Saturday, June 28, 2014

The Hockey Puck Lock: An overview



The Hidden Shackle Padlock or “hockey puck lock” (HPL) as it’s more affectionately known has been a staple in major metropolitan cities for years (photo 1).  However this beefy looking lock is becoming commonplace all over the country from jobsites to cargo and delivery vans (photo 2).  Although this lock has a high intimidation factor,  it’s  fairly simple to over come on the fire-ground.

Before we get into how to defeat the HPL, lets identify the components and it’s operation.  Depending on the exact model it’s either made of solid steel or die cast with a flat or stepped back.  The lock body is 2-7/8" thick with a 1-1/4’’ round-stock shackle (photo 3).  The shackle is located on the backside of the lock face, making it invisible to the general public. The HPL can be used stand alone or paired with a “high security hasp”(photo 4).  This hasp has a shroud that covers the majority of the lock with exception of the keyhole and two side openings to allow the lock to be removed for normal operation. 

Now that a basic understanding has been established, lets transition to what matters most, Fire-ground operations involving the HPL.  Since these locks emerged there has been two basic ways to over come them, shearing or cutting the shackle.

The shearing method is recommended and pictured in many basic fire service textbooks (photo 5). The thought process behind this is to take a pipe-wrench with a cheater bar and exert a twisting force on the shackle with hopes of breaking it and allowing the lock body to be removed from the hasp.  This method has proven to be successful, yet labor intensive.


The second method for removing the HPL is using a saw, with metal cutting capabilities to cut through the lock body and shackle.  This is designed to be a quick and efficient
 operation, however, a solid size up will be required. The first step being to determine if the HPL has a high security hasp or not. If one is present be aware of it while cutting and don’t let the blade “jump” it.    Secondly locating the keyhole and directing your focus ¾ opposite the keyhole on the lock face (photo 6).  This area will be your “sweet spot” as it is directly behind this is the shackle.  If it hasn't already the saw should be procured and started.  Prior to making the first cut think about how the saw should be orientated to the cut (vertical or cradled horizontally) (photos 7 & 8).  As the cut is begun keep the blade steady on an even plane, working your way through the lock
face.  Once through the lock face the shackle should give fairly quickly as the area surrounding it is hollow.  A good gauge of where you're at in the cut is feeling the amount of resistance on the saw while looking  for movements of the lock body.  After the shackle is cut, the final step is to remove the remaining lock body from the hasp.  Once this is done, the lock has been successfully defeated.


A standard hidden shackle padlock or more commonly known hockey puck lock (photo 1, author)

Lock set up on the rear of a cargo van. (Photo 2, author)


1 ¼’’ round stock shackle is what secures the lock through the hasp. (Photo 3, author)


A hockey puck lock in a “high security hasp” (photo 4, author)


Textbook showing the “shearing” method. (Photo 5, photo credit to Fire Officers Handbook, first edition)


The tip of the pen cap points out the ¾ opposite the key- hole area for the cut (photo 6, author )

Horizontal orientation of saw on the lock. (Photo 7, author)    



Vertical orientation of  saw on the lock . (Photo 8, author)