lightweight portable roof-top crane - uc drc home

Lightweight portable roof-top craneIn Partial Fulfillment of the Requirements for the
Degree of
May 2007
© ...... Chad Donner
The author hereby grants to the Mechanical Engineering Technology Department permission to reproduce and distribute copies of the thesis document in whole or in part.
Signature of Author
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ABSTRACT The University of Cincinnati’s Central Utility Plant has no acceptable means of
transporting heavy, bulky, general maintenance items to its roof. Currently, the maintenance
personnel must negotiate a long, narrow staircase, as it provides the only roof access. As a
costly alternative, a rented boom truck is implemented for heavier loads. Therefore, the
client has requested a hoisting device capable of lifting up to 2,000 pounds. The device must
be compact, cost effective, easy to operate and maintain, and provide a safe alternative to
climbing stairs. A roof-top crane system was considered the most probable solution due to
the result of client consultation and analysis. However, there are no commercial roof-top
cranes available capable of meeting the client’s desired capacity and size restrictions.
Consequently, a crane was engineered, fabricated, and tested to meet or exceed the client’s
design criteria.
The crane design criteria for the UC Central Utility Plant were determined by a client
interview and surveys of people with similar needs. The highest ranked element by the client
and the customer surveys was the need for a safe, portable, compact design that incorporated
a lightweight design, as well as the ability to lift a capacity of 1,500 to 2,000 pounds. The
results of the Quality Functional Deployment, based on existing and proposed solutions,
indicated a 10 percent increase in safety and a 9 percent increase in portability, durability,
and a compact design over the plants current means.
The crane design that has resulted from the research and product development is one that
is able to be disassembled into small manageable components to allow for easy transportation
to the roof. The resulting crane is a hybrid design between a jib tower crane and a standard
portable davit crane. The crane can be assembled on the roof at a height that is manageable
to the personnel assembling the crane. Once the crane is assembled, a hand operated winch
will hoist the upper section of the crane to the specified height where it can be secured.
The crane was fabricated, assembled, and tested during the month of May. In this time
frame the design was proven to be accurate and effective by meeting or exceeding the design
standard that were laid out from the beginning. During the capacity test, the crane was able
to lift 125% of its rated load with no problems. The proof of design criteria was met to fulfill
the needs of the customer shown in the customer surveys. The Lightweight Portable Roof-
Top Crane brought great attention and curiosity to the judges at the 2007 Tech Expo.
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The schedule for this project allowed seven weeks of design time, and roughly seven
weeks to build the proposed crane. In the end the project followed this schedule to the tee,
which prevented any issues that may have occurred if the project fell behind schedule. The
budget allowed for this project was $3,000 and the actual money spent was 2,952 dollars,
which fell well within the 10% variance allowed.
Overall this project was a success. The faculty at the UC Central Utility Plant was very
pleased with the design and could not wait to reap the benefits of using this crane in the
future.
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TABLE OF CONTENTS ABSTRACT .........................................................................................................................................................II TABLE OF CONTENTS .................................................................................................................................. IV LIST OF FIGURES ........................................................................................................................................... VI LIST OF TABLES ............................................................................................................................................. VI INTRODUCTION ................................................................................................................................................ 1 DESIGN FEATURES .......................................................................................................................................... 2
JIB TOWER CRANE .............................................................................................................................................. 3 PORTABLE DAVIT CRANE ................................................................................................................................... 4 LIGHTWEIGHT PORTABLE CRANE ....................................................................................................................... 5 FLOOR MOUNTED JIB CRANE ............................................................................................................................. 6
CLIENT INTERVIEW ........................................................................................................................................ 7 SURVEY RESULTS AND EVALUATION ....................................................................................................... 8 DESIGN OBJECTIVES .................................................................................................................................... 11 DESIGN OF THE UC ROOF TOP CRANE ................................................................................................... 14
THREE DESIGNS, ONE SOLUTION ...................................................................................................................... 14 PRELIMINARY CALCULATIONS ......................................................................................................................... 16 JIB CALCULATIONS ........................................................................................................................................... 17 MAST CALCULATIONS ...................................................................................................................................... 20 BASE CALCULATIONS ....................................................................................................................................... 21
FABRICATION AND ASSEMBLY OF THE UC ROOF TOP CRANE ...................................................... 23 FABRICATION ................................................................................................................................................... 23 ASSEMBLY........................................................................................................................................................ 23
TESTING AND PROOF OF DESIGN ............................................................................................................. 24 TESTING METHODS .......................................................................................................................................... 24 TESTING RESULTS/PROOF OF DESIGN ............................................................................................................... 24
PROJECT MANAGEMENT ............................................................................................................................ 25 SCHEDULE ........................................................................................................................................................ 25 BUDGET ............................................................................................................................................................ 25
CONCLUSION ................................................................................................................................................... 26 REFERENCES ................................................................................................................................................... 27 APPENDICIES ..................................................................................................................................................... 1
APPENDIX A – EXISTING PRODUCTS ........................................................................................................... A1 APPENDIX B – INTERVIEW NOTES .............................................................................................................. B1 APPENDIX C – SURVEY ............................................................................................................................... C1 APPENDIX D – SURVEY RESULTS ............................................................................................................... D1 APPENDIX E – QUALITY FUNCTIONAL DEPLOYMENT ................................................................................. E1 APPENDIX F – CONCEPT DESIGNS .............................................................................................................. F1 APPENDIX G – WEIGHTED DECISION MATRIX ............................................................................................. G1 APPENDIX H – PRELIMINARY CALCULATIONS ............................................................................................ H1 APPENDIX I – JIB CALCULATIONS .............................................................................................................. I1 APPENDIX J – MAST CALCULATIONS .......................................................................................................... J1 APPENDIX K – BASE CALCULATIONS ......................................................................................................... K1 APPENDIX L – JIB DRAWING ....................................................................................................................... L1
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Lightweight Roof-Top Portable Crane Chad M. Donner
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INTRODUCTION The University of Cincinnati’s Central Utility Plant, has no acceptable means of
transporting items to the roof. These items may consist of heavy, bulky, general maintenance
items, such as pails of grease, fans, roofing materials, antifreeze, and other miscellaneous
equipment. Currently, the maintenance personnel must negotiate a long, narrow staircase,
shown in Figure 2 and Figure 3, as it is the only roof access. This is labor intensive and
employees are susceptible to personal injury, resulting in workers compensation claims.
As an alternative, a rented boom truck, as shown in Figure 1, is implemented for heavier
loads. However, this equipment can be costly to the customer. With rental prices starting at
$390 per day [1], the cost of buying a roof-top crane could be justified in less than ten lifts.
Therefore, the client requested a hoisting device capable of lifting up to 2,000 pounds that is
compact, cost-effective, easy to operate and maintain, and is a safe alternative to climbing
stairs. A roof-top crane system was considered the most probable solution as a result of
client consultation and analysis. However, there are no commercially available roof-top
cranes capable of meeting the client’s desired capacity and size restrictions. Consequently, a
crane was engineered, fabricated, and tested to meet or exceed the clients design criteria.
Figure 1 - Boom Truck [2]
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Figure 2 - Roof Access Doorway Figure 3 - Roof Access Stairway
DESIGN FEATURES In this section, four different styles of cranes are compared, none of which are
adequate. First, the luffing jib tower crane is typically found on large construction projects,
where building materials need to be set in place. Second, the portable davit crane can be
found on roof-tops, boats, and can be used for many other miscellaneous lifting tasks. Next,
the lightweight portable crane is an option for people to mount in pick-up truck beds for
miscellaneous lifting of pumps, motors, etc. Finally the floor-mounted jib crane is typically
found in industrial applications such as factories, power plants, refineries, etc. for lifting
various materials.
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JIB TOWER CRANE Figure 4, shown below, exhibits features that were highly ranked by the client
interview and customer surveys. The Jib Tower Crane can fit into tight places and can be
broken down into more manageable parts, much like the smaller scale portable davit crane
shown in Figure 5. Another trait of this crane is its high capacity-to-weight ratio, which will
be critical in the design to minimize the overall weight. This will allow two people to
manage the crane’s components. This crane also has a high mast height, much like the jib
crane shown in Figure 7, which would need to be incorporated into the design in order to
clear the parapet wall on the roof of the Central Utility Plant.
Figure 4 - Luffing Jib Tower Crane [3]
Some not-so-highly ranked characteristics of the Jib Tower Crane shown above are that
it is too large for the customer’s application. The luffing jib tower crane has a height of 100
to 200 feet with lifting capacities of 10,000 to 33,000 pounds. The proposed crane only
needs to reach 10 to 15 feet high and only lift 1,500 to 2,000 pounds. Also, this crane’s
lattice type boom would be more expensive to manufacture than a typical I-Beam type jib
crane, shown in Figure 7, affecting the labor budget to build the crane.
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PORTABLE DAVIT CRANE The next product found in Figure 5, exhibits how the Portable Davit Crane can be
broken down into small, manageable pieces. Unlike the lattice boom crane above, when
broken down, the Portable Davit Crane components can be moved by hand and not with a
crane or truck. Another feature of this crane is that it offers flexibility of mounting styles,
either a base plate for solid, fixed mounting positions, or a rolling, portable frame that could
allow rolling the load from one place to another, much like the crane shown in Figure 6, that
is mounted in a pick-up truck bed. This crane also offers a compact design that can be taken
down and stored when not in use. Unlike the crane in Figure 4, this crane offers the
flexibility of using a hand winch or a 110 volt power winch rather than a high voltage power
source.
However, this crane is not tall enough to clear the parapet wall on the building.
Second, this crane does not offer a 1,500 to 2,000 pound capacity to meet the client’s needs.
Since this crane will have to reach over the side of the building and out to the center of a
flatbed truck below, the desired range will be between 5 and 6 feet outward, and 40 to 50 feet
down, like a scaled down version of the Jib Tower Crane.
Figure 5 - Portable Davit Crane [4]
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LIGHTWEIGHT PORTABLE CRANE The Lightweight Portable Crane, shown in Figure 6, is constructed from lightweight
aluminum, unlike all of the other cranes shown. This characteristic offers lightness in
weight, but sacrifices strength. It also offers a disk brake as a safety precaution against
dropping the load. Like the Portable Davit Crane, this crane has the ability to be stored
easily. As seen in Figure 6, this crane folds up into a compact package with no loose parts to
get lost. This differs from the Portable Davit Crane in Figure 5, which has no good way to
store its components.
Some disadvantages of the Lightweight Portable Crane are its inability to carry the
requested capacity at the requested height and range.
Figure 6 - Lightweight Portable Crane [5]
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FLOOR MOUNTED JIB CRANE The Floor Mounted Jib Crane exhibits features like the Jib Tower Crane. It is tall
enough to clear the parapet wall and is able to withstand the required lifting load, although
both cranes are impractical based on their size. This crane could handle the customer’s
capacity without question, but cannot be disassembled when not in use. Also, it would have
to be installed on the roof with another crane due to the size and limited access by the
stairway. This crane has a fixed power hoist that is attached to the boom of the crane.
Typically, this type of crane is found indoors and not exposed to the elements. The main
feature the Floor Mounted Jib Crane offers is the ability to meet the customer’s capacity
requirements.
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CLIENT INTERVIEW Based on the client interview with Raymond Miller [7], Superintendent of the University
of Cincinnati Central Utility Plant, four major areas were focused on for the crane design.
Notes from the interview can be found in Appendix B, which show safety as the number one
priority. Following safety, Ray Miller requested that the crane design incorporate portability,
compactness, and lightweight construction. He had also requested a load capacity of 1,500 to
2,000 pounds. From this interview, a survey was constructed to further develop the crane’s
design criteria. In the customer importance section of the survey, there are fifteen questions,
rated from one to five, with five being the most important. It focuses on what the customers
would like to see in a roof-top crane design, The current satisfaction section of the survey
has the same fifteen questions asking customers to rate their satisfaction of the current means
of lifting material to the roof of their building, with five being most satisfied and one being
least satisfied. Section three of the survey consists of three measurable questions. One
question focuses on determining how much weight the customer would be willing to lift for
the crane’s individual components. Question two asks how much capacity the crane should
be able to handle. Question three determines how much the customer would be willing to
pay for a crane with the improved features.
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SURVEY RESULTS AND EVALUATION The surveys were collected and tabulated for thirty-one people, from both the UC
Central Utility plant and Duke-Energy Zimmer Station, another power generating facility.
The people surveyed included maintenance personnel, engineers, and management staff.
Detailed results from the survey can be found in Appendix D. The results for section one of
the survey, shown below in Table 1, found that safety was ranked as the most important with
a compact design following close behind. The least important feature was the cost of the
crane’s construction. Table 1 - Section 1 Survey Results
Question Sa fe
4. 61
4. 52
4. 52
4. 23
4. 13
3. 81
3. 71
3. 58
3. 52
3. 39
3. 29
3. 23
2. 77
2. 71
The results from section two of the survey found Table 2, revealed that the customers’
biggest complaint with their existing means of lifting material to the roof is the lack of
compact design and portability. They were, however, satisfied with the power winch lift
capability and capacity of the existing means of a rented boom truck.
Table 2 - Section 2 Survey Results
Question Po w
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For section three, Table 3 shows that roughly 77 percent of the thirty-one people
surveyed chose that the weight of the individual components fall between 60 and 80 pounds
per component. This would allow one or two people to transport the components easily.
Table 3 - Customers Willing to Lift Frequency
Customer Willing to Lift
40-60lbs 60-80lbs 80-100lbs Frequency of Responses 6 24 1
Table 4 shows that 65 percent of the people surveyed indicated that they would like to
have a roof top crane that would be able to operate with loads of up to 1,500 to 2,000 pounds.
Table 4 - Customer Ideal Crane Capacity Frequency
Customers Ideal Crane Capacity
1500-2000lbs 2000-2500lbs 2500-3000lbs Frequency of Responses 20 10 1
The last question of section three indicated that 61 percent of the people surveyed would
be willing to pay anywhere from 2,000 to 3,000 dollars for a crane that would meet their
requirements. Table 5 - Customers Willing to Pay Frequency
Customers Willing to Pay
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Once all of the results were tabulated, a Quality Functional Deployment was used to
determine the importance of specific design features of the lightweight roof-top portable
crane. Appendix E shows the QFD report and how the features of the roof-top crane relate to
the engineering characteristics. This comparison is used to determine the absolute and
relative importance of the features that were listed in the survey. The highest relative
importance was given to the ability to be easily disassembled for achieving portability. The
next highest relative importance was given to high-strength materials to help achieve the
lightweight feature of the crane. Next, customer importance, the current means of getting
material to the roof, and the new concept design are multiplied by the sales points and used to
determine the improvement ratio and a relative improvement.
The sales points were based on a scale of 1.5, 1.3, and 1 with 1.5 being a high sales point
and 1 being neutral. When trying to sell a product such as the Lightweight Portable Roof-top
Crane, the design and marketing team sets the sales point to what they think will sell their
product the best. The highest sales points for this product would be safety, durability,
capacity, ease of assembly, lightweight, portability, and compact design. The mid-range
sales points were determined to be ease of operation, ease of maintenance, and mounting
versatility. The neutral sales points were initial cost, appearance, range of motion, lifting
span, and power winch operation. Based on the relative weight, the safety will be increased
by 10 percent and the durability, compact design, and portability will be increased by 9
percent of the current means of hoisting the material, thus resulting in a better, overall design.
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DESIGN OBJECTIVES The following is a list of product objectives and how they were obtained or measured to
ensure that the goal of the project was met. The product objectives focused on a roof top
crane for the University of Cincinnati Central Utility Plant. The crane is intended to lift
general maintenance items that will aid in maintenance activities taking place on the roof.
The first product objective is safety. The UC roof top crane will strive to be a safe
design based on the following factors:
• A factor of safety of at least 1.5 (Mott, Mechanics of Material) will be provided to
show that the structural components of the crane will not fail under repeated load.
• The winch mechanism shall be fitted with an emergency stop brake.
• Hoisting cable shall be rated for lifting at least 1,500 pounds.
The second design objective of this product is to make the crane as compact as possible,
so that if it ever had to be taken down, it could be stored with taking up as little space as
possible.
• Long slender components of less than 8 feet.
Durability and reliability are very important factors in the power generation field. The
UC roof top crane incorporates durability and reliability by the following means:
• Reliability of the attachment measured by proper design criteria specified in the
following spec sheet:
fasteners.
• Any bearing surfaces shall have the proper means of lubrication to prevent
premature wear.
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The fourth design objective of the UC roof top crane is its ability to be portable.
Employees need to be able to maneuver all of the components of the crane to the roof via a
stairway. To make this easier, all of the components weigh less than 80 pounds and must be
of a length less than 8 feet so that two people can manage them with ease.
• Each crane component shall be of a size that can be maneuvered easily down a 3
foot wide staircase.
The capacity of the crane will need to meet the minimum amount of load specified by
the customer.
• The roof top crane shall have a rated capacity of at least 1,500 pounds.
The sixth objective of the UC crane is ease of operation. This is achieved by simplifying
the design with minimal amount of controls.
1.) The crane lifting action shall be performed via simple push button control on electric
winch operated models.
The crane components shall be designed so that they reduce the amount of weight the
facility personnel have to handle, thus reducing the risk of injury.
• Each component of the crane shall not weigh more than 80 pounds.
The crane shall be designed so that no special tools are required to assemble it. The
design should also minimize the amount of fastening points required.
• All crane components shall be able to be assembled with simple hand tools.
• The design will have a max of three different bolt sizes.
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The ninth design objective for the UC roof-top crane is its range of motion. The larger
the range of motion for the crane, the more versatile the crane will be.
• The crane shall have at least a 200 degree range of motion from side to side.
The lifting span of the crane is critical in the location the crane is mounted. There is a
driveway below where the crane will pick up any material. In order to be safe, it would be
preferred to keep the lifted material as far away from the building as possible to prevent
damage to the building from the lifted load.
• The crane shall have a lifting span of at least 6ft at the minimum of 1500 pound
capacity.
The crane shall be designed so that it is virtually maintenance free. Maintenance in the
power generation field has a history of being limited to major components. In order to keep
the crane in good working order it should require as little maintenance as possible.
• All grease fittings shall be of industry standard, i.e. Zerk fittings.
• Maintenance manual shall be provided for selected winch.
The twelfth design objective is the appearance of the crane. The appearance doesn’t
only affect the cosmetic value of the crane, but it also plays a large role in the cranes
protection from the elements.
• Crane components shall have industrial epoxy safety yellow finish.
The last design objective of the UC Roof-top crane is the cost. Across the board in the
power generation industry today, the goal is to get the highest value for the least amount of
investment.
• The crane shall be limited to a cost of 3,000 dollars to the customers with electric
winch models.
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DESIGN OF THE UC ROOF TOP CRANE THREE DESIGNS, ONE SOLUTION There were three possible solutions considered to solve the problems explained above.
Each solution had the same basic scope and limits. The particular features of each design
were obtained using a Quality Functional Deployment. The QFD matrix can be found in
Appendix E of this report. The concept drawings of each design are located in Appendix F.
The scope of these solutions was that the crane would have to be a compact design with
lightweight components. The crane would have to be strong enough to support 2,000
pounds, yet be portable enough that people could manage the crane components when
disassembled. Although it is much less of a priority, the cost of each concept will also have
to be kept in mind when selecting the best option.
There are several main differences between the three concepts. In order to fit the site at
the UC Central Utility Plant, the crane would have to be designed using similar principals as
the davit crane to meet the needs of the customer. It would consist of a single piece tubular
jib that would be fixed to a single piece rotating mast.
Design number 2 would be designed as a small, scaled-down tower crane. Its mast and
jib would be constructed out of small tubing to form a lightweight truss-type component.
The load would be aided by cables to reduce the loading on certain members of the crane.
Design number 3 would be a hybrid combination of the davit-type crane and the tower
crane. The geometry of this concept would follow the davit crane, but it would incorporate
cables to reduce the loadings on certain parts in order to make them lighter and more
manageable.
Before design could begin, a concept had to be selected. To select the best design for the
application, a Weighted Decision Matrix was used. The Weighted Decision Matrix, shown
in Table 6, uses 15 different criteria to weight the features of the three different concept
designs. In the far left column, the most important design criterion, safety, was given a
weight factor of 15. This coincides directly to the results obtained from customer surveys,
which ranked safety as the number one priority. The second most weighted decision
criterion was the need for a compact design, which also mirrors the customer survey results.
Based on the results of the Weighted Decision Matrix, you can see that the concept one was
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the desired option. But once the preliminary calculations began, it was noticed that concept
one had exceeded the safe design stress of the material on some of the components. If the
size of the component geometry was increased to reduce the actual stress to a point below the
design stress, the component weight would exceed the value specified by the customer. With
weight being a concern, after the preliminary calculations, a modified concept three became
the best option. The modified option would not utilize the truss-like jib, but it would use the
links to transfer the load to components that were more capable of doing so. This would
reduce the weight of the components drastically. Table 6 - Weighted Decision Matrix
Weight Factor Features
15 Safety 100 1500 100 1500 100 1500 14 Compact Design 75 1050 25 350 50 700 13 Durability 80 1040 60 780 70 910 12 Portability 50 600 70 840 60 720 11 Capacity 25 275 75 825 50 550 10 Ease of Operation 80 800 80 800 80 800 9 Lightweight 40 360 60 540 50 450 8 Ease of Assembly 80 640 40 320 60 480 7 Range of Motion 50 350 50 350 50 350 6 Lifting Span 30 180 50 300 40 240 5 Mounting Versatility 90 450 70 350 80 400 4 Power Winch Operation 50 200 50 200 50 200 3 Ease of Maintenance 90 270 40 120 60 180 2 Appearance 40 80 60 120 50 100 1 Initial Cost 80 80 40 40 60 60
Total 7875 7435 7640
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PRELIMINARY CALCULATIONS Once the final design was selected, calculations began. All of the preliminary
calculations can be found in Appendix H of this report. The UC roof-top crane is designed
so that it will lift 2,000 pounds at 66 inches from its mast and 144 inches off the roof. First a
design load had to be determined for the crane. The ASME NUM-1-2004 Rules for
Construction of Cranes give guidelines for determining the design load of a crane. For the
UC roof top crane the “Additional” loading condition has been specified, which is the same
as the “Principal” loading condition with the addition of the operating wind load. The factors
determining the design load are the Dead Load of the effective crane equipment, the Lifted
Load, the Vertical Inertia Forces and the Operating Wind Load.
Table 7 - Load Factors [8]
The design load can be expressed as, WLOHLFLLDLFDL +++ )1()( where DL is the
Dead Load and DLF is the Dead Load Factor, which for this case is 1.1, as shown above in
Table 7, for a travel speed of 15 feet per minute. LL is the Lifted Load and HLF is the
Hoisting Load Factor, which is the Inertial Load created by the winch pulling the load up, the
minimum of 0.15 is used from Table 7. The WLO or Operating Wind Load is the last factor
in determining the design load, which was determined to be 2,600 pounds. The remaining
preliminary calculations consisted of determining the link angles and the X and Y
components of the forces at all of the work points of the crane. The force on the link AB was
found to be 7,517 pounds. Link AB transfers its load to link BC, which has a load of 15,988
pounds. This load is then transferred to the base via link CE with a load of 14,300 pounds to
link EF producing a maximum moment of 171,600 inch-pounds on the base of the crane.
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JIB CALCULATIONS The calculations for the jib of the crane began by determining how many positions, or
loading conditions to which the crane was going to be designed. All of the detailed
calculations for the jib can be found in Appendix I of this report. Based on the maximum
allowable load of the 5/16 inch cable, which was given by the manufacturer of the winch to
be 4,000 pounds using a double line configuration, it was determined that there would be
three loading conditions. When summing the moments at the design point of 2,600 pounds at
66 inches, the reaction found at point A on the crane was found to be 2,319 pounds and 281
pounds at point D, this would be loading condition 1. For loading condition 2, the reaction
force at point A would be kept constant. By summing the moments for a point 55 inches
from the mast, the design lifting load would be 3,119 pounds with a reaction of 801 pounds
at point D. For the last loading condition, the design lifting load of 3,899 pounds would be
applied at a point 44 inches from the base. The reaction from that load applied to point D on
the crane would be 1,581 pounds.
From the above information, shear and moment diagrams were created to determine the
maximum amount of moment. The maximum moment of 69,542 inch-pounds was found to
occur in loading condition 3 at the applied load site, which was 44 inches away from the
mast. From this moment, a jib beam geometry could be selected with weight and
maneuverability in mind. Two C5X6.7 C-channels oriented back-to-back with properties,
shown in Table 8, would be the best option based on weight, maneuverability, and strength.
Table 8 - C-Channel Dimensions [9]
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From the selected geometry, the normal stresses due to point A and point C link
reactions, and the bending stress could be calculated to find the total compressive stress,
which was found to be 14,085 PSI. The bearing stress was calculated at the worst case point,
which was point C. The stress was calculated using the C-channel web only, but proved to
exceed the design stress value multiplier for A36 structural steel shown for additional loading
in Table 9 below. To correct the problem an additional 0.25 inch bearing plate would be
welded to each C-channel yielding a 19,781 PSI bearing stress.
Table 9 - ASME Allowable Crane Stresses [10]
The ASME NUM-1-2004 Rules for Construction of Cranes specifies that the deflection
of any member is not to exceed one thousandth of the span; in this case the span would be 74
inches so the jib could not deflect more than 0.074 inches. When calculating the deflection
of the jib, it was determined that the jib was only deflecting 0.033 inches, which proves to be
safe. The maximum compressive stress is limited by ASME for members that are controlled
by buckling (Tables 10 and 11 below). Table 12 is a calculation for the factor of safety
depending on the modifying coefficient in Table 11 for the additional loading case, the
slenderness ratio, and the column constant. When calculated, the factor of safety for total
compressive stress was found to be 2.1 for the crane’s jib.
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Figure 8 - Factor of Safety Equation [12]
All bolts used in crane construction are specified by ASME to be grade A325 bolts with
yield strength of 120,000 PSI, and bolt holes in crane applications are to be only 1/16 inch
oversize. The most critically loaded bolt in the UC crane is acting under double shear with a
force of 15,988 pounds acting on it. When the shear stress is computed for the bolt, the
resulting stress is 13,191 PSI which is well within the safe design given by the multiplying
factor for shear values of additional loading in Table 11.
Table 11 - Bolt Allowable Stresses [13]
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MAST CALCULATIONS The mast of the crane is composed of a 5”x5”x3/16” square tube with two C5X6.7 C-
channels that slide up and down the square tube to allow for easier assembly. As shown on
the assembly drawing of Appendix O, the upper section of the mast and the jib are assembled
in the lower position for ease of assembly. When everything is assembled the upper mast
section and the jib are pulled up the lower mast section using a hand operated winch. After
everything is in place the upper section of the crane is secured in place by four bolts.
The calculations for the mast are relatively simple compared to the jib, they can be found
in Appendix J of this report. The only forces acting on the mast is the normal forces from the
cable of the power winch, the reaction of the design load at point D, and the X components of
link AB and BC on point B. When calculating the total normal stress, the upper mast section
properties were used for the calculations due to the fact that it would create the worse case
scenario. This was based on cross sectional area and moment of inertia. The total
compressive force acting on the mast is 20,800 pounds, which creates a compressive stress of
5,279 PSI based on the cross sectional area. The mast also has a critical bearing load point
that necessitates the additional 0.25 inch bearing plate like the jib as well. The total bearing
stress was found to be 18,569 PSI, which falls well within the safe bearing stress specified by
the multiplier in Table 9 for additional loading conditions.
As with the jib, the mast factor of safety is controlled by buckling. When Equation 15 in
Figure 8 was applied to the mast, the resulting minimum factor of safety was found to be 2.3,
which the mast falls well within having a factor of safety of 6.82. This is due to only having
axial stress. The mast is considered a long column when comparing the slenderness ratio to
the column constant. Calculating Pcr for the mast yielded a critical axial compressive stress
of 143,731 PSI for buckling and an allowable axial compressive stress of 62,534 PSI.
21
BASE CALCULATIONS The base of the crane consists of a piece of 5” schedule 80 pipe that is welded to a pipe
flange which will be bolted to the structure. At the top of the base there is a flat plate welded
across the pipe. There is half a ball bearing welded to that to provide a rotation point for the
top base. The top base is a piece of 6” schedule 80 pipe that slides over the bottom base to
provide the moment reaction for the crane. The top base has a pipe flange welded to the top
of it so the mast can bolt to it. It also has a gusset welded to the side of it for link CE to
transfer the moment to the base. Drawings of the bases can be found in Appendix N of this
report.
The total combined stresses on the base consisting of the bending stress and the normal
compressive stress were found to be 14,523 PSI. The base does not have to be considered a
member controlled by buckling, so Table 9 can be used for the allowable compressive stress
multiplier for the additional loading condition. All of the base calculations can be found in
Appendix K of this report. The force applied to the base by link CE subjects the base to a
bearing stress of 19,067 PSI, which is well within the allowable stress in bearing for A36
steel.
Due to the large amount of moment being transferred to the base, the weld design plays a
critical role in the design of the base. The slip-on flange will be welded to the pipe on both
sides of the flange. The moment of inertia and section modulus for the situation are shown
below in Figure 9.
22
Once the section modulus of the weld was computed, the force in lbs-per-inch could be
calculated from the moment applied to the base, which was found to be 3,295 pounds-per-
inch of weld. This value can then be used to determine what weld material and weld size is
needed to provide the appropriate amount of reaction to the moment. From Table 12, below,
using E70 welding wire fused to A36 base metal, the allowable force per inch of weld is
11,200 multiplied by the size of the weld. In this case, when solving for the weld size, the
minimum size of weld allowed would be 0.294 inches. To simplify things during
manufacturing the weld size will be specified as a standard 0.375 inches weld. Table 12 - Allowables for Welds [15]
23
FABRICATION AND ASSEMBLY OF THE UC ROOF TOP CRANE FABRICATION The fabrication of the UC Roof Top Crane started by purchasing the raw materials
needed for the assembly of the crane. The structural steel members were purchased cut to the
right length from American Metal Supply in Blue Ash, Ohio. Once all of the materials were
purchased and received, they were taken to Niemco Fabricators in Louisville, Kentucky
where they were fabricated according to the design drawings. One week later the parts were
finished and ready to be picked up. After the parts were picked up, it was noticed that some
minor details had been missed by the fabricator, so they were corrected before the assembly
of the crane was started. When all of the fabrication was completed, final measurements
were taken to verify that the parts had been fabricated correctly before the next step in
fabrication could occur. After all components of the crane were verified to be accurate with
the design drawings, painting of the crane could begin. All of the components were painted
individually with Rustouleum Industrial Urethane Epoxy Paint donated by HPP Industrial
Sales in Louisville, Kentucky. The painting required two coats and took approximately one
week to complete.
ASSEMBLY Once all of the fabrication and verification of drawings was completed, the initial
assembly could be performed. The assembly was a learning curve to determine the best way
to assemble the crane. Once the crane was assembled the first time, shortcuts and easier
processes of assembly were found. The following process was found to be the simplest and
fastest method of assembly. First, Base 1 is mounted to a rigid foundation. Then Base 2 is
slid over Base 1. Once the base is assembled, Mast 1 is bolted to Base 2. Then, both Mast 2
sections are attached to both sideplate sections around Mast 1. After the base and mast are
assembled, the Jib is attached to Mast 2. Then, Links 1 and 2 are attached to Mast 2. Next,
Links 2 and 3 are mounted to the Jib, followed by mounting Link 1 to the Jib. Then all of the
pulleys and shackle mounts are mounted to the Jib. Next the winch is attached and the cable
is strung through the pulleys. Lastly, the crane is hoisted into its final position and Link 4 is
attached to Link 3 and Base 2.
24
TESTING AND PROOF OF DESIGN TESTING METHODS The UC Lightweight Portable Roof Top Crane was tested in accordance with the testing
procedure described in the ASME NUM-1-2004 Rules for Construction of Cranes manual.
This procedure required that the crane be able to lift 125% of the rated load. The rated load
for the UC crane was 2,000 pounds, which required a 2,500 pound testing load. The plan for
testing the crane was to temporarily mount it to the concrete floor at the UC Central Utility
Plant and perform the test.
TESTING RESULTS/PROOF OF DESIGN The testing of the UC crane proved to be successful. The crane was able to lift the 2,500
pound testing load with no problems. The load was lifted from the ground all the way to the
top of the cranes boom and then back down as required by the ASME crane design manual.
Once the testing of the crane was proven to be a success, the proof of design had to be
evaluated to determine if the goals of the cranes design were met. Based on the proof of
design agreement with the Senior Design Advisor, all of the design goals were met. The
crane was found to be safe by complying with the ASME crane design criteria. The crane
achieved a compact design by having long slender components of less than 8 foot in length.
Durability and reliability were achieved by the use of grease fitting to prevent premature
wear and grade 8 fasteners to limit the possibility of stripped threads. Portability was
achieved in the crane design by having all of the components weighing less than 80 pounds.
Above were the four most important design criteria based on client surveys. There were
also nine more design criteria, which were proved to be successful at the project
demonstration. Overall the proof of design was a success with the crane being able to do
everything that it was designed to do.
25
PROJECT MANAGEMENT SCHEDULE The proposed and actual schedule for this project did no vary much throughout the
project. The final schedule was for the most part identical to the proposed schedule besides
the few changes in the presentation schedule and Tech Expo. All of the design, fabrication,
and assembly were completed on May 11th for the demonstration to the senior design advisor.
Tech Expo followed the demonstration on the 16th of May, and the final presentation for the
UC crane was held on Wednesday, the 23rd of May. The final report was due during finals
week on June 4th
BUDGET
. A detailed schedule can be found in Appendix P of this report.
The budget for this project, found in Appendix Q, indicates that the proposed and the
actual budget fell very close to one another. The proposed budget indicated that 3,000
dollars would be spent, when in actuality 2,952 dollars were spent. This falls well within the
10% allowance in budget that was given. Although the final numbers were close, the
distributions changed drastically throughout the project. The initial budget showed 1,500
dollars being spent on the electric winch, only 1,000 dollars were actually spent. The manual
hoist was also large spot for uncertainty with the proposed costing 200 dollars and the actual
only costing 50 dollars.
26
CONCLUSION
In conclusion, the Lightweight Portable Roof-Top Crane was a success. The crane had
met all of the proof of design criteria and was able to lift the tested load with no problems.
The crane was a success with its ability to carry out what it was intended to do. The faculty
of the UC Central Utility Plant is very happy with the product that has been designed for
them to make their jobs easier.
With any prototype, there are always certain things that the designer would change if he
or she had to do it all over again. In this case, a second iteration to this crane might bring a
base that would rotate easier by possibly implementing ball bearings. Also, a production
model might incorporate easier assembly of this crane by utilizing a more mechanized
system of assembly rather than manual. Future designs might be able to unfold and fold up
with the simple push of a button. These are all considerations for the design if the prototype
were to go into full production.
As for the original prototype, it will be able to be seen atop the roof of the UC Central
Utility Plant along Short Vine. During the month of July the crane will be assembled there as
its permanent home with assistance from Raymond Miller, the Superintendent of Operations
at the Plant.
27
http://www.manitowoccranegroup.com/MCG_POT_AM/Products/EN/Range_MR.as p, 11/21/06.
4. Portable Davit Cranes [on-line catalog for davit cranes] http://www.thern.com/products.php?loc=pdcranes, 10/2/06. 5. Lightweight Portable Crane [on-line catalog for Northerntool] http://www2.northerntool.com/product/200325075_200325075.htm, 10/2/06. 6. Floor Mounted Jib Crane [on-line information for Abellhowe] http://www.abellhowe.com/j904_spec.asp, 10/2/06. 7. Miller, Raymond BSME. Personal interview. 9/19/06 University of Cincinnati, Utilities Superintendent Tel: (513)556-0252, [email protected] 8. The American Society of Engineers. Rules for Construction of Cranes, Monorails, and
Hoists. NUM-1-2004 edition. New York, 2005. 9. Mott, Robert L. Machine Elements in Mechanical Design. 4th ed. Upper Saddle River:
Pearson Education, 2004. 10. The American Society of Engineers. Rules for Construction of Cranes, Monorails, and
Hoists. NUM-1-2004 edition. New York, 2005.
28
11. The American Society of Engineers. Rules for Construction of Cranes, Monorails, and
Hoists. NUM-1-2004 edition. New York, 2005. 12. The American Society of Engineers. Rules for Construction of Cranes, Monorails, and
Hoists. NUM-1-2004 edition. New York, 2005. 13. The American Society of Engineers. Rules for Construction of Cranes, Monorails, and
Hoists. NUM-1-2004 edition. New York, 2005. 14. Blodgett, Omer W. Design of Welded Structures. Cleveland: The James F. Lincoln Arc
Welding Foundation, 1966. 15. Blodgett, Omer W. Design of Welded Structures. Cleveland: The James F. Lincoln Arc
Welding Foundation, 1966.
APPENDICIES
Appendix A1
http://www.manitowoccranegroup.com/MCG_POT_AM/Products/EN/Range_MR.asp 11/21/06 Luffing-Jib Tower Cranes manitowoccranegroup.com The MR Crane range is specifically suited for congested construction sites. The jib can be
luffed to almost vertical attaining excellent under hook heights and obstacle avoidance. The
interchangeable base provides the option of multiple installation configurations, including
climbing crane and traveling chassis installations. High performance slewing and hoisting
equipment provide precise control of loads throughout the entire working radius.
• High capacity to weight ratio • Good for tight spaces • More time consuming to manufacture • Too large of scale for customers needs • Rotates 360 degrees
Appendix A2
http://www.thern.com/products.php?loc=pdcranes 10/2/06 Portable Davit Cranes -up to 2000 lbs. thern.com • Hand or power winch operated • Disassembles into small pieces that can be moved up the stairs • Quick disconnect anchor • Corrosion resistant finish • Adjustable boom • Rotates 360 degrees • Doesn’t provide enough clearance to clear parapet wall • Inadequate reach @ rated capacity • Some component to heavy for one person to carry
Appendix A3
http://www2.northerntool.com/product/200325075_200325075.htm 10/2/06 Lightweight portable crane northerntool.com • Lightweight construction • Stores easily • Disk brake to control load • Doesn’t provide enough clearance to clear parapet wall • Only rated for 400lbs • Only a 4ft boom • Pivots 360 degrees • Inadequate reach @ rated capacity
Appendix A4
http://www.abellhowe.com/j904_spec.asp 10/2/06 Floor mounted jib crane abellhowe.com • Plenty of capacity • Meets span requirements of customer • Provides enough clearance to clear parapet wall • Mounts directly to structure • Cannot be disassembled and moved easily • Capacity of 2,000 pounds • Cannot be brought to the roof by means of the stairway
Appendix B1
APPENDIX B – INTERVIEW NOTES Through client survey conducted with Mr. Raymond Miller, Utilities Superintendent at the
University of Cincinnati on September 19, 2006, the following interview notes were
recorded.
• Currently take material up narrow staircase that is hard to maneuver
• For heavier loads they have to rent a crane to get material to roof
• Have to get 55 gallon drums of glycol to the roof in the winter
• Would like something that can be taken apart easily and stored
• Doesn’t necessarily need a power winch
• A 2,000 pound capacity would be great
• Would like for only one person to be able to assemble
• Haven’t been able to find anything compact enough
• Crane will go in a corner that is pretty tight
• Would like a simple design
• Would like ease of maintenance
Lightweight Roof Top Portable Crane Chad M. Donner
Appendix C1
1 Safety 1 2 3 4 5 N/A
2 Durability 1 2 3 4 5 N/A
3 Capacity 1 2 3 4 5 N/A
4 Ease of assembly 1 2 3 4 5 N/A
5 Lightweight 1 2 3 4 5 N/A
6 Ease of operation 1 2 3 4 5 N/A
7 Initial cost 1 2 3 4 5 N/A
8 Appearance 1 2 3 4 5 N/A
9 Ease of maintenance 1 2 3 4 5 N/A
10 Portability 1 2 3 4 5 N/A
11 Compact design 1 2 3 4 5 N/A
12 Range of motion 1 2 3 4 5 N/A
13 Lifting span 1 2 3 4 5 N/A
14 Power winch operation 1 2 3 4 5 N/A
15 Mounting versatility 1 2 3 4 5 N/A
Continued on next page
What features are important to you in the development of a roof top crane to meet your facility's needs? Please circle the appropriate answer.
Lightweight Roof Top Portable Crane Customer Survey
My name is Chad Donner. I am a senior at the University of Cincinnati studying Mechanical Engineering Technology. This survey is being conducted to test the market for a better portable roof top crane that is lighter, has more lifting capacity, is easier to assemble, and is less expensive as compared to any portable roof top cranes on the market today. Thank you for taking the time to complete this survey.
Appendix C2
1 Safety 1 2 3 4 5 N/A
2 Durability 1 2 3 4 5 N/A
3 Capacity 1 2 3 4 5 N/A
4 Ease of assembly 1 2 3 4 5 N/A
5 Lightweight 1 2 3 4 5 N/A
6 Ease of operation 1 2 3 4 5 N/A
7 Initial cost 1 2 3 4 5 N/A
8 Appearance 1 2 3 4 5 N/A
9 Ease of maintenance 1 2 3 4 5 N/A
10 Portability 1 2 3 4 5 N/A
11 Compact design 1 2 3 4 5 N/A
12 Range of motion 1 2 3 4 5 N/A
13 Lifting span 1 2 3 4 5 N/A
14 Power winch operation 1 2 3 4 5 N/A
15 Mounting versatility 1 2 3 4 5 N/A
Section 3
When assembling, how heavy could the components be? 40lb-60lb, 60lb-80lb, 80lb-100lb Please circle the appropriate answer.
How much lifting capacity would you like for this product? 100lb-500lb, 500lb-1000lb, 1000lb-1500lb Please circle the appropriate answer.
1500lb-2000lb, 2000lb-2500lb, 2500lb-3000lb
How much would you be willing to pay for this product? $50-$100, $100-$200, $200-$500 Please circle the appropriate answer.
$500-$1000, $1000-$2000, $2000-$3000
Thank you again for taking the time to complete this survey, your cooperation is much appreciated.
Are you satisfied with the current means of transporting material to the roof, either by stair or rented crane? Please circle the appropriate answer.
Appendix D1
APPENDIX D – SURVEY RESULTS
Importance Survey - Please rank the following features of a roof top crane in
order of importance, 1 being least important and 5 being most important.
4.81
Safety Compact Design Portability Durability Capacity Ease of Operation Lightweight Ease of Assembly Range of Motion Lifting Span Mounting Versatility Power Winch Operation Ease of Maintenance Appearance Initial Cost
Satisfaction Survey - Please rank the following current features in order of satisfaction, 1 being least satisfied and 5 being most satisfied.
3.71 3.68
k
Power Winch Operation Capacity Safety Durability Lifting Span Range of Motion Mounting Versatility Appearance Ease of Maintenance Ease of Operation Ease of Assembly Lightweight Initial Cost Portability Compact Design
Appendix D2
77.42
19.35
3.23
0
10
20
30
40
50
60
70
80
90
1
How much lifting capacity would you like for this product?
64.52
32.26
3.23
0
10
20
30
40
50
60
70
1
Appendix D3
How much would you be willing to pay for this product?
61.29
38.71
0
10
20
30
40
50
60
70
1
$2000 to $3000 $1000 to $2000
Frequency of responces for New Features
1 2 3 4 5 Average Safety 0 0 0 6 25 4.81
Compact design 0 0 0 12 19 4.61 Portability 0 0 0 15 16 4.52 Durability 0 0 2 11 18 4.52 Capacity 0 0 2 20 9 4.23
Ease of operation 0 0 4 19 8 4.13 Lightweight 0 0 12 13 6 3.81
Ease of assembly 0 0 17 6 8 3.71 Range of motion 0 1 11 19 0 3.58
Lifting span 0 0 15 16 0 3.52 Mounting versatility 0 5 9 17 0 3.39
Power winch operation 0 4 16 9 2 3.29 Ease of maintenance 0 3 19 8 1 3.23
Appearance 0 14 10 7 0 2.77 Initial cost 2 8 18 3 0 2.71
Question Ranking
Appendix D4
Frequency of Responces for Current Features
1 2 3 4 5 Average Power winch operation 3 1 7 11 9 3.71
Capacity 5 3 1 10 12 3.68 Lifting span 1 7 9 5 9 3.45
Safety 0 5 9 17 0 3.39 Durability 1 3 12 15 0 3.32
Range of motion 4 5 13 1 8 3.13 Mounting versatility 1 16 10 4 0 2.55
Appearance 16 1 7 7 0 2.16 Ease of maintenance 14 11 6 0 0 1.74
Ease of operation 22 7 1 1 0 1.39 Ease of assembly 22 7 2 0 0 1.35
Lightweight 27 4 0 0 0 1.13 Initial cost 27 4 0 0 0 1.13 Portability 29 1 1 0 0 1.10
Compact design 29 2 0 0 0 1.06
Question Ranking
Customers Willing to Pay
Customer Willing to Lift
Appendix E1
M in
im iz
e pi
nc h
po in
ts , E
m er
ge nc
y br
ak e
R ob
t
1 Safety 9 3 1 4.81 3.39 5 1.47 1.50 7.22 0.10 2 Durability 9 3 4.52 3.32 5 1.51 1.50 6.78 0.09 3 Capacity 3 1 3 4.23 3.68 5 1.36 1.50 6.35 0.08 4 Ease of Assembly 3 1 1 9 3 3.71 1.35 5 3.70 1.50 5.57 0.07 5 Lightweight 1 9 3 3.81 1.13 4 3.54 1.50 5.72 0.08 6 Ease of Operation 1 3 3 1 4.13 1.39 5 3.60 1.30 5.37 0.07 7 Initial Cost 1 3 2.71 1.13 3 2.65 1.00 2.71 0.04 8 Appearance 3 2.77 2.16 5 2.31 1.00 2.77 0.04 9 Ease of Maintenance 1 3 3.23 1.74 4 2.30 1.30 4.20 0.06
10 Portability 3 9 3 4.52 1.10 4 3.64 1.50 6.78 0.09 11 Compact Design 1 9 4.61 1.06 4 3.77 1.50 6.92 0.09 12 Range of Motion 3 3.58 3.13 3 0.96 1.00 3.58 0.05 13 Lifting Span 3 1 1 9 3.52 3.32 4 1.20 1.00 3.52 0.05 14 Power Winch Operation 3 3 3.29 3.71 4 1.08 1.00 3.29 0.04 15 Mounting Versatility 3 3.39 2.55 3 1.18 1.30 4.41 0.06
Absolute Importance
10 .0
Appendix F1
APPENDIX F – CONCEPT DESIGNS
The following are concept designs that are being considered for the University of
Cincinnati Central Utility Plant. Each of the three designs has some advantages and
disadvantages over each other. The final design will eventually be determined using a
weighted decision matrix based on certain criterion such as manufacturing, to cost, to
capacity. Concept Design #1
portable davit crane, but will be redesigned and
engineered to meet the higher demands of the
customer. The basis of this design is a tubular mast
and boom that are linked together to transfer the torque
rather than a counterweight. Some advantages to this
design are that it is simple and easy to manufacture. It
will also be relatively cheap to build based on the
minimal amount of fabrication required. This design is
also the most compact of all three designs. Some
disadvantages to this design are that in order to
achieve the customer’s capacity and span
requirements the cross section will need to be
increased or the material will need to be upgraded.
The negative associated with a larger cross section
is the increased weight, thus making the crane
component weight and issue. If the material were
to be upgraded there would be a significant cost
increase to jump from standard carbon steel to a
chromoly type alloy or something similar.
Appendix F2
http://www.thern.com/products.php?loc=pdcranes 10/2/06 Portable Davit Cranes -up to 2000 lbs. thern.com Concept Design #2 The second concept would be based on some of the various tower cranes that you might
see around construction sites where they are building skyscrapers or tall office buildings.
These cranes are rather lightweight in respect to the loads that they are lifting. Their basic
design is a lattice boom and mast or truss that utilizes the strength of triangles to its
advantage. Some of these cranes use counterweights to offset the torque and other use cables
tied to its mast in strategic places to neutralize the torque on the mast. Some of the
advantages to this type of crane would be its lightweight and the ability to lift heavy loads
over long spans. Disadvantages to this type of crane would be the cost to manufacture the
components, there would be a lot of fabrication that is time consuming and labor intensive.
Also, this crane would not be as compact as a simple tubular design in the previous concept.
Although this design is for very large loads a scaled down version could be designed and
engineered to meet the capacity and span requirements of the customer.
Appendix F3
http://www.manitowoccranegroup.com/MCG_POT_AM/Products/EN/Range_MR.asp 11/21/06 Luffing-Jib Tower Cranes manitowoccranegroup.com Concept Design #3 The third design would be a hybrid using good qualities from both types of cranes. The
lightweight boom from concept number 2 could be paired with the compact tubular mast
from concept number 1. Due to the capacity and span requirements, it would be difficult for
design number 1 to maintain a component weight of less than 80 pounds. Concept number 3
would be a viable option, although you would be sacrificing some of the compact design and
manufacturing cost for the lightweight, added span, and capacity.
Appendix G1
Weight Factor Features
15 Safety 100 1500 100 1500 100 1500 14 Compact Design 75 1050 25 350 50 700 13 Durability 80 1040 60 780 70 910 12 Portability 50 600 70 840 60 720 11 Capacity 25 275 75 825 50 550 10 Ease of Operation 80 800 80 800 80 800 9 Lightweight 40 360 60 540 50 450 8 Ease of Assembly 80 640 40 320 60 480 7 Range of Motion 50 350 50 350 50 350 6 Lifting Span 30 180 50 300 40 240 5 Mounting Versatility 90 450 70 350 80 400 4 Power Winch Operation 50 200 50 200 50 200 3 Ease of Maintenance 90 270 40 120 60 180 2 Appearance 40 80 60 120 50 100 1 Initial Cost 80 80 40 40 60 60
Total 7875 7435 7640
Appendix H1
APPENDIX H – PRELIMINARY CALCULATIONS lbs
FAB 7516.64 FABX 7150.00 FABY 2318.92 FBA 7516.64 FBAX 7150.00 FBAY 2318.92 FBC 15987.89 FBCX 7150.00 FBCY 14300.01 FCB 15987.89 FCBX 7150.00 FCBY 14300.01 FCE 14300.01 FEC 14300.01 FCABLE 2600 FFG 18200.01
inches DA 74 DB 24 DC 12 DG 144 EF 12
in-lbs MF-G 171600.08
degrees radians ABAD 17.97 0.31 AABD 72.03 1.26 ACBD 26.57 0.46 ABCD 63.43 1.11
2318.92
A
B
Appendix I1
Jib Calculations -
Design Load @ DJ 2600 lbs DA 74 inches Case 1 DJ 66 inches FABY 2319 lbs RDY 281 lbs Case 2 DI 55 inches FIY 3120 lbs RDY 801 lbs Case 3 DH 44 inches FHY 3900 lbs RDY 1581 lbs Mmax 69567.57 inch-lbs Ijib 14.98 inches4
Ajib 3.94 inches2
σbending 11610.07 PSI σcomp. 2474.62 PSI σtotal 14084.69 PSI σbearing 19780.64 PSI Cc 128.25 ymax -0.033 inches r 1.95 inches Le 59.20 inches Slenderness Ratio 30.36 Le/r > Cc No Short Column Pcr 137865.82 PSI Bolt shear 13191.33
Allowables-
Safety Factor for members controlled by buckling from ASME crane design Minimum FS 2.10 A36 σY 36000 PSI Max delection from ASME crane design -0.072 inches over span Pa 65508.91 Bearing 0.8 σY 28800 PSI Bolt shear 0.17 σY 20400 PSI
Design Actuals - FS
σtotal 14084.69 2.56 Safe σbearing 19780.64 0.55 Safe ymax -0.0328657 <-.072 Safe Pa 65508.91 >36000 Safe Bolt shear 13191.33 0.11 Safe
FCE
FAB
FCB
Appendix I2
Appendix I3
Appendix I4
Appendix J1
Mast Calculations-
σcomp. 5279.19 PSI σbearing 18568.93 PSI Cc 128.25 Amast 8.94 inches2
Imast 49.46 inches4
r 2.35 inches Le 319.20 inches Slenderness Ratio 135.71 Le/r > Cc Yes Long Column Pcr 143730.64 PSI Bolt shear 4080.26 PSI
Allowables-
Safety Factor for members controlled by buckling from ASME crane design Minimum FS 2.30 A36 σY 36000 PSI Pa 62533.6936 Bearing 0.8 σY 28800 PSI Bolt shear 0.17 σY 20400 PSI
Design Actuals - FS
σtotal 5279.19 6.82 Safe σbearing 18568.93 0.52 Safe Pa 62533.6936 >36000 Safe Bolt shear 4080.26 0.03 Safe
FBC
FBA
Fcable
RD
Appendix K1
APPENDIX K – BASE CALCULATIONS Base Calculations-
Base1 O.D. 5.563 inches Wall Thk. 0.375 inches Base 2 O.D. 6.625 inches Wall Thk. 0.432 inches IXB1 41.341 inches4
IXB2 80.981 inches4
AreaB1 6.112 inches2
σbendingB1 11545.489 PSI σbendingB2 7019.212 PSI σcompB1 2977.765 PSI σtotalB1 14523.255 PSI σbearingE 19066.676 PSI Iweld 148.740 inches3
Cweld 2.856 inches Sweld 52.087 inches2
Fweld 3294.477 lbs/inch Weld Size 0.375 inches
Allowables-
From ASME Table NUM-III-8231.1-1 not controlled by buckling
Tension 0.66 σY 23760 PSI Compression 0.66 σY 23760 PSI Bearing 0.8 σY 28800 PSI
From AWS Table 6
Weld Force 4,200 lbs/inch
A36 σY 36000 PSI
Design Actuals-
σtotalB1 14523.255 PSI Safe σbearingE 19066.676 PSI Safe Fweld 3294.477 lbs/inch Safe
FEC FFG
Appendix L1
Appendix M1
Appendix M2
Appendix M3
Appendix N1
Appendix N2
Appendix O1
Appendix O2
Appendix P1
Design of crane boom X Design of crane mast X
Design of mounting system X Design of hoisting system X
Design Freeze 2/22 Touch up design X X X
Oral Design Presentation 3/6 Design Report 3/15 Order Material
Spring Break X Build crane boom Build crane mast X
Build crane mount X Assemble & attach hoist X
Build access platform X Finish and Paint Demonstration 5/3
Correct problems X X Tech EXPO 5/17
Finalize Project Report Project Report 5/31
Oral Presentation 6/7
Winter Quarter Spring Quarter
Appendix Q1
Electric Hoist $1,500.00 $1,058.00 Structural Steel $500.00 $500.00 Manual Hoist $200.00 $50.00 Hardware $200.00 $200.00 Misc services/parts $100.00 $544.00 Fabrication $500.00 $600.00 Total $3,000.00 $2,952.00
Lightweight Roof Top Portable Crane Budget
Appendix R1
APPENDIX R – BILL OF MATERIAL List of Purchased Components Price Quantity Total Price Source Part No. Electric winch $1,320.00 1 $1,320.00 Grainger 3VJ72 Hand winch $27.25 1 $27.25 Grainger 6Z001 5" 150# slip-on flange 1 $0.00 5" schedule 80 pipe 2 $0.00 2" steel ball $13.93 1 $13.93 Fastenal 987716 1/2" A36 flat plate 2 $0.00 6" 150# slip-on flange 1 $0.00 6" schedule 80 pipe 2 $0.00 6" 150# blind flange 1 $0.00 1/4" A36 flat plate 2 $0.00 5"x 5"x 3/16" square tube 6 $0.00 1/2"x 1" flat bar 22 $0.00 5"x 6.7 C-channel 30 $0.00 3/16"x 10" flat bar 10 $0.00 6" wire rope sheave 5 $0.00 1/2" Custom length cable #1 1 $0.00 1/2" Custom length cable #2 1 $0.00 1/2" Custom length cable #3 1 $0.00 1" schedule 40 pipe 2 $0.00 5/8" galvanized heavy hex nuts $0.64 32 $20.48 Fastenal 36756 3/4" galvanized heavy hex nuts $1.31 8 $10.48 Fastenal 36758 1" galvanized heavy hex nuts $2.44 12 $29.28 Fastenal 36762 5/8" galvanized A325 structural washer $0.25 32 $8.00 Fastenal 33173 3/4" galvanized A325 structural washer $0.32 16 $5.12 Fastenal 33174 1" galvanized A325 structural washer $0.66 50 $33.00 Fastenal 33176 5/8"x 6" galvanized A325 structural bolt $2.49 12 $29.88 Fastenal 19687 5/8"x 7.5" galvanized A325 structural bolt $20.42 4 $81.68 Fastenal 19086 3/4"x 3.5" galvanized A325 structural bolt $2.65 8 $21.20 Fastenal 19696 1"x 1.5" galvanized A325 structural bolt $3.81 6 $22.86 Fastenal 19371 1"x 4" galvanized A325 structural bolt $4.88 9 $43.92 Fastenal 19833 1"x 4.5" galvanized A325 structural bolt $6.03 1 $6.03 Fastenal 19835 1"x 8" galvanized A325 structural bolt $11.96 1 $11.96 Fastenal 19386 1"x 8.5" A325 structural bolt $8.92 1 $8.92 Fastenal 11104670 1"x 2.25" clevis pin $3.40 1 $3.40 Fastenal 66183
Grand Total: $1,697.39
Appendix S1
APPENDIX S – PROOF OF DESIGN
Lightweight Roof-Top Portable Crane The following is a list of product objectives and how they will be obtained or measured to ensure that the goal of the project was met. The product objectives will focus on a roof top crane for the University of Cincinnati Central Utility Plant. The crane will be intended to lift general maintenance items that will aid in maintenance activities taking place on the roof. Safety/Power Switch:
1.) A factor of safety of at least 1.5(Mott, Mechanics of Material) will be provided to show that the structural components of the crane will not fail under repeated load.
2.) The winch mechanism shall be fitted with an emergency stop brake. 3.) Hoisting cable shall be rated for lifting at least 1500lbs.
Compact Design: 1.) Crane shall be easily disassembled and stored if need be.
Durability/Reliability: 1.) Reliability of the attachment measured by proper design criteria specified in the following
spec sheets: -Electric Hoist Spec Sheet
2.) Any permanent mechanical assembly will follow allowable torques of mechanical fasteners and the use of Loctite.
3.) Any bearing surfaces shall have the proper means of lubrication to prevent premature wear. Portability:
1.) Each crane component shall be of size that can be maneuvered easily down a 3ft wide staircase.
Capacity: 1.) The roof top crane shall have a rated capacity of at least 1500lbs.
Ease of Operation: 1.) The crane lifting action shall be performed via simple push button control on electric winch operated models, hand or drill operated winch on manual winch models.
Lightweight: 1.) Each component of the crane shall not weigh more than 80lbs.
Easy of Assembly: 1.) All crane components shall be able to be assembled with simple hand tools
Range of Motion: 1.) The crane shall have at least a 200 degree range of motion.
Lifting Span: 1.) The crane shall have a lifting span of at least 6ft at the minimum of 1500lbs capacity. Ease of Maintenance:
1.) All grease fittings shall be of industry standard, i.e. Zerk fittings. 2.) Maintenance manual shall be provided for selected winch.
Appearance: 1.) Crane components shall have industrial epoxy safety yellow finish.
Cost: 1.) The crane shall be limited to a cost of $3,000 to the customer for electric winch models and $2,000 for manual winch models.
Advisor Date Designer Date
Three Designs, One Solution
Fabrication
Assembly
Testing Methods
APPENDIX F – Concept Designs
APPENDIX H – Preliminary Calculations
APPENDIX I – Jib Calculations
APPENDIX J – Mast Calculations
APPENDIX K – Base Calculations
APPENDIX L – Jib Drawing
APPENDIX M – Mast Drawings
APPENDIX N – Base Drawings
APPENDIX O – Assembly drawings

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