Physical Security: An Overview
Continued: Part II
Intrusion Alarm Systems
- One of the first alarm systems was a flock of geese guarding the capitol of Rome in
390BC, they squawking and the Romans were able to defend the Capitol against the
Gauls
- First alarms were put in place about 100 years ago. A simple trip wire was connected to
a bell or a buzzer. These local alarm signals remained on the premises.
Intrusion Alarms
- In 1859 using telegraph local signals were able to be transferred from one location to a
central station.
- First recorded use was on Maiden Lane in New York City where jewelry stores were
protected by American Division of Telegraph (ADT)
- Telephone lines soon replaced telegraph as the vehicle of choice.
Intrusion Alarms
- All intrusion alarms have three main components:
- A sensor (the device that detects the intruder)
- An alarm control (the device that turns the alarm on and off.
- An annunciator (the mechanism by which some one is notified of the intrusion.)
Intrusion Alarms
- Intrusion alarms are always fully powered. The alarm goes off if the power is
interrupted.
- Most alarms operate on low voltage power
- Many alarms have battery backup to maintain the alarm function when electric power is
out of service.
Intrusion Alarms
- There are a number of methods used to accomplish sensing, controlling , and annuciating.
The number of combinations runs literally into the thousands.
Sensors
- Sensors can be divided into three classes:
- Those that protect a perimeter
- Those protecting an area
- Those protecting a single item or spot.
- Perimeter protection is the first line of defense. Sensing devices are on
windows, doors and any other opening.
- 80% of entries are through these openings.
Sensors
- Perimeter sensors are often simple
- Examples are magnetic doors, switches or contacts, metallic foil window tape, wooden
screens containing brittle wire, and wire laced paneling.
- Area Protection: these devices protect spaces within a facility.
- They provide highly sensitive and non detected devices to practice important areas.
Sensors
- Area protectors do not stop intrusions within the facility, they only guard specific
areas. Area protection should be supplemented with perimeter protection.
- Particularly susceptible to false alarms
- Most common types include: Photoelectric eye beams, ultrasonic motion detectors,
microwave radar detectors, and passive heat detectors.
Alarm Controls
- Object Protection provides direct security for special items.
- Capacitance proximity detectors and vibration detectors are the most frequently used.
- Alarm controls: fall into two categories, keyed, or local, controls; and
remote, or central station controls.
- Keyed were the first and most simple, economical, inexpensive and easy to use.
Alarm Controls
- Keyed systems can be compromised by loss copies, and locks being picked.
- Keypads are replacing keys.
- At one time one could not clearly tell if the system was in fact on
todays
systems show when the system is armed.
- Central systems shift responsibility to alarm center
any changes etc. are
investigated.
Annunciators
- Alarm signals indicate that the alarm has been activated.
- Signals can be given locally or sent to a central office.
- Local alarms when activated according to underwriters it must be able to ring for 30
minutes and continue for two minutes withstanding attempts to deactivate it.
Annunciators
- With local alarms there may not be anyone to answer it.
- Some communities allow alarms to be directly connected to the police department
- Central Station has 24 hour coverage over leased lines. When alarms sounds a runner is
dispatched and police are notified.
- Larger facilities have own central alarm
False Alarms
- 95% to 98% of all alarms are false
- Major impact on police resources (Norwalk Connecticut 20% of police time devoted to
handling false alarms.)
- Leads to lackadaisical response to calls. (Cheektowaga P.D.)
Fire Alarm Systems
- Fires follow a definite pattern in starting:
- Incipient stage: hot combustible material burns creating small particles. Ionization
smoke detectors react to these small particles.
- Smoldering stage: combustion increase so that the particles are now visible as smoke.
Photoelectric smoke detectors react to smoke.
- Flame stage: fire hot enough to ignite all the gases and particles in air. Thermal
detectors react to fires in this stage.
Fire Alarm Systems
- High heat stage: heat is rapidly released, heat or rate of rise detectors react to fires
at this stage.
Automatic Sprinkler Systems
- Automatic sprinkler systems significantly reduce fire damage.
- Sprinkler systems since they must be fully armed and are not used frequently fail
because the water has unknowingly been shut off. In the older systems there was frequent
delay in calling the fire department
Automatic Sprinkler Systems
- Water flow protectors (alarms). Water flowing triggers an alarm at a central station.
- Four sprinkler classifications:
- local bell system
- central station systems
- remote station systems
- Proprietary systems
Lock Systems
- The first lock was a large stone rolled into the opening of a Neanderthals cave.
- First bars were used on the inside of the door to insure that no one from the outside
could get in.
- The first locks were found in Nineveh (a massive warded sliding bar. Greeks and Romans
refined the lock until the keys became the size that we are use to today.
Lock Systems
- Early in the 1800 century the lever tumbler lock was developed. Much more difficult to
pick
handmade and very expensive.
- Linus Yale Sr. developed the first rotatable cylinder pin tumbler lock in 1844. His son
improved it in 1865.
- These locks were a vast improvement and became popular world wide.
Relative Security of Locks
- Relative security refers to the relationship between a locks resistance to picking
and the picking ability of an expert, this relationship is gauged in time.
- Warded locks key operated only allows properly cut keys to operate them (specialized
keys can be made to bypass most warded locks)
Relative Security of Locks
- Warded key locks can be opened as quickly by an expert as if they had a key. No
security.
- Disk tumbler locks, key operated designed primarily for automobiles, they are used for
desks etc. They are cheap. For a trained person a disk tumbler lock takes about 3 minutes
to open, double disk tumbler 5...
Relative Security of Locks
- Pin tumbler locks generally more secure than the previously mentioned
- May be shimmied open (credit card) if they have spring loaded locks. Need to have a dead
latch.
- Pin tumbler are rated at about 10 minutes
- Master keying decreases a locks security.
Relative Security of Locks
- Lever locks lever systems under spring load. The degree of security is a function of the
number of levers and the tension under which the lever are under
it is pickable.
- Combination locks
have the same number of numbers as there are tumblers. In
security range from 0 to 40 minutes. Generally more secure than key locks.
Relative Security of Locks
- Combination locks. More secure if there is no key way to gain access to the inside. Also
more secure if it does not have a stamped ID number (reference books available).
- Safe locks like simple combination locks can be opened by manipulating the dial. It
takes a lot of time to do it, more than Hollywood suggests.
Relative Security of Locks.
- Safe locks are generally not opened by manipulation, it is faster to use lock pullers,
core drillers, burning bars, and other ways to defeat such locks.
- Electromagnetic locks use electricity to release. Must have auxiliary power or would
open when power went off.
Relative Security of Locks
- All manufactured locks are pickable
- Lock picking is not difficult, can purchase picks at any locksmith supply house
- Two basic picking tools - the tension wrench and the pick. These vary in shape, size and
angle.
- Most intruders are not skilled so they use other mechanisms, doors can be popped.
Relative Security of Locks
- Bolts can be sawed through with a hacksaw (to avoid this some bolts have floating harden
bearing that can not be cut.)
- Dead bolts are generally good security. Security latches not attached to the frame are
easy to force.
- Lock and key control a crucial security item in any place.
Security Glazing
- Security glazing is the installation of transparent or translucent materials to protect
against loss.
- Glass, three basic types:
- Sheet
- plate
- float
- Glass helps security by opening areas up to routine inspection.
Security Glazing
- Regular sheet, plate or float glass can be tempered by heating and then cooling rapidly,
when it breaks it collapses into small pieces, 3 to 5 time stronger and heat resistant
- Laminated glass, two outer layers of glass bonded with a middle layer of plastic,
burglary resistant 40 foot test...
Security Glazing
- Bullet resistant glass: can take a bullet without it exiting or shattering glass.
- Wired glass resists impacts from large objects..but not bullet resistence
- Plastic glazing acrylic and polycarbonate,
- acrylic (plexiglas is lighter than glass and more than 17 times more break resistent can
resist bullets.
Television in Security
- Close circuit television CCTV been used since 1950s
- remote gates
- environment hazardous
- clandestine monitoring
money rooms
- continuous observation needed
- multiple locations must be observed
- immediate and permanent record needed
Television in Security
- CCTV Components:
- Scene lighting,weather, amount of detail, security threat to cameras
- Camera lens wide angle to telephoto
- the Camera, the higher the quality, the lower the light requirement, the higher cost
- Transmission of the video signal, coaxial, microwave, radio, twisted pair wire, audio
signal.
Television in Security
- Monitoring the Image real time lapse recording
- Control equipment fixed or variable focused lens, sequencers, switchers, lens controls,
and pan and tilt cameras
- Combining alarms with CCTV
go from lapse to real time
- Videotape recording
Files, Safes and Vaults
- Fire resistant storage important
- Burglary resistant
- Both characteristics often at odds.
- File resistant files, thin walls insulation between.
- Underwriters lists the fire capacity of various cabinets
- Remember computer tapes and storage.
Fire, Safes and Vaults
- Older safes are generally riveted which makes them open to peeling.
- Newer safes are welded.
- Explosive resistant plungers in safe doors.
- Acetylene cutting torches-- acetylene resistant materials inside
- Thermal lances and diamond bits heat, water needed, detection
rare use
Fire, Safes and Vaults
- Location and Anchorage
- Locking Mechanisms combination virtually impossible to determine
- Time locks
- key and a combination
- Vault is a walk in safe