• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.9-15
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• 2016

In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by mobile cranes. Fatal injury analyses were conducted with several accident cases by the mobile cranes. For each accident, the causes of the injuries were examined and proper safety measures were proposed. This study proposed a revision of the standard guideline as an accident prevention measures through in-depth analysis of fatal accidents. First, fatality rate per 10,000 persons by the mobiles cranes was 0.57 in 2011. Second, the in-depth analysis of the mobile crane accidents showed that the main factors of the accidents were the overturn of mobile crane, the fracture of connection part between mobile crane boom and rope, the breaking of rope and the misunderstanding over the signal between a mobile crane driver and workers around a mobile crane. Third, the order of high defection of connecting parts was bucket bolt, bracket and extension parts. Fourth, since there were several cases of overturn of mobile crane by itself in the in-depth analysis of the mobile crane, the over slop-proof device was proposed as the main alternative in this study. Fifth, the revision of standards of safety factor that shall be more than 10, of connecting parts of mobile crane was proposed.

• KIEAE Journal
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• v.7 no.6
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• pp.83-90
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• 2007

A mobile crane has been more frequently used to deal with the increased capital-intensive projects in line with the economic growth, but the operation is still heavily dependent on personal experience in the past, resulting in severe overturn accidents that cause the loss of lives and damage to the properties. A crane shall be installed in a systematic manner that proved to be safe in engineering aspect, and should the installation and operation be blindly dependent on experience alone, it would apparently cause a great risk. Particularly the mobile crane, among others, frequently causes a severe overturn accident due to poor ground-fixing device. The study therefore focused on fixing system of mobile crane and the outcome is highly expected to make a great commitment to selecting the optimal type of crane for the project as well as to securing the safety during construction.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.11-17
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• 2013

Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.213-219
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• 2001

This paper describes the power line proximity warning device for mobile crane by using the induced voltage measurement method. A mobile crane worker can be easily exposed to dangerous electrical shock and the electrocution while this are working at near the high-voltage electrical lines. In this paper, the derivation electric-potential of the power lines are simulated and microprocessor-based detecting device and transmitter/receiver modules are introduced to show a solution for the dangerous mobile crane working environment.

• Structural Engineering and Mechanics
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• v.43 no.5
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• pp.679-690
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• 2012

A new concept sea-floating port called mobile harbor has been introduced, in order to resolve the limitation of current above-ground port facilities against the continuous growth of worldwide marine transportation. One of important subjects in the design of a mobile harbor is to secure the dynamic stability against wave-induced excitation, because a relatively large-scale heavy crane system installed at the top of mobile harbor should load/unload containers at sea under the sea state up to level 3. In this context, this paper addresses a two-step sequential analytical-numerical method for analyzing the structural dynamic response of the mobile harbor crane system to the wave-induced rolling excitation. The rigid ship motion of mobile harbor by wave is analytically solved, and the flexible dynamic response of the crane system by the rigid ship motion is analyzed by the finite element method. The hydrodynamic effect between sea water and mobile harbor is reflected by means of the added moment of inertia.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.5
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• pp.493-499
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• 2010

In the sea-floating logistics port called mobile harbor a crane system with the different structure from the conventional above-ground container crane is installed. And, the dynamic stability of whole mobile harbor by the wave excitation is definitely affected by the crane positioned at the top. This paper is concerned with the dynamic rolling analysis of the mobile harbor subject to sea state 3 wave excitation, for which two-step analysis procedure composed of theoretical and numerical approaches is employed. First, the rigid rolling of mobile harbor is obtained according to the linear wave theory. And then, the dynamic rolling response of the flexible crane system caused by the rolling excitation of mobile harbor is analyzed by finite element analysis. The coupled interaction effect between the sea wave and the mobile harbor is taken into consideration by the added mass technique.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2374-2376
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• 2001

In this paper we have developed a Power Line Proximity Detecting device for Mobile Crane by using a Derivation Electric-Potential Detection method. A mobile crane worker can be easily exposed to a dangerous electrical shock and the electrocution while they are working at near the high-voltage electrical lines. The derivation electric-potential of the power lines have been simulated in our experiment, Also, microprocessor-based detecting device and transmitter/receiver modules are introduced to show a solution for the dangerous mobile crane working environment. As a result, It has been shown a good functional field test.

• Journal of the Korean Society of Safety
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• v.36 no.5
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• pp.18-26
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• 2021

The effect of heavy construction equipment on the excavated slope is investigated by slope stability analysis. A mobile crane with 500 kN capacity is applied as a working load to the background surface of the excavated slope, in both sandy soil and clay, designed to guarantee the safety of slope stability. Major parameters such as the distance between the edge of the slope and the mobile crane, groundwater level, and ground plate size of the mobile crane are considered. Only 23.8% and 14.3% of the analysis models with sandy soil and clay excavated slope, respectively, satisfied the slope stability. By changing the slope of the sandy soil from 1:1.0 to 1:1.2, the number of analysis models securing slope stability increased from 23.8% to 40.5%. For the clay excavated slope, the analysis models securing slope stability increased from 14.3% to 42.9% by changing slope inclination from 1:0.8 to 1:1.2. In addition, it is found that the increase in the size of the ground plate of the mobile crane increases the analysis models that secure slope stability. Therefore, it is an effective way to relax the excavated slope's inclination angle and simultaneously increase the ground plate size to guarantee stability.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.2
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• pp.165-170
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• 2011

In this paper, wind force coefficient by wind tunnel experiment is obtained to compute the accurate wind force of the gantry crane model to be used for mobile harbor ship. The first crane model was tested under 20, 30, 40, 52m/s, partially 58m/s and the wind force coefficient is about 2.0 which is very close to the suggested theoretical value. The other is the more reliable crane model and tested under 20, 30, 40m/s also giving the similar realistic wind force coefficient. Also structural analysis of crane model was performed giving the reliable stress level. Since the rolling effect is important for mobile harbor ship, the safety of the crane on the ship needs to be guaranteed. For this, using the computed reaction forces, a tie-down design is suggested which connects the crane and ship to resist the turnover motion of the crane.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.27-36
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• 2012

The mobile harbor is a new concept system to solve the problems of a port. These problems are that container ships cannot be anchored at the dock because they have become larger or the waiting times of anchoring the ships are increased due to heavy container traffic. A new system is designed to carry out the loading and unloading of containers between the mobile harbor and the container ship using the mobile harbor crane at sea. The crane plays an important role when transferring the containers. In this research, various types of the mobile harbor crane are proposed and structural optimization for each type of the crane is carried out. The loading conditions consider the rolling and pitching conditions of the unstable sea state and the wind force are considered. The constraints are mainly the regulations made by the Korean Register of Shipping. The structure of the crane is optimized to minimize the mass while various constraints are satisfied.