CPL Safe Manipulation & Lock Opening 3 — Questions and Answers
Question 1: A UL-listed Group 2M combination lock differs from a standard Group 2 lock primarily in that it:
- Has more wheels in the wheel pack
- Includes a manipulation-resistant barrier or hardened components making manipulation harder (Correct answer)
- Requires a key override in addition to the combination
- Uses electronic components instead of mechanical wheels
Correct answer: Includes a manipulation-resistant barrier or hardened components making manipulation harder
Group 2M locks meet UL requirements for manipulation resistance, incorporating design features like false gates, tight tolerances, and hardened materials.
Question 2: When drilling a safe to bypass the combination lock, the preferred entry point is typically:
- The top of the safe door near the hinges
- A location that provides direct access to the relocker or lock bolt while avoiding hardplate (Correct answer)
- The center of the door face regardless of internal components
- The bottom corner to avoid the bolt work
Correct answer: A location that provides direct access to the relocker or lock bolt while avoiding hardplate
Locksmiths plan drill points to access the lock mechanism or relockers while routing around hardplate and glass relocker plates to minimize damage.
Question 3: What is a 'glass relocker' and when is it typically triggered?
- A tempered glass panel on the safe exterior for decoration
- A hardened glass plate that shatters under attack, releasing spring-loaded bolts that lock the safe permanently (Correct answer)
- A transparent door insert used to view lock status
- A glass-ceramic fire barrier inside composite safes
Correct answer: A hardened glass plate that shatters under attack, releasing spring-loaded bolts that lock the safe permanently
Glass relockers are secondary locking devices that shatter when attacked by drilling or impact, causing additional bolts to engage and making opening much more difficult.
Question 4: The 'try-out key' method for opening certain types of safe deposit box locks works because:
- All safe deposit boxes use the same master key code
- The warding variations in guard lock keys are limited, allowing a set of keys to cover most locks (Correct answer)
- The renter key is always cut to the same depth
- Safe deposit boxes have no security pins in their cylinders
Correct answer: The warding variations in guard lock keys are limited, allowing a set of keys to cover most locks
Safe deposit box guard locks have limited warding variations, so a set of try-out keys covers the range of possible ward configurations.
Question 5: In the context of safe manipulation, what does 'dialing in' or 'parking' a wheel mean?
- Permanently fixing a wheel at a specific position during lock manufacture
- Rotating the dial the correct number of turns to engage a specific wheel and position its gate (Correct answer)
- Removing a wheel from the spindle for inspection
- Setting the dial to zero before beginning a combination sequence
Correct answer: Rotating the dial the correct number of turns to engage a specific wheel and position its gate
Parking a wheel means dialing far enough in the correct direction to engage that wheel and leave its gate at the desired position as subsequent wheels are set.
Question 6: Which safe opening method is considered most appropriate when the combination is unknown and manipulation has failed on a high-security safe?
- Torch cutting through the door face
- Plasma arc cutting around the hinges
- Precision drilling using a carbide or diamond bit with a carbide-tipped pilot point (Correct answer)
- Impact hammering on the dial to dislodge the wheel pack
Correct answer: Precision drilling using a carbide or diamond bit with a carbide-tipped pilot point
Precision drilling with appropriate bits is the professional method for opening high-security safes when manipulation fails, allowing controlled access with minimal damage.
Question 7: What is the function of a 'day-lock' feature found on some combination safe locks?
- It automatically locks the safe after a set number of hours
- It allows the safe to be closed and locked without dialing the full combination, enabling quick re-opening with just a handle turn (Correct answer)
- It disables the lock during daylight hours for convenience
- It requires a secondary combination for daytime use only
Correct answer: It allows the safe to be closed and locked without dialing the full combination, enabling quick re-opening with just a handle turn
A day-lock (or relocking feature) lets the bolt engage by simply closing the door, with the full combination only needed for the next opening — useful in high-traffic settings.
CPL Safe Manipulation & Lock Opening 3
A UL-listed Group 2M combination lock differs from a standard Group 2 lock primarily in that it: