What Are Those Weird Red/Black/White Discs on the Wall? 

man you're having a very bad day when you're rigging 490v wires in a compartment full of water and also possibly on fire

I'm assuming they are called biscuits in humorous reference to the old naval rations, since they resemble ship's biscuits: big round disks, dotted with lots of holes, and as hard as iron.

Thanks for the quick turnaround, Ryan. One point: you wouldn't start at the live power source and work your way to the load (whatever is consuming the power). For safety, you do it the other way. Start at the load, and work your way back to the live power source.

You have convinced me to have 3 phase power installed in my home along with casualty power terminals on all my walls.

as an industrial electrician i found this interesting. good way to delineate each phase with the rings and the notches.

Interesting to see how the designers considered the lowest common denominator in their damage control efforts. Make it as simple as possible, because when the ship is hit, flooding, and on fire, you don't have the time in many of these spaces to refer to the manual (assuming you even have a manual). Power needs to flow. You can do it by feel if need be. Truly an analog solution to a complex problem.

I used to work at the San Francisco Naval Shipyard back in the 1960s. I remember the caveat "Load to Source." Connect the load first and then the source. That way you don't have the live terminals sticking out. It's good to see you still have some of the cables and wrenches on board.

There are charts in Damage Control Central that show the location of every biscuit on the ship. I remember having to participate in damage control drills setting up casualty power as part of Refresher Training (REFTRA) and the Enlisted Surface Warfare qualification.

I do actually have something quite like this in my house. An inlet and outlet on opposite sides of a wall to get power from a generator outside into my basement without having to have a window open to run a cord through. Extension cords to get power from there to critical loads. Including an inlet on the "power box" for the furnace to feed power into that circuit from a cord. (It's a proper transfer switch made for exactly this purpose, so no back-feeding can occur.)

Ryan's video reminded me of how Japan lost many ships because of inadequate damage control, especially fires that raged out of control while the sailors struggled to find a way to extinguish or even control the fire. This one system looks very well thought out, right down to having a system for keeping emergency electrical connections tight, using those special wrenches.

The main reason for the biscuits is to keep the water tight door sealed. Under different "material conditions" like battle stations, fire fighting, flooding, etc., certain doors must be closed and locked or "dogged" and can NOT be opened without explicit permission to do so. And they certainly can't remain opened to allow a power cable to run through it. The sealed door prevents fires from spreading and/or stops flooding from one compartment to the next. If the compartment was filling with sea water, the power cables would be routed around that compartment; otherwise the salt water would short out the 440 volt connections.

Why yes, I DO have an emergency generator. I love it!! Power lines here are surrounded by trees. And then it gets windy....

I spent almost 40 years in the aviation industry so I look at these different options for power routing and every other redundant system as thousands of man-hours to design, document, and implement when they may never be used. It's just staggering to think of the total effort to build one class of ships and then multiply that by the tanks, trucks, fighters, bombers, weapons, etc. required to support the war effort. Unbelievable!

those casualty power pucks arent on all us navy ships. my first ship was a newport class LST. it did not have any provisions for casualty power. its one way to know they consider your ship disposable.

The color/shape coding of that is impressive. Simple, yet effective. At home, I have a pure sine wave inverter and a couple of lead-acid batteries. Not much, but it will keep the fridge going for a little while and power some lights, hopefully long enough for main power to come back on. The disadvantage is obvious--it only runs as long as the batteries last. The advantage is no gasoline engine that needs maintenance and/or that won't start when you really need it.

I learned something. A small detail that could save the ship. Ingenious.

It's interesting that you can hook up 3 different sets of jumper cables at the same time, thus allowing you to shunt power to a specific item.

Also, the power at the emergency source must be off or the 3 phase breaker open, since many load devices such as transformers and motors can be damaged by not having all 3 phases live at the same time. You need to turn on power to all 3 phases simultaneously after wiring up the whole daisy chain.

Yes, they are emergency power connectors for cross connecting damaged wiring. We covered this in DC school. But I don't think there was a lot of drill practice rigging these things. Maybe the electricians did simulations. It seems there should be a special "T" wrench as well as a super heavy supply of cable hanging like firehose nearby on the bulkhead. I did drills on America, Kennedy and Saratoga (late 60's) and never saw this rigged in any way. It would be interesting to hear from any old sailor who actually employed this system as a result of battle damage.

The thinking that went into this ship in all areas. I was especially impressed with the analog fire control computer.

Ryan, I belonged to the Damage Control Education and Training Team (DCETT) on the USS Kitty Hawk, and I just learned something from your video. I knew about Casuality Power. What I didn't know about was the lumps on the cables and the matching notches on the biscuits. Never too old to learn.

I have had to use emergency generators both while on active duty with the US Army and home before I was drafted in Dec 1970. Biggest problem is always once it has been used it needs to be started every week to avoid fuel gumming up the entire fuel system. I trained generator mechanics while on active duty. Every week I had to start our 5 KW generator and let it run for 15 minutes then top up the fuel tank.

Wow! That brought back memories. I had completely forgotten about those on my first ship. I later went to a sub and we didn’t need that system, so, after the first 18 months on my first ship, I never saw them again. The newer cables have all three phases of electricity contained in a single cable & connector to make it easy.

I have an 800A 48VDC telco spec power plant for my telco equipment set up with 16 50A rectifier modules, half of which are powered from the backup generator. Building lighting and HVAC are run from 48VDC solar with an automatic transfer switch to the main power plant if the solar battery string gets low. I also have the option to swing lighting and HVAC directly to commercial power if the situation calls for it. Extreme flexibility is the answer to unpredictable failure modes.

In today's video Ryan jumpstarts a battleship.

Flashlight by the bed - ditto. Uncle Sam is kindly disposing of a lot of MEP-1040 10 KW Diesel generators. I got a very nice one with only six hours on the meter.

After watching Juan Browne's recent video on the loss of power at The Blancolirio World Headquarters, I ordered a Champion duel fuel generator and manual transfer switch. I can now run my gas furnace in the dead of winter even though the power lines might be down. Which is sort of important here in Wisconsin.

Where I grew up we could expect line power failures (plural) during the winter, and without helicopters it could take several days to get the line crews back into the mountains for repairs. For decades I kept candles and matches where I could find them in the dark.

Damage control 300 . I guess. Cool chit. Glad my tank was smaller and not so complex. The 440 BB volts vs 300 tank amps seems about the same. Though a tank ain't floating in salt-water. Much respect to the electrical gremlin either way.😎

That is brilliant! I work in a hospital and we have means of routing power from different sources, sometimes via manual switching and sometimes its automatic. There are also two of everything as in two main feeders to the hospital, step down transformers are in pairs, generators are in pairs etc. Failure of one component is not extremely critical as faults may be isolated and loads get switched and supplied by the remaining "good" component

ideally, I would have street power from the power company, as well as solar, and backup generator all fed through a battery backup. But because that all costs lots of money, I have candles.

"Bypass the EPS relays!" I always wondered what the real-world equivalent of that was.

Great job. I have been curious for years how they reran the power on ships that were battle damaged in the movies. They just show them running the cables, and boom, power.. I just assumed they unwired something, and tied into that power. Thank you for showing us what they are doing..

Looks to me like the notches on that "biscuit" were cut by hand, and not part of the casting process. Maybe the ridged wires and notches were an upgrade based on experience? At home we've got not just flashlights, but LED headlamps. One of my most satisfying accomplishments has been converting my 81-year-old mother to the convenience of reading and doing things, on a dark, powerless night, with a headlamp instead of a flashlight. And I have a lot of spare flashlights from when I was a professional mariner!

Those black discs are for emergency power connections when battle damage severes a main cable. They are keyed on the disc for proper phasing of the feed. One, two, or three pips, and corresponding keying on the cables. Every thing you need in smoke and dark. You might see the biscuits connected to a power panel. Remember to wire from load to source.

After retiring from the Navy some 35 years ago, went back to college and got into industrial electronics and electrical. We setup a similar setup in the plant, we always used the same color coding and checked the phases constantly, sort of like a monthly PM to walk thru the plant and check the 480v outlets to ensure someone didn't make a mistake.

Love these little “what’s this stuff” videos

Finally an explanation of "re route emergency power" and other such start trek things

Okay. Here's what's always been one of my big questions about ships, especially with twin rudders, and especially still the iowa-class. Why are the rudders so small compared to the rest of the ship, and wouldn't bigger rudders be more effective and result in a tighter turning circle? Also why are such little rudders so powerful?

Probably one of the most ingenious additions to a warship.. so simple. Yet so powerful.. unlimited potential in a pinch.

three size port also. you cant plug a red or black into a white plug or a blck into a red plug. triple saftey besides color and hand feel markers

My father, took us on a tour of the USS North Carolina. As a former First Class Petty Officer who was an electricians mate he showed us things about the ship. One of the things was emergency power. It was one of those things we would have missed if there wasn't someone there to point it out.

Could you do a video on the various color meanings on pipes; e.g. purple for fuel, red for fire fighting, etc.?

Kinda funny that directly over Ryan's left shoulder @0:09 is a modern "AED" sign. Yeah, but I don't think 400 volt 3 phase counts as an Automatic Emergency Defibrillator (AED) for anyone but Frankenstein!😄

It's amazing to see how the battleship has systems in place to re-route power when damage control is needed. Ryan asks about the At my home we have two different circuits from city power, one for the house, another for the shop, and rarely do both lose power at the same time, I think maybe once in 17 years. I have run a heavy extension above ground from one to the other to keep the fridge and freezer operational, and the generator keeps lights and fans on. But nothing powers the HVAC running so we have packaged firelogs for the fireplace. We also have multiple flashlights in every room and many spare batteries. All this came about from what we call the Ice Storm, a great cold blizzard that lost our power city-wide for five full days, and destroyed many trees and overhead power lines due to the weight of the accumulated ice.

Ryan makes extension cords interesting!

My home is at the end of the line, on a side street off of another side street. Power goes out often enough that I have a dual fuel generator and store enough propane at home to run it for a couple of days. (propane, unlike gasoline, does not go stale in storage) Also enough extension cords to run in through a window and power critical loads. The furnace, heating fans, fridge, the telephone and wifi, my mom's stairlift and oxygen concentrator, a few LED lights and charger for my laptop and cell phones. I also have a portable butane stove so I can heat food and make tea. Enough heat and serve food for several days in the kitchen cabinets anyway. the stairs also have several of those little LED motion detector battery lights, which are great to have at night to keep from tripping.

for when you have to unplug and plug back in your battleship

We have flashlights, lanterns, candles, some solar power bricks for recharging USB devices such as cell phones, and a small generator which we can use to keep the frig alive for a time.

Watching your videos made my recent visit to the Yorktown and Laffey much more enjoyable. I had been aboard both years ago but I was able to appreciate and understand more of what I was seeing because of what I learned from your videos. Also, it was fun to share that knowledge with my friends. Keep up the good work!

Wow, that's pretty cool. It interesting how they solved the issue of low visibility for both the cable and the outlet.

It would be fascinating to see a wiring schematic used in quickly planning casualty power routing.

Love the video! I'd love a video on the Tennessee class battleships and all of those other standard types that continued to serve through WW2. I find their series of modifications fascinating. Side by side images are crazy!

We run a farm, so yes indeed we have backup power. Two generators. They get exercised monthly... either one can power the essentials.

I remember you talking about there on the Broadway video. I’m fascinated by them and have told many people about this ingenious system.

Lots of trees around the lines, and I'm the last house on the line - the next house over feeds from another area of the grid. I have battery backup systems that run everything that's critical to avoid downtime on (I WFH and the internet can take 15+ minutes to restart), then a standby generator with 7 days of fuel that takes 44 seconds to start transfer load from the mains. I have an additional portable generator that can run critical circuits to allow maintenance of the main generator during extended outages, and the biggest battery backup system is two redundant systems with redundant feeds to the load, so that I can perform maintenance on it without losing protection. Oh, and I also have spike suppression in the breaker box, and the transfer switch detects floating neutral conditions and cuts grid power should that occur, either from wiring issues or something like a solar storm.

That's so cool that they had AEDs in those old ships! Really ahead of their time!

I'm an electrician at an airport. We use our own Natural Gas powered gen sets for power generation, and have the grid as a back-up.

Interesting vid! And yes, I do have a couple generators at home. We always seem to lose power every year, and sometimes for several days now and then.

Black, white, red, a, b, c, 1, 2, 3, had to learn it many years ago casualty power cables should be strung on the overhead.

I love the fact that AED (emergency defibrillator) sign is pointing at 480V three phase power cable. 480V should definitely do the trick!

Backup lighting at home primarily consists of candles and oil lamps/lanterns as well as a flashlight for more focused light. The most recent oil lamp I bought had a wall mount.

If I lose power I just accept my fate and wait patiently for death, or the lights to come back on, whichever ends up happening first.

I'm guessing that the holes are aligned, as well. That is, going clockwise, if the black goes in the first black, then the white goes in the first white and the red goes in the first red, same for it it's going into the second black/white/red, and so on.

The designers seem to have come up with every conceivable way to help the crew deal with battle damage and keep the ship afloat. How tightly do the casualty power cables fit into the biscuit receptacles? It seems tightening the connections with the biscuit wrench would be nearly impossible if you had to plug the cables in by counting ribs/notches.

You're telling me that the sci-fi cliche of "rerouting power" is a real thing from 20th century battleships? That's awesome.

That's really interesting hey, I like how they have the ribs and the notches so you can feel where it has to go in low/no light conditions. Bloody genius but so simple.

The Canadian navy used that same system set up right up to the Tribal class destroyer that were just decommissioned. The newer frigates have a more modern system

I appreciate how all systems in the warship can be rerouted with switches, valve, patches and people, to ensure deep redundancy multiples. From flood spaces, power, gunnery and command systems, you need to destroy many many locations to kill this ship. I didn't realize how deep that went.

We have several backups at home, even being pretty close to the city. First up are automatic emergency lights on each level that go automatically on when outlet power is lost (First Alert makes some very small, very nice ones now). These are rechargeable, and can be unplugged to use as emergency flashlights. Next are multiple LED flashlights, with spare batteries. For computers, we have two laptops good for a couple of hours each, plus a full UPS on the biggest system that can power everything plenty long enough for a safe shutdown. Then, since we have an attached garage, we have an emergency inverter for each car, allowing up to 1400 Watts via extension cords. Each of the cars also have chargers for cellphones, etc. And those cellphones have hot spot settings, so we can still connect to internet on an emergency basis. We also have a pair of weather alert radios. All told, we are likely good for a day or two, without any outside assistance. (I was an engineer for a TV station for a dozen years, and an engineer for medical facilities for over two decades, so having redundant backup plans and systems is not anything new.) As it happens, we lost power for four hours last Saturday, and were not even inconvenienced. We could even watch movies on video until the power company got a crew out to our neighborhood.

Each pie slice has three holes. Are they all connected together, or is the hole choice significant? If you plug into red-1, do black and white also have to be the -1 hole? Do the connections on the other side of the biscuit in the other compartment have to use the same hole?

The kind of small detail that makes Ryan’s videos so interesting. How to rig an extension cord when people are shooting at you with big guns.

That is a very clever system. Both tactile and visual. Simple and easy.

That 440V three phase lead would make for one heck of an AED experience.

As with so many things still in use these are ingenious solutions to critical situations , learned in wars . To a large extent they ensure critical equipment needed for the ships survival can be restored if possible . The leads are super flexible cable to make it more practical and part of many damage control exercises . Like other Naval basics , they are still in use , practically unchanged , on many ships today because they work . I've got a couple of torches & candles at home , but have a few solar garden lights I keep on a window sill which can be useful . I'm thinking solar will , or even may already be , a part of warship design for power .

I work in engineering at a regional hospital, we have redundant electrical systems. Never seen bricks like this and I found interesting. In a hospital environment we practice and plan for power and facilities lose. At my facility we have 5 generators (3 supplies 1150VAc and 2 supply 480VAC). We are fortunate all our power are control by building automation and with consideration to load we can for most part go completely offline from power company and supply 100%. In front of power generators we have several UPS battery backup that support critical and life support systems and IT services. In front of those system all critical and life support systems have their own UPS and most have individual battery back up. Lots of redundant systems, that all require monthly, quarterly, semi Annual, annual and 5 year inspection that is documented.

Great videos, if you're ever in Bath Maine, and want to look at some destroyers, hmu. Thanks you for your commitment to these amazing ships.

Thank you for the very informative video !

Outtages are pretty rare where I live, and the few ones we have don't last long. High voltage lines which aren't below ground run in corridors which are kept tree-free; anything else runs below ground. So, no redundancy here.

When I was going to Engineering school after boot camp in the early 80s we learned about this but my Newport class LST (built during Vietnam) didn't have the system.

I had the opportunity to visit the ship a few years back and I found it to be enjoyable and educational. Thank you.

Great video. I've been wondering what those things were for.

Backup power: AT home: Battery on my Cable Modem & Router. At work: [kK8 School]: UPS on Server Rack to run Wifi, Clocks, PA & Phones. Portable Generator to run the Well. Various fixed and portable battery lights for MPR, Gym and Office.

Ex navy. We had generators we could move that had small jet engines. You could power quite a bit with one unit. Now imagine multiple units. Powering aircraft and supply equipment. Easily moved to where the power is needed so you don't have to run power from, say, a forward power generation room. Then you're only effectively doing repairs in the problem location and not spending a lot of time routing power cables. We did have diesel generators too. Different sizes. After the navy , I installed many Onan Cummings diesel gen-packs at many homes, businesses , government projects, and buildings. As well as natural gas and gasoline units. Some of the largest where the size of semi trailers. The largest was 3 stories tall and could power a small city..lol.

I've actually been thinking of similar stuff for backup power for the house. And I assumed that's what those discs were for. That's the cool thing about electricity. It travels through solid wires which is usually surrounded by solid insulation. So, You can completely seal up a wall that it goes through, or have a connector like that. I don't like those terminal plugs though, you could easily get fried by touching them while they are live. I assume they had caps on them. The 1 to 3 tab and notch system is really cool though. I love the simple solutions to major challenges that people come up with.

In the early 2000's we had a whole switchboard catch fire while at sea on HMNZS Canterbury, lost power to half the ship, we had a similar system on board onboard so had to use them to get critical systems back up and running

Interesting topic. They sure had their ship together when they built those vessels. I have 100W solar with 12v backup batteries for 4 ceiling outlets in the house @12v. And I have full house solar with batts.

I'm assuming that nothing gets energized until all the connections are made?

It's nice that the old battleships are accessible for the blind sailors. 😂

My "emergency power" preparations at home consists a USB power pack for small electronics, a small flashlight, and a jerry can of diesel for the wife's "personal massager".

In computer networking we still call a surface mount box for wiring (even a small plastic one) a biscuit. I'm guessing this is where the name came from.

That is great information and great presentation

looking directly into the camera lens for a few seconds at a time makes the viewers feel like your speaking directly to us. No hate, I love your vids 👍🏼

No clue, sooo cool. Thank you for the information sir

We have battery powered emergency lights which replaced our normal LED lighrs. They go off and on with the switch somwe can extend the run time quite a bit. We also have a pair of Honda geneeators to run imporrant things in the house. Our longest outage somhar has been four days

This is very cool, I love to learn about this sort of design and engineering.

A fascinating video, thank you. However, I would have though having a single three pin plug would be preferable to having separate conductors where current could be fed back from the conductor already connected to the other two via what the other end was connected to. Just a thought.

Love your videos, I need to come visit the ship. I have an automatic standby genset because PECO doesn't seem able to keep the power running way out on the MainLine.

Hmmm. Similar style of those cables gets (but shouldnt be..) used on building sites everywhere... when you have external power and backfeed the power into the house with a double plug "suicide cable" into a wall "outlet". Double Fun with the EU Schuko symmetric plug that doesnt define Phase or Neutral, until your Neutral-PE bridge goes hot and live in the main cabinet.

my dad use to run the generator on the Class C RV back when we lived in the Hoosier State.. right now all we got is a battery backup for the main internet modem and my pc and my brother's pc.