AUTOMOTIVE A Dangerous Lock you to make one, then you have a simple answer to the dilemma. If they refuse to let you repair the lock, you can refuse to make the key. When there is no key, there is no danger. If the lock can’t be secured from the outside, a person can’t be locked in- side. The situation is safe. Leave it that way. If the customer already has a key and they refuse to pay for correcting the flaw, that is a tougher problem. Personally, I would feel very guilty knowing that this hazard has the potential to be deadly. I might offer to repair the lock for a re- duced price, or even for free. This reminds me of a situation we oſten face when a customer has double cylinder deadbolts on every door of their house and they want us to rekey all the locks. Before I start the job, before I even remove one of the locks from one of the doors, I immediately inform the customer that, for safety reasons, they need to have at least one door that they can open from the inside with no special knowledge. I tell them we need to replace at least one of their double cylinder deadbolts with a single cylinder deadbolt. If they refuse, I turn down the job. I will not take those double cylinder deadbolts off the doors, rekey them and put them back. Reinstall- ing the locks would make me partly re- sponsible for the safety hazard. ALOA Technical Standards #20 and #21 can offer some guidance here: 20. Hazardous Conditions: If any ser- vice conditions exist which pose poten- tial risk or lockout hazard, the client will be notified and recommended ac- tion proposed. 21. Codes & Ordinances: No lock or securi- ty device will be installed or recommended for any application which will violate ICC, UBC, NFPAA, ADA or any local code or ordinance or pose a threat to life safety. 18 KEYNOTES APRIL 2021 “Relying on the integrity of the key is a recipe for disaster.” Yes, I am aware that the AHJ (Author- ity Having Jurisdiction, which is usually the local fire marshal) doesn’t inspect private residences. I’m also aware that building codes almost never apply ret- roactively to previous construction. And I’m aware that it’s quite likely that when those deadbolts were installed, the code in place at the time did not prohibit them. Despite these facts, I still say it is my duty as a locksmith not to create a dangerous situation. I won’t touch those locks unless they are safe when I’m done. I have heard it suggested that one way to resolve the safety dilemma is to have the customer sign a waiver that states that they are aware of the danger and give you permission to proceed without fixing it. In my opinion, this makes things worse, not better. All you’ve done is document, in writing, the fact that you knew it was wrong and you did it anyway. I’m not a lawyer, but it seems to me that if some- thing bad happens, this makes you more liable, not less. Do the job safely or don’t do it at all. A Typical Wafer Tumbler Cam Lock Before we get to the details of the flaw that makes these locks dangerous and how to correct it, let’s take a look at a typical wafer tumbler cam lock. The plug contains five wafers that slide up and down. Looking into the keyway, we can see the upper portion of each wa- fer where it contacts the key. When the proper key is inserted, it liſts each tum- bler up just to the right height so that the plug is free to rotate within the shell. There are actually two shear lines at work here rather than just one, as we’d expect in a pin tumbler lock. When there is no key in the plug, all the wafers are pushed down by the springs and they block the lower shear line. When an incorrect key is inserted, some of the cuts may be too shallow. Hence, the wa- fers are liſted up too high, blocking the upper shear line. If either shear line is blocked by even one of the five wafers, that should be enough to prevent the plug from rotating. A typical cam lock has four slots in the shell. Let’s label them top, bottom, leſt and right. Starting with a vertical key- way and no key inserted, all the wafers are pushed down by the springs, and the bottoms of the wafers are resting in the bottom slot, blocking the lower shear line. As we insert the key, with the cuts pointing up, each wafer has to move up out of the way of the key, temporarily crossing the upper shear line. If the top slot wasn’t there, we couldn’t insert the key because the wafers would have no- where to go. Once the proper key is fully inserted, none of the wafers are blocking either shear line. Now let’s turn the key 90 degrees to the right. The cuts of the key are pointing to the right, and the spine is pointing to the leſt. If we withdraw the key, the wafers temporarily move into the right slot to get out of the way of the key. Aſter the key is withdrawn, all the wa- fers are being pushed into the leſt slot by the springs. If the right slot wasn’t there, we wouldn’t be able to remove the key in this position. If the leſt slot weren’t there, we could remove the key but the lock wouldn’t be secured. The plug would be free to rotate because none of the wa- fers would be blocking either the upper or the lower shear line. WWW.ALOA.ORG
