During the
construction of a new (S-80) class of submarines in Spain an error was
recently discovered. One of the design engineers had made a mistake in
calculating the weight of the sub and, as the first one was currently
built, it was nearly a hundred tons too heavy. That means, once
submerged, the sub would have a difficult time surfacing. Under some
conditions (equipment failure or battle damage) it would not be able to
resurface at all.
Subs are designed to survive leaks and taking on additional
weight (water) while submerged and still be able to resurface. But the
unintentional addition of a hundred tons of steel and equipment
eliminates much of this margin of safety. The most practical solution is
to increase the length of the sub by 5-6 meters (15.5-18.6 feet) thus
providing more internal space full of air and buoyancy. This increases
the ability of the sub to float. An American firm (Electric Boat) has
been hired to help implement this modification, which will delay
delivery of the first S-80 sub about two years (to 2017). The
modification will increase the cost of the sub about five percent and
make the S-80s roomier. That will help crew morale, although the
taxpayers are none too pleased with this screw up.
It was a decade ago that the Spanish navy ordered four S-80
"Scorpene" class subs, at a cost of some $280 million each. Construction
didn’t begin until 2007, and the estimated cost grew to $700 million
per boat. The S-80 is a Spanish design and features AIP (air-independent
propulsion). Modern AIP engines for submarines began to appear in the
late 1980s, when Sweden installed Stirling type power plants in their
Nacken class subs. The S-80s use a new type of AIP.
The S-80s are 71 meters (233 feet) long, displace 2,200 tons
on the surface, have a crew of 32 (plus eight passengers, usually
commandos) and are highly automated. The design also concentrates on
quietness and a powerful American built electronic sensor and fire
control system. The six 533mm (21 inch) torpedo tubes will also be used
for mines and cruise missiles.
