Chapter 5 Barriers and Protective Lighting

Question 1

Key Points 1

Answer 1

The purpose of barriers it to 1) restrict or impede access, 2) provide continuous protection, or 3) deter threats.

Question 2

Key Points 2

Answer 2

Barriers can be natural or man-made (structural), and can include animals, humans, and dispensable barriers.

Question 3

Key Points 3

Answer 3

Walls are generally more resistant to penetration than doors, windows, or other openings. Placing two or more walls in a series (close proximity) results in a longer penetration time than one wall of the same thickness.

Question 4

Key Points 4

Answer 4

If hinges are placed on the exterior side of a door, they should be nonremovable hinges or have the hinge pins welded in place.

Question 5

Key Points 5

Answer 5

If the window is below 18 feet (5.4 m) from ground, is less than 14 feet (4.2 m) from trees or larger than 96 square inches (619.3 cm2), it should have some type of protection.

Question 6

Key Points 6

Answer 6

Acrylics (Lucite and Plexiglas) that are less than 1 inch (25 mm) thick can be penetrated in less than 10 seconds and are not typically recommend for security applications.

Question 7

Key Points 7

Answer 7

Window film strengthens the glazing from breakage, blasts (fragment retention film), or ballistic penetration. It can often strengthen glass more than 300 times its original strength and offer 5 times more heat resistance.

Question 8

Key Points 8

Answer 8

Any opening greater than 96 square inches (619.3 cm2) should receive protection measures such as steel bars and grills, wire mesh, expanded metal, or fencing material.

Question 9

Key Points 9

Answer 9

Typically, it is more cost effective and more effective against penetration to install roof security enhancements below the roofline.

Question 10

Key Points 10

Answer 10

A fence or wall is designed to 1) define an area, 2) delay an intruder (may offer a psychological deterrent to a potential intruder), and 3) direct people or vehicles to desired checkpoints/entrances.

Question 11

Key Points 11

Answer 11

Chain link fencing is most commonly used security applications.

Question 12

Key Points 12

Answer 12

A medium security fence height is 7 feet (2.1 m) and this is the minimum height to deter human penetration.

Question 13

Key Points 13

Answer 13

Chain link fence fabric should be 9 AWG or heavier with mesh openings not greater than 2 square inches (12.9 cm2).

Question 14

Key Points 14

Answer 14

A typical fence top guard consists of 3 strands of twisted double-strand barbed wire with 4-point barbs spaced equal distance apart is standard. There are 6 inches (15.2 cm) of separation between the 3 strands of barbed wire. A 3-strand top guard typically increases the fence height by 1 foot (0.3 m).

Question 15

Key Points 15

Answer 15

Blocking barriers can be passive or active. Active barriers must always be attended and must have standard operating procedures (post orders) developed.

Question 16

Key Points 16

Answer 16

Bollard height is typically not more than 30 inches (0.76 m) high, but in no case should be more than 38 inches (1 m) in height.

Question 17

Key Points 17

Answer 17

Safes are portable unless anchored. A safe on wheels is not burglar proof. A safe weighing 750 pounds (340.19 kg) or less must be anchored to the floor.

Question 18

Key Points 18

Answer 18

Criteria for fire resistant safes includes heating the safe and dropping it 30 feet (9.1 meters) and reheating and retesting the safe for internal temperatures.

Question 19

Key Points 19

Answer 19

A fire resistant safe for paper protection does not have a 3-hour rating (1, 2, and 4 hours only).

Question 20

Key Points 20

Answer 20

Vaults installed for protection against forced entry should not be installed on exterior walls of the building.

Question 21

Key Points 21

Answer 21

A minimum of 175 yards (160 m) of illumination is sufficient to detect human movement.

Question 22

Key Points 22

Answer 22

Protective lighting should also allow one to identify a human face at 33 feet (10 m) during nighttime hours and notice individuals at 75 feet (22.9 m) or more away.

Question 23

Key Points 23

Answer 23

Protective lighting serves three main purposes: 1) it can be a psychological deterrent to intruders, 2) it enables detection, assessment, and identification, and 3) it supports or enhances the video surveillance system.

Question 24

Key Points 24

Answer 24

High Mast lighting is typically used in outdoor application such as parking lots and along highways and usually are 70 to 150 feet (21.33 to 45.72 m) in height.

Question 25

Key Points 25

Answer 25

A Metal Halide lamp is a high intensity arc tube in which the light is produced by the radiation of excited metal halides. Metal Halide works well with video surveillance systems.

Question 26

Key Points 26

Answer 26

Low Pressure Sodium is a high intensity discharge arc in which light is produced by radiation from sodium vapor operating under pressure. Due to its poor rendition this lamp is not recommended for security operations.

Question 27

Key Points 27

Answer 27

Reflectance of light should be as close to 100 percent as possible. The closer it is to 100 percent the better the quality of images.

Question 28

Key Points 28

Answer 28

The illumination of the light should be characterized by the light-to-dark ratio, which ideally should be 4:1, but maintained at no less than 6:1. Typical uniformity ratios would be 1:0.7 for working environments, 4:1 on a pedestrian walkway, and 10:1 on a roadway.

Question 29

Key Points 29

Answer 29

For the purposes of pedestrian human camera surveillance, the minimum reflective light is:
Detection = 0.5 FC
Recognition = 1.0 FC
Identification = 2.0 FC

Question 30

Key Points 30

Answer 30

A color camera needs at least 50 percent of its full video signal or color registration starts to fade, whereas black-and-white cameras only need 20-30 percent of full video.

Question 31

Key Points 31

Answer 31

Costs associated with a lighting system are: 8 percent capital items (hardware is the second highest cost), 4 percent maintenance costs, and 88 percent energy costs.

Question 32

Key Points 32

Answer 32

Group replacement of lamps should be considered when the lamps get to 80 percent of their rated life.

Question 33

Structural Security

Answer 33

comprises barriers, protective lighting, locks, and the structure and components of buildings and facilities.

Question 34

purpose of barriers

Answer 34

1) restrict or impede access, 2) provide continuous protection, or 3) deter threats. Three types of barriers are used:

Question 35

Plate (Annealed) Glass

Answer 35

Annealed glass, also called plate glass, is highly frangible and breaks into large shards when broken. Often large windows are made of plate glass. Another type of annealed glass is float glass. Float glass has a uniform thickness because it is made by floating the molten glass on top of molten metal, typically tin. It is the modern glass.

Question 36

Tempered Glass

Answer 36

Tempered glass is like automobile side door windows, which when broken, fall apart into pieces of glass without sharp edges (spall).

Question 37

Wired Glass

Answer 37

Wired glass is often required by fire code to maintain fire ratings in fire-rated doors.

Question 38

Laminated Glass

Answer 38

Laminated glass is formed when two panes of annealed glass are bonded together by a layer of plastic in-between the panes. Laminated glass is often used for mitigating the effects from a blast.

Question 39

Bullet or Burglar Resistant Glass

Answer 39

Bullet and/or burglar resistant glazing comprises multiple layers of glass/polycarbonates and plastics to prevent ballistic penetration or delay forced entry.

Question 40

Fencing barriers and walls

Answer 40

Animal control fence height is 4 feet (1.2 m).
Low security fence height is 5 to 6 feet (1.52 to 1.83 m).
Medium security fence height is 7 feet (2.1 m). Note: This is the minimum height to deter human penetration.
Cargo industry requires a 6-foot (1.83 m) high fence for perimeter protection.
High-security fence height is 18 to 20 feet (5.4 to 6 m) often used in prisons.

Question 41

A few considerations for protective lighting: A

Answer 41

Lighting components are lamp (light bulb), luminaire (fixture), the mounting hardware, and the electrical power source.
Protective lighting should provide a high contrast between the intruder and the background.
Perimeter lighting should illuminate both sides of a perimeter fence.

Question 42

A few considerations for protective lighting: B

Answer 42

Lighting should create a glare for the intruder but not hinder the observation ability of patrolling security officers. Note: Glare can be minimized by increasing fixture heights and using steeper aiming angles—this also reduces light trespass.
Contrast is important for security lighting. Increased contrast between light and shadow can impede observation. Appropriate overlap of light beams will eliminate dark areas.

Question 43

A few considerations for protective lighting C

Answer 43

Imbalance between interior and exterior lighting of a building may allow an adversary to have visibility from the outside.
Create redundancy in lighting and power sources. In other words, include a manual back up in case of system failure or maintain portable emergency lights with auxiliary power.

Question 44

A few considerations for protective lighting: D

Answer 44

Typical light poles are 30 to 45 feet (9 to 14 m) in height.
Ground landscaping lighting should be focused upward into shrubbery and trees.
Protect all lighting systems. Locate the lighting source inside perimeter barriers and install protective covers over the lamps. Bury power lines and mount the lamps on high poles. Protect switch boxes and power sources.

Question 45

A few considerations for protective lighting: E

Answer 45

Light sources should be mounted at a minimum of 20 feet (6 m) high when multiple lighting sources are available in the vicinity. For example, parking areas should have at least two light locations (preferably 4) that illuminate the area (overlap and redundancy) for the narrow areas between the vehicles. However, light poles that are 12 to 14 feet (3.6 to 4.2 m) in height may prove better lighting in parking areas because the light goes through the vehicle windows and reflects off other surfaces, reducing shadows.

Question 46

Color Corrected Temperature (CCT)

Answer 46

An indication of the light’s warmth or coolness. This has an effect on mood and ambience of surroundings. It is measured in degrees Kelvin, which is the Centigrade (Celsius) absolute temperature scale where 0 degrees Kelvin is 272 Degrees C.

Question 47

There are six common types of protective lighting:

Answer 47

Continuous
Glare Protection
Standby
Controlled
Movable
Emergency

Question 48

Four Main Characteristics of Lighting that Affect Security Effectiveness

Answer 48

Quantity of light
Level of intensity of light (illuminance)
Light reflectance of surrounding materials
Color temperature of the light