|Ereksen Tower Listrik di area pegunungan menggunakan Ginpole|
What is ginpole?
GINPOLE (Ginpull) is a three-legged bar used to lift weights. Gin Pole can also be interpreted as "Tiangmas", which is installed at the top of a pulley and combined with a wire loop and a Winchi machine to pull the load / steel material on the tower.
In addition to tower structures, Ginpole is also used to lift loads on tall structures which cannot be reached by cranes, e.g. B. Place antennas on the towers and raise other tower segments during construction.Compared to cranes, the use of gin sticks is more practical and effective, especially in places inaccessible to cranes, e.g. B. in rice fields, mountains and other difficult areas.
Ginpole installationIn the initial phase, the lower end of the ginpole is placed in a flat hole or tied tightly so that it does not move, and positioned so that the upper end is above the object to be lifted. Then it is secured again with a distance of three or more mines so as not to collapse.The mine is also used to laterally move the position of the upper gin posts - which are controlled from below - so that it is always above the load to be lifted.Gin Pole consists of several segments (sections) which can be assembled, added or reduced according to the needs of use.Check out this video:
* video proses fabrikasi Ginpole / Ginpull
When making segmented towers, the gin bars can be removed, lifted and assembled into segments that have just been completed to lift the next one. This process can be repeated regardless of the height of the tower to be built, until the tower is installed at the top.
Ginpole usage app
|Gambar skema penggunaan Ginpole|
|Posisi penempatan Ginpole saat ereksen awal|
|Pengangkatan segmen tower menggunakan Ginpole|
|Pemasangan Ginpole di ketinggian|
The pictures show different types of ginpole / tiangmas in different applications in the field.
Note the pole-gin tower design mechanismIf you've ever built a tower, you may be familiar with gin sticks. The alternative to lifting the tower is to use force. I have done this many times, but only with reliable partners. This is not a recommended practice, even if it is common among amateurs. Other alternatives are usually expensive and inconvenient: cranes and helicopters (no sky hooks were found).
Instead of lending me tower-specific gin bars or producing them to raise my DMX tower, I decided to make simple gin bars that are a bit unconventional but suitable for the job. My reason is to avoid the need for welders (and the costs associated with parts and labor) and only for pleasure. Now I have one that is available for other projects.
|Tiang gin DMX direkomendasikan
Before we look at the gin pole itself, it will be very helpful to understand what we want to achieve. It is very important that it is a task that demands to lift heavy and large parts of the tower safely and effectively. Failure can cause serious injury or death, or at least damage to property.
Troops on the gin pole
If the tower section weighs 25 kg what is the force on the gin pole when it is lifted from the ground? The correct answer is not 25 kg.
When the tower section is in the air and doesn't move, and both sides of the rope are vertical, there is the same downward force on the side of the rope being pulled. This doubles the strength of the gin pole to 50 kg.
Additional downward force is required to move the part up. The greater the force, the faster the part rises. This force must also be supported by gin poles. Another consideration is acceleration: the force needed to change the speed up the tower portion: F = ma, according to Newton.
If you pull the rope hard enough (large acceleration force), you can lift yourself from the ground. What's even funnier is that the acceleration can break a strong gin pole. Never jerk hard on a rope; use gradual fluid movements when lifting the tower.
Vector, not scalar
As a physicist said, force is a vector, not a scalar. This means that the direction of the contribution force must be calculated for the calculation of the total force. You can't just add the quantities of X and Y together. If you let a part float in the air, the scalar net force is 25 + 25 = 50 kg, but this is only a valid value if the two forces act in the same direction.
Since you cannot easily stand directly under the gin bar when pulling the string, the total force acts in a different direction than that down. This not only emphasizes the gin bar, but also requires more scalar power (the force with which you pull the string).
When you pull the string, the gin bar folds in your direction. This creates bending stress along the gin bar and lateral pressure on the bottom connection between the tower and the gin bar. Since the tower section hangs vertically, the extra force that causes the pressure must come from you pulling on the rope. This means that you have to pull harder (extra force) in addition to the same force as the weight of the tower, so that the force that creates pressure when added to the weight of the tower is equal to the force of traction. Not only do they work harder, but they also pose a significant security risk.
If, at any time on the gin bar, the tensions exceed the elastic limit or divide. We don't want it.
Jika pada titik mana pun pada tiang gin, tegangan melebihi kekuatan luluh akan melipat atau membelah. Ini adalah sesuatu yang kita tidak ingin terjadi.
Let's assume that you stand where the angle between the pulley and the rope in your hand is 30 °. Just like in the guy station / wire calculation there are additional lateral force components for the 25 kg vertical force (downward). Scalar value is tan 30 ° x 25 = 14.4 kg. Tension straps on your hands therefore SQRT (25² + 14.4²) = 28.9 kg. When you pull the rope to lift the part (as discussed above) this value is even higher, like the lateral force.
In long poles, this force puts significant pressure on the pole and the attachment between the tower and the pole. Another way to look at the vector equation above is that the additional force of 3.9 kg (28.9 - 25) multiplies 3.7x the lateral force at the top of the gin pole of 14.4 kg. That is, if you stand some distance from the gin pole and you pull it hard, you can easily gain enough mechanical influence to destroy the gin pole, and all the chaos that occurs.
Another area of concern is where the bottom of the gin pole is attached to the tower (usually at two points). The upper attachment acts as a fulcrum for the lateral force of 14.4 kg on the pulley. If the two attachment points are 1 meter apart and the gin is 4 meters long, the lateral force at the lower attachment point is 4 x 14.4 = 58kg. This is in addition to 25 + 25 + lift + vertical acceleration forces.
Bottom line: stand as close to the tower as possible when lifting the tower part manually with gin, and wearing a hard hat. Pole Gin can and does break. Don't turn yourself or your friends into statistics.
The main components to be selected in each gin pole include:
- Postple: More than anything else, the strength and weight of the gin pot determine. Steel cylinders (pipes or tubes) ensure an optimal balance between strength and weight. The wall thicknesses and the possible heat treatments determine the limit point. The longer the bar, the stronger the pressure. It must be long enough to be securely attached to the tower and high enough to place the pulley at least above the center of gravity of the raised part.
- Pulleys: Pulleys must be labeled with their resilience. Unrated pulleys should be avoided. For work on a light tower, the row must be at least 100 kg. However, avoid the pulleys of a row lower than 150 to 200 kg. I recommend avoiding one with a central shaft riveted to the case. The axle must have large flanges and / or clips on the outside of the housing body which cannot easily break or wear out. Make an appropriate match with the diameter of the rope you will be using.
- Fixing supports: like the other components, the fixings must transport all the loads on the gin bar. Since the supports are at stress points, the mast can break in the supports if not properly assembled, causing the post to break or bend. The supports must also ensure that the gin bar cannot be separated from the parts of the tower structure on which it rests, that the tower in the tower can support additional loads and does not need more than two hands (!) To position the gin bar and to secure the gin posts.
- Belt: adjust the diameter of the rope and pulley, but make sure that the force of the rope's workload is at least twice the force (4x the weight of the heaviest tower section) . If the rope is too small for the pulley, the rope may get caught between the wheel and the house. It should not happen. From experience, I can assure you that it is difficult and dangerous to release a rope from a roller that keeps part of the tower above you and out of your hand.
- Light enough to be safe and simple enough to be moved by one person in the tower, with optional ground crew support. I usually do this kind of work with at least one other person, but I decided to design equipment and processes in this case so that I could raise the tower as a challenge for me.
- Support all calculated forces with a large safety margin.
- Easy to build or at least included in a comfortable budget.
- With all of the above thoughts in mind, I made a gin bar for the DMX tower. It is illustrated on the right.
- I use the existing equipment to reduce costs because I do not know if it will be reused except to eventually overturn this tower. A 7.5'18 gauge fence was used upside down instead of the bottom of the version 2.0 I antenna mast for VEE. 4 inch aluminum protractor, mounted at the top with muffler clamps. Pulleys attached at the top on the side facing the tower. The total length is 10.5 '(the photo perspective changes the ratio of the visible length between the stick and the angle).
- Above, a close-up view of the pulley attached to the angle bearing. It weighs 200 kg and is available from Canadian Tires (from all locations) for $ 7. It offers space for ⅜ "and ½" straps without attaching. The pulley installation has enough free shaft to meet the load. It must rotate so that the rope extends and retracts in the plane of the wheel when the load moves. The movement prevents the rope from being pinched between the frame and the rod or the pulley from turning and twisting on both sides of the rope.
- The 5/16 "class hardware is used to tighten the pulley and the two tower supports. I use the ⅜" nut as a pulley spacer and leaves room for the support to grip and rest comfortably on the supports turn X can. The rectangular pieces are made of galvanized steel, thick-walled construction supports that hold the X wire between the bar and the supports.
- I don't weigh the gin bar, but it's very light. I can handle it on the tower with one hand.
- There is an important difference between this gin bar and the design recommended by Wade (Delhi) (see previous photo). The "official" gin mast uses two vertical bars in each support that surrounds the base of the tower and rests on the X supports on both sides of the base. Mine uses a vertical bar in each support and this corresponds to the bottom of the X wire on the left side of the tower surface. This is important because the distance between the X wires in the DMX tower is not constant and varies between 36.5 "and 37.75" for the one measured. Consequently, generally, only the upper support of the two models of gin pole rests on the support X (the support measures 36.5 inches), and therefore the lower support can move laterally. In the official design, the feet of the tower prevent this movement. Since the free support must be attached to the tower so that it does not rotate, I use a heavy rubber lashing for $ 2 which can be easily installed and removed with one hand.
- Another difference is the total height of the gin bar. The official design measures 15 feet tall to see the tower from above. This is not absolutely necessary since the tower should only be removed from the center of gravity. This allows for shorter, lighter and more resistant devices for the same thickness of steel. So instead of the recommended 16 steels, I can also use 18 gauge steel. However, the workpiece continues to deviate from the vertical and must be turned manually if it falls on the ground.
The construction of the security tower is dangerous. You can be killed or seriously injured if you are not careful for a while. It's stupid to build your own tower without experience. Do not do it. Gain experience working with others on a tour project before starting a solo.
That said, here are some security concerns that are relevant to this project.
Have a plan for emergencies. If something is broken and things have fallen, are you standing in a safe place? If obstacles arise in the air, do you have a way to secure everything when you provide a solution? Do partners near you watch over you, and help if necessary? Have you brought a telephone in case you can't move and need to ask for help? This is an uncomfortable thought but you have to think about it before you start. This applies to all tower work, no matter how many people are involved.
- If you have someone who helps you, do you trust them? If you tell them "do this" or "don't do that" will they listen and obey? Equally important, will you take direction when someone points out an error in your plan or execution? Learn to listen to what other people say to you. Stubbornness and arrogance can kill.
- Wear certified hard hats and sturdy shoes when you are under heavy equipment, tools, dangling tower parts, etc. Many do not save you from injury but the injury will decrease, and you can live a little longer.
- Test your equipment before starting. Look at the forces described earlier and then, with the gin pole near the ground, lift a few weights at close range, and try at various angles of the rope. Do this even with equipment that is borrowed or purchased, not just for (as in my case) homemade equipment. For one test, because I weighed 55 kg, I was able to make a 2x + gin pole of the weight of the tower by grabbing both ropes and lifting myself off the ground.
- If you must climb the tower while the tower is in the air, keep your body and hands away from the gin pole and climb to the side of the tower that is not under the tower.
- Plan, don't improvise. Know exactly what will happen, what to do when the wrong thing happens, and describe all the tools and parts that are needed where you will need it. Clean after that.
- Use rope cleats on or near the tower to easily secure the load with one hand and without the knot. I usually lock the shoulder-high cleats on my own tower.
|Aman di luar sana|
To close this article, I will post another photo. Above, you can see the third part (DMX-4) suspended in the air and ready to climb and lock it. Lifting straps are attached to the posts and then attached to the tower for redundancy. I had to climb the tower once when I raised it when this part was taken by a temporary rope. My homemade equipment works well.
The tower section is now attached, the bolts are moved to specification and the first group of people is attached to the "ugly" guy post. The people are not in final tension, but they have been adjusted to bring the tower into good vertical alignment. Now there are 3 games (U-turn) and another male station.
Lifting and fixing the tower takes only 30 minutes, including the time required to remove it from the human rope. It took me another 90 minutes to climb and hug people and dive into the tower.