Basic Types of Road Work and Work Site Lighting Systems|
Article- Oct, 2013 By Larson Electronics.com
Larson Electronics Mobile Light Tower
Because working during nighttime hours offers the advantages of reduced traffic volumes and reduced impact on nearby businesses, maintenance and road crews have tended to shift operations towards these hours on an increasing basis. Working at night does present some challenges not normally present during daytime hours however, in particular the need to illuminate the worksite at high levels in order to maintain safety and productivity. There are a whole slew of considerations to be taken into account when putting together a plan for illuminating a night time work site, and here we’ll look at some of the options that have proven most popular.
The main goal when setting up outdoor work site lighting is to provide a high enough level of illumination to allow workers to perform their duties in a safe and efficient manner. Secondary considerations include keeping the effects of this lighting on passing traffic and nearby residences as low as possible and finding ways to provide power for this illumination independent of any local power sources. Considering the fluid nature of road way construction and the need to keep illumination targeted on areas being actively worked, this can be a serious challenge indeed.
One of the first things those charged with setting up site illumination need to do is consider the level of existing illumination that will be present. Street lights commonly provide a significant amount of light that can be taken advantage of when setting up illumination, and savvy operators will choose and deploy their lighting systems accordingly to make the most of these light sources. Other light source such as nearby parking lots, sports fields, residential areas and the like can provide some measure of ambient light, but in most cases the level of light from these sources is negligible and not worth much consideration.
The most common and popular lighting systems used during road work operations are portable light towers. Powerful and capable of providing their own power with onboard generators, these lighting systems can be used to illuminate sites ranging from a few thousand feet in size to sites covering over three acres. Light towers come in a wide variety of sizes and designs, with smaller towers being designed for easy transport and setup and requiring an external power source, and fully contained units including masts reaching over 20 feet in height and generators producing thousands of watts mounted atop a wheeled chassis intended for towing behind vehicles.
Gaining in popularity are equipment mounted lights. Lights mounted on equipment have the advantage of being able to tap into the electrical system of the equipment being used as well as moving as the equipment is moved, thus always providing well targeted light on the work area. Halogen and metal halide equipment lights are currently the most commonly used types, but LEDs are gaining in popularity due to their high power and low energy requirements which makes them less of a drain on the battery and electrical system of vehicles and heavy equipment.
Flagger lights are usually a small tower design that is intended to brightly illuminate flag operators as they manage the flow of traffic through and around the work area. Due to the critical nature of a flagger’s job and the high concerns with safety, these small towers need to provide high intensity and high light quality to produce maximum visibility of the operator. Portable and collapsible battery powered towers equipped with high output LED lamps are becoming quite popular for this task as they can be easily transported and moved as needed and run for many hours without any loss in intensity.
Some of the problems that must be considered with all of these lighting systems include properly positioning the lights for maximum coverage of the work area and dealing with the glare that can potentially blind drivers in oncoming traffic as they approach the work area. In most cases, mounting the lights as high as possible, particularly in the case of light towers and directing them at a downward angle can help alleviate the problems with glare quite a bit. For very powerful towers with multiple metal halide fixtures, using lamp assemblies fitted with directional shields and hoods is often necessary in order to contain glare while still providing sufficient illumination to the targeted areas.
Equipment lights can also present a glare problem if not properly mounted and positioned. Lights mounted low on equipment tend to be the worst offenders for glare, and if aimed outwards will likely waste more light than this used. Equipment mounted lights usually are intended to illuminated the area directly around the machinery, and so do not need to have long range and are better suited producing output in a flood rather than spotlight beam. Equipment lights should be mounted as high as possible and not aimed at an angle greater than the lamps useful range, meaning the lamps should be angled downwards enough to prevent directing light outwards and still take full advantage of the light produced.
Less talked about but equally important forms of work site lighting included indicator and warning lights. These lights alert oncoming traffic as well as workers on site that equipment is in motion, workers are present, and hazardous conditions are present, and so caution must be exercised. These are typically yellow and amber colored and designed to revolve or strobe much like the emergency lighting on police and fire vehicles. They can be mounted in pairs, and in many cases are simply a small portable light that flashes at a set rate and can be moved from one vehicle to the next, or one location to another as needed. These lights need to be positioned where they will not be obstructed from any angle and lenses and housings should be kept clean and clear to produce the maximum warning signal strength.
Effective road and construction site lighting plays a critical role in productivity, safety and efficiency and should be chosen with these parameters in mind. Operators unsure of their sites’ specific requirements of regulations regarding the proper illumination of their site should check with regulating bodies such as OSHA to ensure compliance with any applicable rules and requirements and safe work site operation.