P.S.
"Sheet piles" are those sheets of metal which were driven into
the ground to a depth of up to 30 feet and which encompassed
the site of the Aomon crypt.
(In fact, buckling of the pilings
toward the end limited the depth of the excavation.
The pilings
interlocked and were made of 3/8" steel, were 18" in width, and
varied from 15-30' in length. The pilings facing the water were
left in place; those outlining the other three sides of the crypt
were removed and decontaminated for use elsewhere. )