Another possible factoris the precise way this structure was built. After working at the...

[narrator]
Another possible factor
is the precise way this structure was built. After working at the silo
for more than 20 years and witnessing its strength,
Bryan Verrall explains the process known
as slip form. Silos were made in one piece,
where the whole thing Silos were made in one piece,
where the whole thing went up in the air
as they poured until
the desired height and the walls were
about a foot thick. [narrator]
In slip form construction, the structure
isn't built in sections. Instead, concrete is poured
into a vertical mold, with the liquid rising
slowly enough
for the growing walls to support the weight above. Once fully cured,
the continuous
concrete structure is incredibly strong
and has no joints
to create weak points. is incredibly strong
and has no joints
to create weak points. Which is why it took
an awful lot to blow it up