WRT Saratoga, the problem was Philly Naval Shipyard developed a new method to retube propulsion boilers that would save a lot of money if followed. NAVSEA HQ signed off on it. But after the ship left overhaul and in service the repair method proved to be a failure.
For BHR -- the ship was in an industrial availability. Part was done at NASSCO (right next door to 32d St naval station) including the dry-docking. Then the ship was moved to 32d street for the remainder of the availability. In any repair period there is a negotiated agreement between navy and repair contractor over who is responsible for what. A general problem is that the ship has no direct control over the contractor (there is a concern of creating a "constructive change order" that results in a claim against the gov't). The responsibility is with the Navy Regional Maintenance Center. Every contract I've seen had specifications for fire responsibility. But it's always a hassle and ship's force is always unhappy that yard workers don't take good care of the ship, in particular house-keeping. It appears ship's force was moved off-ship for the availability (typical in big ones). If no particular yard work was scheduled for that Sunday, it would have been typical in-home port duty section. I'm just guessing, but at this point I would expect there to be equipment or system level testing, some might have been scheduled for the weekend. It appears that fuel had been onloaded prior.
Note that US Navy has not used "bunker fuel" since the 60s/70s. (Also BHR is one of only a few conventional steamships left.) All ships now carry either/both "diesel fuel marine" or "JP-5". There isn't that much difference (JP-5 has a higher spec for entrained water and contaminates. Typical is JP-5 system is available as emergency fuel for main propulsion.) The characteristic is a minimum flash point of 140 degrees F. I don't know BHR configuration, but common practice now is to use compensated fuel tanks meaning tanks are always full with fuel or sea water. The tanks are built in "banks" with sluice pipes between tanks in the bank, with a final tank open to the exterior hull (discharge) and a pressured connection to the sea water service system that maintains a static head pressure on the tank bank.
As far as cabling, historically ships have been built to the "general specifications for ships" and that in turn invokes the Electrical Plant Installation Standard Methods (EPISM). In the 60s the navy moved away from armored cable to PVC-jacketed cable (weight savings). But then in the 80s there was concern about toxic smoke from PVC in a fire and the navy switched to a low-smoke cable. Don't know if there have been changes since. There's standards on the through-boxes / stuffing tubes where cableways transit water or fume tight barriers. But it was decided "GenSpecs" was too expensive and now the navy has invoked a modification of civilian maritime ABS construction standards. There has been considerable concern about the damage resilience of these specs (N/A to BHR).
After Falkland Islands, the navy began a massive review of firefighting procedures, much based on lessons learned from the RN. In fact the Chief Engineer of the HMS Sheffield came over and spent a year or two at NAVSEA HQ to advise. A lot of stuff I see in the BHR pictures are a result of that review (eg fire fighters ensemble).
Don't know current practice, but in the past navy installed Halon 1301 systems in manned machinery spaces. At the required concentration, it was supposed to be non-toxic. at least so crew could egress the space. Other, unmanned primarily electronic spaces (typically small) had Halon 1211 systems. This stuff was supposed to be bad for you. But, at least in the 90s, Halon was a no-no because it is an ODS. So it was being removed in some cases or no new installations in others. But Halon has to have the right concentration so I don't think it is applicable to the large open spaces in BHR (well deck, upper vehicle storage, hangar). In those places at least in my day they were always protected by fixed foam (AFFF) systems. Of course during a yard availability, those systems might be inop from time to time. But any time a fire fighting system is inop, you have to have an assessment of risk and mitigating procedures. Storing amounts of combustible materials in those places (not really designed for it) is an obvious question. Moreso, is the reported "explosion" not long after the initial report of fire. We need to find out what that was about as it appears to have halted all firefighting.
Hope this helps.
scott s.
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