Compliance Guide for MSHA's Regulations on Diesel-Powered Equipment Used in Undergound Coal Mines
Section 75.1902 -- Underground Diesel Fuel Storage -- general requirements
Q. If equipment is being installed or removed, isn't it true that there is no real loading point?
A. The final rule addresses this issue by providing that temporary underground diesel fuel storage areas must be located within 500 feet of: the actual loading point; the last loading point, for areas where equipment is being removed; or the projected loading point, for areas where equipment is being installed.
Q. On an outby project using diesel-powered equipment, would a diesel fuel storage facility located within 500 feet of the project site be acceptable as a temporary fuel storage area, since there is no loading point?
A. The final rule does not permit storing of diesel fuel anywhere other than in a temporary fuel storage area or a permanent storage facility. A temporary storage area must be located within 500 feet of : 1) the section loading point; 2) the projected loading point, in cases where equipment is being installed; or 3) the last loading point, in cases where equipment is being removed.
Q. If a fuel transportation unit stays in the same location and does not move, will it have to be parked in a permanent storage facility? What if the existing temporary storage area is not located within 500 feet of the section loading point?
A. The fuel transportation unit must be parked in either a permanent fuel storage facility or a temporary fuel storage area when not in use. The temporary storage area must be located within 500 feet of the section loading point.
Q. Under the final rule, are any of the diesel fuel handling and storage requirements grandfathered?
A. No. All diesel fuel handling and storage facilities in underground coal mines must comply with the requirements of the final rule no later than November 25, 1997.
Q. Under paragraph (e), permanent underground diesel storage facilities may not be located in escapeways. Can they be located in crosscuts off the primary escapeways and/or in intake entries adjacent to primary escapeways if the operator takes the same precautions as those that are taken with respect to the location of compressors in such areas?
A. Permanent underground diesel fuel storage facilities may not be located in the primary escapeway [§75.1902(e)] and must be ventilated with air that is coursed to the return or the surface and not allowed to further ventilate a working place [§75.1903(a)(4)]. A permanent underground diesel fuel storage facility may be located in a crosscut off of the primary escapeway or in an entry adjacent to the primary escapeway, provided that the facility is
physically separated from the escapeway by the noncombustible construction, and the air that has ventilated the storage facility is coursed to the return or the surface, and does not ventilate a working place. Automatic closing doors that typically remain open would not provide the necessary degree of separation.
Q. What are some examples of acceptable collision protection on diesel storage facilities? Would fuel tanks that meet the U.S. Department of Transportation standard for collision protection be considered protected from collision under this rule?
A. Stationary tanks in fuel storage facilities must be protected from damage by collision with other mine vehicles. One method of achieving this is through the installation of curbs or posts. The Department of Transportation design specifications for the fuel carrying tank on cargo tank motor vehicles (fuel trucks) exceed the requirements in this rule for the actual tanks on diesel fuel transportation units. However, the rule's requirement that tanks be protected from damage by collision imposes an additional requirement, beyond design specifications for the tanks themselves.
Q. Is the distance of 500 feet from the loading point measured as a straight line or measured around the coal pillars?
A. The 500-foot distance is measured in a straight line (a 500-foot radius) from the loading point.
Q. Can you have two temporary fuel storage areas on a super section (i.e., fish tail with two MMUs)?
A. No. Only one temporary fuel storage area is allowed. Although a super section may operate with two MMUs, the section has only one belt line and one intake escapeway. This limitation is intended to allow fuel storage in close proximity to the mining section , while at the same time recognizing that safety concerns necessitate that limitations be placed on where fuel may be stored.
Q. Can one diesel fuel transportation unit be brought to a temporary fuel storage area to refuel another fuel transportation unit, or is this prohibited by the limitation of one diesel fuel transportation unit per section?
A. This would be allowed under the final rule. The rule prohibits more than one diesel fuel transportation unit from being parked at a time in a temporary fuel storage area. A diesel fuel transportation unit that is actively refueling equipment, another diesel fuel transportation unit, or a storage tank is not considered to be parked.
Q. The restriction of one temporary underground diesel storage area per section or per area where equipment is being installed or removed could be construed to mean that
temporary diesel fuel storage is permitted only in those areas. Will temporary diesel storage areas be allowed in outby areas for short time periods and if attended at all times?
A. Section 75.1902(c)(1) limits the location of temporary underground fuel storage areas. However, diesel fuel transportation units may be brought into other areas, including outby areas. The final rule provides that diesel fuel transportation units that are not in use must be parked either in a permanent underground fuel storage facility or in a temporary diesel fuel storage area. The phrase not in use means that the unit is not being trammed or used to dispense fuel or lubricants or waiting to refuel another piece of equipment.
Q. If a mine has a piping system from the surface but does not have a borehole fill tank, and does not plan to build a permanent underground fuel storage facility, what are the options?
A. Under the final rule, a diesel fuel piping system from the surface may only transport fuel to a stationary tank or a diesel fuel transportation unit, either of which must be located in a permanent underground fuel storage facility (§75.1905-1(g)). The final rule provides no exceptions to this requirement.
Section 75.1903 -- Underground diesel fuel storage facilities and areas; construction and safety precautions
Q. What is the difference between requirements for temporary underground fuel storage areas and for permanent underground fuel storage facilities?
A. Only one temporary diesel fuel storage area is allowed per working section, and it must be located within 500 feet of the loading point, the last loading point, or the projected loading point. There is no limit on the number of permanent fuel storage facilities, and the facilities' location is not tied to the section loading point.
Permanent fuel storage facilities, unlike temporary fuel storage areas, may not be located in the primary escapeway.
A temporary fuel storage area may provide storage for no more than one diesel fuel transportation unit, which may contain no more than 500 gallons of diesel fuel. A permanent fuel storage facility may store a total of 1,000 gallons of diesel fuel in stationary tanks, and may also be used to park any number of diesel fuel transportation units. Permanent fuel storage facilities are the only location underground where safety cans may be stored.
Finally, permanent fuel storage facilities, unlike temporary fuel storage areas, must be: constructed of noncombustible material; provided with either self-closing doors or a means for automatic enclosure; be provided with a means of containment for 150 percent of the capacity of the fuel storage system; and be equipped with an automatic fire suppression system that complies with §75.1912.
Q. Are double wall storage tanks acceptable as a means of containmentunder §75.1903(a)(6)?
A. No. The requirement for a means of containment capable of holding 150 percent of the maximum capacity of the fuel storage system is intended to control the spread of fuel where, for example, a valve breaks off and the fuel is leaking out. A double wall tank would not serve this purpose.
Q. Could a concrete stopping or a competent rock footwall serve as a means of containment under §75.1903(a)(6)?
A. Whether a concrete stopping or a competent rock footwall would qualify as a means of containment would depend on whether either method would effectively contain a fuel spill.
Q. Does the means of containment have to be located right at the facility, or can the spillage be directed away from the storage tank to another area?
A. The means of containment must be an integral part of the permanent fuel storage facility and provide containment for 150 percent of the capacity of the fuel storage system.
Q. With respect to §75.1903(a)(6) requiring containment capability in permanent storage facilities equal to 150 percent of the maximum capacity of the fuel storage system (including the surface), would the requirement apply even if the surface storage facilities are equipped with shut-off devices to prevent uncontrolled flows into the underground system?
A. Yes. The requirement for 150 percent containment capacity applies to fuel kept in surface storage facilities equipped with shut-off devices and delivered underground through a piping system. This is because the requirement for a means of containment addresses the consequences of fuel spills, which shut-off devices cannot prevent.
Q. Is a fire suppression system required for storage tanks for a battery-operated fuel center?
A. Yes. All permanent underground diesel fuel storage facilities must be provided with a fire suppression system that meets the requirements of §75.1912. Additionally, all non-self-propelled diesel fuel transportation units with electrical components for dispensing fuel that are connected to a source of electrical power must be protected by a fire suppression device that meets the requirements of §§75.1107-3 through 75.1107-6, and §§75.1107-8 through 75.1107-16.
Q. If a diesel-powered machine is trammed in and out of the section and is never actually parked, does the final rule require that rock dust be available?
A. No. If the machine is never actually parked, a temporary fuel storage area or a permanent underground fuel storage facility would not be required for the machine. Rock dust would therefore not need to be provided under the final rule, which requires that rock dust and/or fire extinguishers be provided at temporary fuel storage areas and permanent fuel storage facilities. However, §75.1906(h) does include certain requirements for fire suppression and fire extinguishers for diesel fuel transportations units.
Q. The final rule requires that permanent underground fuel storage facilities be ventilated with intake air that is coursed into a return air course or to the surface and that is not used to ventilate working places. Does this mean that if there are common intake entries, the air from any of those entries could not be used to ventilate the working place?
A. If some of the ventilating air is split off from the common entry before the air course is used to ventilate the fuel storage facility, the split would not be considered to have ventilated the facility and could be directed to a working place. Air that has been used to ventilate a fuel storage facility cannot be used to ventilate a working place.
Q. If there are vents in the self-closing doors on permanent underground fuel storage facilities, are the vents required to be closed as well?
A. The vents would be required to close automatically in the event of a fire.
Q. Is a metal stopping with a 2' X 2' or a 3' X 3' self-closing door acceptable for isolating the permanent diesel fuel storage facility?
A. Use of such a stopping, properly installed, could be an acceptable method of achieving isolation of permanent diesel fuel storage facilities. MSHA has accepted properly installed metal stoppings as complying with the noncombustibility requirements for permanent ventilation controls in §75.301, which are essentially the same as the noncombustibility requirements for permanent fuel storage facilities.
Q. Are lights permitted in a temporary fuel storage area or in a permanent fuel storage facility? If so, are there any special requirements?
A. There is nothing in the final rule that would prohibit lights in either a temporary fuel storage area or in a permanent fuel storage facility. The electrical safety rules in part 75 would apply.
Q. Do you have any examples of what would be equivalent to a concrete floor? Is a liner covered with crushed rock to prevent damage to the liner acceptable?
A. This requirement in §75.1903(a)(7) is intended to ensure that spilled diesel fuel can be easily cleaned up and will not accumulate, creating a fire hazard. A steel floor would therefore be acceptable. A liner with crushed rock would not be acceptable, because the crushed rock would absorb a fuel spill and would prevent cleanup of a spill. Additionally, a liner could be punctured by crushed rock, enabling fuel to leak into and saturate the mine floor.
Section 75.1904 -- Underground diesel fuel tanks and safety cans
Q. Does the 3/16" thickness requirement for diesel fuel storage tanks also apply to metal storage containers?
A. The 3/16" thickness requirement applies to steel diesel fuel storage tanks. Tanks of other metal would have to be of a thickness that would provide equivalent strength.
Q. Does the prohibition against leakage in §75.1904(a)(4) apply to venting devices required in paragraph (b)(1) that are designed to leak when pressure in the tank exceeds 2.5 psi?
A. The venting devices required under paragraph (b)(1) are designed to vent only in an emergency situation, to relieve pressure inside the tank when it is exposed to heat, such as in the event of a mine fire. Some discharge of fuel in such an emergency situation would be expected, and would not be considered a violation under paragraph (a)(4). The prohibition against leakage under paragraph (a)(4) applies under normal (non-emergency) conditions.
Q. What is the maximum capacity of safety cans?
A. The maximum capacity for safety cans is 5 gallons.
Q. Are the safety cans required by the regulations commercially available?
Q. Is the automatic closing, heat-actuated valve required on each withdrawal connection below the liquid level commercially available?
Q. Would a self-closing flap in the neck of the fuel tank satisfy the requirement for a self-closing cap?
A. No. Self-closing flaps, similar to those provided on gasoline-powered pickup trucks, are not designed to prevent outflow of fuel, and would therefore not satisfy the requirement for a self-closing cap. Such flaps are not typically provided on diesel-powered equipment.
Q. Would painted fuel storage tanks be considered protected from corrosion?
A. Yes, painting the outside of fuel storage tanks would comply with this requirement.
Q. Do existing fuel storage tanks used underground need to be pressure tested again, or if they don't leak, would they be considered tested?
A. Section 75.1904(e) of the final rule requires that tanks and their associated components be tested for leakage at a pressure equal to the working pressure. Tanks that are already in service that meet all of the design requirements of the standard and are performing adequately (not leaking) are not be required to be pressure tested.
Q. Will MSHA expect recordkeeping of the pressure testing referred to in §75.1904(e)?
A. No. The final rule contains no recordkeeping requirements for pressure testing.
Q. Do the requirements of §75.1904(a) apply to onboard fuel supply tanks of diesel-powered equipment?
A. No. Paragraph (a) applies to tanks used for storage of diesel fuel.
Q. If the section has a temporary fuel storage area, are the temporary fuel storage tanks required to be wheel-mounted?
Section 75.1905 -- Dispensing of diesel fuel
Q. Do the requirements governing dispensing of diesel fuel apply to fuel dispensing taking place on the surface?
Q. The rule prohibits the use of latch-open devices for the dispensing of diesel fuel by gravity feed or with a powered pump. Does this mean that the Wiggins Refueling System, which incorporates an automatic fuel shutoff, is prohibited?
A. The use of latch-open devices is permitted only with the use of a manual pump. The Wiggins System, referred to above, does not meet the requirements of the final rule. The intent of the rule is that powered pump systems, such as the Wiggins Refueling System, require the person dispensing fuel to maintain physical control over the dispensing process at all times, to minimize, if not eliminate, accidental spills during fuel dispensing.
However, because the Wiggins System is an engineered system, it may be possible to modify the system to meet the requirements of the rule. Any such modification should be undertaken only in consultation with Wiggins.
Q. Would devices similar to the automatic cut-off nozzles used at gas pumps at commercial filling stations satisfy the requirement for a self-closing valve under §75.1905(b)?
A. Such a configuration would satisfy the requirement for a self-closing valve. However, the latch-open devices that are typical at gas stations would not be permitted except when used with a manual pump.
Q. Can lube trucks be running when taking on or dispensing fuel? Some lube truck must be running for there to be power to transfer diesel fuel to the lube truck.
A. Section 75.1905(d) of the final rule prohibits diesel fuel from being dispensed into the fuel tank of diesel-powered equipment while the equipment engine is running. The intent of the rule is to prohibit accidental spillage of fuel on hot surfaces that would be present if the equipment being refueled was running. In the situation described, diesel fuel is not being dispensed into the lube truck's engine fuel tank, but rather into the storage tank. The final rule therefore does not require the lube truck's engine to be shut down when taking on or dispensing fuel into its storage tank. However, when the lube truck is being refueled into its own engine fuel tank, its engine must be shut down. Similarly, the equipment being fueled by the lube truck must be shut down.
It should also be noted that §75.1916(d) prohibits the idling of mobile diesel-powered equipment, except as required in normal mining operations.
Q. Does §75.1905(c) allow for compressed gas powered motors that are used to power the pump that is dispensing the diesel fuel?
A. Yes. The final rule does not prohibit compressed gas powered motors used to power the pump that is dispensing the fuel.
Section 75.1905-1. -- Diesel fuel piping systems
Q. If a mine has a borehole fuel system with a 150-foot 1-inch line, and the mine operator does not plan to store fuel underground, must the mine have a tank underground in order to be able to refuel into machine fuel supply tanks, rather than fueling from the surface line directly into machine fuel supply tanks?
A. Yes. The mine must have a tank underground. This tank may be a stationary tank or a tank on a diesel fuel transportation unit. Under §75.1905(a), diesel-powered equipment in underground coal mines must be refueled only from safety cans, from tanks on diesel fuel transportation units, or from stationary tanks. Additionally, under §75.1905-1(g), diesel fuel piping systems from the surface are only to be used to transport diesel fuel directly to stationary tanks or diesel fuel transportation units in a permanent underground diesel fuel storage facility. The purpose of these restrictions is to minimize hazards associated with fuel spills. Therefore, the mine operator must also install a permanent storage facility if the borehole system is used to transport fuel underground.
Q. Does the final rule essentially force the storage of diesel fuel underground when a mine uses a surface-to-underground piping system?
A. No. The final rule does require an underground diesel fuel storage tank if a surface-to-underground piping system is used. However, fuel may be piped into a diesel fuel transportation unit, and immediately dispensed from the transportation unit into the tanks of diesel-powered equipment, thereby avoiding underground fuel storage.
Q. Doesn't the restriction on fueling all but stationary tanks or fuel transportation units from the borehole under §75.1905-1(g) increase hazards, inasmuch as the fuel has to be dispensed twice -- once to the stationary tank or transportation unit and again to the diesel equipment?
A. The intent of this provision is to prohibit fueling directly from the borehole, where there may be as much as 2,000 feet of head, into a relatively small equipment tank, with the resulting risk of accidental spillage into the underground mine environment. There is also a risk of spillage of fuel onto hot equipment surfaces.
Q. If a mine has a borehole system and does not want to build a permanent underground fuel storage facility, what options exist for the mine?
A. Diesel fuel piping systems that originate from the surface can terminate only in a permanent fuel storage facility. Likewise, these systems may only be used to transport fuel directly to a stationary tank or a diesel fuel transportation unit that is located in a permanent fuel storage facility.
Q. Are there any pressure requirements on the pipes in the borehole installation? Line pressure?
A. Section 75.1905-1(b) requires that all piping, valves, and fittings in diesel fuel piping systems used underground be: capable of withstanding working pressure and stresses; capable of withstanding 4 times the static pressures; compatible with diesel fuel; and maintained in a manner that prevents leakage. There is no maximum value for line pressure in a borehole or piping system. The final rule requires only that the system be designed and constructed to meet the demands of the particular installation.
However, underground fuel piping systems can be very complex and may require specialized expertise for their design and installation. Mine operators should ensure that an engineering evaluation, including a fault analysis, is performed in developing a fuel piping system.
Section 75.1906 -- Transport of diesel fuel
Q. Can a diesel tank that is secured to a trailer with wheels, be carried to the section in the bucket of a scoop or in a supply car?
A. No. Section 75.1906(a) allows diesel fuel to be transported only by a diesel fuel transportation unit or in a safety can. A diesel fuel transportation unit is defined as a self-propelled or portable wheeled vehicle used to transport a diesel fuel tank. The regulations further require that the fuel tank be permanently affixed to the transportation unit whether it is a trailer, scoop bucket, or other wheeled vehicle. The tank in this example, while permanently fixed to a wheeled trailer, is not being conveyed in a safe manner as it was designed or intended.
Q. If a fuel storage tank, such as a 300-gallon tank, is emptied inside the mine, is it permissible to leave the tank in the mine for 3 or 4 hours, until the end of the shift when the tank is brought out?
A. Section 75.1906(a) provides that diesel fuel shall be transported only by diesel fuel transportation units or in safety cans. This restriction applies whether the tank is full or empty. Consequently, the tank in question cannot stand alone but must be part of a diesel fuel transportation unit by being permanently fixed to the unit. Section 75.1906(i) provides that diesel fuel transportation units may be parked only in temporary fuel storage areas or permanent fuel storage facilities.
Q. Are there any restrictions on the number of safety cans that can be transported in a vehicle at one time?
A. Yes. Section 75.1906(b) provides that no more than one safety can shall be transported on a vehicle at any time.
Q. If 4 supply cars (trailers in a trip being towed by one conveyance) are taken into the mine, is it permissible to carry a total of 4 safety cans into the mine -- one can on each supply car?
A. No. This would be considered one vehicle, and only one safety can may be transported on it at a time. This is consistent with the purpose of the regulation, which is to minimize the use of safety cans, as well as eliminate their use as a primary means of supply and transport of diesel fuel.
Q. If each vehicle is allowed to carry only one safety can, every vehicle will carry one safety can as opposed to only a few vehicles equipped with safety cans? Doesn't this standard also discriminate against small operators who may not have the wherewithal to utilize permanent underground fuel storage facilities or fuel transportation units?
A. MSHA does not expect that the requirements of §75.1906(b) will result in the proliferation of safety cans underground. The rule does not discriminate against small operators, as the
requirements for a diesel fuel transportation unit can be satisfied relatively easily and cheaply. The construction of a simple wheel-mounted tank with the requisite safety features would not be unreasonably costly.
Q. Can empty safety cans be stored in a temporary diesel fuel storage area?
A. No. Section 75.1906(b) requires that safety cans used for diesel fuel must be stored in a permanent fuel storage facility.
Q. How many safety cans are allowed underground at one time?
A. The final rule does not limit the number of safety cans allowed underground, but there are specific limitations on the transport and storage of safety cans. Only one safety can at a time may be transported on a vehicle, and safety cans may be stored underground only in a permanent underground diesel fuel storage facility.
Q. Do empty safety cans fall under the same restrictions as safety cans containing diesel fuel?
A. The restrictions on safety cans would apply regardless of how much (or how little) fuel the can may contain. Any amount of diesel fuel, including trace amounts in empty cans, provides a fuel source for a fire. Although smaller amounts of diesel fuel present a reduced fire risk, even small amounts, once ignited, could spread fire to adjacent combustible material. It is the intent of the rule to control the use of safety cans to reduce the fire risk presented by even small quantities of diesel fuel.
Q. Can safety cans be marked as containing combustible liquid, or are they required to be marked as containing diesel fuel?
A. Section 75.1906(d) provides that both diesel fuel transportation unit tanks and safety cans must be conspicuously marked as containing diesel fuel.
Q. What is meant by the term permanently fixed in §75.1906(f), with regard to tanks on diesel fuel transportation units?
A. The term permanently fixed means that the tank is bolted, welded, or attached in an equivalent manner. Lashing a tank down with a chain in the bed of a truck would not be sufficient to comply with the requirement of the final rule.
Q. Can the tank on a diesel fuel transportation unit be compartmentalized with multiple compartments, with 500 gallons or less of diesel fuel in each compartment?
A. It depends on what the total diesel fuel capacity is on the fuel transportation unit. Section 75.1906(e) provides that diesel fuel transportation units must transport no more than 500 gallons of diesel fuel at one time. Section 75.1906(f) provides that tanks on diesel fuel transportation units must have a total capacity of no greater than 500 gallons of diesel fuel. Therefore, the total diesel fuel capacity of all of the compartments of the tank together must be no greater than 500 gallons.
Q. Can an existing 1000-gallon tank on a lube unit be partitioned into two compartments, with 500 gallons for diesel fuel and 500 gallons for hydraulic fluid?
A. Yes. Section 75.1906(f) places a 500-gallon diesel fuel capacity limit on tanks on diesel fuel transportation units.
Q. If a portable storage tank trailer is hooked to and towed by a piece of self-propelled equipment, does this constitute one diesel fuel transportation unit or two units?
A. Such a conveyance would constitute one diesel fuel transportation unit. However, if the equipment used to tow the tank trailer is diesel-powered, the equipment would be considered heavy-duty equipment under §75.1908(a)(5), and is required to be equipped with an automatic fire suppression system that meets the requirements of §75.1911. If the towed trailer contains only a tank without electrical components, it is not required to be covered by the fire suppression system.
Q. Does the requirement for two fire extinguishers in §75.1906(h) apply to any vehicle on which a safety can is being transported?
A. The requirement for two fire extinguishers applies to any vehicle on which a safety can is being transported, regardless of what other fire protection features may be provided on the vehicle.
Q. Would a lube car be required to be stored in either an underground fuel storage area or facility?
A. Yes, if the lube car is used to transport diesel fuel. If it does, it would be considered a diesel fuel transportation unit, and, under §75.1906(i), it must be parked either in a permanent underground diesel fuel storage facility or a temporary underground diesel fuel storage area when not in use.
Q. What is the definition of mantrip for purposes of the restriction on carrying safety cans in §75.1906(k)? Many vehicles perform double duty as supply vehicles and personnel carriers. How will MSHA distinguish them for purposes of the standard?
A. The term mantrip means a vehicle or elevator used to take a work crew into and out of the mine. A vehicle that is being used for double duty, i.e., that may serve sometimes as a mantrip and at other times as a supply vehicle, would be considered a mantrip for purposes of this standard only when it is performing that function. Additionally, a vehicle used, for example, by a mechanic and his helper would not be considered a mantrip. The safety can prohibition on mantrips in the final rule addresses the inherent hazards associated with the transportation of diesel fuel on personnel carriers.
Q. Would an elevator bringing a work crew into the mine be considered a mantrip, and subject to prohibition against carrying safety cans in §75.1906(k)? Would the elevator
that is not carrying a work crew be considered a vehicle and subject to the one safety can limitation under §75.1906(b)?
A. An elevator bringing a work crew into the mine would be considered a mantrip, and therefore may not be used to transport a safety can into the mine at the same time. However, the final rule does not limit the number of safety cans that can be transported into the mine on an elevator or slope car when the conveyance is not being used as a mantrip, because neither would be considered a vehicle. However, it should be noted that once the safety cans are in the mine they may only be transported one can per vehicle or stored in a permanent fuel storage facility.
Q. Does the prohibition on carrying diesel fuel on mantrips in §75.1906(k) include an exception for the single safety can authorized in paragraph (b)?
A. No. The prohibition in paragraph (k) on carrying diesel fuel on mantrips does not permit either mantrips or conveyor belts to be used to carry even a single safety can of diesel fuel.
Section 75.1907 -- Diesel-powered equipment intended for use in underground coal mines
Q. If the engine on a unit of nonpermissible diesel-powered equipment is sent out for rebuilding, what requirements apply?
A. After November 25, 1999, all engines on nonpermissible diesel-powered equipment must be approved under subpart E of part 7. Therefore, any engine used in an underground coal mine on or after that date must be an approved engine. If an approved engine is sent for rebuilding or repair it must be rebuilt or repaired to an approved condition.
Q. Will existing part 32 engines meet the part 7, subpart E, category B requirements by November 25, 1999?
A. Although most if not all engines that have been approved under part 32 would satisfy the gaseous emission requirements of part 7, the engine manufacturer must obtain formal MSHA approval under subpart E of Part 7 for the engine by November 25, 1999. If the engine manufacturer does not obtain approval by the effective date of that requirement, the equipment cannot continue to be operated in an underground coal mine. The equipment engines must be replaced with engines that have been approved under subpart E of part 7.
Q. Who is responsible for determining the particulate index and the approval plate air quantity under §75.1907(b)(4) for existing permissible diesel-powered equipment?
A. MSHA has worked with NIOSH to arrange tests by the Center for Diesel Research in Minneapolis, Minnesota, to determine revised ventilating air quantities and particulate index for the four most common engines in part 36 equipment currently in use in underground coal mines. MSHA has already made information on 3 of these engines available to the mining community through Program Information Bulletins and postings on MSHA's Internet Home Page. The test results for the remaining engine will be released as soon as it is available.
Q. By November 25, 1999, nonpermissible equipment will have many of the same features as permissible equipment. Can nonpermissible equipment then be taken into face areas?
A. No. Although the final rule requires a number of safety features similar to those required permissible equipment to be provided on nonpermissible equipment, the fact remains that this equipment is not permissible. The safety features required on nonpermissible equipment, although similar in some cases to the features required on permissible equipment, do not provide the explosion-proof protections which are key for permissible equipment.
Q. Will permissible equipment be required to have automatic fire suppression systems if they are used in return air courses?
A. No. Permissible diesel-powered equipment may be provided with either a manual or an automatic fire suppression system, regardless of where it is operated in the mine. The one exception is set forth in §75.380, which pertains to equipment operated in the primary escapeway.
Section 75.1908 -- Nonpermissible diesel-powered equipment -- categories
Q. What is the definition of longwall components for purposes of §75.1908(a)(3)?
A. The term longwall components includes large, heavy, equipment, such as shearers, shields, and pan lines. It would not include such small items as cables and lights, even though they are used on a longwall system.
Q. Is there a weight limit for longwall components?
Q. Is a vehicle used on the belt line to clean up spilled coal considered heavy-duty or light-duty equipment?
A. The equipment would be considered heavy-duty because it is used to move coal.
Q. Would a vehicle used to haul gravel be considered heavy-duty?
A. Yes. The equipment would be considered heavy-duty because it is used to move rock.
Q. Would a vehicle pulling a trailer containing concrete blocks be considered light-duty or heavy-duty?
A. The vehicle would be considered to be light-duty equipment because it is used to haul supplies rather than rock or coal.
Q. Would a road grader be considered heavy-duty equipment?
A. Yes. A road grader would be considered heavy-duty equipment because in the process of grading roads it moves rock.
Q. Would a tug used to move supplies be classified as heavy-duty equipment?
A. No. That equipment would be considered light-duty equipment because it does not move rock or coal.
Q. What does the term lube unit mean as used in §§75.1908(a)(4) and (5)? Is a lube unit something that is used to carry diesel fuel?
A. A lube unit is a conveyance that carries any combination of one or more of the following: grease; hydraulic fluid; gear oil; diesel fuel; or brake fluid.
Q. Would a lube unit be considered heavy-duty equipment, even if it does not carry diesel fuel?
A. Yes. A lube unit that does not transport diesel fuel would still be considered heavy-duty equipment. Sections 75.1908(a)(4) and (5) specifically include both self-propelled and portable diesel-powered lube units within the definition of heavy-duty equipment.
Q. When a permissible rock duster is operating and the operator goes through either a door, a curtain, or a stopping, would the rock duster be considered attended or unattended?
A. Section 75.1908(c)(1) provides that any machine or device operated by a miner is considered attended. This requires a miner to be at the controls of the machine and within close proximity of the diesel engine. Examples would be a scoop operator or a roof bolter operator. Paragraph (c)(2) provides that equipment is attended if it is in the direct line of sight of a job site located within 500 feet of the machine, and that job site is occupied by a miner. This is intended to allow the operation of certain portable equipment, such as welders and sealant machines.
MSHA does not intend to prohibit, for example, a miner at a job site which is within 500 feet and in the line of sight of the welding machine from performing the welding operation when his view of the welder is obstructed for short periods of time. Conversely, this requirement is not intended to allow a miner to be at the end of a rock dust hose at a job site that is out of sight of the rock dusting machine. The purpose of this requirement is to ensure that a person will be in a position to check the operation of the diesel machine and intervene if for any reason the machine should start to present a hazard.
Q. Would equipment used for multiple uses be considered heavy-duty at all times or only while performing heavy-duty tasks? Example -- a vehicle used to pull a trailer full of cinder blocks would be light-duty; however, the same vehicle pulling a fuel storage trailer would be heavy-duty?
A.Section 75.1908 distinguishes between light-duty and heavy-duty equipment based on the work the equipment is actually performing, not based on the work it is capable of performing. Equipment that may have the capability of performing work under heavy load may in fact not be considered a heavy-duty machine under the regulations because it is used to perform only light-duty work. However, a machine that performs heavy-duty functions, even if only intermittently, must comply with all of the requirements for heavy-duty equipment. Once installed, the equipment features must be properly maintained.
The requirements are almost the same for both categories of equipment. The only difference is that heavy-duty equipment must be provided with an automatic fire suppression system, a supplemental braking system, and undergo a weekly check of undiluted exhaust emissions.
Q. A diesel-powered locomotive is used for heavy-duty work only for limited and discrete periods several times a year, i.e., to move shields during longwall moves. During the rest of the year the equipment is used only for light-duty work, i.e., to move supplies. The locomotive will be provided with all of the equipment features required for heavy-
duty equipment under §75.1909. Is the equipment required to undergo the undiluted
exhaust emissions tests required by §75.1914(g) every week, regardless of whether the equipment is being used for heavy-duty work in that week?
A. The undiluted exhaust emissions tests required under §75.1914(g) would only be required in those weeks when the equipment is used to perform heavy-duty work. However, MSHA recommends that the emission test be conducted in the week immediately preceding any week that the equipment will be used to perform heavy-duty work, to eliminate any question as to whether the requirement has been satisfied.
Additionally, it should be noted that the intent of this requirement is to monitor engine performance to determine when engine maintenance is necessary. Conducting this test intermittently or only a few times a year may not provide adequate data for this evaluation, particularly since the records of these tests are not required to be maintained for longer than a year. Mine operators should take these factors into account in developing their testing and evaluation procedures.
Q. If diesel-powered emergency vehicles comply with the requirements of §§75.1909 and 75.1910, must they still be included in the firefighting and evacuation plan?
A. No. The emergency vehicles are required to be included in the firefighting and evacuation plan only if the mine operator is claiming an exemption for that equipment from compliance with the requirements of §§75.1909 and 75.1910.
Q. If a piece of nonpermissible diesel-powered equipment has an onboard hydraulic system capable of operating a small rock/coal drill used for spot roof-bolting in outby areas, does this mean that it is heavy-duty equipment? (i.e., hydraulic PTO's on converted 320 tractors used to pull supplies).
A. If the equipment is used to perform drilling, it will be considered heavy-duty equipment.
Q. Does the use of drags on equipment make the equipment heavy-duty?
A. Light-duty equipment equipped with drags, which is performing its normal function, would not be considered heavy-duty equipment. However, equipment that pulls drags in order to function as a road grader would be considered heavy-duty equipment.
Section 75.1909 -- Nonpermissible diesel-powered equipment; design and performance requirements
Q. Section 75.1909(a)(2) requires that fire extinguishers be within easy reach of the equipment operator. Would this allow them to be mounted outside of the cab?
A. The rule does not require that the extinguisher be located inside the equipment cab, only that the extinguisher is within easy reach of the operator and protected from damage.
Q. Section 75.1909(a)(2) requires that nonpermissible equipment be equipped with a portable fire extinguisher, which must be protected from damage. To what degree does a fire extinguisher have to be protected? Will a guard on the gauge and control handle suffice, given that the extinguisher tank itself is substantially constructed and does not need additional protection?
A. The intent of this standard is to ensure that a fire extinguisher is readily available and functional in the event of a fire on diesel-powered equipment. Compliance with this standard could mean that the extinguisher is either located in an area of the operator's cab where it is out of the way of damage, or that the extinguisher itself is guarded to protect it from damage during normal operation of the equipment. Substantial construction of the extinguisher tank alone does not meet the intent of this requirement.
Q. Are there any requirements for on-board vehicle fuel tank construction? There have been occasions at our mine where equipment fuel tanks leak on the equipment engine.
A. This section of the final rule addresses that hazard. Section 75.1909(a)(3) includes fuel system requirements for diesel-powered equipment. Leaking equipment fuel tanks would be in violation of paragraph (a)(3)(I), which requires that the fuel tank and fuel lines not leak. Paragraph (a)(3)(v) further requires that the fuel tank, filler, and vent be located so that leaks or spillage will not contact hot surfaces.
Q. What is considered a hot surface under §75.1909(a)(3)(viii), which requires that primary fuel lines must be located so that fuel line leaks do not contact hot surfaces? Is a cold surface anything under 302 °F?
A. No specific temperature limit defines what constitutes a hot surface. Hot surfaces would include surfaces of the engine's exhaust system, but may include other machine surfaces that are heated through machine operation. The intent of this requirement is to prevent leaking fuel from coming into contact with any surface that is hot enough to ignite diesel fuel. The autoignition temperature of diesel fuel is generally above 400 °F.
Q. Would the fuel piping systems on diesel-powered highway vehicles such as Isuzu, Dodge, General Motors, or Ford products, meet the requirements for fuel line piping under the final rule?
A. Most of the fuel systems on commercially-available diesel-powered vehicles substantially comply with the requirements of the final rule, and either need no modifications or can be brought into full compliance with minor modifications.
Q. To what extent must fuel lines and electrical wiring be separated to comply with §75.1909(a)(3)(ix)?
A. There are several different methods that can be used to comply with this requirement. These include physical separation by distance of the fuel lines from the electrical wiring. Other methods include placing the wires or fuel lines into a conduit, or bundling the electrical wires above the fuel lines, to ensure that no fuel will drip on the wires.
Q. If all electric wires are located in conduits, would that constitute separation from fuel lines required under §75.1909(a)(3)(ix)?
A. Yes, so long as the conduit prevents the leaking fuel from coming into contact with electric wires.
Q. With regard to the manual shutoff valve requirement in §75.1909(a)(3)(x), can the shutoff valve be located in utility vehicles (Ford, Isuzu, etc.)?
A. Yes. The accessibility to the shutoff valve is as important a consideration in determining the location of the valve as is the proximity of the valve to the tank.
Q. Can a solenoid-operated fuel shut-off valve tied into the vehicle's ignition switch replace the manual shut-off valve required by §75.1909(a)(3)(x)?
Q. Are cylinder head temperature sensors required on water-cooled engines?
A. No. Section 75.1909(a)(4) requires sensors to monitor the cylinder head temperature only on air-cooled engines.
Q. What means are available to comply with §75.1909(a)(10), which requires that a means be provided to prevent the spray from ruptured hydraulic or lubricating oil lines from being ignited by contact with engine exhaust system component surfaces?
A. The requirements of this paragraph are performance-oriented, and are intended not only to allow flexibility in compliance but also to accommodate new technology developed in the future. One method of achieving compliance with this requirement is through the use of water-cooled exhaust components. A safety component system certified under part 36 or a power package approved under subpart F of part 7 also satisfies the requirements of this paragraph.
Non-absorbent insulating materials are also available for use on mining equipment to reduce the surface temperature of diesel exhaust system components. Such materials, which were first developed for diesel-powered military vehicles, are impervious to hydraulic fluid, lubricating fluids, and diesel fuel, and have been successfully used on mining equipment in the United States and Canada. Use of these materials can reduce surface temperatures of exhaust components to less than 300 °F, and may also be used to prevent contact of hydraulic fluid and lubricating oil with hot surfaces.
The use of shielding or partitions to isolate hydraulic components from the engine would also satisfy the requirement of this paragraph, preventing the fluid from contacting the engine in the event of a leak.
Q. Section 75.1909(a)(10) requires that a means be provided to prevent spray from ruptured hydraulic or lubricating oil lines from being ignited by contact with engine exhaust system component surfaces. What are considered engine exhaust system component surfaces?
A. Engine exhaust system component surfaces would include any component that exhaust gas touches, including but not limited to heads, turbochargers, manifolds, mufflers, exhaust pipes, and catalytic converters.
Q. How many braking systems are required for nonpermissible equipment?
A. The answer to this question depends on whether the equipment is self-propelled, and also whether the equipment is heavy-duty or light-duty. There is no requirement for a braking system for nonpermissible diesel-powered equipment that is not self-propelled. Sections 75.1909(b)(7) and (b)(8) require that all nonpermissible self-propelled equipment be provided with service brakes. Section 75.1909(c) requires that nonpermissible self-propelled heavy-duty equipment, except rail-mounted equipment, be provided with a supplemental braking system that meets specific requirements. Section 75.1909(d) requires that self-propelled nonpermissible light-duty equipment, except rail-mounted equipment, be provided with a parking brake that meets specific requirements.
Q. Aren't accumulators built into machines to assist in steering? Won't compliance with the provisions of §75.1909 (b)(1) -- which requires a means to ensure that no stored hydraulic energy that will cause machine articulation is available after the engine is shut down -- result in a hazard due to loss of steering ability? Will a slow bleed-off of stored hydraulic energy be acceptable?
A. The standard does not require an immediate loss of hydraulic pressure. The intent of this requirement is that the pressure drain off over a short period of time, to keep the machine from having steering cylinders activated when the machine is shut down. This feature is already provided on many permissible diesel-powered machines.
Q. Section 75.1909(b)(6) requires service brakes that are designed such that failure of any single component, except the brake actuation pedal or other similar actuation device, must not result in a complete loss of service braking capability. Does a service brake that operates off a disc welded to the input pinion of an axle comply with this requirement?
A. Yes, if there is a separate disk for both axles.
Q. Section 75.1909(b)(6) requires that self-propelled nonpermissible equipment be provided with service brakes that act on each wheel of the vehicle. A small diesel 3-wheel carrier is being designed to use a single mechanical disk brake on the rear driveline (which in turn acts on both rear wheels) and a single mechanical brake on the sole front wheel. Would this meet the requirements of paragraph (b)(6)?
A. Yes, provided that all of the regulatory requirements are met. The regulations require that the braking system safely bring the fully loaded vehicle to a complete stop on the maximum grade on which it is operated. Additionally, the brake system design must be such that failure of any single component, except the brake actuation pedal or other similar actuation device, does not result in a complete loss of service braking capability.
Q. A six-wheel vehicle similar to a highway grader has brakes on the rear four wheels. The vehicle is equipped with an independent left to right side service braking system and a spring-applied, air-released secondary brake located on the transmission output. Supplying front brakes would be difficult. What does §75.1909(b)(6) require for this type of brake design?
A. The standard requires that service brakes be provided that act on all six wheels. In the example given, the front wheels would have to be equipped with service brakes.
Q. Section 75.1909(b)(7) requires that service brakes must safely bring the fully loaded vehicle to a complete stop. Is safely defined as a stopping length, a g factor, or as a length of time from actuation?
A. While this standard does not specify stopping times or distances, whether or not the service brakes stop the vehicle safely depends upon the operating conditions. Compliance is highly site-dependent because of the variations in equipment use as well as mine grades. The mine operator is responsible for ensuring that the equipment has adequate braking and holding capabilities based on the loads the equipment hauls and the grades on which the equipment operates.
Q. How do the requirements for service brakes on self-propelled, nonpermissible diesel-powered equipment apply to equipment that utilizes hydrostatic wheel motors as the means of power transmission to the wheels?
A. For purposes of answering this question, it is assumed that the hydrostatic wheel motors are used to provide a substantial portion, if not all, of the equipment's service braking capability.
Section 75.1909(b)(7) requires that service brakes safely bring the fully loaded vehicle to a complete stop on the maximum grade on which the equipment is operated. The preamble to the final rule describes the desired stopping performance, and further states that the mine operator is responsible for ensuring that equipment with adequate grade-holding capacity is used at a particular location.
The intent of the final rule is that the service brake stop and hold the equipment in place, whether the braking capability is developed by means of hydrostatic motors, by a separate service brake, or by a combination of the two. Where hydrostatic wheel motors provide the service braking capability, it is not acceptable to expect the machine operator to feather the tram pedals in order to hold the machine stationary.
Section 75.1909(b)(8) prohibits the installation of devices that trap a column of fluid to hold the brakes in the applied position. The preamble language clarifies that this prohibition is not intended to apply to hydrostatic drive wheel motors that are designed and maintained to function as service brakes, if the motors meet the performance requirements of the rule, i.e., both stopping and holding the equipment stationary. It may be necessary to supplement the hydrostatic wheel motor braking effect with a separate conventional service brake when the equipment will be used on slopes, to move heavy loads, or if the design of the hydrostatic drive system results in an unacceptable stopping distance or vehicle movement after the equipment is stopped.
Q. Are there any service and supplemental brake requirements for crawler-mounted equipment?
A. The requirements in §§75.1909(b)(7) and (b)(8) of this section of the final rule would apply to nonpermissible crawler-mounted equipment, as well as some of the requirements in paragraphs (c), (d), and (e), depending on whether the equipment in question is heavy-duty or light-duty.
Q. With regard to the requirements of §§75.1909(c) and (d), aren't supplemental and park brake systems one and the same? Are they two separate systems?
A. The final rule requires that parking brakes be provided on self-propelled nonpermissible light-duty equipment, and the brakes must meet the requirements of paragraphs (d). Self-propelled nonpermissible heavy-duty equipment must be provided with a supplemental braking system that meet the requirements in paragraphs (c)(1) through (c)(5). The supplemental systems required for heavy-duty equipment provide the same parking brake capabilities as on light-duty equipment, and additional braking functions that are required on similar electric-powered equipment under §75.523-3.
Q. Section 75.1909(c)(1) requires a supplemental braking system for heavy-duty equipment that engages automatically within 5 seconds of the shutdown of the engine. Is it MSHA's intent that the brakes engage within 5 seconds or that the vehicle come to a stop within 5 seconds?
A. MSHA intends that the brakes engage within 5 seconds of the shutdown of the engine, consistent with the language of the standard. This interpretation is the same as that for a similar requirement in §75.523-3, which apply to brakes on electrical equipment.
Q. Section 75.1909(c)(5) requires that the supplemental braking system for heavy-duty equipment have a means in the equipment operator's compartment to release the brakes manually. Will a hand pump inside the operator's cab meet the requirements of the standard?
Q. Can releasing the pressure from a spring-applied, hydraulically release brake slowly through a reverse modulating valve be used for service braking?
A. Whatever system that is used for service braking must meet the requirements in §§75.1909(c)(6) and (c)(7), which apply to those braking systems.
Q. Does §75.1909(e) require the park brake to be automatically applied when the equipment operator is not at the controls?
A. No, the park brake can be applied with a manual control.
Q. Section 75.1909(g) requires that any nonpermissible equipment that discharges its exhaust directly into a return air course be provided with a power package approved under subpart F of part 7. Does this requirement apply to diesel-powered air compressors?
A. This requirement applies to all diesel-powered air compressors that discharge their exhaust directly into a return air course. The basis for this requirement is the possibility that the return air course may contain high levels of methane, which could be drawn into the machine's exhaust system as it cools down after engine shutdown. This creates the potential for ignition of the methane by the hot surfaces of the diesel engine.
Q. If we choose to put an automatic rather than a manual fire suppression system on a piece of light-duty equipment (which is required to have only a manual system) does the system have to meet all the requirements of an automatic system, which are more extensive than for a manual system?
A.Section 75.1909(I) provides that self-propelled nonpermissible light-duty equipment must be equipped with an automatic or manual fire suppression system meeting the requirements of §75.1911. If an automatic system is provided on light-duty equipment, it must still meet all the requirements for automatic systems under §75.1911.
Q. Section 75.1909(j)(1) requires that nonpermissible equipment that is not self-propelled be provided with a means to prevent inadvertent movement of the equipment when parked. Would the use of wheel blocks or chocks be an acceptable method of complying with this requirement?