Tuesday, May 19, 2015

Hammer Time

Trusty Cook – Model #10, 9.6 pound shot-filled polyethylene
(by Ron Beckman)

The sledgehammers used for the Firefighter Combat Challenge are manufactured with a steel rod inside the handle welded to a hollow steel tube inside the head filled with welding slag, or metal shot.  The polyethylene injection molding process fills in voids and surrounds the metal components held in a mold during the process and produces a very durable dead blow hammer that weights 9.6 pounds.

For placing these hammers into service for competition, several slight modifications are needed in order to allow officials to monitor their correct use under the Rules.

There are five (5) small ⅛” (2mm) holes on each hammer on the handle and the head resulting from the injection process.  Duct tape is used to cover each of these holes so that hand placement can be watched, as well as foregoing any possible debris loss (of the shot inside the head) onto the Keiser Force Machine while conducting the forcible entry evolution during the Challenge.

The polyethylene is very slick and the tape does not stick readily to the hammer surfaces.  A belt sander, sand paper, or other roughing tool must be used to rough up the area circumfrencial on the handle in order to cover the holes, as well as the area on one side of the head.   There are three areas on the handle and two holes along the depression on one side of the head.  Once the light sanding is completed, clean the areas with denatured alcohol.  Black tape is used on the hole closest to the head of the tool to indicate incorrect (too high) hand placement.  All other holes are covered by red tape.  A “patch” of red tape approximately 5” (w) X 2” (h) is placed over the holes on the head area.  A razor knife is used to trim the tape so that the tape fits neatly into the depression cast on the side of the head.

Once the taping of the holes is done, the hammer is subjected to pre-loading.  Fifteen hard strikes are delivered per side of the hammer onto the end of a Keiser beam standing vertically upright.  A concrete curb may be substituted for the Keiser beam.  A date is written on the head area of each hammer with a “Sharpie” marker documenting the date that it was placed into service.

The hammer is now ready to be used officially for competitions.  The hammer is pre-loaded before each run by delivering one (1) solid strike to one side of the head before it is set on the ground.  The pre-loaded side of the hammer (head) is faced towards the outside of the course so that each competitor can choose to use the pre-loaded side for the first strike.  The middle section of tape on the handle is also used as an indicator for proper positioning of the hammer at the ready resting against the Keiser beam.  This allows for a precise and consistent 11° from plumb (vertical) angle so that each competitor can grab the tool for driving the beam during the evolution.

No comments: