Print this page Electric Overhead Traveling (EOT) Cranes and Hoists
A. Bhatia, B.E.
Course Outline
Selecting a right overhead crane for any industrial application is important, for reasons of efficiency, safety and productivity. Buying lifting equipment is an expensive business and overhead cranes used in production operations are no exception. Get the choice wrong and an entire production process could grind to a halt.
This 4-hr course
on "Electric Overhead Traveling (EOT) Crane" will help you understand
the scope of lifting equipment options available to you, and allow you to make
sound decisions that lead to increased productivity and the greatest possible
return on investment.
The course includes a multiple-choice quiz at the end, which is designed to
enhance the understanding of course materials.
Learning Objective
At the conclusion of this course, the reader will:
- Describe the various types of overhead traveling cranes and lifting devices;
- Learn the basic terminology of single girder and double girder cranes;
- Understand the various parameters required for specifying an overhead crane;
- Understand the various modes of operation, intensity of use and crane duty groups/classification: CMMA, HMI, FEM etc.;
- Learn the different crane hoisting mechanisms and hoist selection considerations;
- Learn the various type of crane loads impacting the design of building structures;
- Learn by example the sizing procedure for crane runway girder;
- Understand the methods of crane electrification: conductor bars and festooning;
- Understand the electrical and control requirements: motors, enclosures, pendant control, radio control, safety limit switches etc;
- Learn the salient features and specifications of key crane components;
- Understand the crane inspection, safety and testing considerations; and
- Learn the key
words, definitions and international codes & standards as applicable to
cranes and steel buildings.
Intended
Audience
This course is aimed at students, engineers, designers, architects, facility managers, H &S professionals, supervisors, plant operation and maintenance engineers, technicians and supervisors.
Course Introduction
Cranes represent another family of material handlers that are common on many job sites. They are used for lifting, moving and placing heavy material such as raw material, finished goods, oversized objects, steel beams, pre-stressed concrete sections for building or bridges, materials and supplies to the upper stories of a high rise, unloading trucks, and a host of other essential jobsite material handling tasks. For this course, we will look at the basic type of electric overhead traveling cranes found in manufacturing and process industries.
Before a purchase
is made, a whole range of selection criteria need to be addressed including:
What is the required capacity? How often and regularly will the crane be used?
What is the required span? How high must the hoist lift? Will the crane be motorized,
hand-geared or a combination? If motorized, how fast? Will it be controlled
by pendant or remote control? And, it doesn't end there. Once the crane has
been installed, an increase in production output or equipment wear and tear
may mean the modification and modernization of the equipment further down the
line. Safety issues are obviously of vital importance and should be in any user's
best interest, economically and in terms of personal health.
This course reviews
the above criteria in detail.
Course Content
The course content is in a PDF file Electric Overhead Traveling (EOT) Cranes and Hoists. You need to open or download this document to study this course.
Course Summary
How material is
handled between the time it arrives at the "receiving" door and exits
through the "shipping" door can determine how close a facility is
to operating at its optimum level of productivity and safety. Most industrial
facilities employ cranes and lifting devices as part of their normal operations.
Cranes vary widely
in configuration, capacity, mode of operation, intensity of use, working environment
and cost. The variety of forms, operating conditions, environmental factors
make the design of cranes challenging. Usually a new design need arises when
existing cranes do not meet the requirements for a new application. However,
in most of the cases the required knowledge on configuration and structure of
a crane can be obtained from previously accumulated technical information. The
technical information is generally standardized. Besides that, the available
crane components and crane design procedures are highly standardized all over
the world, main effort and time spent in crane selection is for the interpretation
and use of the design standards.
Loads from crane
wheels have a static and a dynamic component. Both components are functions
of time and vary with crane position and the magnitude of the load. The loads
handled by the crane consist of a spectrum of light, medium and heavy loads.
The dynamic forces due to acceleration and braking, hoisting and unevenness
of the rails also vary from installation to installation. To ensure economical
design of cranes, they are normally divided into several classes depending on
the frequency of their use, the average ratio of the loads lifted to the safe
load, and the dynamic effects experienced in service. In this way it is possible
to assess the fatigue risk to the crane and its runway girder during its design
life. Per the CMMA 70, crane classification, class A, B, C, D, E and F represents
light standby to continuous severe duty application.
This equipment
can pose a safety concern and therefore correct maintenance and inspection is
not only necessary but is, in many cases, a legislated requirement. OSHA standards
(OSHA 1910.179) require cranes be inspected on a daily, monthly and yearly basis.
Additional inspections may be required due to hours of operation, environment
and/or severity of service. The inspection requirements of ANSI (B30.2, B30.11
and B30.17) and the manufacturer must also be followed.
The selection of
the proper overhead crane system is critical to the safe and economical operation.
Often when a crane stops, so does productivity. By the rule of thumb, spending
a few dollars more on better quality equipment is the least expensive solution
in long run.
Quiz
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
