Loading Rack Safety – Beyond Fall Protection
Loading and unloading of rail cars and trucks is a necessity for many companies who produce and use various chemicals, ethanol, edible oils, crude oil and NGL’s as example. What seems on the surface to be a very simple process can hide risk that can result in citations and fines or worse, can cause death. Project Managers, Engineers, EH&S professionals face a confusing landscape of guidelines, regulations, and solutions offered by various suppliers. They must consider fall protection, ergonomics, spill containment, vapor recovery, grounding and bonding, overfill prevention, emergency shutdown of systems, various permissives to help ensure all safety protocols are in place before loading and unloading begins, all with no real standard model to follow.
Of course, many companies have adopted their own “standard” based on what good looks like to them and with the intent of meeting regulations and guidelines set forth by agencies like OSHA and their individual States they operate in and most do a fair job. But here is an example of where the confusion can start. We have all seen articles written about OSHA 1910 Subpart D, OSHA 1926, the General Duty Clause, letters of interpretation on rolling stock and the OSHA Hierarchy of Controls. Only a few aspects of loading or unloading rail cars and trucks are addressed, with the primary one being falls from heights, walking and working surfaces. Out of the gate, one of the first things considered is how to access and work safely on top of a rail car or truck that can be 10’ to 13’ or more above the ground. Should you use active fall protection equipment like overhead trolley beams or tie off points with full body harnesses and retracting lifelines that arrest a fall and keep the operator from hitting the ground below? Or should you consider a passive system like guardrails or cages that surround an operator and keep them from falling off the top of the rail car or truck? This one topic can lead to a lengthy article on its own and a discussion covering products, initial cost, long term cost of ownership, increased productivity, lower insurance cost, personnel buy in and adoption, various sizes, lengths and configurations of the cars and trucks, etc… Both active and passive fall protection are solutions, both meet the criteria set forth by OSHA and State regulations and both passive and active fall protection come in a variety of configurations. For the purposes of this article, we will simply say, installing fall protection is a necessity when designing and building a truck or rail car loading or unloading rack and its best to consult with both internal and external resources to decide which direction to take because each has its pluses and minuses.
But where else are the risk and how does one go about identifying and mitigating them. A thorough process safety analysis taken up by a team of all stakeholders from EH&S, operations, logistics and engineering looking at the entire loading and unloading process will uncover those risks. At times it’s good to consider bringing in a 3rd party consultant versed in all aspects of the loading and unloading of cars and trucks that can supplement the team and provide an “outside looking in” perspective. When doing a process safety analysis, it’s important to look at the entire process from the truck or car entering the plant to completion of the loading or unloading process and the car or truck leaving the site. For this discussion let’s assume the car or truck has already been spotted at the loading or unloading rack and all the boxes have been checked and the process can begin. Also, let’s consider from here we are loading a rail car through an open dome. The process for unloading is similar but there are a few steps that are not required.
We have noted getting on top of the car and providing active or passive fall protection is a must. Now that we have safe access to the top, we must consider what the operator will use to load the car. The choices are hoses or loading arms with swivel joints. Both will get product into the car, but each has its pluses and minuses. Hoses can be heavy and difficult to maneuver and can cause lifting, back strain type injuries. Hoses are initially less in cost but can rupture or burst and require an ongoing cost for a hose inspection program and have to be replaced on some frequency based on usage and damage. Hoses can cause a tripping hazard if they are left lying around a loading rack and not stored properly. Heavy valves, and cover plates cannot typically be left connected to the hose end, requiring the operator to carry the equipment to the top of the car. To mitigate lifting, back strain type injuries, and trip hazards one can utilize a “hose handler” to carry the hose making it easier to swing the hose out to the car and minimize the heavy lifting. Replacing hoses is easy and does not require the rack to be shut down. The hose handler allows the hose to be stored away from the loading rack walking and working areas, eliminating the trip hazards.
Loading arms are made of hard pipe and swivels and have a higher initial cost. Loading arms will not rupture or burst and with spring balance mechanisms are easy to move, eliminating any concerns with lifting, back strain type injuries. Heavy valves and cover plates can be hung on the arm ends further reducing the risk associated from lifting and carrying the equipment to the top of the rail car from the loading rack. Loading arms can last 20 plus years. Swivel joints can leak and require seals to be replaced. Depending on the configuration of the loading arm and type of swivel joint, the rail rack must be shut down to do arm maintenance and, in some cases, must be taken down with heavy equipment requiring more labor to do the job exposing workers to further risk. This task takes longer, increasing rack down time. Again, another area where each solution has its pluses and minuses and is riddled with confusing information that must be weighed much like that of the active and passive fall protection systems in order to make the “right” choice.
Typical grounding systems for tank cars or tank trucks loading / unloading stations
Now let’s look at the actual pumping, overfill detection, ground verification, fire suppression and controls. Companies that design and fabricate integrated pump skid packages are an often-overlooked safety resource and are an integral part of any loading rack design. Through controls and automation, permissives and automated shut down of equipment can be designed into the skid package to help minimize or eliminate human error and mitigate risk. Many rail car loading racks will require pumping of the material to the rail car from the process area or from storage. Let’s assume the operator has placed a hose or loading arm into position and the car is ready to load. With products that are flammable a means to ensure the car is grounded is necessary. A ground verification unit with light indication so an operator can visually see the car is grounded and bonded and has permissives integrated into the controls system, will ensure the pump cannot be started until a proper ground is made and or shut down the pumping process should grounding be lost during the loading process. Other considerations, as found in NFPA 77, Figure G.1(k), should be considered such as the recommendations for typical grounding systems for tank cars or tank trucks loading /unloading stations all of which can be monitored through automation.
Typical grounding systems
Overfilling of rail cars can cause many regulatory issues. To help mitigate the risk, high level detection systems can be utilized to ensure a car is not overfilled and provides a means with automaton to shut down the filling process when the liquid in the car reaches a pre-determined high level. Overfill cases have been reported where cars were not attended during the filing process and the pump not shut down in time or where the heel in the car was not accounted for and too much product was loaded into the car. This risk can be eliminated with well thought out controls and automation. Risk of fire is very real around flammable products loading and a fire suppression system can be integrated into the overall rack design. The installation of fire suppression to knock a fire down around the actual rail car is known, but an overlooked area again is the actual pumping skid systems where the potential of fire can occur. To mitigate the risk, flame and gas detection sensors can be installed on and around a pumping skid system that is tied into the controls/ automation package that will shut down the pump, send a signal to alert the control room, and trigger a fire suppression system.
In conclusion, these items only cover a few of the risk found around the loading and unloading of rail cars and trucks and how one might go about mitigating those risks. It’s of most importance to get a team of all stakeholders together from Logistics to EH&S and ensure that your external resources you engage for help are indeed focused on your need to identify and mitigate all risk and help eliminate the confusion. Ideally, a company who has the knowledge, expertise and can help provide a complete solution is best because they can look at the entire process from front end to back end with no vested interest in just “selling” a part of the puzzle. Taking the extra effort up front will help your company develop its “standard” and will provide a safer work environment and have a direct impact on your company’s bottom line.