Frequently Asked Questions
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What is a restoration Tower?
A restoration tower, also called a transmission modular restoration tower, or temporary tower, is a tower designed to be erected very quickly to replace a permanent steel tower that has been damaged. When a permanent tower collapses, often caused by harsh weather or other natural catastrophes, power is disrupted and must be restored as quickly as possible. A temporary tower is used to replace the collapsed tower temporarily so that power can be restored without delay. After the damaged tower has been repaired, the power lines are transferred to the new structure and the temporary tower is removed and placed back into storage until it’s needed again. Designed for emergency work, a restoration tower can also be used for regular maintenance of towers and high voltage conductors as well, avoiding the need for cranes and other expensive equipment. A restoration tower is slim and lightweight but is structurally very strong. Supported by only a few guywires, a restoration tower can reach exceptional heights and hold very heavy loads in extremely demanding weather conditions.
Why do I need a restoration tower?
By having a restoration tower on hand, you will be ready to respond to a power outage emergency on a moment’s notice so that your customers’ supply disruption will be kept to an absolute minimum. This will reduce your revenue losses and penalties and will improve level of service reliability to your customer base. The restoration tower is also a very versatile everyday tool, making scheduled maintenance work faster and easier and at lower cost.
What does a restoration tower consist of?
The Tower Solutions restoration tower consists of four principal components.
- Foundation plate on which the tower rests
- Articulating base that permits free movement and distributes load evenly
- Tower sections that make the column of the tower
- Attachment plate for connecting insulators and guywires to the tower.
In addition to the tower itself, there are specialized tools that are used to erect the tower. These include the following.
- Gin-pole, used to hoist tower sections up and down the tower
- Pivoting lever, used to raise the first tower section from the horizontal to the vertical position
- Pionjar, used to drive pinning rods into the ground to hold the foundation plate in place
- Rod extractor, used to remove the pinning rods from the ground after removal of the tower
- Capstan winch, used for hoisting tower sections
- Alignment tool, used for holding adjacent tower sections in position while being joined
- Fall-arrestor, a travelling safety device that securely tethers the line worker to the tower
In addition to the erection tools, Tower Solutions offers a number of tools that make working on the tower easier.
- Extendible working platform, used for installing insulators when working out from the tower at conductor height
- Lineman’s step, makes standing on the tower easier on the foot when working at one level
- Anchor testing tool, to verify the holding capacity of an anchor once it’s installed
How high can the tower reach and what load can it carry?
There really is no limit to how high the tower can be erected, because it can be supported by guywires as needed. However, a practical limit is reached at some point. The highest tower that Tower Solutions has erected so far is 70m in height, and the largest conductor to be supported so far is 4/0 MCM. The tower is adaptable to any load scenario ranging for conductors exceeding 1200 kV, in any configuration requirement, and in any weather conditions.
What configurations can the tower accommodate?
The tower system can be adapted to a wide range of configurations, including: • Suspension tower in Delta configuration • Suspension tower in Running Angle configuration • Anchor tower (for line angle between 30° and 60°) • Dead End tower (for angle >60°) • Chainette (for small angles) etc.
What equipment will I need to erect an emergency tower?
Restoration towers are very easy to erect and they go up quickly. Any conventional lifting equipment can be used. But if you don’t have any lifting equipment available, then your available manpower can do the job. A small crew of 4 people can erect a typical tower in half a day. The components can be carried to a hard to reach area, if necessary. The tower system includes tools that avoid the need for heavy lifting equipment, and everything is included in a 20’ container. Tower Solution supplies its tower system in a modified shipping container and all components are laid out in a pattern that makes retrieval very easy. An easy to follow erection guide makes assembly quick and easy.
How long does it take to install a tower?
Installation time depends on many variables, such as the location of the site, the terrain, the height, the number of attachments required, and of course the equipment and manpower available to do the job. However, on average, a typical tower of 30m height can be erected in 2.5 hours using a team of 5 line workers.
What are the towers made of?
The towers are constructed of structural aluminum 6061-T6, which gives the tower its high structural strength and durability. This material is also lightweight and completely maintenance free. Welding material is aluminum alloy compound 4043. Casting elements are aluminum 356.2-T6. Bronze alloy C954 is used for the centre of the articulation module, providing a low friction contact at the load bearing surface of the tower. The steel used for the articulation module adheres to standard G40.21-44W, equivalent ASTM A36/A36M – 93a4, and is hot-dip galvanized in accordance with ASTM 123-89a. Other steel parts are stainless steel SS304. Bolts used to connect tower sections are standard ¾” diameter (19 mm), or 5/8” (15.8 mm) type A325, HDG.
How are the towers anchored?
The tower can be anchored by any available anchoring system suitable for the terrain, as determined by your utility’s soils engineer. A detailed anchoring plan is specified by software which optimizes the installation parameters for any given situation, which includes guywire and anchor locations. Typical anchor types include Manta Ray, Anchor plate, Helical Anchor, Rock Anchor, and Concrete Block. Tower Solutions provides installation tools for installation the type of anchor that the utility might require.
How is the tower packaged?
Tower Solutions supplies its tower system in efficiently packaged containers designed for secure transport and easy unloading and re-loading. The container is a specially modified 20 foot “high-cube” sea container. The modifications are simple storage concepts that take maximum advantage of the available space inside the container and that make retrieval of the tower and its components easy, which can be vitally important during an emergency when time is of the essence. Two typical complete tower systems will fit inside a single 20’ container.
Can the tower be re-used?
Of course! The tower is designed to be re-used over and over, without limit. In an emergency, the tower can be quickly transported to the field and used to restore power, and then later returned for storage until the next time it’s needed. The tower can be used repeatedly, without concern for wear and tear or damage, provided of course that the product is not abused. There are no corrosion worries because the parts are made of aluminum or galvanized steel. Any parts that can be easily lost, such as nuts and bolts, are standard items available from any hardware supplier, so there is never any worry about replacing pieces that are easy to lose. The storage system makes sure that the tower always has a home so that it’s ready when you need it.
How much does a tower cost?
The cost of the tower itself is only one small part of the equation. In order to determine the true cost of a temporary tower, you need to take into account all the financial benefits of using such a tower, not only for emergency situations when rapid restoration of power can mean millions of dollars or lost revenues and penalties avoided, but also for regular maintenance activities, avoiding expensive equipment. The direct cost of a tower depends on its height, the guying attachments needed, and the tools that are requested for assembly. For a true cost assessment, the direct cost of the tower must be offset by the labour savings, and the dollar savings associated with foregoing heavy equipment charges, avoiding the cost of building access roads, the incremental revenue earned by connecting power sooner or avoiding a disconnection altogether, as well as any savings from avoiding disconnection penalties.
What about training?
Tower Solutions provide a comprehensive 10 day training program to every customer. This program includes both classroom training and hands-on field training. The classroom part teaches the basic design principles of the tower system and includes software training designed to provide the utility’s employees with an understanding of the optimization concepts behind tower design and the relevance of the design parameters together with the selection of values for those parameters. The field training part provides each student with practical hands-on experience with the tower erection process. An exam is provided at the end of the training session and a certificate is provided to each successful student.
Does the tower require any software?
The tower does not require software. However, software is provided that helps the user verify the tower configuration for every loading scenario that might be encountered, taking into account all the relevant parameters, such as weather, terrain, conductor type, span length, etc, in order for the tower to safely perform to its required duty. It is important that the utility have the means to quickly assess how these conditions affect the plan and configuration of the tower, as every tower installation is different. The software provides the means to do this in an efficient manner.
How many towers should my utility buy?
Tower Solutions will help you to determine your requirements, with a view to minimizing your overall cost burden. Based on the criteria for the applications to which the towers will be used, Tower Solutions will work with you to determine the optimum tower strategy for your needs, which will specify the configurations and numbers of towers needed. In most cases, a tower toolchest and strategy can be put together that will give you the system-wide assurance that you need while minimizing your acquisition burden.
We also keep an eye to minimizing the number of guywires and anchors you will need.
Do these towers comply with applicable standards?
Absolutely! The Tower Solutions temporary tower complies fully with IEEE 1070-95 standard for testing emergency towers in North America. This test requires that all the components of a temporary tower pass specified testing in controlled conditions in a testing lab. The tests include the following.
- Bending of Column
- Torsion of Column
- Compression of Column
- Combined Bending and Compression of Column
- Ultimate Strength Bending – Bolts
- Ultimate Strength Bending – Welds
- Test of Insulator Attachment
- Test of Guy Attachment
- Test of Bolt and Nut Ultimate Strength
- Test of Column Buckling
- Test for Compression of Gimbal
- Test for Gimbal Transverse Load
Tower Solutions’ tower is the only tower to also comply with IEC 60652 standard for testing emergency towers in Europe. This test requires that a complete tower pass specified loading conditions as a complete system in real field conditions, according to loading criteria specified by the client. The Tower Solutions tower has passed loading tests of 160,400 N.
Are the towers tested or certified before they are shipped to me?
The tower fabrication process is verified by a specified protocol for selecting components from the production line to test compliance to spec. Each tower is tested before it leaves the factory. The customer is always invited to attend the factory to witness the tests and a comprehensive report is included with each tower shipped. A certificate is issued with each tower confirming its fabrication standards and qualification to standards. All fabrication of tower components is carried out under ISO certification. A complete bill of materials is included as part of the shipping documents with every tower shipped to you. All mill certificates are made available for your inspection at any time. The Tower Solutions tower is also the only tower on the market that has undergone actual on-site testing in real conditions in the field.
What is the environmental impact of using the tower?
A temporary tower imposes a much smaller physical footprint on the environment than other alternatives. If the site is environmentally sensitive, you can avoid the need to use heavy trucks to approach the site as well as the need to build an access road. If needed, all parts can be carried to the worksite manually from any convenient staging area nearby in a less sensitive area. If the site is confined, you can use a smaller area. You can avoid the use of fuel-powered equipment altogether, relying purely on manpower to erect the tower. The tower itself is made of durable aluminum, one of the world’s most abundant materials, and it will last virtually forever. Even though aluminum is abundant, the tower itself is fabricated from less material than other alternatives, which reduces the strain on material consumption. Once you have the tower in your stores, you can use it over and over again without having to replace it.
What are some applications where a temporary tower is used?
- Emergency restoration of HV power lines following a storm or natural catastrophe
- Construction of a by-pass for damaged lines or for maintenance work
- Substitution of line sections for preventive or corrective maintenance
- Quick installation of electrical power lines during construction projects
- Temporary installation of electrical power lines to a mine
- Substitution of communication towers in the event of emergency or maintenance
- Substitution of frames or substations in the event of emergency or maintenance
- Meteorological towers for monitoring wind conditions
- Temporary towers for river crossings