question about circuit breakers during sinking.

[Zirnitra]

i have 3 big questions about electrical system function after collision.

1. what caused the breakers tripping so forward boiler rooms were engulfed in darkness? how they solved this problem? did power go out in few/couple cabins aswel at time of the boiler rooms losing lights?.

2. did wireless operators left their posts due to power outage or they decided to go help others? if there was power outage, was it instant or it progressed over time? what was powering the radio equipment,was there some sort of small steam engine in radio room to provide power? did titanic send last transmission at 2:07 ?

3.are there any photos of circuit breakers on wreck? if yes did people on expedition see their position? are there any worth to read inquiries about power going out in some ship areas after collision?

 

[Gordon Mooneyhan]

A circuit breaker will trip when the amperage on the circuit exceeds the breaker's rating or capacity.. For instance, a 20 Amp breaker will not trip if the circuit is drawing 20 Amps, but it will trip if the circuit draws 25 Amps. Whether it is a fast trip vs a slow trip depends on the design of the breaker. What will cause a circuit to exceed its capacity is either too many items plugged into the circuit all running at the same time, or, in the Titanic's case, seawater getting into the circuits and shorting them out. Seawater is an excellent conductor of electricity. The only way to solve the problem would be to install a larger capacity breaker and that is a moot point on a sinking ship. As each breaker tripped, the lights on that circuit would go out.

All reports indicate that the wireless operators remained at their post until they were relieved of duty by Captain Smith shortly before the sinking. The wireless room, like most of the ship retained power almost until the very end, although the voltage gradually decreased over time, causing the lights to dim and the transmitter to have less power. The wireless drew power from the ship's electrical circuit.

What we do know, based on the survivor's reports, is that the engineers did an amazing job of keeping the lights on as the Titanic sank. Most reports indicated that a majority of the lights were on (although getting dimmer as the night went on because of lower voltage) until the ship split in two.

If a wiring diagram of the Titanic still exists (or Olympic/Britianic as all three ships would have been fairly close electrically), you could trace to see which breaker controlled which area, although that would still be extremely difficult to prove what time lights went out where on the ship. Also, IIRC, the Titanic ran 100 Volt DC (Direct Current) as opposed to AC (Alternating Current) which is standard for house and commercial wiring now. There are some differences in wiring for AC versus DC. I believe the biggest difference between AC and DC is AC needs two wires going to every point where power will be drawn (i.e. every light, every electrical plug, etc.). With DC, you have a common ground, much like your car. There's one wire that goes from the battery to the fuse box, then one wire from each fuse to the item it protects. The return wire is a common ground that goes to the chassis, and from there back to the battery.

 

[Incony]

Also, fuse boxes were local to the area they served, and on any circuit, the first weakest point will fail first, the intention being the fuse nearest the fault is that weakest point, but it is not always the case, especially going back to the time of the Titanic, fuse ratings were very approximate. What would cause a fuse to break..? a faulty fuse for example, not even a fault in the circuit it was designed to protect.. a broken light bulb,a broken bulb filament, etc.. just as now in uk houses a bulb failure can cause a protection circuit to trip... In credit to the electrical engineers, the fault was traced to a local fuse box, and the electric light restored.... As to why lights appeared to still shine underwater.. its not a direct short circuit in saltwater.. it is an additional resistance path to ground, , in a DC circuit that would cause electrolysis, the circuit on the water would bubble with hydrogen and oxygen... and one can do the same thing now with a small DC battery and a couple of wires, into a glass of water.. i remember doing it at school in my science classes... i can post a typical circuit diagram of the Titanic era electrical circuits, here, ive already posted some... basically big fuses and breakers in the control room. fed port and starboard circuits for lights and machinery ( two lines ) along each deck... and they could serve areas together in central parts of the ship.. each section or area having its own fuse box and breaker ( isolator ) Lights immersed in water might dim, because there was another path for the electricity to reach ground, through the water... and of course some light glass would break if hot on contact with cold water, even so the fuse might not blow.. And even a fuse box under water, may not cause enough short circuit to the next fuse box - even in the control room.. Remember, that even in the initial flooding when electrical circuits were compromised, the crew could still look down shafts and stairways and see the water rising.. and the electrical engineers isolated the machinery circuits.. no one was going to use the forward cranes again.. no one needed the big electrical motors etc,, one has to think about how long it takes to replace a fuse, even if one knows the value and where to find its replacement.. its going to be over 10 minutes at least.. these were not spring clip fuses, they were screw in....