LITTLE JOHN® and BIG JOHN® Mine Prop
With helper and using the attached handles, carry the LITTLE JOHN or BIG JOHN Mine Prop to the location where it is to be set.
Prepare the mine floor and roof as required to provide a suitable bearing surface for the prop.
Stand prop up and have helper hold prop by upper carrying handle. The end of the prop with the smaller od pipe goes against the mine roof.
Insure the bolt is aligned in the stop and nut and bolt are snug in the housing by rotating the nut downwards by hand.
With helper still holding prop in upright position by upper carrying handle, remove plastic tie spacer. The tie spacer is located between the prop wedges and the steel retaining ring. Cut tie with suitable side cutters or snips.
Stand on the lower plate and raise the top pipe portion of the prop to the desired height. The steel wedges will be pulled slightly out of the housing to be released when encountering the retaining ring. The painted line on the smaller pipe is an indicator that you are approaching maximum extension of the prop. Do not over-extend the top pipe. There are two color coded lines around the pipe. A yellow line indicates 6" of extension remain to maximum extension. A red line indicates maximum extension. Do not extend beyond the red line.
When the desired height is reached, allow the steel wedges to seat against the pipe in the housing by slowly releasing the upward extension force and allowing the top pipe to retract slightly.
Insert one or more wooden wedges between the mine roof and the top plate. Drive the wedges together with a hammer, which should compress the top pipe slightly and securely lock the wedges onto the upper pipe.
Test the prop to insure it is tight and stable. If necessary, retighten prop by additional hammering of the wooden wedges.
Insure the nut and bolt are tight in the housing by rotating the nut downwards with a suitable wrench.
Do not place hands or fingers anywhere on prop where they might be pinched while extending prop or tightening. Handles should not be used for any other purpose except carrying and holding prop during installation process. Always wear appropriate protective gear: gloves, safety glasses, etc.
The installation is now complete. Repeat above steps for next installation.