The Medellin Project in Colombia

Transcription

1 The Medellin Project in Colombia Philippe Adrien Export Director Pomagalski SA Page 13.1

2 Abstract: The Medellin Project in Colombia Philippe Adrien 1 ) The municipal council of Medellin has chosen the gondola lift solution to connect the hillside district of Santo Domingo to the city's overground metro network. The MetroCable project, as it is called, is jointly funded by the city and the mass transit company, Metro Medellin. The system is an ARIANA 8-10 gondola lift from the SATELLIT range, equipped with aluminum DIAMOND gondolas made by SIGMA. The line is scheduled to run 18 hours/day, all year round. It is 2 km long, with a vertical rise of 400 meters, three sections and four terminals, including two intermediate stations, the first of which includes a 15 turn. Ground on which the lift is built calls for extremely deep anchoring for the single-shaft towers, each of which rests on four piles, with a diameter of 2 m, driven down to a depth of 8 meters. 1 Export Director, Pomagalski SA, 109 rue Aristide Beregs, BP 47, Voreppe Cedex, F-38341, , Fax , philippe.adrien@poma.net Page 13.2

3 A New Application of the Aerial Ropeway Transportation Technology METROCABLE in MEDELLIN - COLOMBIA Philippe ADRIEN 1 A. PRESENTATION: 1 1. MEDELLIN: a. Located at an altitude of 1,200 m, Medellin is COLOMBIA second largest city and a major economic center of this country of 50 million people. b. MEDELLIN is famous for its coffee its clothes manufacturing along with an important role played in the fashion business. The city also hosts some large foreign companies such as car manufacturer Renault which activities cover the whole Andes Community of Nations (CAN). c. The city is located along a river and stretches for 25 km from North to South surrounded by high crests some 800 meters. d. In order to cope with this specific mountainous environment of the city some important infrastructures have been realized lately. Most of The Metro Medellin network after the them are dedicated to traffic completion of the cable car extension and urban infrastructure improvement. 2. METRO MEDELLIN: a. The mass transportation system is an over-ground metro linking various places and suburbs along 3 main lines. b. The Metro counts 30 km of tracks, some 25 stations. c. It is supported by the City of MEDELLIN and the Government of COLUMBIA since it is considered as a very important tool of social development. Export Director, POMA, BP 47 F VOREPPE Cedex, T: , Fax: philippe.adrien@poma.net Page 13.3

4 3. HISTORY of the PROJECT: a. One of the major problems the Metro has to face is the lack of passenger traffic at its northern part of the network. Populations in these areas are poor and leave in typical barrios. They prefer to use traditional means of transportation such as taxis and small buses, only capable to cope with the narrow and tortuous streets. In addition, ground profile does not allow using any traditional and viable solution to reach potential clients. b. This is why the Municipal council of MEDELLIN has chosen the gondola lift solution to connect the hillside district of Santo Domingo to the City Metro Network. The MetroCable project, as it is called, is cofunded by the City and the mass transit company, Metro Medellin. The contract was signed with POMA on March 31 st, 2003 for the supply of an ARIANA 6-10 gondola lift from the SATELLIT range, equipped with aluminum DIAMOND gondolas made by SIGMA. With a ceiling height of 2.10 m, each of the 93 gondolas has room for 8 seated or 10 standing passengers, and includes a radio and battery-solar powered lighting for nighttime operation. The line is scheduled to run 18 hours/day, all year round. It is 2 km long, with a vertical rise of 400 meters, 3 sections, 4 terminals, and 2 intermediate stations, the first of which includes a 15 angle. 4. THE SANTO DOMINGO AREA: Located in the SANTO DOMINGO built-up area, construction of the lift required the issue of a number of compulsory purchase orders on various properties. In addition, the ground on which the lift is Page 13.4

5 built calls for extremely deep anchoring for the single-shaft towers, each of which rests on 4 piles, with a diameter of 2 m, driven down to a depth of 8 meters. Three companies have formed a Joint Venture to complete the project: POMA to supply the lift, the supervision of erection and necessary training for maintenance and technical operation. CONCONCRETO for all civil works. TERMOTECNICA for the erection and supply of local fabrication (structure, roofing ). B. LIFT MAIN TECHNICAL CHARACTERISTICS: The line is scheduled to operate 18 hours/day, 365 days/year. Even though there is no specific requirement by Metro Medellin for POMA to guarantee a minimum availability, the lift has been designed so that it is capable to remain operable in case of a problem in the drive machinery. 2 electric motors in tandem configuration are ensuring the maximum service (base/degraded). The maintenance has also been rescheduled to fit with the large number of hours the lift is expected to operate every year. The lift consists in: 1. Mechanical Equipment: o 4 stations, single loop, single drive located at the lower terminal o Tensioning located at upper terminal o Garage for the 93 cabins located at lower terminal o Length: 2,000 m 6,000 ft o Vertical rise 4,000 m 1,320 ft o Number of stations 4 o Capacity (base/degraded): 3,000 pph / 1,500 pph o Rope diameter: 51 mm 2 o Angle at the level of station Nr. 1: 15 o Number of cabins: 93 o Type of cabins: DIAMOND 8/10, 2.10 m ceiling height o Installed power: 2 x 455 kw o Volume of concrete in civil works: 17,000 m3 o Rope speed (base/degraded) 5 m/s / 2.5 m/s Page 13.5

6 o Power is taken from the rope for acceleration and deceleration ramps in both terminals o Transfers in intermediate stations are electrically powered o In both terminals, cabins cadencing system is electrical in base and degraded operation conditions. o Braking is standard: One service brake One emergency brake 2. Electrical Equipment: o The terminals (drive and return) are controlled by a safety automate (S7 400F by Siemens) equipped control system (SEMER design and fabrication). o The 2 intermediate stations are controlled by a separate safety automate (S7 400F by Siemens) equipped control system. o Both automate cabinets are located in bottom terminal. o The lift can be controlled from each station by remote control. o Diagnosis and trouble shooting can be performed remotely from POMA in France. o Fully automated garage is also controlled by its dedicated automate. C. MAIN ECONOMICAL DATA: o Total value of the investment: o Cost of electro-mechanical equipment: o Pre-project duration: o Project completion time: o Price of the metro passenger ticket: 25 Millions US Dollars 12.7 Millions US Dollars 3 years 16 months 30 cents D. DESCRIPTION OF THE LIFT: The metro system follows the river valley where Medellin City has developed. The purpose of the project is to create a feeder line connecting the area of Santo Domingo to the metro station of ACEVEDO as shown on the following picture. Page 13.6

7 The Metro Station of ACEVEDO where the existing metro network (on the bottom) connects with the Santo Domingo gondola lift line. Garage for the 93 gondolas is also visible on this picture. Page 13.7

8 1. Bottom Terminal: ACEVEDO: It is the drive terminal. It is also equipped with the fully automatic garage for the 93 gondolas with retractable platform. 2. Intermediate Station Nr 1: ANDALUCIA: The line makes an angle of 15. This deviation is made with sheave batteries. Embarkation / disembarkation of passengers are possible in both directions. 3. Intermediate Station Nr 2: POPULAR: The line goes straight through this station. Embarkation / disembarkation of passengers are possible in both directions. Page 13.8

9 4. Top Terminal: SANTO DOMINGO: This is the return and tensioning terminal. Stress gauges are used to control the tension value applied by the hydraulic circuit. Embarkation / disembarkation of passengers are possible in both directions. 5. The Line: The line is 2,000 m long with a vertical rise of 400 m and an angle of 15 at the level of intermediate station Nr. 1. It comprises: o 23 towers o Rope diameter: 51 mm o 3 sections o Double safety line 6. The Cabins: There are 93 passengers cabins as follows: o DiamonD 8/10 type 2,100 mm ceiling height o 10 passengers standing of 8 seated o Interior lighting with batteries and solar panels o Full duplex passenger communication devices between the cabins and the drive terminal. Page 13.9

10 E. SPECIAL FEATURES: There are several points, which have been reconsidered taking into account the use of this technology to be integrated in an urban transportation system. 1. Availability: a. The drive unit is designed so that the occurrence of a total shut down of the lift in case of mechanical or electrical problems is as minimized as possible. Base operation is made at 5 m/s rope speed: There are 2 electric motors M1 and M2 used together to reach the 5 m/s rope speed in normal operation, each motor delivering half of the requested power. These 2 motors are connected with U joint to the POMA/KISSLING main gearbox. Page 13.10

11 b. In case of electric failure caused by one electric motor or one power supply cabinet, the lift is operated in degraded mode at 2.5 m/s: The mechanical integrity of the 2 electric motors M1 and M2 is preserved but only one (M1 or M2) is available. An intermediate temporary gearbox (ration ½) is inserted between the 2 motors and the POMA/KISSLING main gearbox. The operation is possible at 2.5 m/s until the next maintenance operation to repair the electric failure or replace the damaged motor. Page 13.11

12 c. If electric motor M1 is mechanically damaged: The U joint between M1 and M2 is removed and tachometer is moved from M1 to M2. M2 is connected to the POMA/KISSLING main gearbox via the intermediate gearbox (ration ½). Operation is possible at 2.5 m/s until the next maintenance operation to replace M1. Page 13.12

13 d. If electric motor M2 is mechanically damaged: The U joint between M1 and M2 is removed and M2 is moved to the side. M1 is connected to the POMA/KISSLING main gearbox via the intermediate gearbox (ration ½) and a long U joint. Operation is possible at 2.5 m/s until the next maintenance operation to replace M2. Page 13.13

14 e. The lift is also equipped with 2 safety lines to guarantee the monitoring of the line in all conditions. Both are activated in normal operation. In case one is out of order, it is possible to operate with one line only until the next maintenance operation. 2. Maintenance: The contract includes a 3 months technical assistance period to train the client s personnel in actual operation and maintenance conditions. Further assistance can be provided by POMA after the completion of these first 3 months upon client s request. POMA has delivered with the lift a complete set of documents including: As built drawings Description of each main assembly Maintenance manuals to ensure a perfect knowledge of the lift design. This is also helpful for parts identification and ordering by the client. Maintenance program has been adapted to the actual operation conditions: There are 4 stations, each with embarkation/disembarkation capabilities in both directions. A grip supports 6 opening/closing cycles for each travel. The lift is operated 6,500 hours/year to be compared with an average of 1,500 hours/year in a ski resort. The next table shows some examples of adapted maintenance program for some critical components. A set of critical and long delivery time components has been sold with the lift: 3 cabins are kept in stand by in the garage. One POMA/KISSLING main gearbox; One electric motor. Page 13.14

15 Example of a page of the maintenance manuals. The up dating of the maintenance manuals and technical notices can be done directly by the client downloading the latest issue on Page 13.15

16 Components Operation to be performed Medellin Periodicity Standard Periodicity (according to French code) Braking test no load 6 months N/A Brakes Braking test full load Yearly Yearly Rope Magnetoscopic inspection 6 months After 1 st, 4 th, 7 th, 10 th, 15 th year, later yearly Grips 1 st inspection One year and after yearly 5 years Cabin Structure Integrity check Every 18 months 20,000 hours or 15 years whichever occurs first Example of some critical components, maintenance program of which has been adapted to the actual operation conditions. Page 13.16

17 3. Safety of Operation: a. In case of complete failure such as: No more electrical power Main failure of the main POMA/KISSLING gearbox Both electric motors M1 and M2 are damaged emergency procedure is activated: The main POMA/KISSLING gearbox and the bullwheel are uncoupled, 2 hydraulic motors are coupled to the bullwheel through the crown gear. High-pressure oil comes from a hydraulic pump activated by a diesel engine. Passengers reach the next station at a speed of 1 m/s. Page 13.17

18 b. Cabins are equipped with a full duplex addressing device powered by batteries and solar panel so that passengers can send information and receive instruction in case of emergency. c. Since the lift has a limited clearance to the ground, it is always possible to vertically evacuate people in extreme situation in less than 3 hours. Medellin Fire Brigade and dedicated Metro teams have been trained to this purpose. Page 13.18

19 F. SOME KEY POINTS for SELECTING A CABLE CAR: Here are some reasons why clients select this product for urban transportation: The investment cost is low compared to other mass transportation systems. It minimizes ground occupancy. It allows easy crossing of rivers and other natural obstacles at reasonable cost (no big infrastructure required). It allows easy access to mountainous areas. It is environment friendly. Quiet operation is guaranteed in inhabited areas. It offers a great flexibility of operation. Maintenance costs are optimized. It is a proven technology used in thousands of lifts, most of them installed in extreme environmental conditions. G. OTHER PROJECTS: There are other projects at different stages of development in the world. 1. ESPARAGUERRA: This project is under construction by POMA in the suburb of BARCELONA in Spain. It is made of a jig back system with 2 cabins of 16 passengers with a capacity of 200 pph to be increased to 400 pph in the future by adding 2 cabins. The lift is 1,300 m long with a vertical rise of 100 m. It connects a train station to a new urban development accessible only by a difficult road. Page 13.19

20 2. KAOSHIUNG: The project under development consists in the extension of existing metro lines KTRC 01 and LRT G1B into the harbor of Kaoshiung. One line (in yellow interrupted line) will use a mono-cable gondola lift while the other (red interrupted line) will need the use of multi-cable technology. Page 13.20

21 H. CONCLUSION: The lift has been inaugurated on July 30 th, 2004 by the President of the Republic of COLOMBIA in the presence of the Mayor of MEDELLIN and the Governor of the Province. It has entered commercial exploitation since August 7 th, Here is a selection of some very representative pictures of the final installation. The drive terminal upstairs the ACEVEDO metro connection station. Page 13.21

22 The gates to MetroCable boarding platform. The drive terminal embarkation/disembarkation platform. Page 13.22

23 The first section of MetroCable line viewed from ACEVEDO terminal. The main reason of shut down, kites. Page 13.23

24 The whole line view from a cabin in the third section. Page 13.24

25 History of the Detachable Grip Jon Mauch Lift Director Breckenridge Resort, Keystone Resort Jon started at Breckenridge in 1977 and have work through various jobs in the lift department. Currently he is the Lift Director with responsibilities of Lift Operations, Lift Maintenance, Lift Construction and Planning, and Ticket Scanning. We have installed many unique and different types of lifts, including the worlds first detachable quad, a fixed grip lift with a 45% turn, a double loading six passenger lift, the first conveyor lift for kids ski school, and have experimented with different types of loading configurations including loading conveyors and contour loading. I have participated with the Colorado Passenger Safety Board as a Technical Committee Member and served as chairman on numerous ad-hock committees. I also served on the Rocky Mountain Lift Association board. I have been an ASC B77 Committee Member since In May 2001, I assume the Chairmanship of the committee. I have worked the better part of my life in the Tramway business and am very dedicated to promoting safety and innovation. This is more than just a job for me, I truly enjoy the interface with tramway people throughout the world. Page 14.1

26 Abstract: History of the Detachable Grip John Mauch 1 This is a historical look at the detachable grip. We will look at the development and theories of Detachable Grips as the progressed from gravity to the grips we use today. Many of the grips started out in the mining industry and migrated to passenger usage. Through the use of drawings and photos we will be able to see the progression and changes to grips as they work in today s systems. 1 Lift Director, Breckenridge & Keystone Resorts, PO Box 1068, Breckenridge, CO 80424, (970) F (970) , jon@vailresorts.com Page 14.2

27 Utility Conduits Suspended Between Ropeway Towers Chuck Peterson, P.E. President Tramway Engineering The author was the design engineer for the Iron Mountain Tramway project including all aspects of the utility lines. He was also one of the project owners and is the president of Tramway Engineering, a consulting firm specializing in ropeways. Page 15.1

28 Abstract: Utility Conduits Suspended Between Ropeway Towers Chuck Peterson, P.E. 1 The presentation will be based on experience gained in the installation of a natural gas, potable water and wastewater utility lines on the Iron Mountain Tramway in Colorado. We will look at the design construction, and operation of the utility lines that are suspended between the tower heads. 1 President, Tramway Engineering, P.E., P.O. Box 398, Glenwood Springs, Colorado USA. (970) chuck@tramway.net Page 15.2

29 Utility Conduits Suspended Between Ropeway Towers Chuck Peterson, P.E. 1 Tourist tramways are often used to provide access to remote locations in mountainous terrain. In many cases, the upper terminal is a multiuse facility that requires basic utilities such as electrical power, water, natural gas and sewer. Fortunately, in most cases, these utilities can be economically provided by direct burial of the utility lines. However, the use of aerially supported utility lines can be considered in those rare conditions where traditional buried lines are either environmentally, economically or physically impracticable. In 2003 aerial utilities lines were installed on the fixed grip pulse gondola manufactured and installed by Leitner Poma of America. The ropeway has a slope length of 4433 ft (1351m) and a vertical rise of 1352 ft. (412m). As installed, there are four groupings of two 6 passenger gondola cabins. Ultimate design capacity is 12 groupings of 3 carriers. The ropeway accesses a multifunctional upper terminal at the Glenwood Caverns in Glenwood Springs, Colorado. The utility lines provide potable water, natural gas and gray water disposal for a 13,000 ft 2 (1,207 m 2 ) upper station that includes a 150 seat restaurant, a 1200 ft 2 (111 m 2 ) gift shop and support facilities. The tramway is operated year round. A mountain roadway provides limited year round access to the upper terminal. During the first 18 months of operations the utility lines have proven to be an acceptable alternative to the traditional buried lines with certain limitations. 1 President, Tramway Engineering, P.E., P.O. Box 398, Glenwood Springs, Colorado USA. (970) chuck@tramway.net Page 15.3

30 Design and Construction Support Cable. The three utility lines (natural gas, water and gray water) are supported by a 7/16 (12 mm) IWRC EIP cable suspended directly under the tower crossarms. The selection of the cable size took into consideration live and dead loads of the utility lines, wind and the sizing of the available cable hangers. It was decided to use a standard 3 bolt guy clamp to connect the utility hanger to the support cable. A 7/16 cable was selected because it was the largest size cable that was compatible with this clamp. The factor of safety was designed for the longest span of 442 ft (135 m) with a 3% sag ratio. Local climatic conditions did not require that icing be taken into consideration. The support cable has a factor of safety of 2.5 when the utility lines are full with a 70 mph (112 km/hr) crosswind. Clearance between the utility lines and the carriers must be taken into careful consideration. The assumed 3% sag ratio has resulted in less clearance than was anticipated. Although the ropeway haul cable was designed for a maximum 3% sag ratio, the sag of the haul rope on individual spans varies depending on the installed number of cabins within the pulse group and the loading of the cabins. In retrospect, the sag of the utility lines should have been designed to be less than the haul rope sag under the lightly loaded conditions of the initially installed capacity. Because the support cable is secured to each tower crossarm, these conditions may require that the incoming and outgoing support cable tensions differ. In these cases, the additional torque on the tower tubes and connections must be considered. The cable was connected directly under the crossarm at a point adjacent to the tower tube for clearance issues and to reduce the amount of torque on the tower tube. Although installing the connection point on the lifting frame would have improved clearance, it was decided that the additional moment arm above the crossarm created unacceptable stress. The support cable was pulled from the upper terminal to the lower terminal across nylon rollers on each tower at the connection point. Once the cable was tensioned to provide a 3% sag ratio for the longest span, the cable was secured to each tower with strand vices. Page 15.4

31 Utility Conduits. The utility conduits are three 1-1/2 (38 mm) inside diameter fiberglass reinforced plastic tubing that is commonly used in the petroleum industry. The connections are integral threaded and coupled. The pipe which was manufactured by Star Fiberglass 2 has been tested to confirm that there was no structural deterioration caused by ultraviolet radiation over the five year test period. The rated pressure for the pipe that was used on the project was 2000 psi (137 bars) for the lower section of the profile and 1500 psi (103 bars) for the upper half of the profile. The ultimate burst pressure rating for the lower section was 5000 psi (344 bars) The pipe had been certified by a European testing agency for use in the transport of potable water. There was no similar United States certification available. The authorities having jurisdiction allowed the pipe to be use for this application in spite of no United States certification with the understanding that the pumped water would be tested monthly to confirm acceptable water quality. The pipe was connected to the support cable at 10 ft (3 m) intervals. The connection was made with three bent plate parts that were bolted together to form a triangle. The triangle was bolted to the support cable with a 3 bolt guy clamp. The bent plates surround and lock into place a rubber gasket. The gasket was made by extrusion to match the profile of the three pipes. The goal was to ensure that the steel triangle would not contact the pipe and possibly cause abrasion. A communications line, which was electronically connected to the lift control system, was attached to the utility line to monitor the line integrity. The pipe was installed in 30 foot (9.1 m) sections. The pipes were assembled into the support hangers before being placed into a rack that was suspended between two work carriers. The pipe laying crew started at the upper terminal and worked downhill on the light side. Each pipe assembly was attached to the support cable and then each pipe was mated with the uphill assembled pipes. The pipes were screwed together with a fabric pipe wrench to the recommended torque. Once the pipes were secured, the bolts on each hanger support were tightened to squeeze the triangular frame around extruded gasket. The entire process took about three weeks to complete. 2 Star Fiberglass Web site contains technical design criteria for the fiberglass pipe used in the project. Page 15.5

32 Utility Connections. Steel utility pipes were attached directly to the first and last towers for the connection to the underground utilities. At the top of the terminus, reinforced rubber hoses were used to transition to the fiberglass pipes. This flexible connection allowed for movement between the suspended lines and the fixed steel lines attached to the towers. A special bracket was fabricated for the crossarm on the first tower for the gray water line. The bracket was designed to act as a thrust block for the gray water as it transitioned from a high velocity flow within the fiberglass line to the steel line attached to the tower. Vacuum breakers were attached to the lines at the upper terminus to allow for air to enter the lines during water drain back. These vacuum breakers were wrapped with heat tape for winter operations. Operations Waterline. The only source of potable water for the operation of the upper facility is the aerial waterline. During peak summer operations, approximately 5000 gallons (19,000 l) per day are used. This demand is reduced to about 2000 gallons (7570 l) per day during the winter. Water is pumped from the base terminal directly to a 34,000 gallon (128,000 l) holding tank located vertically 157 ft (47 m) above the upper facility. Water gravity feeds the building with a static water pressure of 68 psi (4.6 bars). The holding tank provides for a 17 day water supply in the winter when the waterline may not be operational due to cold temperatures. When the system was commissioned, the water was pumped by two positive displacement pumps at a rate of 30 gpm (113 lpm) with a total head of 1000 psi (69 bars). These pumps were subsequently replace with a single 37 stage centrifugal pump with a flow rate of 42 gpm (159 lpm). Since water is drained from the line during colder temperatures, the piping system was designed to allow for drainage water to bypass the pumps to prevent pump damage. Since the waterlines is not insulated, pumping in the winter is problematic and requires careful monitoring. If the water in the pipe was to freeze, there would be no technique that could thaw the pipe and prevent the frozen water from splitting the pipe. The upper tramway terminal is located at an elevation of 7100 ft (2164 m). An analysis of 100 years of daily temperature records for Glenwood Springs, Colorado with an elevation of 5700 ft (1737 m) shows that the average January monthly maximum temperature is 36.9 F (2.7 C). Only the first ten days of January have an average daily maximum temperature (with a 68% confidence level) below 32 F (0 C). Therefore, it is statistically possible to pump water during the coldest month. However, during colder winters or during extended stretches of cold temperatures, there are periods where pumping is not possible. Page 15.6

33 In order to monitor the water temperature, a waterline temperature gauge was installed at the upper terminal for the upper attendant to monitor conditions when pumping. Pumping was suspended when the incoming water temperature was 38 F (3.3 C). By suspending pumping operation at this point, there was sufficient latent heat to allow the water in the line to be drained back to the lower terminal before it reached the freezing point. With the initial incoming water temperature of 50 F (10 C) it was possible to continue to pump when the air temperature was 28 F (-2.2 C). Even with careful monitoring of the pumping parameters, it was a challenge to keep the water level in the reservoir tanks to an acceptable level during the month of January. Although there was often a period of time during the day when pumping was possible, the total quantity of water pumped was dependant on the length of the pumping window. During the first winter of operation water levels in the tanks remained adequate for normal operation in the facilities even though there were days when pumping was not possible. Gray Water. When the system was commissioned, there was no waste water disposal system at the upper facility. All waste water was conveyed to the lower terminal via the aerial pipelines for disposal by the local municipal waste water treatment facilities. Due to the small size of the aerial pipes, waste water was pretreated at the upper terminal to remove the solids. Waste water at the upper facility was pretreated with two 2500 gallon (9460 l) septic tanks installed in series. Solids were collected in these tanks and pumped from the tanks twice a year by pumper trucks. Pretreated sewage was collected in a 5000 gallon (18,900 l) storage tank at the upper facility. A high water level sensor within the tank would start to pump the sewage to the top of the terminus tower. Pumping would continue until the low level sensor turned off the pump. The intent was to provide intermediate pumping of the sewage at higher flow velocities in order to avoid freezing of the downgoing sewage. It was assumed that water flowing at a high velocity had sufficient energy to prevent freezing even at low temperatures. This assumption proved to be incorrect. During the first winter, the automatic pumping during low temperatures resulted in a freeze up of the gray water in the utility line. Fortunately a warming trend allowed the line to thaw within a couple of days. Following the event, the sewage was only pumped when the air temperature was above freezing. In order to avoid a reoccurrence of this event, a 2000 gallon (7560 l) per day septic system was installed during the 2004 construction season to allow all sewage to be disposed of on mountain during the winter months when demand is limited. Because the upper facility includes a 150 seat restaurant, the waste water includes a grease component. There was great concern that grease could accumulate on the walls of the aerial lines and eventually totally clog the line. In order to avoid this occurrence, all waste from the kitchen passed through a grease trap which was periodically pumped and hauled off the mountain. As an additional precaution, enzymes were added to the grease trap in an attempt to keep the grease in suspension. During the first summer of operations, there were indications that even these precautions were inadequate to prevent grease from accumulating on the walls of the utility line. Since there are limited options available to clean grease from the lines, the build up Page 15.7

34 of grease was a major concern. Ironically, the first winter of operations provided an unexpected solution to the problem. Apparently night time temperatures during the coldest months of the winter froze the accumulated grease that lined the pipe walls. It appears that the frozen flakes of grease were flushed down the lines when waste water was periodically pumped down the utility lines. A change in the type of enzymes used in the grease traps during the second summer of operations has apparently reduced the buildup of grease in the lines. Natural Gas The transportation of natural gas on aerial lines attached to a ropeway could be perceived as a safety issue. The authority having jurisdiction had concerns that if the line ruptured and the gas was ignited, a blow torch effect may endanger the passing carriers or the haul rope. The incoming static pressure of the natural gas was about 50 psi (3.4 bars). The factor of safety for the 1500 psi (103 bar) fiberglass pipeline therefore was about 30:1 for rupture. The total volume of natural gas in the line is 54 cubic feet (1.5 cubic meters). Because of these factors it was decided that the risk to the tramway was minimal. As a safety feature, a valve was installed on the supply line that would shut off the flow of the natural gas if there was a sudden drop in downline pressure. In addition, on an annual basis, a pressure test is conducted on the gas line whereas the line is isolated and the pressure in the line monitored to determine if there is any loss of pressure during the test. If there was a loss observed, the line would be inspected to detect the odor that is added to the natural gas. Conclusion. The use of aerial utilities on a ropeway has proven to be successful. The lines have been in operation for about 18 months with no major problems. Based upon the experience of the aerial utility lines at the Iron Mountain Tramway, the following observations can be made. 1. Aerial utility lines are not as reliable as the traditional buried lines. The aerial lines are subject to more operational and atmospheric variables that could effect the functionality of the utilities that are critical for the operation of the upper facilities. 2. Under most conditions, aerial water lines should only be installed in warmer climates where freezing temperatures will not become a threat to the lines. 3. If an aerial water line is used, there must be a reservoir at the upper facility large enough to supply water for a reasonable amount of time if the utility line is temporarily not available. 4. The use of aerial utilities is not practical in areas where icing is possible. The cross sectional area of the lines could result in an ice load that is not supportable by any reasonably sized support cable. Page 15.8

35 5. The use of an aerial gray water disposal line must be limited to times when the atmospheric temperatures are above freezing. High velocity flow is not adequate to prevent freezing of the gray water in extremely low temperature conditions. 6. If the upper facility includes a kitchen, extreme care must be taken to pre-treat the gray water to remove all grease that could accumulate on the walls of the line and eventually render it non-functional. 1 Author, Charles R. Peterson P.E., P.O. Box 398, Glenwood Springs, Colorado USA. (970) chuck@tramway.net The author was the design engineer for the Iron Mountain Tramway project including all aspects of the utility lines. He was also one of the project owners and is the president of Tramway Engineering, a consulting firm specializing in ropeways. Page 15.9

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37 Do I Need A Rocket Scientist Michael Clotman Lift Maintenance Manager Angel Fire Resort, NM Page

38 Abstract: Do I Need A Rocket Scientist Michael Clotman 1 The level of technology, and with it increased safety categories, has been impressive over the last few years. However, it seems with every increase in technology comes increased fragility. PLCs and PCs are very particular about their environment. Combining CPUs with lift systems is like hooking your computer to a giant antenna. Thanks to all these electronics, lift problems are becoming more complex. While ten lifts may function perfectly, though, there are occasionally installations that will experience problems due to their environment. Angel Fire ski area in New Mexico has one such lift. It encountered numerous shutdowns and electrical issues, and we couldn t seem to eliminate them. We basically had to start over from the ground up when investigating the sources of our problems. The problems we were having with this lift came to a head in ski season. We discovered this also coincided with one of the worst years in recent history for sunspots and solar storms. We discovered that two aspects of this lift were contributing to the electronic nightmare: with its length, nearly two miles long, and its orientation, along a perfect east-west axis, the lift was acting as a giant catch net for any solar winds that pushed geomagnetic storms down from magnetic north. Then we looked at other environmental factors that might effect the lift. There were induced voltages on the haul rope from a power line that ran parallel to the lift. The towers themselves were acting as antennae, picking up radio communications from 100 miles away. The power quality we were getting was not the cleanest. Ultimately, though, it was the Angel Fire Lift Maintenance and electrical department that had to sort through all the data and come up with solutions. And these proved to be as complex as the problems. 1 Lift Maintenance Manager, Angel Fire Resort, NM 2 Page 16.2

39 Do I Need A Rocket Scientist? Michael Clotman 1 Do I need to hire a rocket scientist? I thought to myself while running correlations between lift faults and sunstorm activity.* The level of technology, and with it increased safety categories, has been impressive over the last few years. However, it seems with every increase in technology comes increased fragility. PLCs and PCs are very particular about their environment. Combining CPUs with lift systems is like hooking your computer to a giant antenna. Thanks to all these electronics, lift problems are becoming more complex. While ten lifts may function perfectly, though, there are occasionally installations that will experience problems due to their environment. Angel Fire ski area in New Mexico has one such lift. It encountered numerous shutdowns and electrical issues, and we couldn t seem to eliminate them. We basically had to start over from the ground up when investigating the sources of our problems. The problems we were having with this lift came to a head in ski season. We discovered this also coincided with one of the worst years in recent history for sunspots and solar storms. We discovered that two aspects of this lift were contributing to the electronic nightmare: with its length, nearly two miles long, and its orientation, along a perfect east-west axis, the lift was acting as a giant catch net for any solar winds that pushed geomagnetic storms down from magnetic north. Then we looked at other environmental factors that might effect the lift. There were induced voltages on the haul rope from a power line that ran parallel to the lift. The towers themselves were acting as antennae, picking up radio communications from 100 miles away. The power quality we were getting was not the cleanest. In the summer, lightning was taking a large number of proximity switches along with I/O blocks and fuses in the filter bank, and it was damaging our computer operating system, which became corrupted due to the constant noise and power fluctuations.* There is a radio station transmitting tower on one side of the drive, and the diesel APU would seek the radio frequency instead of the magnetic pickup frequency, causing the lift to surge and droop. Discovering the sources of these problems and their solutions required much research. We consulted with people from diverse fields: power quality experts, grounding experts, surge protection people, consultants who worked with NASA, lift specialists with years of experience and radio communications professionals.* 1 Lift Maintenance Manager, Angel Fire Resort, NM Page

40 Ultimately, though, it was the Angel Fire Lift Maintenance and electrical department that had to sort through all the data and come up with solutions. And these proved to be as complex as the problems. Exorcising the Demons Starting from the ground up, we looked at grounding and bonding. We installed a ground loop around the top and bottom terminals and bonded together through all the towers. This eliminated any potential differences and gave all the noise we were picking up a place to go. This also helped with the lightning in the summer. Surge protectors and filters were put on all incoming power, including the power to the battery chargers for the control circuits. We also put protection at the end of our power rails on the towers. The power line was buried, and the top one third diverted away from the lift. We went through all bonding and tried to equalize all potential differences. A new operating system was installed that did not require top to bottom I/O links.* We also installed Franklin rods on all the towers to divert lightning away from the proximity switches. We discovered that the haul rope needed to be grounded at all times, especially in the summer when trying to unload the lift with severe weather approaching. This was achieved by putting grounding studs in the bullwheel at the return and grounding brushes at the drive. The fix was not perfect, but lift downtime was dramatically reduced in both summer and winter. We no longer lost proximity switches and other components due to lightning. We were also able to reduce the weather window. Before we completed our fix, lightning 40 miles out would fault the lift. Last summer a tower took a direct hit and the lift stopped but reset immediately, with no lost components. Our equipment was also protected when the local Power Company decided to drop the power to both our quads this past winter, without notification. The same occurrence two years before took out blower motors and other 480 VAC equipment. The faults on the operating system were reduced to nuisance faults and did not cripple the lift. Lessons of Experience Our experience shows just how much lift maintenance has changed. Lift maintenance personnel are now required to be acquainted with more than just mechanical systems. They must also know electrical, electronics components, computer operating systems, PLC programs and troubleshooting, power quality, grounding, bonding, and the effects of environmental factors on lift systems. These environmental effects can be local, such as poor harmonics due to unfiltered DC drives, or global, such as sunstorm activity. And so the answer to the question posed back in the beginning is yes, for at least one resort we know of. Taos Ski Valley in New Mexico has an electrician so well versed in multiple disciplines that they did, in fact, hire a rocket scientist to apprentice with him. The resort management reasoned that only a rocket scientist would be able to replace head electrician Dan Craybill when he eventually decides to retire. Simply hiring another electrician even a very good one would not cut the mustard. 4 Page 16.4

41 The answers to modern lift problems are not cut and dried. They require eliminating as many detrimental factors as possible and taking a broad overview of the problem. Lift maintenance personnel can not let themselves get tunnel vision. Ultimately we cannot put ski lifts into a Faraday cage isolating them from their environment. The lift industry needs to begin to look at lift-specific environmental technologies. This will be a hard task, since most lift technology comes off the shelf from technologies that fit a wide range of applications. But we must find ways to adapt them for our purposes, and our extraordinary environment. 1. Space Environment Center- for real time space weather, alerts and forecasts. 2. MTI surge protection, Power QC power quality and grounding, Decker communications radio and other telecommunications. Leitner-Poma Mikel Carhart extensive lift professional. 3. Leitner-Poma operating system courtesy Mikel Carhart 4. Conversation with Dan Craybill Rocky Mountain Lift conference 2002 Page

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43 Lightning and Methods of Protection Stephanie Woodbury President Power QC, Inc. Page 17.1

44 Abstract: Lightning and Methods of Protection Stephanie Woodbury The importance of proper electrical site protection, including grounding theory, testing and design, different methods for earth grounding. Page 17.2