Removable closure apparatus for hollow columnar members

A removable closure apparatus for open-ended hollow tubular members, comprising:

• (a) plug means disposed inside said tubular member;
• (b) a seal formed around said plug means between the inner surface of said tubular member and the outer surface of said plug means comprising a bonded rubber cylinder;
• and
• (c) means including a cable spiraled around said plug means and embedded within said cylinder with one end thereof extending out of said seal for manipulation from the upper end of the columnar member, said cable unspiraling from around said plug means and tearing said seal upon the application of said force to said end for destroying the structural integrity of said seal to permit removal of said plug means from within said tubular member.

A removable closure for open-ended tubular members used in offshore platform structures, comprising:

• (a) plug means concentrically positioned within said tubular member defining a substantially uniform annulus between the inner surface of said tubular member and the outer surface of said plug means;
• (b) a seal formed in the annulus between the inner surface of said tubular member and the outer surface of said plug means by bonding a rubber cylinder to each of said surfaces, said seal extending over less than the entire length of said tubular member;
• and
• (c) a cable spiraled several times around said plug means and embedded within said cylinder with a first end being affixed to the top of said plug means and the second end extending out of said seal for manipulation from the upper end of said tubular member, said cable unspiraling upon the application to said second end of a force sufficient to tear said seal and permit removal of said plug means out the upper end of the member.