Fate Favors HMAS Farncomb & Minor Leaks
Wednesday 25 July (Australian Eastern Standard Time), while participating in Exercise RIMPAC, HMAS Farncomb suffered a minor flood in one of the submarine's machinery spaces after a hose split. The submarine surfaced in response. The incident has been traced to a split in a hose on the submarine's weight compensation system.
Australia's Defence Force reported that recent flooding in the Collins Class submarine HMAS Farncomb was "minor". The description "minor" was deemed appropriate with good reasons:
1. The sub experienced no related casualties.
2. The sub itself was not sunk.
3. Significant equipment damage has not been reported.
4. Pre-planned procedures were immediately executed and the situation was dealt with quickly.
Potential hazards of flooding in a submerged submarine (HMAS Farncomb was operating at periscope depth) were entirely ignored, however, to a degree most non-submariners might find deceptive:
1. Submarine compartments individually and collectively are "confined spaces" wherein the rapidity of flooding is proportional to depth, and entrapped crew members can potentially be exposed to drowning as well as pressure-related injection, laceration or amputation. Of course, the worst case would be hull rupture beyond crush depth due to subsequent loss of depth control.
2. At periscope depth while charging batteries (as HMAS Farncomb reportedly was), submarines can also be vulnerable to major flooding through improper operation of main induction safety features.
3. The conductivity of seawater in contact with electrical controls and equipment can cause abnormal operability.
4. Seawater in contact with submarine battery cells electrical can generate toxic gas and, in worst cases, explosion.
Fortunately, fate and preparedness favored Farncomb's crew. This was not the first time a similar hose failure occurred in a Collins class sub. Following the failure of a sea water cooling hose in HMAS Dechaineux in 2003, response procedures and equipment were improved. One upgraded involved automated closure of hull valves in similar upsets.
Minor flood is certainly an oxymoron on a submerged submarine. For that matter, the only minor leaks on a submerged sub are connected with crew visits to the head.
Submarines are always silent and strange.