Selecting the right Communication Tower We sell, supply and install three different types of communication towers:1. Self-supporting towers 2. Guyed towers 3. Cantilever mounted towersIn general, towers are constructed out of solid round steel bars, welded together in 10 ft or 20 ft sections or they are constructed out of angle iron. In some cases, the diagonals and horizontals are bolted to the tower legs while other towers use only solid-weld connections. Some light duty towers are riveted, built in 8 ft sections which are then bolted together. Some towers are erected by crane or boom truck, others by employing the gin pole method where each section is raised individually. In some remote areas or on mountain tops towers need to be erected by helicopter. Light-duty towers can at times be erected in their entirety if the base is hinged. We have successfully installed towers using all of these methods. We deal mostly in towers that are hot-dipped galvanized after fabrication. These towers can be painted upon request. Not all towers need to be built according to CAN/CSA-S37-M94 in order to be safe and reliable. Towers are designed by identifying safe antenna loading, kip-shear values, torque values and other physical parameters which are indications of specific environmental parameters such as wind speeds, radial ice and others. You will need to provide answers to the following questions so that we may quote you the right tower:
- What is the required height of the tower?
- How many antennas of what type have to be mounted where on the tower?
- What is the azimuth of each antenna?
- What type of transmission lines will be used?
- Is the tower going to be rooftop or penthouse mounted, will it be installed in a city, field,
- forest or mountain top and is it guyed or free-standing?
- Is enough space available to use a guyed tower assuming that the guying radius is about 3/4 of the tower height?
- Does the tower have to conform to CSA-S37-01?
- Does the tower require a fall-arrest system?
- Are tower lights required?
- Does the tower require painting or other obstruction markings?
- Is safety a concern? Is a fence or an anti-climbing shield required? and we will also need to know the following:
- Where is the tower site located?
- Is the tower site accessible by 2-wheel drive vehicles?
- Is the site accessible to commercial cranes and commercial concrete mixers?
- Are the results of a recent geological survey available?
- What is known about the ground and water table?
- Are hydro lines or other obstructions near by that need to be considered?
- Have the utilities been notified regarding buried cables and pipes?
- Does the excavated material of the tower foundation have to be hauled away?
- What is the expected completion date of tower installation?
- Are wave guide bridges required?
- How far is it from the base of the tower to the communications room?
- What restrictions are there with respect to noise and working hours?
Cantilever mounted towers are usually the most economically priced but they have some inherent limitations: A strong wall is needed for mounting the tower and the tower height is often limited to 60 feet. Guyed towers require enough space for the guy cables and a provision for mounting anchors - this could be a problem, especially for rooftop mounted towers. As a general rule, the smaller the guying radius, the stronger and heavier the tower when maintaining tower height. As the guying radius decreases, the cost increases. A guying radius of 2/3 to 3/4 of the tower height is usually optimum but lower ratios can also be used.
Self-supporting or freestanding towers require the least amount of space for their height but are generally the most expensive. A freestanding tower needs a very solid foundation. This can be a concrete footing or the tower can be anchored into the ground via rock bolts. In either case, the cost for building and/or preparing the footings can exceed the cost of the tower. In many cases, no thought is given to future expansion when a tower is selected. It is expensive to reinforce and upgrade an existing tower that has exceeded its loading capacity. It is best to anticipate additional antenna loading at the beginning when a tower is selected to save money later on. We look at wind charts to identify the maximum expected wind velocity in your area. Ice-loading has become an even greater concern after the ice storm in January 1998 and radial ice build-up is a serious concern. In some cases where towers are installed near smoke stacks or within the wind direction of industrial pollutants that contain a high sulphuric content, additional tower protection should be considered. This is to prevent the tower's breakdown of its zinc coating with subsequent formation of iron oxide.
FALL ARREST SYSTEM Accidents on communication towers are often very serious in nature. One way of reducing life threatening injuries caused by falling is by way of safety rail, ladder or safety cable that runs down the entire side of a tower. Depending on height of tower and location, a fall arrest system might be a mandatory code requirement. Please contact us for a fall arrest system that is within your budget and meets C.S.A. compliance or other code requirements. TOWER & TRANSMISSION LINE GROUNDING This is a much disputed science but everyone agrees: Proper grounding is vital for system survival and public safety. At a minimum, all towers should be grounded via copper cables and/or grounding rods/grids and transmission lines should be grounded every 150 feet, before they enter a building and whenever the bending radius approaches 90 degree. This applies to all towers,whether installed in open areas or on roof tops. Lightning arrestors/suppressors are installed before the transmission line connects to the transceiver and various types and models are available. One of their functions is to prevent excessive static discharge from destroying the front-end of your receiver. We sell various types and models. Please specify frequency when ordering same. These are but a few of the considerations that need to be addressed before we are able to quote on a tower that is right for you.
PERMITS
The kind of permits that are needed for the installation of a tower depend mostly on height, location and application.
- Some municipalities require building permits for any tower that is installed on an existing building;
- Some municipalities require a building permit for any tower beyond a certain height;
- Some municipalities recognize that telecommunication towers may be erected without municipal approval since they are federally regulated and thus, are not subject to the Building Code Act, however, since January 1, 2008 Industry Canada requires the written support of the local Land-Use Authority (LUA) before approving the installationm of a communication towers.
- Transport Canada should be contacted for an Aeronautical Obstruction Clearance Form, subject to the Canadian Aviation Regulation s (CAR). This is also the governing authority that determines as to whether or not lights, beacons and/or other markings are required on the tower;
- You may want to contact Industry Canada to ensure compliance with environmental spectrum management concerns, etc. This applies mostly if your tower is tall and/or antennas are transmitting at a high effective radiated power (ERP).
- It is imperative that the installation of antennas on towers, roofs or any other structure is in compliance with the provisions set out in Health Canada's SAFETY CODE 6;
You need a well designed tower that is is affordable, provides many years of dependable service and can accommodate the type and quantity of antennas that are needed today while anticipating future expansion. The kind of permits that are needed for the installation of a tower depend mostly on height, location and application.
- Some municipalities require building permits for any tower that is installed on an existing building;
- Some municipalities require a building permit for any tower beyond a certain height;
- Some municipalities recognize that telecommunication towers may be erected without municipal approval since they are federally regulated and thus, are not subject to the Building Code Act, however, since January 1, 2008 Industry Canada requires the written support of the local Land-Use Authority (LUA) before approving the installationm of a communication towers.
- Transport Canada should be contacted for an Aeronautical Obstruction Clearance Form, subject to the Canadian Aviation Regulation s (CAR). This is also the governing authority that determines as to whether or not lights, beacons and/or other markings are required on the tower;
- You may want to contact Industry Canada to ensure compliance with environmental spectrum management concerns, etc. This applies mostly if your tower is tall and/or antennas are transmitting at a high effective radiated power (ERP).
- It is imperative that the installation of antennas on towers, roofs or any other structure is in compliance with the provisions set out in Health Canada's SAFETY CODE 6;
- Click here for more information
