Here is a monster LAPP insulator that is in front of the Edwin E. Richie Observatory located at the Battle Front Park on Bainbridge Island, Washington.
I guess it is a stand off insulator of some sort.
Tom Miller has informed me the following:
That monster LAPP insulator is a tower base insulator. They used these at the base of AM radio towers to insulate the tower. These insulators are extremely high strength. Some of them even had oil to fill up the hollow cavity between the top and bottom metal sections.
I have an old LAPP insulator book at home that shows the tower base support insulators, types and strengths. LAPP does not make these anymore, but a company called Austin Insulator in Canada can custom make these for radio towers.
10/16/2010 I found out today that this insulator was actually used at this site by the military for a communication tower and the stand for it, that I thought was an unfinished statue stand, is still sitting about thirty feet to the left (not in picture).