One of the disappointing trends in modern ship construction has been the steady decrease in armor and high strength steel in the construction of ship hulls thus rendering the ships more susceptible to damage. This trend has culminated in the thin aluminum construction of the LCS, among other examples. Just to put things in historical perspective, WWII ships were built to absorb a lot of damage and examples of that capability abound. Those ships were built much tougher than today’s ships with both stronger and thicker steel used.
Let’s look at a specific example from the modern U.S. Navy – the bombing of the USS Cole. The expert commentary related to the photos below come from GM1(EXW) David Walsh.
"Most people don't realize it, but the damage done to the USS Cole shows the stunning difference between HY-80 and High Strength Steel (HSS) which is slightly stonger than mild shipbuilding steel. Take a look below at the horizontal weld line that runs the length of the hull about halfway between the rail and the water. You can see where the line going all the way across practically draws the top of the hole. The area above the weld is called a "strake" and that is one of the strengthening members for the hull made out of HY-80. The rest of the hull below the weld line is simply made out of HSS."
|HY-80 Strake Defines the Upper Bound of the Damage|
"In this next photo, at the top along the weld line, you can see that the HY-80 stopped the upward expansion of the blast and damage. The HSS literally tore away from the weld at the HY-80:"
|The HSS Tore Away at the Weld|
"You can see here how much of her underside was destroyed as well. If that HY-80 strake had not been there it is likely that a chunk would have been carved out of her entire side."
|Extensive Damage to the HSS Plating|
Aside from the obvious weight and cost savings, I don’t really know why the Navy has gotten away from building better armored ships capable of taking damage and continuing to fight. For multi-billion dollar ships, It certainly seems like a penny-wise and pound-foolish decision.
On a related note, at one point, the Navy learned the lesson about the dangers and drawbacks of aluminum structures but has recently forgotten the lesson with the return to the all or mostly aluminum LCS versions.
Clearly, the Navy could build much tougher and better protected warships but has chosen to put ships and crew at greater risk. As the Cole bombing illustrates, the price has already been paid and will continue so. On a positive note, some documents indicate that the Navy is looking into constructing the Burke Flt III out HY-80 and HY-100 which would offer significant survivability improvements.
Thanks to GM1(EXW) David Walsh!