ufc_4_179_02_2020_CHAPTER 4 ONLY.pdf

UFC 4-179-02

5 March 2020

CHAPTER 4 INDOOR RANGES

4-1 GENERAL.

Indoor ranges have open bays with shooting generally straight downrange into a bullet trap. Ballistic containment is provided by ballistic side walls, overhead baffles, and a bullet trap. Indoor ranges can be built using conventional or modular construction methods. A push-pull ventilation system supplies air from behind the firing line and exhausts at the trap end to move airborne contaminants downrange and away from personnel inside the range. Design and construct Army and Marine Corp indoor ranges IAW applicable portions of this UFC and the design and safety requirements found in DA Pam 385-63; the DA PAM controls in case of conflict.

Coverage.

The ballistic containment criteria in this chapter is intended for indoor ranges that support weapons and ammunition with energy up to 2,500 foot-pounds (3,390 Newton-meters) including handguns, 5.56 mm rifles, and 7.62 mm rifles. It does not support:

Tracers, explosives or incendiary rounds.

Armor Piercing (AP) rounds.

5.56 mm or 7.62 mm Enhanced performance rounds (EPR), (M855A1 or M80A1).

Design the range systems for the specific, worst-case rounds for these or other higher-powered weapons. The ballistic containment system includes baffles, floors, walls, splatter protection, and bullet trap.

Range Areas.

An indoor range facility can be divided into three functional areas:

The training area between the rear uprange wall and the bullet trap where live fire occurs. The training area requires a ballistic envelope to contain rounds within the facility.

The direct support area that includes the range safety officer’s office, entrance vestibules, storage areas immediately off the training area, and the area behind the bullet trap.

The indirect support area and all other spaces including administrative, restrooms, classrooms, hallways, and other storage areas.

4-2 TRAINING AREA.

Define training requirements, ammunition, target distances, and maintenance issues prior to developing a floor plan. For ranges approaching 100 ft. (30.5 m) width and wider, the cost and size of structural components can increase significantly and should be taken into consideration when determining number of lanes and range width.

Consider multiple bays to provide flexibility and reduce structural loads.

Navy: The Navy standard qualification range has an 82 ft. (25 m) target distance with 4 ft. (1.2 m) lane widths. Note that while some Navy training only requires a 25-yard target distances, a 25-meter range provides additional capability and safety. For Naval Special Warfare indoor ranges, the layout is not standard and will vary depending on type of training supported.

Air Force: Use Air Force Facility Criteria FC 4-179-03 for planning and layout of indoor ranges along with general requirements provided in Chapter 1. This Air Force FC provides general guidance on lanes and detailed planning requirements for the indirect support areas.

USMC: Typical indoor ranges have either 82 ft. (25 m) or 164 ft. (50 m) target distances.

Army: Base layout on training and installation specific requirements.

4-3 DIRECT SUPPORT AREA.

Range Control Booth.

Ventilation, Layout, and Sound Attenuation.

Include a ventilation system independent of the training area range ventilation system and a 2 ft. (0.8 m) wide, full-length work counter at the base of the window. Locate all range controls and utility panels in this area. Locate lighting and communications controls to allow adjustments while maintaining clear visibility downrange. Provide sound attenuation to allow personnel in the booth during live fire without the need of hearing protection as described by the noise paragraphs in this chapter.

Visibility.

Design range control booth to provide full line-of-sight visibility from a center seated position 4 ft. (1.2 m) behind a 4 ft. (1.2 m) high window to 4 ft. (1.2 m) behind the firing line on both sides and extending downrange to the target area. See Figure Fig 4-1.

Coordinate window level with that of the ventilation supply diffuser so the downrange view is not blocked by the diffuser when standing. Windows and doors within the booth must not restrict or distort the view downrange. Closed-circuit television monitors may be used to enhance, but will not replace, this requirement. Provide windows with views into the hallway behind and vestibules to the sides that allow monitoring of movement in and out of the training area. Use sliding closures or other method on the windows into hallways and vestibules that can be used to completely block light from coming into the range control booth during low light conditions. For Air Force ranges, raise floor in booth a minimum 2 ft. (0.6 m) minimum above the range floor to promote visibility downrange and to all range entry points.

Airlock Vestibules.

Entrance vestibules with doors at either end are required to allow movement in and out of the range without disturbing the air balance of the range. A minimum of one vestibule for ranges with seven lanes or less, and two vestibules for ranges with more than seven lanes is required. Place vestibules adjacent to the Range Control Booth with windows to allow monitoring of movement from the booth. All doors into the training area must swing outward from range to help seal doors under negative pressure. Seal around doors and place sweeps at bottom to provide an airtight closure.

Vacuum Storage.

Include a storage area with direct access to the training area for portable High Efficiency Particulate Air (HEPA) vacuum and equipment storage.

Brass Storage.

A 55-gallon drum may be placed next to side wall behind firing line for brass storage immediately after collection.

4-4 TRAINING AND DIRECT SUPPORT AREA LAYOUT.

The width of the range is determined by the number of lanes, width of lanes, and the space provided against each side wall. The length of the range is determined by the distance behind the firing line, the target distance, the depth of the bullet trap, and the space behind the bullet trap. The height of the range is determined by the clear height between floor and bottom of the ceiling baffles, the ceiling baffle height, and the distance above the baffles needed for structural and mechanical systems. Make all surfaces downrange in direct line of fire non-reflective when lasers are allowed in training.

Use Figures 4-1, 4-2, and the following minimum distances:

Range Control Booth: 10 ft. (3 m) front to back.

Get Ready Area: Table 4-1.

Target Distance: As required for training. Do not extend target system into the trap.

Bullet trap: Approximately 27 ft. (8.2 m) – coordinate with trap manufacturer.

Maintenance Area: Minimum 6 ft. (1.8 m) behind bullet trap. Verify there is enough space in maintenance area for all trap components, compressors, and other hardware. This is area must not be used for storage.

Clear Height: Table 4-1 for minimum distance. May need higher ceilings if vehicles are used in training.

Distance between top of baffles and bottom of roof: As needed, including space for structural components and ventilation ductwork.

Distance between edge lanes and side walls: Minimum 2 ft. (0.6 m). This distance is needed to help achieve proper airflow and prevent shooting near side walls.

Lane Width: Minimum 4 ft. (1.2 m). Service and training requirements may dictate wider lanes.

Avoid interior columns when possible. If provided, include a 2 ft. (0.6 m) buffer between column and lanes.

Safety Ceiling: Extend ballistic coverage to 4 ft. (1.2 m) behind firing line.

Standard Range Layout

Standard Range Section.

Table 4-1 Range Heights and Get Ready Area Distances.

Target Distance (TD) Clear Vertical Height Get Ready Area (Backwall to FL)

Up to 82 ft. (25 m). 8 ft. (2.4 m) 16 ft. (5 m)

Over 82 ft. (25 m) up to 165 ft. (50 m). 10 ft. (3 m) 18 ft. (5.5 m)

From 165 ft. (50 m) to 328 ft. (100 m) 12 ft. (3.7 m) 18 ft. (5.5 m)

4-5 INDIRECT SUPPORT AREAS.

Required Indirect Support Area.

The following areas are required:

Administrative Area: This area contains offices for the range safety officer, instructors, and maintenance personnel along with file and shelf storage for operations data and maintenance records.

Restrooms, Shower, and Locker Room Areas: Size restrooms based on occupancy and range use. Size shower and locker based on range staff.

Laundry: For range laundry use only.

General Storage: Provide adequate storage for targets, filters, tools, and maintenance equipment.

Maintenance and Storage area.

Other Indirect Support Areas.

The following areas may be necessary:

Brass sorting: Include table with raised perimeter and holes to collection buckets or drums underneath.

Classrooms: This includes space to conduct classroom training prior to live-fire and after-action debriefings.

Weapons Cleaning Area: This space accommodates workbenches, degreasing tanks, and spray hoods. Exhaust hoods and vapor proof electrical fixtures may be required. Provide a lavatory with potable water and eyewash in the immediate area.

Arms and Ammunition Storage: UFC 4-215-01 Armories and Arms Rooms. When provided, include an issue and clearing area adjacent to the weapons storage and cleaning area.

Break Room: Room for meals and breaks with space for refrigerator, sink, countertops, microwaves, coffee machines, table, and chairs. Provide signage that prohibits food inside the training area.

Weapons Simulator Room: Design to accommodate anticipated system.

These rooms may require raised flooring, compressor area, darkened or no windows, and a small control room. Signs must clearly mark room as simulation weapons only, with no lethal ammunition allowed.

4-6 FIRE PROTECTION.

The training area and trap area do not require a sprinkler system. Coordinate with the DFPE early in the design process for detailed requirements for the rest of the building.

Provide 2-hour fire rated construction separating the training and direct support areas from indirect support areas.

4-7 COLLECTION, TEMPORARY STORAGE, AND DISPOSAL.

Design for the collection, storage, and disposal of:

Brass, typically recycled.

Supply filters, non-contaminated.

Exhaust filters, contaminated after use.

Filters from the dust collection system, contaminated after use.

Dust captured in the dust collection system.

Vacuum waste, contaminated.

Trap collection waste, contaminated.

Projectiles captured in trap collection system.

Note: Contaminate refers to material with lead, copper, and other compounds typically at levels that classify them as hazardous waste for storage and disposal purposes.

4-8 STANDARD INDOOR RANGE FEATURES.

Design a ballistically contained structure that:

Contains all shots from each intended firing location, at all respective targets, for all weapons and calibers based on the intended training in the facility.

Provides airtight connections between walls and roof to prevent air leakage into the range that can interfere with the ventilation system’s negative pressure.

Seals all utility connections leading into the range.

Provides proper detailing and door hardware for an airtight closure.

Provides a maintenance double door behind the firing line.

Provides at least one maintenance double door in the area behind the bullet trap. Two double maintenance doors, one on each side, may be necessary to provide access to all heavy items and equipment.

4-9 MULTIPLE BAYS.

To increase flexibility and reduce spans, ranges may be divided into separate bays with structural walls extending the length of the range from floor to roof that prevent air movement between bays. Ranges that have a partial dividing wall or an interior row of columns are not multiple bay ranges. Design each bay to operate independently from adjacent bays with separate and independent:

Ventilation systems and controls.

Bullet traps and trap related equipment.

Target systems.

Range control booths.

4-10 CEILING, WALLS, AND DOORS.

Design walls to reduce noise transmission to adjacent occupied spaces and to withstand negative and positive pressures that would be encountered should the ventilation supply or exhaust fans fail. Walls must provide an airtight enclosure to maintain negative pressure inside the range as required for range ventilation. Seal any penetrations in wall including ductwork and utility penetrations.

Uprange Ceiling and Wall Behind Firing Line.

Slope suspended ceiling from back wall to edge of safety ceiling behind firing line to provide a gradual transition for supply air movement to firing line. Place removable suspended ceiling panels along the width of the back wall under ventilation balancing dampers for maintenance access.

Ballistic Side and Downrange Walls.

Make side walls and the downrange wall behind the bullet trap a minimum of:

Concrete: 8 in. (203 mm) thick using either cast in place, tilt up, or precast construction. Structural design and internal thermal insulation may dictate thicker walls. If internal cavity is provided, the interior section must meet the minimum thickness requirement. Walls must be smooth and flat with no protrusions, indentions, cavities, exposed steel, or any other feature presenting a ricochet hazard.

Steel: Minimum 0.375 in. (9.5 mm) AR500 steel plate.

Provide splatter protection on steel and concrete up to 8 ft. (2.4 m) above the floor and a minimum of 16.4 ft (5 m) down range of all firing positions, except do not place any splatter protection within 10 ft. (3 m) of the bullet trap. This is to allow inspection of the wall where it is most susceptible to bullet strikes.

Wall Joints.

Provide complete ballistic integrity across joints. For side walls, this includes joints from finished floor up to the highest point of the ceiling baffles. For the downrange wall behind bullet trap, this includes up to 12 ft. (3 m) above finished floor. Ballistic integrity can be accomplished using keyed construction joints or by placing 0.375 in. (9.53 mm) thick AR500 steel plate over the joint. When used, design plate to protect the joint and reduce chance of ricochets by:

Flush mounting plate to wall.

Placing a 45-degree bevel on the leading edge of the plate that faces the shooter, with the plate fitted securely to the wall with no gaps over 0.0625

in. (1.6 mm) between plate and wall.

Downrange Doors.

Avoid doors between the firing line and bullet trap, but they may be necessary on large ranges to meet Fire and Safety codes. When placed downrange past the firing line, doors and door hardware must meet UL 752 Level 8 protection standard. This includes doors on back wall behind the trap so that rounds cannot escape during a trap failure.

Doors behind the bullet trap that are located on the side walls are not required to meet this UL level. Use locking hardware, panic hardware, or magnetic door locks to ensure personnel do not inadvertently enter during live fire events. For doors on the side wall between the firing line and bullet trap, a wall baffle must be placed just uprange of door extending from the floor to the height of the door to reduce the chance of an errant shot striking the door hardware.

Maintenance and Vehicle Entrance.

For each bay, include a 6 ft. (1.8 m) wide maintenance double door uprange at least 4

ft. (1.2 m) behind the firing line. A larger door may be required if vehicles will be used in training. These doors are not operated during training and therefore do not require a double airlock vestibule.

4-11 FLOORS.

Concrete floors must be level with a smooth finish, without any protrusions or irregularities.

Seal all floor joints and design to minimize ricochet potential.

Locate longitudinal floor joints between firing lanes. Provide backer material when necessary to support sealant.

Sawed control joints more than 0.25 in (6.3 mm) wide are not permitted.

Traditional chamfered construction joints are not permitted.

Surface seal floor with a waterproof sealant to facilitate cleaning.

Use non-reflective flat or flat satin sealant when range is designed to allow lasers.

Steel floors may be 0.375 in. (9.5 mm) AR500 steel plate with support to prevent sagging.

Provide a slip-proof coating.

Do not apply any surface on the flooring that prevents the bullets from reaching the bullet trap or that will entrap firing residue and hinder the cleaning of the range floor.

4-12 RANGE MARKINGS.

Provide permanent range markings as required by the service. Use nonreflective paint when designing for laser use. The following are recommended:

4 in. (100 mm) wide red floor stripe across the width of rear uprange firing line.

4 in. (100 mm) wide black stripe across the width of the range in front of the trap at the last target line.

4 in. (100 mm) wide vertical black stripes up both side walls with critical target distances starting at the floor and extending 4 ft. up the wall.

Provide 4 in. (100 mm) letters above this line indicating distance with units in either yards or meters depending on training requirements. For ranges with fixed firing lines and movable targets, the distances must be measured starting at the firing line. For ranges with a fixed target line at the trap end, the distances must be measured from the target line back towards the firing lines.

Lane markings at the firing line and the last target line are to be coordinated with users on size and type of markings. For Air Force projects see Chapter 2.

4 in. (100 mm) wide yellow ready line 8 ft. (2.4 m) behind the firing line.

4-13 TARGET SYSTEMS.

Choose target systems based on the type of training anticipated and scoring accuracy required. The type of target system used will influence the floor plan, baffle design, and range height and must be considered in the design. Polices for procuring range target system equipment vary between services. All target systems must be designed to prevent ricochets and splatter from returning to shooters, with steel and other hard material angled and no blunt edges presented to the firing line. A variety of systems are available. Some options are presented below.

Static Target Stands.

Basic target stands allow for manual placement of target. Stands may be of wood, poly synthetic, steel angled away from line of fire, or other material designed to reduce ricochets.

Overhead Target Rail System.

Overhead monorail target systems have:

Rigid overhead rails.

Capability of 180-degree turning targets.

Capability of moving and stopping target at all target distances.

AR500 angled steel plate on front of carrier, target clamps, and connections between clamp and carrier designed for anticipated weapons and ammunition.

Target rails approximately 7.5 ft. (2.3 m) above the finished floor.

Ability to control single targets from individual lanes.

Ability to control both single targets individually and all targets collectively from controls in the range control booth.

Programmable target positions in both yards and meters.

Programmable parameters including positions, start/stop times, and edge face targets.

Drive system located behind the firing line using a cable system for moving targets.

Optional:

Dimmable light illuminating target on target carrier.

360-degree target turning.

Self-driven target carriers with internal motors and drive system.

Running Man Targets.

Running man targets are typically mounted on overhead rails that move targets left and right across the width of the range near the last target line. Running man targets can be either a single target system or a double system that runs two targets in opposite directions at the same time. Coordinate rail location with bullet trap, overhead baffles, other target systems.

Fixed Turning Targets System.

Turning targets are located at the trap end and have a target clamp on a vertical pivoting rod to rotate targets between face and edge. Clamps must hold targets securely but allow one-handed placement and removal of targets. The target clamp and vertical rods should be protected by 0.375 in. (9.5 mm) AR500 steel plate placed at an angle to extend life and help prevent ricochets. The unprotected components of the system must be placed behind overhead baffles to block line of sight from all shooting positions.

4-14 SHOOTING STALLS.

Shooting stalls may be used to provide shooting barriers, separate shooters, mount target controls, block ejecting brass from adjacent lanes, and limit ability of shooters to accidentally shoot sideways. Fold down or swing out tables and barricades may be included. Check individual service policy for requirements.

4-15 BARRIERS AND BARRICADES.

Training may require barriers or barricades and must be addressed in the design.

Include storage space when they are not permanently affixed to the building. These may be portable wooden frames or features incorporated into shooting stalls. Other options include swing out barriers that fold flat to a side wall and barriers that can be temporarily attached to the wall and removed for storage when not in use. Check individual service policy for requirements and procurement policy. The following provides geometry for some service specific barrier and barricade requirements:

Air Force: Position barricades as described in Chapter 2.

Navy: Standing, low, and window barriers for Practical Weapons Courses in OPNAV 3591.

4-16 OVERHEAD BAFFLES AND SAFETY CEILING.

Design baffle system to provide complete overhead containment within the training area in accordance with Figure 4-3 and the following:

Minimum 0.375 in. (9.5 mm) AR500 steel plate.

Maximum 25-degree angle from horizontal.

Minimum 6 in. (0.15 m) horizontal steel-steel overlap between adjacent baffles.

Maximum 0.0625 in. (1.6 mm) mm) gap between steel plates for butt joints and 0.125 in (3.2 mm) where backing plate or lap joint is used.

Non-ballistic vertical closure sections from the lower end of one baffle to the upper end of the next baffle downrange to prevent air from moving between open area below to space above baffles.

Complete coverage from side to side with no gaps. This can be accomplished by using an AR500 plate connected to the side wall that overlaps with the overhead baffles.

Provide intermediate support to prevent steel plates from sagging.

Sealed off baffle section between steel plate and splatter protection to prevent the creation of a plenum that would allow air to move between training area below and ceiling space above. Spacers may be run in either direction provided ends are sealed between steel plates and splatter protection.

Splatter protection provided on all baffle surfaces a minimum of 16.4 ft (5

m) down range of all firing positions.

A closure baffle as shown on the downrange section in Figure 4-2 above may be required to complete ballistic protection when a running man target system is used.

Figure 4-3 Overhead Baffles

4-17 BULLET TRAPS.

Unless directed otherwise, all new indoor bullet traps must be commercial steel traps.

Design the trap for the most powerful round to be used. Steel traps must have:

Minimum 0.375 in. (9.5 mm) thick AR500 steel plate. A thickness of 0.5

in. (12.7 mm) is recommended to increase the life of the plates. All plates will eventually wear and warp depending on weapons, ammunition, and usage.

Capability to replace individual plates as they become worn or warped.

Maximum lower ramp slope of 15 degrees off horizontal.

Maximum slope of 15 degrees off horizontal for upper ramp plates immediately above the deceleration chamber. The upper ramp is typically hung from the roof.

Continuous throat across the width of the trap with no vertical connector sections such that a rod placed inside the slot can move unimpeded across the width of the trap.

Dust collection system to reduce dust at the trap end of the range. Provide forklift access to the dust collection drums.

Spent round collection system. Provide forklift access to collection drums.

Cantilevered Upper Ramp Support.

On existing ranges where a steel trap is being added, verify the roof can handle the additional load. Where the additional load of the trap cannot be supported, a structural cantilevered arm mounted to the floor behind the trap may be used. The cantilever option reduces roof load but takes up more floor space and increases cost. Account for the extra space required when using a cantilevered arm mount.

Dust Collection System.

The trap must include a system to capture and collect airborne contaminants at the deceleration chamber that provides:

Noise levels below 80 dB when measured 10 ft. (1.2 m) from the system.

Fans and filters located outside on back or side wall of range.

Monitoring from within range control booth with indicators that show when system is running, filter status, and when dust collection drums are full.

The ability to turn system on and off from within range control booth.

A minimum volumetric flow of 500 cfm (14 m3/min) for every 10 ft. (3 m) of trap.

Sealed ductwork that prevents the escape of dust.

HEPA filters on the exhaust.

Spent Round Collection System.

Choose either a simple bucket system or mechanical system:

Bucket System.

Bullets fall from the deceleration chamber into buckets underneath. System must be sealed to contain lead dust and allow for easy removal and replacement with no special tools.

Mechanical System.

These increase complexity and cost over the bucket system but reduce the labor involved in collecting projectiles. These can be either:

Auger Bullet Collection Unit: Spent rounds fall from the deceleration chamber into a sealed trough below. An auger pushes the bullets and fragments to one side of the room where another perpendicular inclined auger raises and drops them into a collection drum below.

Drag Conveyor: Same as auger system except a conveyor belt is used to move spend rounds and fragments to the collection drum.

Include capability to monitor status of mechanical system and to turn system on and off from within the range control booth.

Granular Rubber Trap Option.

A granular rubber trap may be used when approved. Do not use on Air Force or Navy ranges.

Advantages and Disadvantages.

Compared to steel bullet traps, granular rubber traps:

Take up less space.

Cost less.

Capture rounds more intact and thus reduce lead dust at the trap end.

Can provide some limited reduction in sound reverberation time.

Require more routine maintenance.

Will fail if rubber levels are not maintained properly.

Can ignite if not used and maintained properly.

NOTE: Rubber trap fires have caused significant damage on several DoD indoor ranges, mostly from using tracers which should never be allowed at indoor ranges.

Design.

Do not reduce the range length when a rubber trap is chosen since it will eliminate the option of replacing the rubber trap with a steel trap in the future. Coordinate baffle and trap layout so that any round fired from any firing position will contact either 2 ft. (0.6 m) of rubber or an overhead steel baffle. Design the trap frame to hold the weight of the trap, rubber, and 120,000 7.62 mm projectiles for every 4 ft. (1.2 m) of trap across the width of the range. Design the trap to reduce the amount of rubber that spills onto the floor and include:

Shredded rubber material with average diameter of 0.375 in. (9.6 mm) to

0.875 in. (22 mm).

Clean chopped rubber that is 99.9 percent free of loose wire or exposed steel, by weight.

Fire retardant and adhesion promotion treatment.

Minimum 2 ft. (0.60 m) of rubber as measured perpendicular to the sloping face.

Coordinate with the local fire authority for design requirements that help contain smoke in the event of a fire including:

Plenum and roof vents above the trap area to collect and release smoke.

Vertical smoke barrier above the ceiling baffles across the width of the range towards the trap end to limit the movement of smoke uprange.

Fire protection plan showing recommended access to trap in the event of a fire.

4-18 COMMUNICATIONS.

Include a loud speaker system between range control booth and range with volume control and capable of producing 110 dBA at the firing line. Locate as to not interfere with supply air flow. Include wall mounted handheld microphones for communication back to the range control booth, with one on each side wall and one on back wall below the range control booth window.

4-19 LIGHTING.

Design lighting system to reduce glare and provide independent lighting zones in accordance with Table 4-2 and:

Locate downrange lights out of the line of fire. This can be accomplished by placing them behind the vertical section of the overhead baffles.

Size and locate light and fixtures behind the firing line so they do not interfere with the supply airflow.

Provide fully dimmable areas with flicker free lighting from 0 to 100 percent intensity levels.

Locate lighting controls in the range control booth to allow adjustments with clear view of training area. Label controls to allow intuitive operation so that an operator unfamiliar with the system will be able to select and manipulate the controls accurately without any instructions.

On ranges where training will occur using Night Observation Devices (NODs), all lighting, including emergency lighting, must be able to be turned completely off. Red lighting may be added downrange to assist visibility during low light training.

Table 4-2 Lighting Requirements

LOCATON **FT CANDLES TYPE

Range Control Booth. 60 Fully dimmable + dimmable red light.

Vestibules. 40 On/Off with switches in vestibule + range control booth.

Get Ready Area and Uprange Firing Line.

60 Fully dimmable + dimmable red light.

Target Area. 80 Fully dimmable.

Last Target Line. 100 Fully dimmable.

Area Behind Trap. 40 On/off.

** Measured at 4 ft. (1.2 m) above the floor.

Range In Use Lights.

Include a red Range In Use light above and outside vestibule entrances that indicate when range is in use. Light is on when range is operational. Locate switch in range control booth.

Security Training Lights.

Optional flashing lights may be required behind or above the firing line to simulate the flashing lights from security vehicles. Choose location to provide desired effect downrange while minimizing impact on ventilation air movement. Check with local security force for proper color and flashing effects.

Emergency Lighting.

For exit lighting, provide low profile lights oriented with smallest profile pointing downrange to minimize interruption of supply airflow.

4-20 NOISE.

Design range to meet:

The maximum ambient and live fire noise levels in Figure 4-3.

Reverberation Time 60dB (RT60) less than 1.3 seconds as described in the sound decay rate testing paragraph below.

Noise to Adjacent Land.

Consider all notable sources of noise associated with the training facility when determining its layout. Noise transmitted outside of indoor ranges can be significant and depends on several factors including weapons and ammunition, thickness and material of walls and roof, roof to wall connections, and direction of fire. Air handling and dust collection systems can also produce significant noise. Noise transmitted outside of indoor ranges can be reduced through a combination of strategic layout, acoustic dampening characteristics of construction materials, and construction methods.

The location of the range and the adjoining land use will determine the acceptable level of noise transmitted outside of the range.

Noise Inside the Training Area.

The training area design must incorporate acoustic control elements to reduce internal ambient noise levels and reverberation time. To meet these levels, the acoustic design should incorporate strategic layout, construction materials with acoustic dampening characteristics, and intentional construction method types. The seals on doors and windows should be tight to minimize the direct transmission of noise out of the firing range and into other interior rooms or occupied spaces of the facility. Absorptive acoustical surfacing will reduce the noise level in the range. Ambient noise does not include the impulse noise generated by gunfire but does include other noise sources such as air handling and dust collection systems. Ambient noise levels are generally controlled by preventing the noise from reaching the occupied spaces. Some noise sources can be isolated from the occupied spaces. Walls with designated Sound Transmission Class (STC) ratings can also be used to separate noise generating equipment from occupied spaces. Extending partitions to the ceiling or roof level and sealing air gaps will reduce noise transmission.

Short duration impulse noise peaks created by gunfire will exceed the 85 dBA level and could exceed 160 dBA. Reflective surfaces in a range will reverberate noise during firing, extending the decay time of the noise.

Acoustical Treatment Locations.

Acoustic absorbing materials may be used behind the firing line and on the wall, ceiling, and ceiling baffle surfaces extending down range. Treat the ceiling baffle nearest to the firing line with acoustic absorbing materials as it is the most important ceiling baffle regarding noise levels behind the firing line. Floor areas of the range must remain bare concrete or steel. The floor behind the firing line may be covered with rubber or other acoustic mitigating materials so long as the materials are suitable for floor application and do not impede the removal of ammunition residue. Include the acoustic design calculations in the design analysis.

Acoustic Panels.

Acoustic panels may be installed on walls, ceilings, and baffles. Blown-on acoustic material and carpeting are not permitted due to the difficulty of cleaning accumulated ammunition residue. Acoustic materials must be nonflammable and not impede the vacuum removal of ammunition residue. Do not paint acoustic tiles or surfaces as paint significantly degrades the sound absorbing qualities of the acoustic surfaces. Acoustic panels often serve dual purpose to mitigate sound and provide bullet splatter protection.

Acceptance Testing.

For all new, addition, and modification projects that include modifications to the sound-absorbing materials within the range, acceptance testing must be performed by an independent acoustic specialist whose firm is a member of the National Council of Acoustic Consultants.

Sound Decay Rate Testing.

The acoustic design must include mitigation methods and construction materials to reduce the measured Reverberation Time 60dB (RT60) to less than 1.3 seconds in the 250 Hz, 500 Hz, 1 kHz, 2 kHz, and 4 kHz octave bands in accordance with ASTM E2235. Testing must be performed in accordance with ASTM E2235 with noise generating devices placed at the firing line. Aim device parallel with the line of fire when not using omni-directional devices. The contractor must provide certified test results showing that the reverberation time requirements are met.

Ambient and Live Fire Noise Level Testing.

The contractor must provide certified test results showing that the ambient and live fire noise levels within the range do not exceed levels shown in Figure 4-3.

All Ambient and peak noise level measurements must be taken with all range equipment on, including the air handling and dust collection systems, and no gun fire.

All live fire noise levels must be taken with all range equipment on and with continuous gunfire from four Government provided shooters firing the maximum caliber design weapon, at full automatic if applicable, and using ball ammunition. Firing must be from the most uprange firing line without using suppressors.

Table 4-3 Maximum Noise Levels

Maximum Ambient Noise Levels (dBA)

Maximum Live Fire Noise Levels (dBA)

Inside the Firing Range 75 Sound Decay Rate Test

Inside the Range Control Booth

60 85

Offices 45 55

Classrooms 45 55

4-21 RANGE VENTILATION.

In order to provide safe training and working environment, the ventilation system must limit exposure to airborne lead, copper, and other contaminants generated during small arms training. To achieve good air flow across the entire firing line, compliance with the following paragraphs is required. A recommended contracting strategy to help achieve these stringent requirements is provided in Appendix B.

General Ventilation Requirements.

All ventilation system controls must meet the cyber-security requirements found in UFC 4-010-06. The training area ventilation system must be separate and independent from the support and administrative area ventilation system. Design the training-area ventilation system to meet the following:

An air flow of 75 fpm (23 m/min.) at the firing lines meeting the acceptance standards included later in this section.

100 percent outside air with no recirculation.

A negative pressure inside the range of -0.05 +/- .02 in (1.3 mm +/- 0.5

mm) of water column relative to the non-training areas in the range.

Paired supply and exhaust units with each exhaust fan interlocked with one corresponding supply fan.

The preferred location of the supply Air Handling Units (AHUs) is on the roof to reduce the amount of turbulence in the air before it reaches the supply plenums.

The preferred location of the exhaust AHUs is on the ground to simplify filter changes.

AHU motors limited to 75 horsepower or less.

Variable Frequency Drives (VFDs) on all supply and exhaust AHU motors.

Supply intake vents separated from exhaust outlets by a minimum 30 ft. (9 m).

Location of exhaust ductwork coordinated with baffle and trap design to protect against direct hit and ricochets.

Independent local control. Base-wide control systems may connect to the system for monitoring purposes but must not control or alter the system settings.

Ductwork protection for all ranges within approximately one mile (1.6 km) of salt water bodies. Include a sprayed-on weather and corrosion resistant coating, such as the polyurea coating used to line truck beds, for all ventilation ductwork exposed to the environment. Consider for all other locations where corrosion is a problem. Choose material and thickness based on local conditions and ductwork material.

See Figure 4-4 for a schematic range ventilation system.

Range Ventilation Schematic

Climate Control.

Heating.

Provide heat when sustained temperatures are under 50 degrees F (10 degrees C).

Specify design heating temperature and heating type. Chose a dry bulb discharge temperature between 65 and 70 degrees F (18 and 21 degrees C) that minimizes temperature differentials between winter and summer temperatures inside the range.

Air-to-air heat exchangers may be included in cold climates when cost savings are supported by life cycle analysis.

Cooling.

Provide cooling only in climates with both sustained temperatures over 100 degrees F and humidity over 70 percent. Evaporative cooling may be considered if reduced temperatures do not drive humidity over 65 percent.

Supply Distribution System.

Design system to provide:

Supply air from the air handling unit through a continuous graduated plenum that is gradually tapered to produce an even pressure along the length of the plenum.

A single or double duct with an adjustable damper leading from the tapered plenum to each diffuser section.

Interconnected double wall radial diffuser sections at the top of the back wall above the viewing window, with each section a maximum 5 ft. (1.5 m) long. Design and size diffuser sections to provide enough surface and free area to smoothly transition air as it moves to the firing line. Radial diffusers may be half or quarter round.

Noise from supply system limited to 70 dBA or less when measured at the most uprange firing line, with no whistling noise coming from the diffusers.

Single stage Minimum Efficiency Reporting Value (MERV) 8 supply filters as a minimum.

A supply filter system that prevents filters from being pulled into fan.

Align dampers within the diffuser sections with lane dividers in order to facilitate testing and balancing.

For high debris areas, provide double stage supply filters consisting of a minimum MERV 8 filter followed by a MERV 13 filter. Take the direction of the prevailing local winds into consideration when selecting location and direction of supply intakes.

Exhaust System.

Design exhaust system to provide:

An air volume of minimum 110 percent of the rated supply volume of air.

An exhaust plenum located above and downrange of the trap entrance, with a semi-continuous slot at the intake spanning the entire width of the shooting lanes.

Minimum exhaust duct velocities of 2000 ft./min (57 m/min).

Air velocities of 350 to 450 fpm (10 to 13 m/min) across the filter media.

A two-stage filtration system with a MERV 15 Bag filter no less than 26 in.

long (66 cm) followed by a HEPA filter with a 99.95 percent efficiency rating.

Three-stage HEPA rated racks, leaving one stage empty for future flexibility.

AHUs sized to provide minimum 5 in. (127 mm) of external static pressure for filter loading over clean required static pressure.

Factory HEPA rated filter housing for the HEPA filter.

AHUs and filter housing with a minimum 4 ft. (1.2 m) clearance from all adjacent features.

Filters capable of being removed and replaced by hand without any special tools or equipment.

Controls.

Incorporate a Direct Digital Control (DDC) system to:

Initiate supply and exhaust fans at low speeds that ramp up to field adjustable levels as necessary to reach desired negative pressure inside the range.

Provide gradual adjustments to power and prevent noticeable hunting and modulation of the AHUs.

Note: Values for adjustable parameters must be selected during design and adjusted during balancing as necessary to optimize air movement.

Incorporate the following:

Two clearly labeled emergency red mushroom cutoff switches wired directly to the supply and exhaust VFDs and the heat enable that manually and safely shut off the entire ventilation system. Locate one switch in the training area behind the firing line and the other inside the range control booth.

Ability to connect to the internet and allow remote diagnostics. The government will provide the internet connection.

A ventilation control panel located in the range control booth with diagnostic screen, an on/off switch, and three condition lights on the panels: Safe to Shoot, Warning, and Do Not Shoot. Locate panel such that all condition lights are easily visible from all positions inside the booth.

Diagnostic screen that scrolls though all conditions, settings, and status.

Require all controls and logic necessary to produce the following light conditions:

(1) Condition-Green Safe to Shoot light:

All systems are within operating parameters.

(2) Condition-Yellow Warning light:

Pressure drop across exhaust pre-filter is past adjustable set point.

Pressure drop across exhaust HEPA filter is past adjustable set point.

Pressure drop across supply filters is greater than an adjustable set point.

Range temperature is outside given adjustable set points.

(3) Condition-Red Do Not Shoot light. If any of these conditions occur, controls will sound alarm and shut down range ventilation system:

Either supply fan or exhaust fan is off.

Pressure differential for any of the air filters is outside extreme limits.

Doors leading into the range from the air lock vestibule remain open for more than a given set point, with an adjustable set point initially set to 5 min.

Door into trap area is opened.

Any door leading into the range training area from outside is opened.

Range pressure is outside the upper limit of zero in. of water and the lower adjustable limit for a given time limit initially set to 2 min.

Supply static pressure is below adjustable limit.

Acceptance Testing.

Test all new ventilation systems and any system where modification or adjustments have been made that would impact airflow.

Controls.

Test all controls for proper operation including fan start up and initiation, emergency cut offs, control panel operation, and all light conditions.

Air Flow.

Uprange:

Take measurements at the most uprange firing line in the center of each lane at 1 ft.

(0.3 m), 3 ft. (0.9 m), and 5 ft. (1.5 m) off the floor. Test with clean filter first, then block off portions of HEPA filters to simulate a yellow warning condition and retest.

Acceptable readings for both scenarios are:

No single reading under 50 fpm (15 m/min) or over 120 fpm (37 m/min).

Each lane average between 60 fpm (18 m/min) and 90 fpm (27 m/min).

Range average between 71 fpm (22 m/min) and 79 fpm (24 m/min).

Downrange:

With clean filters and measurements taken at the most downrange position nearest bullet trap but no closer than 9 ft. (3 m) from trap, take three measurements at each lane at 5 ft. (1.5 m) off floor.

Average of three lane readings must be between 50 fpm (15 m/min) and 80 fpm (24 m/min).

Retest as necessary until all acceptance standards are met.

Notes:

These acceptance test standards only apply to new ventilation systems and replacement of existing systems. For existing systems use NEHC TM 6290.99.

All meters can be unreliable when measuring non-ducted air flow of 50 fpm (15 m/min) and below. When 90 percent of the measurements along one line are acceptable, smoke tests should be used to verify the unacceptable readings. If the smoke tests show steady air movement downrange at these locations, they should be considered acceptable.

4-22 RANGE OPTIONS.

Relocatable Ranges.

Relocatable ranges constructed of modular sections are designed to be disassembled and relocated using standard overland transportation to alternate locations as the training requirements change or are relocated. To provide this relocatable capability the relocatable modular range must meet all requirements for indoor ranges above with the following exceptions:

Indirect Support Areas are not required.

The range control booth may double as the air lock vestibule on small ranges with three or fewer lanes.

Buffer between end lanes and side wall is not required and distance from back wall to firing line may be reduced to 12 ft. (3.6 m). These modifications are allowed because relocatable ranges can be sealed better than typical indoor ranges and this improves the airflow control.

The range control booth back to front distance may be reduced to 8 ft. (2.4 m).

The floor may be 0.375 in. (9.5 mm) AR500 steel plate with support to prevent sagging. Provide a slip-proof coating. Do not apply any surface on the flooring that prevents the bullets from reaching the bullet trap or that will entrap firing residue and hinder the cleaning of the range floor.

For ranges with defined lanes where no angled shooting is allowed, a more compact steel trap may be used with 0.5 in. (12.7 mm) AR500 steel plates, a vertical throat with replaceable knife edged sides lined up with lanes and rated for the intended ammunition. The range ventilation exhaust may be routed though the trap to function as the dust collection system.

A granulated rubber trap may be used when approved.

In lieu of concrete, the downrange wall behind the trap may use 0.5 in.

(12.7 mm) AR500 steel plate for ballistic containment.

Combination Fixed and Tactical Range.

A range with a ballistic center wall extending from the firing line to the base of the bullet trap can be used to increase flexibility by ballistically dividing the training past the firing line. An example is shown in Figure 4-5 that allows the range to operate as either:

One 12 lane range with a fixed firing line to accommodate the Navy’s OPNAVY 3591 rifle qualification course.

Two tactical lanes with moving and shooting downrange at the same time to accommodate the Navy’s OPNAV 3591 Practical Weapons Courses

(PWC).

Range with Ballistic Divider Walls

Steel Reactive Range.

Advanced training with a knockdown steel target system provides immediate feedback to the shooters. One example is shown in Fig 4.6 but can be varied to meet training and maintenance objectives. This example has 16 ft. (5 m) wide lanes with a series of popup steel head plate targets in each lane. Limit ammunition to frangible rounds or as necessary to prevent rounds and splatter from coming back towards shooter and to minimize damage downrange. Design side walls and lane divider walls for direct hits and splatter where targets are placed near side walls. A control system and hit sensors can be designed to track and score hits. Protect target bases from direct hits.

Steel Reactive Range

Wide Angle Shooting.

Ballistic protection can be provided on side walls to allow shooting at angles of 180-degrees (side to side) or more. Downrange protection is provided by a bullet trap.

There are several design options for protecting the walls with varying degrees of protection, space, and cost including:

Placing 0.375 in. (9.5 mm) thick AR500 steel plates with splatter protection to a height of 8 ft. (2.4 m). This is only recommended when all rifle ammunition can be limited to frangible rounds.

Covering the concrete side walls to a height of 8 ft. (2.4 m) with AR500 steel plate, with another wall in front consisting of a series of angled overlapping AR500 steel similar to a venetian blind trap and covered with splatter protection. The removable plates are sacrificial and should be sized and designed to meet the intended training and allow for easy removal and replacement. This is only recommended when all rifle ammunition can be limited to frangible rounds and rounds that do not have penetrators in the tip.

Placing an 8 ft. (2.4 m) wall section designed with 0.375 in. (9.5 mm) AR500 steel plate, an approximate 2 ft. (0.6 m) air space, and a 12 in.

(300 m) thick ballistic rubber block wall on the exposed shooting side. A wooden support system may be needed to secure the ballistic rubber blocks in place. The space is required to allow inspection of the underlying steel plates.

Placing bullet traps along the side walls. This provides a high level of protection to the side walls but requires a significant amount of space.