Larry Jordan II Buffalo NY

1. MAE 494: Senior Design Project Report  The Ascension Project  Group # 27  Nicholas Altanian, Jason D’Souza, Andrew Lewis, Joshua Matter, Alec Brewer  May 8, 2015 

2. LIST OF TABLES Table 1. List of customer requirements………………………………………………………...………………….3 Table 2. Technical specifications………………………………………………………………………….........….4 Table 3. Decision matrix……………………………………………………………………………………….……8 Table 4. Tower stress analysis results…………………………………………………………………………...14 Table 5. Pulley housing floor stress analysis results………………………………………………………..….16 Table 6. Total cost breakdown………………………………………………………………………..…………..17 Table 7. Tower income………………………………………………………………………………………….....17 Table 8. Estimated savings………………………………………………………………………………………..18 iii 

3. EXECUTIVE SUMMARY This report consists of detailed design information pertaining to the design of a monopole, telecommunications tower, intended to eliminate the need for climbing in order to maintenance communication equipment located on the tower. The tower design is based on a conventional elevator, pulley/counterweight, lift system that lowers six individual antenna platforms to ground level for maintenance. The design process, embodiment design, design feasibility analyses and manufacturing/assembly considerations are discussed in detail. iv 

4. 1 INTRODUCTION This section consists of a description of our senior design project’s motivating problem. Project goals, deliverables and metrics of project success are also clearly defined. An overview of the contents of this report is provided in section 1.4. 1.1 Problem Overview Our senior design project is focused on the development of a design for a new cell phone tower aimed to eliminate the issues currently associated with cell phone towers. The primary issue we are concerned with is the dangerous task of maintaining the equipment on these towers. Tower workers need to climb towers ranging anywhere from a few hundred to over two thousand feet in height. With eighteen deaths in 2019 alone1, tower climbing is considered to be one of the most dangerous jobs in America1. Our project sponsor, Larry Jordan (CEO of SAT Corp), proposed his idea for a tower that would make tower maintenance entirely risk free. Instead of having workers climb a tower, Mr. Jordan wants us to design a tower that will bring the equipment down to ground level. The tower will need to be capable of allowing maintenance of one carrier without interference of service to any of the other carriers on the tower. 1.2 Expected Project Deliverables Due to the size and complexity of this project, it is important that we define reasonable expectations for final project deliverables. By the end of the project period, we plan to have a fully detailed design that addresses a majority of the customer requirements. This design will take shape through 3D CAD software (Creo Parametric). In order to better convey the function of our design, we plan to animate the 3D model through Creo. The goal is to provide enough detail and information, such that a prototype of our design can eventually be built for future testing. 1.3 Metrics of Project Success We have decided upon several performance metrics that will allow us to properly evaluate the success of our final design. These metrics include: • How well customer requirements (defined in Section 2.1) are met Estimated payback period Factors of safety of critical components based on finite element and fatigue life analyses Our overall measurement of success will be how well our design meets the customer requirements defined in our House of Quality. We will perform combinations of qualitative and quantitative assessments to gauge how well each customer requirement was met. The highest weighted requirements are focused on the cost and reliability/integrity of our design. The cost of our design will be compared to the cost of a 200 ft. monopole tower (estimated at $80,000) 1. Assessment of overall system reliability/integrity will require Finite Element Analyses (FEA) on major components of our design. Major components of our design will consist of the tower’s structural elements. We will use Creo Simulate to perform our FEA. The goal of our FEA will be to simulate stress responses of major components placed under worst case loading scenarios (includes responses to wind forces) and compute corresponding factors of safety. 1.4 Report Overview This report consists of a detailed breakdown of the problem at hand, concept generation/selection process, and embodiment design details. The layout of the report follows the structured design process we have been following since we began the project in the Fall semester. Descriptions of each major stage in the process, along with their respective outputs, are provided for each section. 1 http://www.wirelessestimator.com/  1 

5. 2 PROBLEM CLARIFICATION This section consists of the customer requirements defined for the design of our tower and their corresponding technical specifications. The requirements break down the overall design problem and represent the main driving factors that will dictate the design of our tower. The technical specifications represent quantified design performance targets. 2.1 Customer Requirements A majority of the customer requirements, listed in Table 1, were developed after our kickoff meeting with our project sponsor, Larry Jordan. These requirements consist of both innovative and standard features that Mr. Jordan expects to see in our tower design. After receiving our review on our Mini Project 2 Reports, redundant and unnecessary requirements were removed. Requirements more specific to our proposed design were appended after receiving Mr. Jordan’s review on our embodiment design of “The Octotower”. The customer requirements were weighted according to importance and incorporated into our House of Quality to analyze relationships between requirements and technical specifications (See Appendix A). Table 1. List of customer requirements # 1 Customer Requirement Safe to service Antennae can be remotely pointed in the azimuth necessary Description The tower should make maintenance absolutely risk free. Individual antenna direction should be capable of fine remote adjusts. 2 The structure must conform to the painting and lighting specifications set forth in the FAA’s final determination of “no hazard” and the associated FAA study for that particular structure. The tower should not be disruptive (too noisy, dangerous, etc.) to surrounding residents and/or wildlife. This is a requirement for design set by the project sponsor, SAT Corp. The tower should be sufficiently grounded, such that all equipment on the tower is protected in the event of a lighting strike. Every component of the tower must be able to withstand the strong wind forces expected at tall heights. Failure of any tower component is a potential safety hazard. The time it takes for technicians to reach the communication equipment on the tower should be as short as possible. The tower should not negatively impact the environment on both local and global scales. The tower should be designed in such a way that construction/assembly of the tower will involve little to no life safety risk. Individual components of the tower should be easily capable of shipping via ground, air, and water. The overall cost of the tower should be low enough to justify use over a conventional tower. The overall diameter of the tower should be as small as possible. The tower should also be aesthetically pleasing. The tower should allow a technician to service one of the carriers on the tower without having to take any other carrier out of service. The tower should have space for advertisement to be clearly displayed. 3 Meets FAA visibility standards Non-disruptive to surrounding inhabitants Capable of supporting at least five carriers 4 5 6 Must withstand lightning strikes Must withstand forces due to strong winds 7 8 Fast maintenance speed 9 Environmentally friendly 10 Safe to construct 11 Easy to transport components 12 Low Capital Cost 13 Sleek Design Equipment maintenance should be isolated 14 15 Ample advertising space 2 

6. Easy to climb in the event of mechanical failure In the event of a mechanical failure, there should be a relatively safe/easy way for workers to scale the tower. The design of the tower should accommodate the use of personal protection equipment (PPE) as specified in OSHA safety standards. Consistent proper function of the tower is crucial in order to ensure that any need for tower climbing is kept to a minimum. The tower should be capable of delivering the power cables needed by carrier communication equipment at any height along the tower. 16 Complies with OSHA Safety Standards 17 18 High Reliability Deliver power to carrier’s Equipment 19 Capable of accommodating all current communication equipment on the market The tower should be able to properly hold all types of communication that are commonly used in the industry. 20 2.2 Technical Specifications Technical specifications were established by translating the customer requirements, defined in Section 2.1, into quantifiable design performance targets. Each technical specification corresponds to a customer requirement and can be measured according to some type of unit. The importance of each technical specification was derived through by establishing the strength of relationships with the weighted customer requirements in our House of Quality (See Appendix A for HOQ). The relative weights/importance from the HOQ, as shown in Table 2, indicate that overall cost and the structural factor of safety are the most important technical specifications that will need to be addressed in our design. Table 2. Technical specifications Relative Weight/ Importance Technical Specification # Units Target Description This is a ratio of the maximum stress that key components of our design can withstand to the maximum stress experienced. Structural Factor of Safety 1 12.7 1.5 ??? Degrees of Freedom for Antenna This the amount of rotation the each antenna is capable of. 2 1.5 Max ??????? The distance the tower can be seen is an important consideration not only for the avian wildlife but as well as for low flying aircraft. The decibels that are emitted from lifting the antennas should not disturb people that live in the vicinity. The tower should be designed to support the weight of all the communication equipment that will be placed on the tower along with the weight of the tower itself. Maximum amount of voltage the tower is able to withstand (all components and equipment on the tower still properly functioning) from a lightning strike Maximum Distance Tower is Visible From 3 2.9 Max ??. Noise Level During Operation 4 2.3 Min ?? Maximum Weight Supported 5 8.5 Max ???. Maximum Voltage Able to Withstand 6 2.0 Max ? 3 

7. Maximum Wind Load Before Failure Maximum force, due to wind, that the tower can withstand without any failure. The speed at which the platform containing all the communication raises and lowers will need to be fast enough for quick service projects. This is a measure of the total estimated greenhouse gas emission associated with the manufacturing processes and function of our tower design. 7 5.3 Max ???. Speed of Platform Lift 8 3.9 Max ??/? Carbon Footprint ???.?? ??? 9 1.6 Min Maximum Height Required to Climb During Construction This is the maximum height that a worker would be required to work at during construction of the tower. 10 1.8 Min ??. This describes the size of the largest (disassembled) component of the tower. Important for transportation requirements. This includes the cost of material, manufacturing, and installation. The overall diameter of the tower includes the tower base plus the span of any extending structural members. This is the average time that a carrier’s communication equipment is out of service when NOT being maintenanced. This is the amount of space available to use for clearly visible advertisements. This is the amount of space available to incorporate a ladder/pegs/etc. for climbing in the event of lift system failure. This is the factor of safety of any fall protection system to be integrated into the design of the tower. This is the expected life span of major moving components of our design under worst case scenario conditions. This is the amount of power our tower is required to deliver to any communication equipment located at any height. Dimensions of Largest Component 11 2.5 Min ??.? ??.? ??. 12 Overall Cost 12.4 Min $ Overall Tower Diameter 13 5.8 Min ??. Average Time Out of Service 14 6.3 Min ??????? Available Advertising Space ??.? 15 4.8 Max Climbing Space Available ??.? 16 5.6 Max Factor of Safety of Fall Protection System 17 6.5 5 ??? Fatigue Life of Moving Parts 18 5.2 Max ????? Power Delivered to Antennas 200 W per channel 19 2.1 ? Available Space for Communication Equipment Total space available to hold the communication equipment for all carriers on the tower. ??.? 20 6.2 Max 4 

8. 3 CONCEPT DESIGN This section discusses the process we followed to arrive at a design concept that promised to satisfy a majority of the customer requirements defined in Section 2.1. Our process comprised of two different stages. During our divergent design stage (discussed in Section 3.1), we used two different idea generation methods to pool together as many distinct design ideas as we can. We turned to convergent processes (discussed in Section 3.2), to filter our pool of design ideas and finally arrive at a design concept to further pursue. 3.1 Concept Generation Our group’s concept generation process consisted of one group generation method and one individual generation method. Our first batch of ideas were generated using the 6-3-5 technique. While we were able to generate many ideas through this method, we quickly realized that there wasn’t a lot of variation amongst the pool of ideas. We then decided to try an individual idea generation method in hopes of developing a larger variety of design concepts. We used a forced connection approach through photographs. Each group member posted five photos taken from the internet onto the group’s google drive. We gave each other a few days to develop concepts inspired by these photos and the result was a larger pool of ideas with greater variety. Each group member communicated their ideas by sketching and writing short descriptions. In total, we developed a pool of seventeen distinct design ideas. A few examples of the photos we used are shown in Figure 1. Figure 1. Concept generation photos 5 

9. 3.2 Concept Selection In order to determine the best overall concept out of our pool of ideas, we rated each idea (on a scale of 1- 100) in accordance to six of the most important technical specifications. We organized this information into the decision matrix, shown in Table 3, to arrive at the concept we would further pursue. Table 3. Decision matrix The weighting system used in the decision matrix is designed to apply relative emphasis on the design attributes that are most important to the desired outcome. The weights chosen reflect the importance of the specific design attribute. After assigning weights to each design, each design was scored 0-100 based on its conformity towards that attribute. The Octotower received the highest overall score of 89. This score reflects the overall best coverage of each attribute. The three runner ups are the Bloom “Stacking” System, with a score of 71.2. The Overlapping Platform system, with a score of 70.7, and the Exterior Lifting System, with a score of 69.4. The Octotower design beat these designs by a significant amount. However, the runner-up designs still have potential with some redesign. These redesigns provide alternatives and also possible design ideas that can be used to optimize the Octotower design. 6   

10. 4.1.1 Tower Structure The tower structure is designed to a height of 190 ft. and has a tapered profile (0.574 degree). The taper provides a robust structural design along with sleek aesthetics. The tower’s structural design consists of eight separate sections. Each section has a hexagonal cross section (See Figure 4). Sections 2 – 7 have I-beams bolted on at each face of the tower. These I-beams serve as guiderails for the antenna platforms to ride along via guide shoes. There is one antenna platform that rides along each face of the tower (six platforms total). The bottom section houses the drive motors and has a door for easy accessibility when maintenance is needed. The top section of the tower houses the pulleys. Each section is bolted together via external flanges. Figure 4. Tower cross-section Manufacturing considerations were key driving factors of the tower’s structural design. Bolted connections were chosen because we wanted to keep the need for welding down to a minimum and wanted a design that would be able to use common machinery currently used to make monopoles. Transportation and assembly considerations were also crucial to the tower’s structural design. The tower was designed such that the largest component of the tower is capable of transportation via trucks, freight boats, and cargo planes. External flanges were chosen for joints because they provide a strong structural connection and easy assembly.   Figure 5. Section 4 model In order to ensure safe structural stability of the tower structure, stress analyses were conducted at three major areas of concern (see Section 4.2).     Figure 6. Drive housing     Figure 7. Flange joint 8   

11. 4.1.2 Antenna Platform and Guide Shoe Each antenna platform is designed to hold ten standard sized (8 ft. x 1 ft. x ½ ft.) antennas and has roughly 36 square feet of floor space for additional carrier equipment. The front face of the platform provides 120 square feet of area per platform for advertising space (see Figure 8). The framing of the platform consists of 2 in. round tubes connected to grate flooring. These tubes are connected, via U-bolts, to 1 ¼ in. tubes that the antennas mount onto via mounting brackets. Figure 8. Full platform model Each platform has two custom designed guide shoes that ride along the I-beams bolted along each face of the tower. The guide shoes keep the platform in place such that it is only capable of moving vertically. Each shoe consists of eight purchased wheels with load ratings well above the estimated platform weight. Incorporated into the guide shoes are two eyebolts that connect to the steel cables used to lift/support the platform. The guide shoes are connected to the antenna platform via steel I-beams and bolted connection. Figure 9. Guide shoe assembly/section view Design for environment concerns were taken into account when designing the antenna platform. A common problem with communication towers is that they often serve as nesting spots for birds. Often times, if there is a nest on a tower, tower workers are either prohibited from working on the tower and/or have to contact local wildlife agencies for further instruction on how to handle the situation. This can severely impede necessary tower maintenance. A simple, cheap and effective solution to this issue would be to place netting along the back side of the platform and bird spikes on the top of the platform in order to avoid nesting. 9 

12. 4.1.3 Drive/Lift System The drive/lift system is similar to that of the conventional elevator. Six gearless traction motors, located at the base of the tower, release and retract steel cables, connected to the counterweight, in order to lower and raise the platform, respectively. There is one motor for each platform/counterweight, thus allowing for each platform to be raised/lowered independently from one another. Maintenance for one carrier does not interfere with the service of the other carriers located on the tower. In order to significantly reduce costs, an existing gearless motor that meets necessary specifications was chosen. These gearless motors can be operated remotely via a control box located outside of the tower. Figure 10. XINDA WWTY gearless traction motor The counterweight is designed to be roughly 75% of the load placed on the antenna. The weight of the counterweight can be easily adjusted to account for varying loads placed on the platform. With the counterweight counteracting the load of the platform, the motors at the base of the platform are only responsible for providing enough power to lift the difference in weight between the platform and counterweight, thus significantly reducing the required motor size. Tension is kept in the cables between the motor and counterweight in order to keep the counterweight in place as it travels along the tower. Counterweight frame and weights that meet the weight and geometrical design requirements are readily available for purchase from numerous elevator supply companies. Figure 11. Hollister Whitney counterweight frame Two pulleys per platform, located at the top of the tower (see Figure 12), change the direction of the steel cables that attach the antenna platform to the counterweight. Both the pulleys and steel cables are purchased components that meet the load requirements with a factor of safety of 3. Figure 12. Pulley housing configuration and model 10 

13. 4.1.4 Brake/Fail-safe The primary brake is integrated into each of the six gearless traction motors. This brake will hold the antenna platform in place during regular operation. In the unlikely event that the cables snap/fail, elevator buffers, designed to bring free falling elevators to a safe stop, are located at the bottom of the tower. These buffers are bolted into the ground directly underneath each antenna platform. Purchased hydraulic buffers, that meet impact load/speed requirements, were chosen for our design. The buffers require little to no maintenance and can be easily replaced if needed.       Figure 13. Oleo SEB 18 Hydraulic Buffer   4.2 Detailed Design Analysis Due to the fact that a majority of the tower’s design is comprised of purchased components with known load ratings, design analyses was only performed on several components of major concern. These components include the overall tower structure, the I-beam guiderails, and the top section (pulley housing) of the tower. 4.2.1 Tower Stress Analysis Finite Element Analysis (FEA) was used to determine the wall thickness of the tower that would achieve a target factor of safety of 1.5. The design was tested under worst-case-scenario loading conditions.  Known: Material properties of the tower structure (ASTM A572 – 65), tower geometry, air properties at STP, and platform/counterweight loads are known.  Assumptions: The following assumptions were made to simplify analysis of the tower model while still maintaining validity of results: 1. 110 mph wind 2. Angle of attack is at 0 degrees 3. Joints at the flange are rigid connections 4. Base of tower is rigidly constrained 5. Weight from antenna platforms and counterweights act vertically downward from the top of the tower 6. Tower drag coefficient is 0.95 11   

14.  Free Body Diagram and Relevant Equations: Figure 14 represents a simple free body diagram showing the location of the wind and platform/counterweight loads on the tower. Eq. (1) was used to determine the force from the wind acting on the tower. Wind Force ????: ? ??????? ??.?1? ??? ? ? ??? ??????? ? ? ???? ????? ??? ???? ??????????? ? ? ????????? ???? Figure 14. Tower free body diagram  Results: After simulating the stress in the tower with five different wall thicknesses, the optimal wall thickness was found to be 3/8”. This thickness resulted in a maximum stress of roughly 41,000 psi and a corresponding factor of safety of roughly 1.56. Table 4 shows the simulation results and corresponding factors of safety. Wall Thickness (in.) 1/8 1/4 3/8 7/16 1/2 Max Stress (psi) 98,333 62,152 41,605 34,893 26,475 Table 4. Tower stress analysis results Factor of Safety 0.66 1.05 1.56 1.86 2.45 Note: Von-Mises, displacement and convergence diagrams can be found in Appendix F 12 

15. 4.2.2 I-Beam Stress Analysis The I-beam Guide Rail is the component in which the antenna travels on. The operation of the tower strongly depends on the reliability of this component, so it is necessary to perform a stress analysis that will confirm the reliability. The antenna is supported in the vertical direction by a cable that is connected to the top guide show. At any given position, the mass of the antenna creates a moment about the top guide shoe, which is resolved into normal forces applied to the outer face of the I-beam at each of the lower guide shoes. Additionally, any wind exerts a force on the antenna, which results in a moment on I-beam at each guide shoe.  Known: The platform geometry, I-beam material (ASTM A36), I-beam size (W14x90), and air properties at STP are known.  Assumptions: 1. 110 mph wind load 2. Angle of attack is 0 degrees 3. I-beam is rigidly connected to the tower face  Free-Body Diagram/Equations: Figures 15 represents two simple free body diagrams showing the wind forces and load/moment from the antenna platform acting on the I-beam. The wind force acting on the antenna platform was calculated using Eq. (1) and the antenna platform moment was calculated using Eq. (2). Antenna Platform Moment: ? ? ??? ??.?2? ??? ????? ?? ??????? ?? ???????? ? ? ???????? ???? ????? ?? ?????????? ?????? ?? ??????? Figure 15. I-Beam free body diagram  Results: The results from the FEA stress analysis show a maximum stress of 384 psi. In comparison to the steel I-beam’s yield strength of 29,000 psi, this results in a factor of safety of roughly 76 and is therefore structurally sound. Note: Von-Mises, displacement and convergence diagrams can be found in Appendix F 13   

16. 4.2.3 Pulley Housing Stress Analysis The floor of the pulley housing experiences a great deal of force since the weight from all six antenna platforms and counterweights are acting on the pulleys bolted onto it. FEA, through Creo Simulate, was used to determine if the housing design was structurally feasible and, if so, the optimal floor thickness that would provide a factor of safety of 6.  Known: The floor geometry, pulley housing material (ASTM A572 – 65) and platform/counterweight loads are known information necessary for analysis of the pulley housing floor.  Assumptions: 1. Forces from wind loads are negligible 2. Platform/Counterweight load is perfectly vertical 3. Pulley housing floor is rigidly constrained at the bolted flanges  Free-Body Diagram: Figures 16 represents a free body diagram showing the force locations from each of the six counterweight/pulley systems. The X represents a vertically downward force.                            Results: After simulating the stress in the housing floor with five different floor thicknesses, the optimal thickness was found to be 9/16”. Table 4 shows the simulation results and corresponding factors of safety. This thickness resulted in a maximum stress of roughly 7,700 psi and a corresponding factor of safety of roughly 8.5. Table 5 shows the simulation results for each thickness and corresponding factors of safety. Wall Thickness (in.) Max Stress (psi) 3/8 40,470 7/16 26,890 1/2 14,225 9/16 7,700 5/8 4,350 Table 5.Pulley housing floor stress analysis results Note: Von-Mises, displacement and convergence diagrams can be found in Appendix F Figure 16. Pulley housing floor free body diagram Factor of Safety 1.61 2.42 4.57 8.44 14.9 14   

17. 4.3 Production and Cost Analysis This section discusses intended manufacturing and assembly procedures for our design along with a cost analyses that provides an estimated payback period on the tower’s initial investment. 4.3.1 Cost Analysis A detailed cost analyses was conducted to determine the payback period of the initial investment for our tower design. The cost estimation of the design was broken down into material, manufacturing/assembly, servicing, and insurance costs. The following assumptions were made for cost estimations: 1. The cost for the fabricated steel sections were estimated at a rate of 600$/metric ton of ASTM A572 – 65 high strength low alloy steel 2. The insurance cost for coverage on the tower and location site is estimated to be $250,000. 3. The rental rates for the trailer and crane were received from a rough price quote from a local heavy equipment supplier. 4. The operating rates for the manufacturing process is estimated after consulting several workers employed in the industry. 5. The prices for all purchased (off the shelf) parts are based on quotations received directly from suppliers. 6. The overall savings on the project was calculated based on data obtained from wirelessestimator.com (as suggested by project sponsor). Table 6 shows a breakdown of the total cost for the tower design. A detailed breakdown, along with a list of all parts/materials, can be found in Appendix D. Type of Cost Material Cost Amount ($) $141,038.40 $4,651.00 $134.00 $250,000 $395,823.40 Manufacturing/Assembly Cost Tower Servicing Cost Insurance Cost Total Cost/Investment Table 6. Total cost breakdown The payback period of the tower’s initial investment is an important metric of costing and overall design success. It is defined as the length of time required to recover the initial investment. The payback period was calculated using Eq. (3) and Table 7 which lists estimated sources of income from the tower design. ????? ?????????? ????? ?????? ??? ???? ??.?3?  ??????? ?????? ? Income Source Carrier Lease (6 Carriers) Advertising Total Income per Year Rate ($/month) $1500 $1000 Income ($) $108,000 $72,000 $180,000 Table 7. Tower income ??????? ?????? ? ? ????? ??? ? ?????? In addition to the payback period of the initial investment, an important cost metric for the design is how it stands against existing monopoles of similar size. Table 8 shows estimated cost savings per year. 15 

18. Cost Estimated Savings ($) $1,000,000 $2,000,000 $28,288 $4,000 $125,000 $3,157,288 General Liabilities Coverage Umbrella Coverage Statutory Workers Compensation Coverage for Property of Others OSHA Fines from Fatalities and Injuries Total Estimated Savings Table 8. Estimated Savings 4.3.2 Manufacturing Details This section discusses intended manufacturing operations for custom components of the tower’s design which includes the tower structure, guide shoe, pulley housing, counterweight and the antenna platform. Tower Structure Manufacturing The tower sections are thin walled members and will therefore be manufactured from sheets of steel. The sheet will be cut into a slight trapezoid shape to allow for the taper of the cross-section of the tower. The trapezoid will be cut to length (height of the desired section), with the top and bottom sides supplying the perimeter length of the tower section along with a 3 inch overlap for the weld to close the section. The channels where the guide rail will later be attached will then be pressed into the sheet in their respective locations. The sheet will then enter a metal break to be bent to 60 degrees, thus creating the hexagonal cross section of the structure. The remaining overlap will then be stick welded to close the tower section to insure a strong bond. The external flanges begin as steel extruded to a 1” X 8” cross section. This stock will be cut to a length matching the perimeter length between the guide slots on the tower section it is to be mated with. The work piece is then bent 90 degrees lengthwise along its center, then 60 degrees at the midpoint of its length, matching the corner of the section. Holes are then drilled into the outer flange surface to allow them to be bolted together during assembly. Guide Shoe Manufacturing The guide shoe will be a cast product. Steel will be poured into a plaster mold designed to specified dimensions. The resulting finish of plaster casting is relatively smooth and will likely not require machining. This will, however, be confirmed to insure the proper alignment of the wheels that are to be later attached. Once the casting is finished, holed will be drilled to allow the wheel assembly to be bolted to the guide shoe in their respective locations. The wheels and bearings are purchased parts that are fixed to the guide shoe via short bolted axles. Pulley Housing Manufacturing The floor of the pulley housing is made up of a steel plate that is die pressed to the specified geometry so the pulley assemblies can be mounted to their respective locations. The remaining portion of the pulley housing (same manufacturing procedure as the tower structure) is welded onto the steel plate floor. The purchased pulleys are bolted onto the floor. 16   

19. Antenna Platform Manufacturing The curved steel tubes of the antenna platform begin as standard steel pipe and are bent to the specified radius. Flanges are welded onto the end of each curved tube. The antenna mounting pipes are simply standard steel pipes cut to specified length. The tubes are connected together via brackets and U-bolts. The two platform arms are made of I-beams with two plates welded on at each end. Holes for the bolted connection are drilled into each plate as one side is attached to the flanges of the rounded tubes and the other side is attached to the guide shoe. 4.3.3 Assembly Details The following steps outline the tower’s general assembly process: 1. The concrete tower foundation is poured to the depth and size specified by the size of the tower to be installed. The base consists of concrete and rebar structure to give strength and support to the concrete pad. Conduits are utilized to bring the power and signal carrying wires to the center of the tower from the external control box. 2. The drive housing section of the tower is bolted to the concrete base and the required electrical lines are installed. The gearless motors are bolted to the base of the tower in their respective locations and necessary electrical connections are made. 3. The buffers are bolted into the ground directly underneath where the antenna platforms would land. 4. A crane is used to lift the remaining sections atop the lower sections. The sections are bolted together on their flanges. After section 2 is bolted in, a crane will fix each antenna platform into place on the guiderail. 5. When the top section is installed it is propped up on spacers allowing the required clearance to spool the lifting cables down the interior of the tower to the winding drums. A temporary scaffolding is mounted near the top of the tower to allow technicians to guide the cables and attach the counterweight. The cables are lifted to the top of the tower using the crane and the counterweights are attached to the cables to their proper positions as the cables pass over the pulleys. The lower part of the cable is attached to the winding drum and wound about the drum to insure good connection before the weight of the antenna platform is on the cable. When the cables are secured the spacers are removed and the top section is bolted to the tower. 17   

20. 5 CONCLUSIONS, RECOMMENDATIONS & FUTURE WORK After conducting multiple stress analyses on critical components and an overall detailed cost analysis, results point towards the conclusion that the design is feasible and development efforts should be further pursued. The tower’s design was capable of bringing together numerous existing parts, mainly associated with the common pulley/counterweight elevator system, to create a system that will eliminate the risk of death or injury while servicing telecommunication towers. This added safety feature significantly reduces high insurance costs currently associate with communication towers. With ample advertisement and carrier leasing space available, the tower’s design is capable of generating large amounts of income, thus making up for the higher initial investment costs. Referring back to the customer requirements (listed in Table 1), the tower’s design meets most specified requirements. Major requirements, including ‘safe to service’, ‘capable of supporting at least five carriers, and ‘isolated carrier maintenance’, have all been met. Certain requirements, including ‘remote antenna control’ and ‘deliver power to communication equipment’, still require further designing, but incorporation into the current design should not be an issue. In addition, another failsafe incorporated into the design would be highly recommended. One potential location for an additional failsafe would be a friction brake located in the platform’s guide shoe. The next step to take with this design is to conduct further testing via prototyping. It would be best to build a full scale model of the tower and have it exposed to harsh environments that these towers will need to endure. Since this tower is heavily influenced by the conventional elevator, it is recommended that professional elevator engineers are hired to oversee the prototype stage of design. Civil/structural engineers should also be hired to ensure that proper foundation and overall structural requirements are met. Further development of the design will result in a well optimized tower that would surely be an attractive alternative to the conventional monopole currently in the telecommunication industry. 18   

21. REFERENCES 1)Elevators (Third Edition). By F. A. Annett, McGraw- Hill Book Company - Provided us with majority of the inspiration on our tower’s lift system design 2)Larry Jordan (CEO of SAT Corp.) - Provided us with design feedback and helped establish majority of our customer requirements 3)Hollister Whitney - Provided us with information/specs on counterweight/frame - http://www.hollisterwhitney.com/ 4) - McMaster Carr Provided us with information/specs on pulleys, cable, wheels and bolts 5) - - Oleo Provided us with information/specs on elevator buffers http://www.oleoinc.com/products/elevator 6) - - Wireless Estimator http://www.wirelessestimator.com/breaking_news.cfm Provided us with majority of the information on communication towers 7) - - XINDA Provided us with information/specs on gearless motor http://www.xindasz.cn/ 19 

22. B.4 – Collapsible Arm System Description: This system consists of several levels of mechanical arms that surround the tower. Each arm belongs to a specific broadcaster and provides 360 degrees of signal. When it is necessary to lower a specific broadcasting arm, the arm folds in several different calculated locations to collapse the arm to a size that can fit inside of the other arms without any interference. Each level will ride on its own specific track that will carry it up and down the tower when the arm is collapsed. Sketch: B.5 – Suspended Tier Design Description: This design is a series of tiers supported from above by several rigid vertical arms, all connected to a structure at the top of the tower. The tiers are located at different levels and they get progressively smaller going down the levels. This allows for each tier to fit around all of the tiers below it, and the individual levels allow for full 360 degree coverage. When an individual tier needs to come down for maintenance, a transporting device travels to the selected tier and supports the tier from below. The upper supports disengage and the tier is allowed to travel down the tower. The size of the tiers can either increase or decrease going down the tower, depending on the benefits of each scenario. Sketch: 22 

23. B.6 – Rotating Antenna Tier  Rotating Antenna Tier Description: This design incorporates several tiers or levels of rotating antennas. There are 9 antennas on each tier that broadcast a range of 40 degrees a piece. The tiers, however, are divided into 10 sections: 9 antennas and 1 open section. This open section provides the space for individual antennas to move up and down the tower. When maintenance is needed on a specific tier, the tier will rotate and, one by one, align each antenna with the transporting track, where it can travel down the tower to be serviced. Sketch: 23 

24. B.8 – Foldable/Expansion System Description: The tower here is hexagonal shaped. Each tier is designed in such a way that it can completely expand from its triangular shape to a completely horizontal beam and be brought down from a side of the tower. There is a traveler for each tier on a side of the tower. There are electro mechanic locks and hydraulics involved to ensure proper expansion/folding of the mechanism to bring it up and down the tower safely. The main holding arm which is housed on the traveler is a hydraulic enforced telescoping arm that can expand and retract. It is designed such to ensure the tier being brought down does not interfere with the other tiers. The traveling mechanism here is a bunch of rollers housed in a bracket. The system is hydraulic in nature and this is what drives the rollers. The mechanism is controlled from the bottom of the tower by an operator/technician. This provides great deal of accessibility considering each individual tier can be brought down without interrupting operation of the others. Maintenance runs will be very quick if all the steps are properly followed by the operator/technician. Sketch: 25 

25. B.9 – Exterior Lifting System Description: The individual antennas can be sent up the traveling system like on a conveyor belt. The travelling system is on both sides of the main central monopole structure. The antennas can be sent up and brought down from either side based on their position on the structure. The travelling system is on the main central monopole structure and also on each of the individual tiers housed on the monopole. The arm about which each antenna is mounted has degrees of freedom in the spherical coordinate system and can be remotely controlled from the ground by the operator/technician to align the antenna is the desired orientation. The limitations to this design are that the antennas would have to be wireless and also be powered by solar or a wireless medium. Another limitation is that, in some cases, multiple antennas on the same tier would have to be brought down during a single maintenance run, even if the run is scheduled only for one specific antenna. Sketch: B.10 – Concentric Rings Description: The use of concentric rings that attach to the tower at two points along a track system. The track system raises and lowers the rings. The workings of the track system will most likely be a simple chain-pulley system powered by an electric motor at the bottom. The rings would be lowered independently, the antennas serviced, repositioned and then sent back up. Sketch: 26   

26. B.11 – Rotating Collars Description: There will be a track system to send the brackets that hold the antennas up and down. There is rotating collars at predetermined heights along the tower. The bracket to hold the antennas will be connected to the tower by two points of contact for stability. Sketch: B.12 – Spiral Track Description: There will be a track that wraps around the tower letting the brackets that hold the antenna to get up to the collars that allow them to set their azimuths. Sketch: 27 

27. B.13 – Overlapping Platforms Description: There are four tracks on the tower. There are four platforms that can hold one antenna each. The loops are all differing diameters, letting the antennas be lowered and serviced independently. Sketch: B.14 – Antenna Retriever Description: There is an inner antenna retriever that sends the antenna up to a set cut out portion of the tower and it pops through the tower. The antenna would not be able to change azimuths. Sketch: 28 

28. B.15 – Multiple Towers Description: There is a circular array of “towers” (bars) that each house a track and can hold one antenna. The circular array of bars will need to have a circular ring on the inside to support the bars in a vertical orientation. Sketch: B.16 – The Willow Tree Description: This design incorporates long cables supporting each tier of antennae at its respective height. The tiers are circular and each of different radius allowing them to pass by each other so they can be lowered independently. The top and bottom of the tower would have fixed guides for the cables and pulleys to direct them back to the center of the tower. At the base of the tower some sort of transmission could deliver the power to mobilize the tiers. Coarse azimuth adjustment would be carried out on the ground but fine tuning would be remote controlled motors at each antennae. Sketch: 29 

29. B.17 – Circular Tiers Description: The towers would have a fixed c-shaped frame at the predetermined heights were the antennae’s are desired. The gap in each tier would align with the other gaps and mounted on the tower in that gap would be the lifting mechanism for the antennae frame segments. The antennae would be mounted to the segments on the ground and then elevated to their respective tier. Another mechanism at each tier would rotate the segment onto the fixed frame. Again coarse azimuth adjustment would be carried out on the ground but fine tuning would be remote controlled motors at each antennae. Sketch: B.18 – Fixed Collapsible Frame Segments Description: Each tier would again have permanent supports around the portion of the tower that does not contain the elevating mechanism. The structures that hold the antennae’s will be three sided figures that are collapsible into triangles. When the structures are “folded” they can then be translated around the tower to the elevating mechanism. The design of the fixed framing of each tier allows the folded structure to pass without disturbing the lower towers. Corse azimuth adjustment would be carried out on the ground but fine tuning would be remote controlled motors at each antennae. Sketch: 30   

30. APPENDIX C – Supplier Specification Sheets C.1 – Guide Shoe Wheel (Supplier: McMaster Carr) C.2 – Guide Shoe Wheel Axle (Supplier: McMaster Carr)       31   

31. C.3 – Mounted Pulley (Supplier: McMaster Carr) 32 

32. C.4 – Steel Wire Cable (Supplier: McMaster Carr) 33   

33. C.5 – Hydraulic Buffer (Supplier: Oleo)                                                                                   34   

34. C.5 – Gearless Motor (Supplier: XINDA) 35   

35. C.6 – Counterweight Frame (Supplier: (Hollister Whitney)   36   

36. APPENDIX D – Detailed Cost Breakdown (Bill of Materials) D.1 Material Costs D.1.1 Tower Structure  *The tower sections listed below are fabricated using ASTM‐A572‐65, High Strength Low Alloy  Steel. Qty (#) 1 Tower Section I 1 Tower Section 2 1 Tower Section 3 1 Tower Section 4 1 Tower Section 5 1 Tower Section 6 1 Tower Section 7 1 Tower Section 8 6 Section 2 I –Beam W14 x 90 6 Section 3 I –Beam W14 x 90 6 Section 4 I –Beam W14 x 90 6 Section 5 I –Beam W14 x 90 6 Section 6 I –Beam W14 x 90 6 Section 7 I –Beam W14 x 90 TOTAL COST D.1.2 Bolts *The below listed bolts are all ASTM A307 grade A Hex bolts.   Item Description Mass (lbs) 5650 29891 21793 15247 12091.5 9225.12 6614.9683 2041.0037 23500.0 12533.76 915.1 762.5665 610.053 457.54 Unit Price ($ / lb) 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb 0.27/ lb Cost ($) $1,537.7 $8,135.1 $5931.1 $4,149.5 $3,290.8 $2,510.7 $1,800.3 $555.8 $38,070.0 $20,304.7 $1,482.5 $1,235.4 $988.3 $741.2 $84,738.6 Qty (#) 30 30 30 30 30 30 30 432 Item Description Unit Price ($/item) $0.55 $0.55 $0.55 $0.40 $0.40 $0.40 $0.40 $1.10 Cost ($) $16.5 $16.5 $16.5 $12.0 $12.0 $12.0 $12.0 $475.2 $572.7 Sections 1-2 Flange Bolts 2 ½” Sections 2-3 Flange Bolts 2 ½” Sections 3-4 Flange Bolts 2 ½” Sections 4-5 Flange Bolts 1 ¾” Sections 5-6 Flange Bolts 1 ¾ ” Sections 6-7 Flange Bolts 1 ¾” Sections 7-8 Flange Bolts 1 ¾” I-Beam Bolts ½” - 13 TOTAL COST 37   

37. D.1.3 Antenna Platform Assembly Qty (#) 12 Guide Shoe Housing Custom Built - ASTM-A572-65 96 Rollers Nonmarking Polyurethane Wheel 4” 96 Wheel Axles w/o Grease Fitting, ½” Diameter, 3” Length 12 Steel Eye Bolts w/ Shoulder for Lifting,¾” - 10 Thread Size 84 Guide Shoe Bolts ASTM A307 grade A, Hex, Thread Size ½”-13 30 8 ft Mounting Pipe A500 Carbon Steel, 1¼” Diameter 18 Tubular Semicircular Platform A500 Carbon Steel, 2” Diameter 8 Tubular Flange Bolts ASTM A307 grade A, Hex, Thread Size ¾” - 10 18 Guide Shoe Platform Bracket A500 Carbon Steel 1 U- Bolt for 1¼“ Pipe 304 Stainless Steel 1 U- Bolt for 2” Pipe (Extra Long) 304 Stainless Steel 12 Platform I-Beam Arm Structural A36 Steel Wide Flange Item Description Unit Price ($/item) $22.95 Cost ($) $275.4 $22.14 $2,125.4 $2.26 $217 $8.40 $100.8 $1.10 $92.4 $25.00 $750.0 $60.00 $1,080.0 $1.10 $8.8 $8.00 $144.0 $5.30 $5.3 $7.45 $7.5 $25.38 $304.6 TOTAL COST $5,111.1 D.1.4 – Drive/Lift System Qty (#) 6 WWTY Gearless Traction Machine 800 kg, 1 m/s speed, 2:1 traction ratio 6 Counterweights Lead Filled Counterweights, MARS Metal 12 Mounted Pulleys + Axle Heavy Duty Steel w/ Easy turn bearings, 6” 6 Buffers SEB 18, Gas Hydraulic Buffer, Oleo International 12 Cables Steel Rope, High Strength, 3/8”diameter – 420ft Item Description Unit Price ($/item) $2,581.00 Cost ($) $15,486.0 $2,475.00 $14,850.0 $511.00 $6,132.0 $300.00 $1,800.0 $1,029 $12,348.0 TOTAL COST $50,616.0 38   

38. D.2 – Manufacturing/Assembly Costs Item Description Rate Operating Hours (day/hr) 8 hours 2.5 hours 6 hours 1 day 1 day Cost ($) Welding – Hand Welding Operator w/ consumables Sheet Metal Bending Bolting 60 ft Trailer (6 trips) 300 ft Crane $66/hour $10/hour $16/hour $1500/day $2500/day $530.0 $25.0 $96.0 $1500.0 $2500.0 $4,651.0 TOTAL COST D.3 – Tower Servicing Costs Item Description Rate Operating Hours 2 hours 1 day Cost ($) $37.0 $30.0 $67.0 $134.0 1 Telecom Technician 1 Service Truck + Equipment $18.5/hour $30/day Total per Service/Upgrade TOTAL COST/YEAR D.4 – Insurance Costs Item Description Cost ($) $250,000 Insurance Coverage for Tower + Property APPENDIX E – Design Drawings PDF files of design drawings have been attached to this report 39 

39. APPENDIX F – Analysis Results F.1 – Tower Analysis Von Mises Fringe Plot Displacement Fringe Plot 40 

40. F.2 – I-Beam Analysis Von Mises Fringe Plot   Displacement Fringe Plot   41   

41. F.3 – Pull Housing Floor Analysis Von Mises Fringe Plot Displacement Fringe Plot 42