If amusement attractions use mechanical, pneumatic, or hydraulic energy, these systems shall have a means of being locked out, when necessary, for performing maintenance or inspections. Pressure vessels and pressure vessel systems shall conform to the requirements of the Maryland Boiler and Pressure Vessel Safety Act, Public Safety Article, §§12-901—12-919, Annotated Code of Maryland, and COMAR 09.12.01, including the inspection requirements. Hydraulic Systems. Hydraulic systems and other related equipment used in connection with an amusement attraction shall be: Maintained to ensure safe operation at all times; Equipped with a relief valve; Equipped with a manual lowering valve, if applicable; and Inspected for leaks, damaged pipes, and worn or deteriorated hoses before each operation. A pressure gauge shall be required for all hydraulic systems and conspicuously marked with the maximum safe working pressure. A flexible hose shall be: Compliant with the manufacturer's specifications; Compatible with the fluid used in it; and Inspected to ensure proper installation. Welding. Welding, welding procedures, and welding procedure documentation shall comply with ASTM F 2291—04, Section 15. Fasteners. All fasteners shall conform to the manufacturer's specifications or accepted engineering practices. Owners shall comply with: The manufacturer's torque specifications and replacement schedules; or Accepted engineering practices. Machinery and Machine Guarding. The owner shall install machine guards or apply other appropriate measures to protect persons from contact with belts, chains, pulleys, gears, and similar moving components. Guards shall be: Designed to perform a specific task; Properly secured; and Properly maintained in a condition consistent with the intent of the guards' design. Before a guard is removed for maintenance purposes, the equipment shall be locked out or tagged out. The guard shall be replaced before normal operation is resumed. Power transmission devices and any associated moving parts shall be shielded, enclosed, or barricaded to provide proper protection. If it is reasonably foreseeable that parts can break free from a power transmission device, the owner shall make provisions to contain the components. Temporary guards shall be secured to prevent movement or tip-over if a person falls or stumbles against the temporary guard. A guard or barrier shall be designed so that it does not pose a hazard in itself. Hair Guards. If it is reasonably foreseeable that a mounting on an amusement attraction can catch or entangle long hair, the amusement attraction shall be equipped with a hair guard. Seating. Tubs, cars, chairs, seats, gondolas, and other carriers used on an amusement attraction shall be designed, constructed, and maintained in accordance with this chapter and manufacturer's specifications. Parts of an amusement attraction that riders may reasonably be expected to come in contact with shall be smooth and free from unprotected protruding studs, bolts, screws, sharp edges, and rough or splintered surfaces. Parts on or against which a rider may be thrown by action of the amusement attraction shall be adequately padded to prevent or minimize the possibility of injury. Upholstery and padding shall be kept in good repair and free of loose portions. Safety Retaining Devices. Safety retainers shall be provided, where possible, on tubs, cars, chairs, seats, gondolas, or other carriers that depend on a single means of attachment or support. Safety retainers shall be designed and installed to prevent a carrier from being catapulted if it becomes disengaged from its support or attachment. Restraining and Containing Devices. A restraining or containing device, or a combination of the two, shall be provided on tubs, cars, chairs, seats, gondolas, or other carriers if: Forces resulting from operation, mechanical malfunction, or both, may unseat or dislodge a rider; Inadvertent movement of a rider may cause injury to the rider or another rider; or The speed of the amusement attraction may present a hazard to a rider. A restraining or containing device shall be designed, constructed, installed, and maintained to withstand the intended forces produced by the amusement attraction and the reasonably foreseeable actions of the rider. Anchorage for a restraining or containing device shall have strength at least equal to the strength of the device. A restraining or containing device: Shall provide safe support for riders; Shall be designed to prevent inadvertent release by a rider or by accidental means while the amusement attraction is in motion; and May not pose a hazard in itself. Speeding and Overloading. An owner may not permit an amusement attraction to be: Loaded beyond its rated capacity; or Operated at an unsafe speed or at any speed other than that prescribed by the manufacturer's specifications. Speed-Limiting Device. If the amusement attraction is capable of exceeding the maximum speed, then a speed-limiting device shall be installed and functional to ensure that the amusement attraction does not exceed the maximum prescribed speed. Brake System. The owner shall ensure that a braking system is utilized if coasting renders the operation dangerous: During the period the amusement attraction is being loaded or unloaded; In the case of power failure; or In any other situation. If the failure of the braking device results in an unsafe condition, the braking device shall be fail-safe. If cars or other components of an amusement attraction may collide and cause personal injuries on failure of normal controls, an emergency system sufficient to prevent these collisions shall be provided. An amusement attraction using inclined tracks, designed to operate in only one direction and having a lift hill with a vertical height exceeding 15 feet, shall have an automatic antirollback device sufficient to prevent rider-carrying units from moving backward if the propelling mechanism fails. Internal Combustion Power Sources. Internal combustion power sources shall be: Of adequate type, design, and capacity to accommodate the design load; Located to permit proper maintenance; and Protected by guards, fencing, or an enclosure to prevent exposure to hazards and to secure the equipment. Engine exhaust shall be discharged away from the public, so as not to create a hazard. Fire extinguishers shall be placed in locations that are readily accessible and compliant with COMAR 09.12.60.12B. Fuel Tanks. With the exception of go-kart operations as regulated under COMAR 09.12.64.10D, an amusement attraction shall be closed down and unloaded during refueling. Refueling shall be in an area remote from the public. Fuel supply may not be replenished while engines are operating. Enclosed Areas. An enclosed area in which an internal combustion engine is operated shall be adequately ventilated. Engine exhaust fumes shall be discharged outside the enclosed area.