1-2014 and the GB/T 6974 series serve complementary roles. The GB/T 6974 series is organized by crane type (Part 1: general principles, Part 2: mobile cranes, Part 3: tower cranes, Part 5: bridge and gantry cranes) and focuses on defining the structural and mechanism terminology specific to each type. The GB/T 31051 series, by contrast, addresses the classification framework itself — answering "how cranes should be classified" and "what defines the boundaries between crane types." Together, these two series form the twin pillars of the crane terminology standard system: GB/T 31051.1 first establishes the category to which a crane belongs, and the corresponding part of GB/T 6974 then provides the detailed term definitions for that specific type. The Kelude technical team applies this classification framework when discussing product selection with customers, ensuring accurate and unambiguous machine descriptions.

Crane Terminology and Classification Reference Table

The reference table below lists the core parameter configurations of the crane terminology and classification standard for the convenience of selection and operating personnel.

Kelude Heavy Industry: Engineered for the Toughest Lifting Challenges

Kelude Heavy Industry is a specialized manufacturer of heavy-duty industrial cranes and hoisting solutions. We focus on the design and production of overhead traveling cranes, gantry cranes, and electric hoists, delivering reliable performance for demanding applications across manufacturing, logistics, and energy sectors.

Frequently Asked Questions

Q: What is your lead time for a standard double-girder overhead crane?
A: Typical lead time is 8–12 weeks after approval of the general arrangement drawing, depending on capacity and customization level.

Q: Do you provide cranes for explosion-proof environments?
A: Yes, we offer explosion-proof configurations with certified electrical components and sealed enclosures, suitable for Zone 1 and Zone 2 hazardous areas.

Q: Can you retrofit an existing crane with a new hoist or control system?
A: Absolutely. We supply hoists, end carriages, and control panels that can be integrated into most existing crane structures, improving safety and performance without full replacement.

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