I was Army so I know nothing about Navy vessels. However, I assume there are redundant alarm systems if ships get too close? Should the bells and whistles all have been blaring before the crash on the Fitzgerald and the tanker???
The radar system would alert to intersecting tracks or close proximity tracks.
No "alarm systems" per se; the ship had ample sensors to detect surface traffic. The "alarms" were watchstanders on the bridge, lookout stations, and in the Combat Information Center. There had to be a minimum of dozen people--perhaps as high as two dozen--that should've seen the presence of the ACX Crystal.
I was Army also but I do know soldiers or sailors need to be on watch/guard at night and to be extra vigilant. This thing stinks.