Lifting cranes and crane operation precautions

During lifting operations, will be used steel crane  and hoists, both the device itself has certain risk, if done incorrectly, it is prone position, so the operation must be careful, that which specific precautions do ? Here's to eleven elaborate, is divided into several areas.
1 Crawler crane on the ground requirements: fixed at the level of firm soil.
(1) furnishings crawler, if tilted a degree, then a decrease of approximately 10% improved performance; tilted 3 degrees declined by about 30 percent, that enhance the load up to 130% of rated load, exceeding the mechanical stability limit, resulting in mechanical tipping .
(2) crawler crane lifting machine in place to seriously pay attention to the flatness of the ground, the ground is a certain inclination, the opportunity to generate a self-hanging rotation to the lower trend, when the  overhead gantry crane  near full load or crane is rotating critical state rotational inertia force of its own large crane will produce a sharp rotation to the lower case, and even crane rotating or counter-rotating brake operation is also unable to stop the rotation of its own inertia.
(2) the object must be vertical lifting, if horizontal drag will cause: crane damaged rotator damage, mechanical tipping over.
(1) vertical lifting objects, based on the compression force and luffing jib rope tension to support. If the horizontal direction to the drag force of the crane into a bending compression, even if only slightly crane driver feeling, 5% of the horizontal force sufficient to damage the crane.
(2) even if the object to enhance the vertical direction, if the state machine in an inclined position fixed, if the rotation, with the same transverse drag effect, so the machine must be fixed in place on the horizontal direction.
3 lifting heavy overload is strictly prohibited.
(1) the stability of mobile  hoist gantry crane  , generally tipping moment with a steady torque and the ratio described, based on the stability of construction places a mechanical angle described. Tipping angle increases, that is speaking against the overturned crane stability is higher.
(2) box-shaped boom weight, improve the overall center of gravity position, tipping angle is small, less stable.
(3) lifting load higher position, the higher the overall center of gravity position, tipping angle becomes smaller, the stability is reduced.
4 mobile crane in stability, strength, operational by the impact of wind, but also easily lead to accidents.
(1) The larger the area of ​​suspended load, the higher the height of the hanging load, the longer arm, the greater impact on the strength of the wind.
(2) all become the subject of wind load and overturning torque, reduced mechanical stability.
(3) lifting load pressure area is larger, the greater the load caused by the wind, the greater the swing hanging load to operate the machine in hand to bring great difficulties.
5 Crane main hook, auxiliary hook, after the bell rope should be regularly inspected and found anomalies must be replaced immediately.
Rope Update Standard:
(1) wire rope due to wear, the original diameter decreased by 7% or more;
(2) at a pitch of more than 10% broken wires, broken wires or concentrated in one more than 5%;
(3) there is a serious rope kink phenomenon;
(4) Rope significant deformation flattening;
(5) Ma Heart serious outstanding;
(6) have serious corrosion.