If you have ever received a crane quotation with codes like QD, MG or LX, you may have wondered what the letters mean. Chinese crane manufacturers use short letter codes to describe the crane type, structure and hoisting attachment. Once you know the logic, a model name tells you the basics at a glance. This guide explains how crane model codes work, gives a full reference chart for the most common types, and shows how to use the codes when comparing suppliers. Are Crane Model Codes a Mandatory Standard? No. Older Chinese standards, such as GB/T 14405-93 for overhead cranes and GB/T 14406-93 for gantry cranes, did define code tables. Those standards have been withdrawn. Newer versions, including GB/T 14405-2011 and GB/T 14406-2011, no longer include a model-code system. Today, under China’s TSG 51-2023 safety technical code for lifting equipment, a crane “model” simply identifies cranes of the same type that may differ in main parameters. The code is made up of letters describing the product type, main structure and mechanism layout, and each manufacturer defines its own model code.…

Hook drift is the uncontrolled downward slide of a crane hook or load after the controller has been returned to zero, beyond the permitted braking distance. It is also called load drift, and it means the hoist brake is no longer holding the way it was designed to. Any drift beyond the limit should be treated as a safety fault, not a nuisance. The difficulty is that a small slip is easy to ignore. The hook settles a few centimeters, the operator corrects it, and the shift carries on. But hook drift rarely stays small. A contaminated brake surface, a worn lining or a mis-set spring gets worse with every lift, and the same defect that lets a load sink 20 cm today can let it fall tomorrow. This guide gives you the allowable drift limits for overhead cranes, gantry cranes and electric hoists, with a worked calculation. It then covers the six most common causes, a symptom-to-cause diagnostic table, practical fixes, and the design choices that prevent hook drift in high-duty work. Hook drift is the non-commanded downward movement…

Crane over-hoisting — sometimes called an over-winding or over-travel accident — occurs when a hook block rises past its designed upper limit and collides violently with the hoist drum, trolley frame, or crane structure. The impact can snap the wire rope instantly, dropping the load and the hook without warning. Understanding why it happens, and what stops it from happening, is one of the most practical things a crane manager or maintenance engineer can know. This guide covers the root causes (equipment and human), how to restore safe operation after an event, and the layered prevention system that keeps it from recurring — from limit switch selection through operator discipline. What Crane Over-Hoisting Actually Means Over-hoisting is the loss of control over vertical hook travel at the upper extreme of the hoist’s range, as defined under hoist safety standards including ASME B30.16 and OSHA 1910.179. In normal operation, the upper limit switch cuts power to the hoist motor before the hook block can reach the drum. Over-hoisting happens when that cut-off fails — for any reason — and the hook…