More than ever, margin pressures are necessitating that grading work be completed with as little wasted time as possible, yet as safely and with as little disruption to “job-site neighbors” as possible. An example that is in the public eye more than most construction is highway work, which is increasingly taking place at night and on tight schedules so as to minimize the inconvenience to neighbors (read motorists). Of course, the unstoppable force of progress is running into the dual immovable objects of the need to keep the public safe and to keep crews working productively.
Artificial lighting and auxiliary job-site power are two of the most mission-critical items on a remote nighttime job site. Manufacturers of this equipment would tell you that, despite their importance, contractors spend the least amount of time selecting and maintaining this equipment. That should not be the case, with manufacturers offering more choices in lighting quality and power capacity than ever. In buying and renting decisions, the contractor may opt to focus on lighting or auxiliary power as separate entities, or combine these items in one piece of equipment.
Lighting Coverage, Quality, Portability Stressed
The SHO-HD lighting system from Allmand Bros. is designed to provide increased brightness and whiteness of light for better visibility and greater coverage. The system is now standard on the company’s Maxi-Lite Series and Night-Lite Pro Series portable light towers.
The system utilizes the company’s SHO parallel lamp fixtures and has 1,250-watt lamps and ballasts and produces 150,000 lumens per lamp, a 36% increase over the 110,000-lumen output of standard 1,000-watt lamps. This increase is said to light up to 45% more surface area to one-half footcandle or higher compared with 1,000-watt fixtures.
The system is also designed to increase lighting quality as it utilizes an enhanced color rendering index of 70 CRI and higher Kelvin color temperature of 3,954ºK, compared with 65 CRI and 3,700ºK for standard 1,000-watt lamps. The result, according to the manufacturer, is whiter light and improved color recognition for workers in night environments. The towers’ fixtures are equipped with “flex” mounting yokes and tip supports that help reduce lamp breakage.
Baldor Electric Co. has launched a new 30-foot light tower kit that is designed for portability and ease of assembly. It is compatible with the company’s TS35T towable generator, and assembly reportedly takes about two hours. Assembly consists of installation of the specially designed brackets and ballast box—with no need for drilling—and attachment of the self-contained telescoping light mast. The new light-tower kit reportedly provides 5–7 acres of light saturation.
A different concept in lighting is balloon lights, so dubbed because they utilize flexible shroud material that reduces glare. These fixtures are deployed at a lower height than towers—in locations such as on a stand, truck bed, or on construction equipment itself. These units are configured to produce intense, daylight-like light to allow precise, safe grading and paving work at night.
Airstar America’s Sirocco 2K is designed for 360-degree illumination without “hot points” and is said to allow workers to look directly at the unit without eye discomfort. The balloon contains two spring-mounted 1,000-watt lamps suspended inside a protective grid. This design reportedly allows the light to withstand greater vibration than competitive units, and the two-lamp lighting harness protects from blackout if one of the lamps should burn out. The quartz halogen lamps, which are available in most local retail outlets, are also interchangeable and available in different wattages for compatibility with any generator capacity.
The unit is equipped with the company’s safety system, which is designed to turn the unit off if the system encounters problems. Additionally, the units self-inflate, and when the balloon reaches 90% air mass inside the envelope, the pressure sensor disengages and the lights automatically turn on. The unit also is reportedly resistant to winds exceeding 60 miles per hour.
The units’ minimal glare and quick-deployment capability are becoming increasingly valued for nighttime highway work, says John Caldwell, project manager for APAC, Asheville, NC. “The majority of our work, particularly interstate work around Asheville, is night work right now,” he says. Caldwell estimates that he has purchased 12–14 of the units over the past two years. The units “give you a lot more coverage around the area and the [North Carolina Department of Transportation] likes it, especially because they can see a lot better behind and to the side for their inspection purposes. One of the biggest advantages is that you can set up one of these in five minutes. They’re great as far as putting the lighting right wherever we need it.”
Another balloon light, the Powermoon, has a similar general design. The difference from the Airstar unit is that it uses an umbrella-like mechanical open/close system, rather than a fan, to deploy the shroud. According to the manufacturer, the fixture allows the contractor to work in daylight-like conditions. The underside of the balloon distributes the light and the upper side is covered with aluminum for highly efficient downward reflectivity of light.
Reducing glare is something that Larry Owens, equipment manager, and C.R. Jackson, Columbia, SC, do for safety, not because DOT regulations call for it. “You get more [footcandles] out of the balloon-type lights because you can raise it up and it disperses the light more readily,” says Owens. “You get much less glare to the traveling public and you also give yourself better visibility because [drivers] can see you a lot better.”
Auxiliary Power Comes in Handy
A new line of XP portable generators has been designed for high performance, long periods of operation, and rough handling at job sites, according to Generac Power Systems, Inc. The gasoline-powered units have oversized full-wrap frame tubing and impact-resistant corners to prevent damage from rough handling. The three units feature the manufacturer’s OHVI Engine, which is designed specifically for generators and is said to last three to four times longer than competing engines. The engine can be operated on uneven surfaces, in contrast to “splash-lubricated engines.”
A control panel contains engine controls for ease of use and an hour meter is included to facilitate maintenance tracking. For safety, the generators are equipped with ground fault circuit interrupter (GFCI) protection to protect from overloading.
Three new conventional generators from Subaru—the RGX5100, RGX7100, and RGX7800—feature the latest models of EX series overhead cam engines. The generators are constructed of heavy-duty steel for durability.
The RGX5100 is powered by a 10-horsepower EX30 engine. The unit delivers a maximum output of 5,000 watts (4,200-watt standard output rating) and offers a continuous operation time of 8.3 hours. The RGX7100 has a maximum output of 7,100 watts (5,000-watt standard output rating) and provides 8.3 hours of continuous operation. The RGX7800 utilizes a 14-horsepower EX40 engine and provides a maximum output of 7,800 watts (6,000-watt standard output rating and can operate continuously for 7.5 hours.
The models have either a recoil or electric starting system. A high surge capacity reportedly allows the generators to take on up to 150% of the rated power for as long as 20 seconds. Each unit houses a large zinc-plated steel fuel tank and electric components that feature copper windings with high-temperature insulation. Solenoid-actuated AC circuit breakers provide overload protection and GFCI receptacles help ensure operator safety.
An automatic idle control, standard on all models, lowers the engine speed when no electrical power is needed to reduce fuel consumption while minimizing noise. Other standard features include an hour meter, low oil level sensor and shutoff, and low-tone muffler with a US Forestry-approved spark arrestor. Two-wheel kits are optional.
One common task on a job site requiring auxiliary power is welding. Eric Snyder, engine-driven welders product manager for Lincoln Electric, notes that grading and excavation contractors also involved in general contracting work often need to weld rebar, and the company’s Vantage 400 welding unit suits this type of work. The unit also provides 19,000 watts (peak) of three-phase or 12,000 watts of one-phase AC generator power for other equipment, such as lights, grinders, and power tools.
Snyder stresses that the 400-amp unit is designed for compactness because it is commonly mounted on a service truck and contractors are often concerned about their truck’s gross vehicle weight rating. When equipped with a four-cylinder 1,800-rpm Perkins diesel engine, the unit weighs 1,230 pounds, 1,245 pounds when equipped with a four-cylinder 1,800-rpm Kubota diesel engine.
According to Snyder, other differentiating features include standard a stainless-steel roof and case sides, a sliding engine access door for tight spaces in case the contractor truck-mounts the units, GFCI, a new sealed module to keep moisture out, battery access on the control panel side of the unit machine, a tilt-down panel from the control panel that provides easy access, and a latched cover for the radiator cap on the roof, which eliminates the need to loosen bolts.
By Amy Willson
Never Forget the Engine Job sites would be left in the dark without an engine to power the light tower. Undoubtedly the most important part of the tower, the engine also is the component that requires the most frequent maintenance to ensure it continues to run smoothly.
Start by always keeping the engine and surrounding components clean, because fuel and oil leaks can easily be detected as soon as a problem starts.
Additionally, begin each day with checking the oil level. It only takes a few seconds to check, yet neglecting this simple step can lead to engine problems and cause premature wear. Check the coolant level at this time, as well. Ensure that it’s at the proper level before starting the machine, since it’s dangerous to remove the radiator cap when the engine is hot. While inspecting the coolant system, inspect the condition of the radiator hose and look at the condition and tension of the fan belt. Replace the parts or adjust the tension as necessary.
Once the fluid levels have been verified, check the air cleaner for dirt and debris. If it needs to be cleaned, pull the filter element out and tap it on a hard surface to remove excess dirt. Never use an air compressor to force dirt from the filter, since this may tear holes in the medium.
Air-cleaner elements will need to be changed based on hours of operation and, more importantly, application. Adverse weather and dusty conditions will require more frequent replacements. Use care when changing the element, since carelessness can introduce the element’s dirt into the engine.
The oil and oil filter also need to be changed regularly. Light-tower power units typically require oil and filter service every 200 to 300 hours, but check the owner’s manual for specific service recommendations. Always refill the system with the correct grade and type of oil as recommended by the engine manufacturer.
The fuel system needs to be inspected regularly and serviced, as well, again depending on manufacturer guidelines. Check for leaks daily and replace the fuel filter as recommended. Each year, take time to drain the fuel and clean sediment from the tank.
Rest of the Package Although the engine requires the majority of a light tower’s maintenance checks, other components also need regular care. A quality generator in a light tower typically requires little maintenance and provides years of service. However, it is important to occasionally check the output voltage and frequency of the generator. If the voltage and frequency are not as specified by the manufacturer, typically 120 V at 60 hertz, the rpm of the engine should be adjusted. The rpm directly affects the voltage and frequency of the electric power produced. Operating the light tower with voltage too high or too low can lead to lamp and electrical component failures. It also is important to keep the generator clean and inspect the wiring for damage or loose connections.
A light tower’s electrical system also should be inspected and checked for proper performance. The components used for the typical metal halide lighting system are designed to provide dependable operation. However, it will only function correctly if the components, wiring and connections are undamaged, clean and secure. Visually examine the system regularly, checking for damage and loose connections.
Warning: Light towers contain high-voltage circuits capable of causing serious injury or death. Only a qualified electrician should troubleshoot or repair electrical systems.
Other components of a light tower that are critical to its function are the tower and lighting fixtures. Most towers consist of multiple telescoping sections that are extended and retracted as required to position the lights. The towers typically consist of steel tubing sections operated by a manual or electric winch, cable, and pulley system. All components of the tower system should be inspected and tested for correct operation. Cables can be worn or damaged and should be replaced before operation. The erecting winch also should be inspected for damage and serviced as recommended by the manufacturer. If designed for mobile applications, light fixtures typically require minimal service. Inspect the fixtures, along with the wiring, for physical damage and function.
As with any trailer-mounted products, the towing hitch, trailer lights, and running gear need to be inspected. Look for loose, damaged or missing parts. Check that the stop, turn, and brake lights are functioning. Be sure the tire condition and tire inflation pressures are correct according to the manufacturer’s recommendations. Stabilizing and leveling jacks and outriggers are unique features that need to be inspected for proper function. Repair or replace the jacks and outriggers as necessary before raising the tower.
One often overlooked but critical part of a light tower is the instruction and warning decals placed on the machine itself. The manufacturers install decals with information on proper and safe operation. A routine inspection should always include a review of the decals, ensuring that they are in place and readable. Manufacturers also provide operation manuals that are intended to stay with the product for correct operation and maintenance. A manual is not going to provide critical information required to operate and maintain the light tower if it is in buried in a desk drawer.
In addition to performing the recommended maintenance, selecting a quality light tower from a manufacturer with high-quality components will ultimately provide the most dependable performance. Although there are low-cost, low-quality components available, they may not provide the best choice when the light tower is being counted on to provide the light on a construction site or event.
In short, spending a little more money up front will pay dividends over the life of the equipment, especially in the harsh reality of the rental industry.
Preventative checks and services aren’t something to make light of. A few minutes a day and some recommended maintenance could add hours and years to a light tower’s existence. While there is no documented life expectancy for a light tower, well-built, well-maintained towers will certainly have the best chance of providing the highest level of dependability and performance. Regular, scheduled maintenance will bring light towers out of the shadow of equipment that can’t hold a candle to the towers’ lengthy service life.
Lighting Units Provide Useful Auxiliary Power
Several manufacturers promote the auxiliary power—in addition to illumination of the job site in low-light conditions—that their lighting units provide.
The ML 30 EX is Allmand Bros. Inc.’s latest addition to its Maxi-Lite portable light towers and provides up to 30 kW of available power, an increase of 10 kW from the manufacturer’s next-largest unit. The unit’s 135-gallon fuel capacity provides up to 135 hours of run time without refueling.
Utilizing SHO-HD 1,250-watt parallel lamp fixtures, the unit produces up to 150,000 lumens per lamp, a reported 36% increase over competing light towers. An optional Saf-T-Visor attachment directs previously wasted light onto the worksite. A modular engine/genset, designed to simplify engine/generator removal or changeout, is standard. Other standard features include a hinged ballast panel requiring only removal of two bolts for full access and a captive latch on the tower support and outriggers that eliminates the potential for lost pins. Optional inside lamp storage for both four- and six-light models allows for better security of the lamp fixtures when the lighting system is not in use.
Manufacturers indicate that the recent nationwide trend toward nighttime highway construction work is increasing the demand for lighting and auxiliary power in one unit. “Right now, there isn’t a great deal of new road construction, but there is a lot of maintenance work on roads and bridges,” points out Rachel Luken, product-marketing manager with Doosan Infracore Portable Power. “Therefore, you have a lot of existing traffic moving through and your space is limited. So if you’re able to get a light tower with supplemental power to power any other tools, heaters, or tripod lights, for example, the need for an additional piece of equipment, like a generator, is eliminated. With one machine instead of two, you have a smaller footprint, less maintenance to worry about with one diesel engine to worry about, and there’s just the lower overall cost of ownership—you can get more with less now.”
Doosan has the Ingersoll Rand L20, a combination light tower and mobile generator designed for use on job sites where no reliable power source is available. The 20-kW generator powers the lighting system, consisting of four 1,000-watt metal halide lamps, and provides power to several receptacles. While the lighting is in use, the unit provides up to 63 amps at 240 V and 126 amps at 120 V. When the lighting system is not in use, the generator can output up to 80 amps at 240 V and 160 amps at 120 V.
The unit suits the grading and excavation contractor, who often is first on the job site and needs to supply auxiliary power for the job-site trailer because no local power source is available. The L20 is actually designed for rough terrain with an axle rating of 3,500 pounds. Luken adds that the unit is designed with wide, strong running gear and a center-mounted engine to increase stability on rough job sites.
Other features include controls centralized on a front panel, which has a protective coating to prevent debris contamination and corrosion; power load protection against surges; and rectangular, reflective cast aluminum fixtures with horizontal bulb positioning for greater light distribution.
An example of an L20 application where a local power source is not available is ongoing construction of a junior high school building in Drayton Valley, AL, Canada by Marshall-Lee Construction Corp. of Spruce Grove, AL. Construction began fall 2008, scheduled to be completed in March 2010. Due to the bid process, Marshall-Lee needs to be flexible and build through the winter months, when construction typically is light or suspended. As a result of the scheduling, Marshall-Lee commonly uses equipment such as ground thaw heaters, propane heaters, and because a local power source is unavailable, light towers also must be used during the short winter days.
The light and power combination provided by the units rented from 4-Way Equipment Rentals in Edmonton, is very helpful in these conditions, says Dave Somerville, construction manager. “You have to make concrete work and things of that nature effective during the course of what would normally be daylight hours, so you need auxiliary lighting.” Also, “we sub out a lot of our foundation and concrete work, so we are responsible for providing safety and task lighting to certain subcontractors—it’s built into our contracts.”
Somerville recalls that Marshall-Lee used some light towers with lower auxiliary power capacity at first and experienced problems. When equipment with high power demand was plugged into these towers, they routinely went down due to overloading, he says.
“A lot of times we’d be using a [circular saw] and we’d get stuck in a piece of wood that was either wet or a bit hard and we’d blow the breaker. We’d have to go all the way back to the light tower and push the breaker back in—that’s dead time to us. We haven’t experienced that kind of thing with the larger unit.”
The new TML-4000 light tower from Genie Industries uses galvanized steel for the mast, control box, ballast boxes, and outriggers for corrosion protection. The unit also has standard 120- and 240-volt outlets to accommodate both hand tools and equipment demanding a larger power draw. The unit provides 1.6 kilowatts when all four lights are on and 6 kW when the lights are off.
The light fixtures and ballasts are equipped with quick-disconnect fittings to facilitate routine maintenance. The ballasts are also numbered and interchangeable, eliminating the need to remove the covers or use specialized electrical tools during maintenance. Horizontal, square aluminum lights feature Quick Aim horizontal and vertical light casing adjustments and each of the four lights can be individually adjusted. The horizontal mountings disperse light more widely, although in a shorter beam than vertical mountings. Quick-deploy outriggers allow deployment of the unit on tilting surfaces.
Another Genie light tower, the AL4000, extends to a height of 30 feet and provides 4,000 watts of light to illuminate up to 7.5 acres. A single winch system with an ergonomically positioned handle is incorporated for easy raising and lowering. The stowed width and length are 5 feet, 2 inches and 14 feet, 11 inches, respectively.
Branch Manager Bill Fewless and outside sales representative Carl Openshaw of ESCO Supply, Billings, MT, report that a large grading and excavation contractor customer—Riverside Contracting Inc., Missoula, MT—rents AL4000s due to their ruggedness and reliability. Particularly useful features of the unit that lend themselves to productivity, Openshaw says, include a photo cell option that starts up the unit at sunrise and shuts it down at dusk, and the electric winch.
New wide-body LTW series light towers from Wacker Neuson combine job site lighting with power up to 20 kW in a heavy-duty steel frame. The light towers feature a wide track width, independent torsion axles and a heavy-duty tongue-and-hitch assembly to accommodate off-road towing. Equipped with large, 60-gallon fuel tanks and simple engine controllers with various fault protections, these units are designed for illuminating and powering remote and/or long-run applications.
The series of light towers consists of three models. The LTW 6K has a 6-kW generator and 13.1-horsepower Kubota diesel engine. The LTW 8K has an 8-kW generator and is powered by a 15. 2-horsepower Kubota diesel engine. The LTW 6K and LTW 8K have 2-12-V, 20A Duplex GFI and 1-120/240V, 30A twist locks. The LTW 20Z1 has a 19.2-kW generator with a 35.4-horsepower Isuzu diesel engine; power equipment and specs include 4-120V, 20A Duplex GFI, 2-120/240, 30A twist lock and 1-240V, 50A California.
The company notes several features of the series. These include a 30-foot adjustable tower that rotates 360 degrees, elliptical light fixtures that provide diffused and even illumination without glare, storage of the lights inside the unit for added security and convenience, a heavy-duty steel skid for protection from road debris, and multiple power outlets. Full length, 11-gauge steel doors are used for maintenance accessibility and a mast-mounted base winch provides operator ergonomics and easy operation by allowing the operator to raise the mast without bending.
By Doug DahlgrenGary Johnson could not have foreseen 25 years ago that a routine equipment purchase would still be paying off after all of these years. Light towers can last indefinitely, but seeing the proof and benefiting from it made Johnson a believer.In 1981, Johnson purchased two Allmand light towers for his Fort Pierre, S.D.–based highway heavy contracting business, AGE. At the time, AGE was doing a large-scale earth moving project at the Black Thunder coal mine in Wyoming, working in shifts around the clock. Johnson decided he was tired of renting the equipment whenever he needed it and “having nothing but a receipt to show for it” when he was done.AGE decided to buy the light towers used, and picked up two relatively new models, manufactured in 1979 and 1981. Between the work at the mine and highway work late in the construction season, Johnson decided the investment was worth it, especially after a little encouragement from his crew.“There is enough potential for accidents even in natural daylight, and when it starts to get dark it increases dramatically,” Johnson says. “My crew had worked for people that didn’t have light towers, and loved them. Like they said, it beats the heck out of using a flashlight.”Perhaps most impressive is that in addition to the hours of use the light towers get at AGE, they also see added work when Johnson rents them out. Despite this grueling schedule, Johnson says his maintenance responsibilities are almost nonexistent.
“After years of sitting in all kinds of weather, we have had to replace cords a few times,” Johnson says. “Other than that though, in 25 years we haven’t done anything but oil changes and bulb replacements, very basic maintenance.”
Johnson says it’s hard to believe that the light towers have been part of AGE longer than his sons, Gerad, 23 and Andy, 20—fourth-generation employees of AGE — have even been alive. And, he says, the towers still work like they did back in 1981.
For the time being, just two light towers fulfill AGE’s requirements, but Johnson says he wouldn’t hesitate to purchase an Allmand tower again if he needs to expand, or when his current light towers finally wear down—if they ever do.
