 Hazards and safety practices on surge piles. Maintaining stockpiles of raw and processed materials are important parts of most mining operations. Some mines store material in surge piles where it is recovered from draw off points or feeders located beneath the pile. This video will illustrate the most common hazards at surge piles and show how these hazards can be avoided. To work safely around surge piles there are three conditions that you must be especially aware of. First, the material feeding into the draw point will not support weight and will act like quick sand. Second, the material around the edge of the draw hole is only marginally stable. And third, sometimes material bridges over the draw point causing a hidden void in the pile. This model demonstrates how a cone shaped zone or draw hole forms above a draw point of a surge pile as material flows down through the feeder opening. The material used in this model has been chosen for its contrasting color and has been layered to increase the visual effectiveness of the demonstrations. When the feeder is activated, note how quickly the material directly above the draw point flows to the feeder. If a person or piece of equipment is above the feeder when it is activated, they will be drawn into the flowing material. This is why section 9312 of parts 56 and 57 of the regulations requires that, unless platforms or safety lines are used, persons shall not position themselves over draw holes if there is danger that material may be withdrawn or bridged. The zone of flowing material is obviously dangerous, but be aware that the area near the edge of the draw hole is also potentially hazardous. As material is withdrawn through the feeder, support for the edge of the draw hole is continually being removed. This keeps the edge standing at a steep angle and on the verge of collapsing. For this reason, no one should walk near the edge of a draw hole. And equipment operators must avoid getting into a position where the weight of their equipment may unexpectedly collapse the edge of the cone. Another reason why surge piles are potentially hazardous is the possibility of material bridging or arching over the draw point, creating a void inside the pile. This condition is extremely dangerous because the cavity cannot be detected from the surface. Many mining accidents have occurred when a dozer has driven over a hidden void, and the weight of the equipment collapsed the bridged area, burying the machine and the operator. To better illustrate the danger of bridged material, let's look at the model again. Here we see a bridged condition developing. There are many different conditions that can cause the material to bridge. Moisture and fines in the material may cause it to cake together, making it less free-flowing. Material that has been undisturbed for a period of time will settle in and be more prone to bridging. Heavy equipment operating directly on the pile can pack the surface material and form a crust, while material deeper in the pile stays looser and continues to flow. Bridging might also be caused by freezing, where ice binds the material near the surface, making it temporarily strong enough to bridge over the opening. To emphasize how unstable and dangerous a bridged condition is, see what happens when the heavy weight of the dozer is driven onto the bridged material. A key point is that the bridged material may have enough strength to support its own weight, but may not support the additional weight of a piece of equipment. As the bridge may gradually weaken from spalling underneath or thawing, it can collapse without warning. To avoid surge pile hazards, several safety measures should be followed. Equipment operators should avoid driving directly over the feeder location, because the weight and vibration of the equipment tends to pack the surface material and promotes bridging. Driving over the feeders also exposes the operator to the possibility of driving over a hidden void. To let equipment operators know the exact location of the drop points, a brightly colored marker or a light can be suspended directly over each feeder. Lights can also be used to let equipment operators know which feeders are in use. A chart can be developed indicating how the size or diameter of the draw off cone increases as the height of the pile increases. The chart provides guidance to operators on how close to the feeder they can safely operate. When pushing material to the draw points, equipment should always be operated perpendicular to or straight toward the edge of the draw hole. This puts the operator in a safer position and gives the operator more time to react should any shifting of the material occur. When material is fed through the feeder at a faster rate than it is pushed into the draw hole, a deep draw hole can develop. The limited field of vision from the dozer cab and the danger of collapse of the edge of the draw hole makes pushing material into the deep draw hole potentially hazardous. The amount of material being discharged should be regulated so that the hole is kept nearly full or the edge material should be carefully worked into the hole. If equipment operators are in place on the pile at the start of loading and throughout the loading process, they can observe how the material is feeding into the draw points, keep the draw areas full of material and better know what areas of the pile are safe to operate on. Reliable communication between plant personnel and equipment operators is essential. Before starting or changing feeder operations, the plant operator should be certain, visually or by other means of communication, that no one will be endangered. An effective means of monitoring a surge pile operation is by the use of strategically placed video cameras. This allows continuous viewing of activities from the control room. Control room to 563 dozer operator. We're going to be shutting down that feeder one on two right in front of you there. A good safety practice for all mobile equipment that operates on surge piles is to have a fully enclosed cab. In accidents where equipment has become engulfed in material, fatalities have resulted because material broke in cab windows and filled the cab. Mining companies and equipment manufacturers are encouraged to equip the cabs of surge pile equipment with strong window mountings and high strength window material or window guards so that the cab will stand being buried in loose material. And remember, operators should always wear their seat belt to avoid being injured or being thrown from the cab in the event of an accident. If equipment does become trapped in a pile, the operator should stay in the cab, shut off the engine and use the two-way radio to call for help. An operator attempting to leave the cab will most likely be pulled into loose material and die from asphyxiation. Special precautions should be taken if a feeder becomes blocked. If vibrators or high-pressure water does not free the blockage, it will be necessary to excavate into the pile to free the material. Equipment operators should notify their supervisors before performing such work or any time a cavity forms or is suspected. Material should be removed starting from a safe area off to the side of the feeders so that the equipment operator is not exposed to a hazard when the material breaks free. No steep slopes or overhangs should be created. Any time that a person would be exposed to the hazards of a feeder area, such as during maintenance or repair work, the requirements of section 16002 in parts 56 and 57 must be followed. These include locking out the equipment, wearing a safety belt or harness equipped with a lifeline, and having a second person positioned to keep the lifeline adjusted. It's vitally important that mine personnel, especially new employees, be trained to recognize the potential hazards at search piles and be instructed to only use safe work practices. Mine operators should also make sure that any contractors or repair persons who may occasionally have to work on a search pile are aware of the hazards. It's only with the active participation and cooperation of everyone involved, miners and mine management, that the occurrence of search pile accidents can be eliminated and a safe work environment can be ensured. Keeping storage piles of raw material and processed is an important part of any mining operation. Some mines store materials in regulation piles to later recover them with feeders located under the pile. This video will illustrate the most common risks of regulation piles and show how they can be avoided. To work safely around these piles, there are three factors that must be present. First, the material with which the coal is fed cannot bear any weight and acts as a movedisa arena. Second, the material that is close to the edge of the extraction mine is never very firm. And third, sometimes the material forms a bridge over the coal which forms a hidden void in the pile. This model perfectly illustrates how the fall of the material to the food forms a conical area or extraction chimney over the coal. The material used in this model was chosen by its contrasting color and was separated into layers to increase the visual effect of the demonstrations. After activating the food, see the speed with which the material falls from the coal to the food. If a person or machinery was on the food when this was activated, surely the material would go together. That is why Part 56 and 57 of Article 9312 of the Federal Code of Regulations demand that, unless used on platforms or life lines, no one should be placed on the extraction chimney when it is believed that the material has formed bridges or will be removed. The fall zone of materials is potentially dangerous, but it is aware that the surrounding area of the extraction chimney is also. The fact that the material has always been removed towards the food makes the edge of the chimney never stable. This causes the edge to have a pronounced slope and that it is always about to fall. For this reason, no one should walk near the edge of the chimney and the operators must avoid placing themselves in places where the weight of their vehicles can cause the unexpected slope of the edge of the cone. Another reason why regulation piles are potentially dangerous is the fact that the material can form a bridge or false arc and create a void inside the pile. This is extremely dangerous, as this cavity cannot be detected from the surface. Many mining accidents that have occurred and that have been caused by the operator and the machinery have been caused because some drivers have handled their heavy machines on those cavities. To better illustrate the danger of bridge formation, let's see the model again. Here we see how a bridge is formed. There are many factors that can cause the material to form a bridge. The humidity and the thinness in the material can cause the agglutination of the material and prevent its fall. The material that has not been touched for a certain time sits down and is more likely to form bridges. The machinery that is used directly on the pile can compact the material on the surface and form a layer while the one on the bottom is still loose and continues to fall. The bridge formation can also be caused by freezing, that is, the ice can join the material on the surface and cover the excavation. To better illustrate the unstable and dangerous that can be one of these bridges, see what happens when one of the heavy ladders goes over the excavation. As you can see, the material can, in a given moment, support its own weight, but that is not a guarantee that it can support the weight of a vehicle. A false bridge like this can weaken and fall unexpectedly due to weariness or freezing. To avoid risks in the regulation piles you have to follow several security measures. The crew operators must avoid managing the food area since the weight and vibration of the vehicles can compact the material on the surface and create bridges. In addition, managing the food area exposes the operators to manage on a hidden and empty space. To make the operators know the exact location of the dust cones, they must place live colored lamps suspended on each of them. The lamps can also be used to indicate that the food area is in service. You can also make a graph to show how to increase the size or diameter of the extraction cone by increasing the size of the pile. This graph can indicate to the operators the distance to which they can work without exposing themselves to risks. When pushing the material towards the dust cones, it should always be handled in front or perpendicularly at the edge of the extraction chimney. In this way, the operator is less exposed to risks and gives more time to react in case a leak occurs. When the operator takes more material from what is being placed on the surface, it can create a crack in the ground. The limited field of vision it has from the top and the risk that, according to the edge of the extraction chimney, it makes the push of the material become a potentially dangerous task. The amount of material to be unloaded must be controlled so that the pile is almost always full and it represents less danger to the workers who push the material. In case there are operators in the pile throughout the process of loading operations, they will be able to observe how the material is falling on the dust cones, maintain the dry areas full of material and know that areas of the pile are the safest to work with. Confident communication between the staff of the plant and the crew operators is vital. Before starting the food operations, the operator of the plant should be monitored visually or by other means of communication that no one can run at any risk. An effective means to monitor the operations in the pile of regulation is the use of strategically placed video cameras. This allows the continuous monitoring of the activities from the control room. Control room at the top at 563. We are going to stop the fooders number one and number two who are in front of you. A good security procedure for all mobile teams that operate in such piles is to have completely closed cabins. In vehicles that have been flooded, the deadly accidents are due to the fact that the material has broken the windows and has entered the cabins. That is why the mining companies and machinery manufacturers continue to slow down to reinforce the windows of the cabins of the vehicles that operate in this type of pile. To put materials for windows that are highly resistant or to put protections on the windows. Remember that the operators must always use safety belts so as not to get hurt or well so as not to be projected from the cabins in case of an accident. If the team reaches a pile, the operator must remain in the cabins, turn off the motor and use the bidirectional radio to ask for help. In case an operator tries to get out of the cabins, it is most likely that you will die fixed due to the lack of oxygen. When blocking a power plant, you must take measures of special precautions. If the vibrators or high-pressure water cannot be uncovered, you will have to excavate inside the pile to release the material. The operators must notify their supervisors when they go to execute that type of task or when they believe or are sure that a cavity has been formed. In order not to expose the team operators at any risk when the material has been released, the material must be removed in a safe area that is far from the feeders and must not be created dependent on the feeders. Every time a person is exposed to the risks of the feeding area such as preventive or corrective maintenance, it must comply with the requirements imposed in parts 56 and 57 of article 162002. These are understood to stop the team. The use of safety belts or harnesses equipped with life lines and the count with someone to make sure that the life line is adjusted. It is of vital importance that the staff of the mine, especially the new employees, be able to identify the potential risks of the piles and to work only safely. The mine operators must also make sure that the contractors or those who come to make repairs occasionally know the risks. Remember that only the cooperation and active participation of all can eliminate the frequency of accidents in the regulation piles and at the same time create a safe working environment.