wmoser

Well, the old way to do it is to use sea water flushing which leads to its own problems over the life of the ship with pipes corroding. New(ish) environmental regulations dictate that you can't just flush everything overboard anymore, it needs to be processed through a sewage plant. Despite probably being able to ignore most environmental laws, the Navy normally at least tries to abide by the current laws to be a good citizen and not pollute the oceans as well as having an easier time when visiting foreign ports.

The process plants run better on fresh water but fresh water is expensive and heavy on a ship so a vacuum system allows for less water per flush and really works pretty well if people don't flush stupid things.

Stupid things that my co-workers have fished from sewage plant besides the things mentioned in the article: Towels Screwdrivers Glasses Rags baby wipes/ flushable wipes Pens

As long as only body waste and a small amount of toilet paper are used, the systems are actually fairly reliable. Teaching people that that is ALL that can be flushed is an on going problem. The chemicals seem to be another issue, possibly a design issue but there are ways around that too. Urine crystals build up on the walls of the pipes and reduce the diameter for the waste water to flow. The vaccum systems typically have smaller diameter pipes then the old style "gravity" flush systems. There are companies that make continuous dosing systems that go in the end of the branch lines to help keep them clear.

A lot of issues with maintenance can be solved by design of branches in the piping system with isolation valves so the whole system doesn't have to be shut down to fix something. Even replacing a toilet means shutting off the branch or system since it opens a hole in the vacuum system and leads to loss of vacuum.

Some more information: https://www.boatus.org/clean-boating/sewage/msd-types/

Manufacturers: https://jetsgroup.com/jets-group/the-highest-standards/the-h... https://evac.com/

You’ll have to excuse me because I’m not in front of a windows computer right now, but if you open excel first, there is a data tab on the ribbon and an import data wizard or something like that and you can tell it what the delimiter is. You can also apply types to columns and whatnot before importing. Not the quickest but does help extract the data.

Again, not necessarily a work around, but you might check with your local library in the US. Our library gives us access to online NYT.

The pumps are probably pretty large just so it doesn’t take that long. It’s more of a large volume of water problem than a push it forcefully problem if that makes any sense. There’s something called hydraulic head or pump head that determines how high a pump can pump. It’s sort of a trade off between height it can pump and flow rate. The pumps used are more than likely centrifugal pumps rather than positive displacement. As an aside on pumps, on the ship I work on, we have two fire pumps that are run off 11kV motors, they have to pump a large volume of water potentially pretty high for a deluge/sprinkler system. Our normal ballast pumps are 480v and when they come on the lights flicker but we don’t do much ballasting of the same type as the heavy lifts, it’s more for trim and heel. There are also considerations that a partially filled tank can lead to instability (free surface effect) and they have a definite sequence that they must pump out the tanks to prevent excess stress on both the vessels (on ships the bending is called hogging and sagging). Some ships if they are loaded/ballasted in a certain configuration can actually potentially break in half.

But also easier to order. I've taken more than one waiter outside and pointed at the plastic food.

This is sort of incorrect, it is possible to flag a foreign built ship under the American flag, it just isn’t eligible for Jones Act trade. There are a few reasons why a company might want to do this but for the most part, companies will choose a flag of connivence over American flag if they can sail between US ports anyways.

You are both sort of correct. A foreign built ship can be us flagged, it just isn’t eligible for Jones act trade. I am a US Merchant Mariner who has worked on a US flagged, Australian built ship in Asia. There aware other considerations besides just cabotage laws about where one might want to flag one’s vessel.

The one thing I never understood was why everyone gets bent out of shape over shipping rules but don’t consider or care about airline cabotage.

I believe RADAR was a technology that was honed during the war that had a significant impact. They had experimental RADAR before Pearl Harbor but thought it was a glitch when they saw the Japanese approaching. I’m pretty sure later the newer more advanced sets had a significant impact on Uboat hunting.

I wasn’t very clear, if the NaK is liquid it could flow through a radiator and could still be considered air cooled.

While there are some pure air cooled engines, lawn mowers, motor cycles, etc. A typical car engine is also considered air cooled since it gives off its heat to atmosphere even with assistance of a coolant radiator system.

Most marine engines, some power plants and some industrial equipment is considered liquid cooled since the coolant passes through a fluid to fluid heat exchanger and then that cooling water gets put back into the ocean/river. An example would be some ABB drives come in a LC liquid cooled or AC air cooled package. The motor drive lineups are the same with primary coolant going through all the drive bays the difference is at the end if they put an liquid to air or liquid to liquid heat exchanger.

Probably a giant radiator. Lots of equipment that is “air cooled” has an intermediary coolant that is actually cooled by air over a heat exchanger (radiator).

I just use it to turn my caps-lock key into an esc since I’ve been using vim as my go to text editor.

I work on an offshore oil rig and have to undergo Helicopter Underwater Egress Training (HUET) every 3 to 4 years. They tell us to wait until the "violent motion has stopped." I think it's so you don't get thrown around the cabin. And yeah, it happens really quick and even when you're expecting it and have been training for it, if you panic you won't get out.

All the figures are at the back of the book, if you happen to start reading and were wondering where all the pictures they were referencing were.

For those of you that enjoyed the site, you might enjoy this one as well. It was the first thing I thought of when reading the description of the McMansion Hell website:

http://blog.buildllc.com/2010/04/couch-cushion-architecture-...

I'm going to preface this by saying I don't know much about aeronautics engineering but I am familiar with another niche engineering industry, Naval Architecture and Marine Engineering. Another avenue to consider is to find out what the professional society(s) are for the type of engineering that you're interested in. Look on there website for biographies of leaders for the society, example president, committee chairs, etc. You will likely find a few universities that are more representative than the others. That's a good sign people are actually working in the field. Another good place to just get an idea is the US News and World report site. I know filling out all the applications is a pain, but in the long run it's worth it just to see what you get offered and perhaps there will be another school that seems to be a better fit.

A few other good local/ interesting engineering schools you might want to check out: Lehigh University, they were doing some jet engine research there when I was looking at schools. I think Pratt of Pratt and Whitney fame may have been an alumni.

If you're interested in foreign language and globalism, university of Rhode Island has an international engineering program where you double major in a language and an engineering discipline. They also had an international internship component.

Again I don't know if it's a good program but Embry Riddle is always the first school that pops into my head when someone mentions aerospace/aeronautics engineering.

I know good engineers from Virginia Tech and Georgia Tech too.

Good luck, it's really a tough decision to pick a college but really it's a pretty personal one. I think like most things in life there are more than one right way to do things but definitely wrong ways. You seem to at least be on the right track.

Profession: Electronics Technician on an ultra-deep water drill ship.

Full Time- Rotational 28 Days On - 28 Days Off

[0430] Alarm goes off.

[0500] Call wife before work.

[0530] Morning meeting with all departments to find out plan for the day. Try to pay attention to what others may need help with or where there might be a window of opportunity to work on certain equipment.

[0540] Grab breakfast.

[0600] Meet with night guys to find out what happened during the night and what might need to be continued to work on during the day.

[0620-0640ish] Drink coffee, have departmental meeting to determine what supervisor learned in supervisors meeting. Discuss any issues that may have come up.

[0600-1800] Do maintenance, troubleshoot equipment, install capital projects, research on equipment and projects, check email, do training, fill out paperwork. Eat lunch sometime between 1100 and 1300.

[1800-1820] Discuss day with on-coming crew. Tell them what happened during the day and any issues that need to be dealt with.

[1820ish-0430] Eat dinner, call wife, read, watch movie maybe, practice programming, sleep.

Sundays - Fire drill either during the day or at night.

Tuesdays - Weekly safety meetings after work, discuss any safety issues that have occurred in the fleet or particularly bad ones in the industry. Regulatory safety training on lifesaving equipment.

Repeat for 28 days.

{edit- Trying to get formatting right.}

They are also used quite a lot in building trades or wood working or machining. Pitch of roofs are often given as a ratio, tapers on machinery shafts, making sure your pipes have sufficient slope to drain properly. Another construction example would be how long of a board do you need for the stringers (the long boards that are notched for the stairs if it has to go up 10ft over a fifteen foot distance, etc. whether they might end up the designer or the constructor of things it's probably one of the more practical math concepts.

The last few books I've read I heard interviews with the author or discussed on NPR. Everything else is technical manuals or books on computer things I am trying to learn. Those are normally what I pick up from OReilly or No Starch or Humble Bundle when they're on sale and the topic interests me. Also tech manuals for work on various prices of equipment.

When I was in HS some of my classmates got in trouble for something similar. In MS word there is a dictionary that can be edited for the auto-correct. Example changes teh -> the, etc. You can put a name or common word as the common misspelling and anything else as the auto-correct.

While it's somewhat small, I always try to stop by the MIT Press store in Cambridge MA if I'm headed through the area.

I haven't had any problems with spotlight on Mac, in fact I've come to rely on it at work. For searching PDFs of wiring drawings, I can put in a cable tag and it will come back with the documents it found it in. I open them in preview and the search is already filled in and it takes me right to the specific sheet. I guess your use case is different but I wouldn't trade it for any other searches methods I've tried.

Edit: Sorry meant to reply to root.

Not if you get good generators and the systems on standby. On an oil rig our engines always have their lube oil prelube running and heaters on. We can go from blackout to online in under a minute. Like most other things it's an engineering problem and how much money you're willing to spend to solve the problem.

I'm not quite sure how I feel about this. Mechanical equipment lifespan normally follows a well curve. Premature failures from manufacturing defects and improper component installation or commissioning taper off to a period where there is relatively low failure rates with proper maintenance until a certain point where equipment fails from age (fatigue, worn parts etc). If the end user is the one to specify the component, this could be great, you're not paying for unused time at the end of the components life. Some components are going to be replaced on a time schedule regardless of if there is usable life in it or not, some things are better to do on your schedule than a broken components. There is a warranty on the component for the full life of the pump so if you're doing the spacing you can be reasonably assured it will last its required life span or replaced. On the other hand, if I purchase a piece of equipment from a different company and expect it to last N years, but they are using this component to save money and only opt for it to last M years, and don't disclose the life span, I could end up paying for N-M years of expected service that I don't get to use. As an aside of other software limited hardware, Caterpillar c-series Diesel engines are software limited to a certain extent. If you need more horsepower call the service tech and they can increase the HP. Disclaimer: I heard this from another marine engineer so don't know if they need to upgrade other components as well or if it's completely a software de-rating.

You would think so, but having worked on a ship built at SHI there is still a lot of installing part c, cutting it out, installing A, D, and L and then reinstalling C.

Make magazine had a cover story about how to make one a few issues ago.

http://makezine.com/video/nuclear-fusor-star-in-a-jar/

I've taken numerous (1 EPA, 2 FCC, 16 USCG) government administered tests and they are all have these poorly written, blatantly wrong answers. Fortunately, with larger question pools and more questions on a test it doesn't throw your final score off if you get one or two where the wrong answer. I wouldn't want to take a test with 100 question pool and only 10 questions.

Japan

I agree. The nature of my work is very cyclic. I would love to be able to work on courses during down time and put them on hold during busy periods. A coursera course that I was taking is just finishing up now and a few weeks ago work was busy and I feel behind. I'll end up 'failing' the course but at least I did manage to learn from it and hopefully the videos will stay up so I'll be able to finish it on my own schedule. There are also coursera and edx classes I've signed up for with no intention of participating so I have access to the material when I have time. To me, one of the biggest potential benefits of online learning isn't being utilized, everyone being able to work at their own pace.

There are a lot of people looking at fuel efficiency as well as carbon/sox/nox emmissions. For the companies running ships, the more efficient the plant is, the more money they save on fuel. About ten years ago we did a rough back of the envelope calculation in one of my engineering classes when I asked a similar question. The extra weight of the solar panels would negate any small benefit they would provide plus the cost of maintaining extra equipment. A lot modern ships run a shaft generator which uses the power from the shaft turning the propellor to turn an alternator to make electricity. When the ship slows down at the end of the trip, they go back to running smaller 'port' generators.

Well to be fair, regardless of its suitability as a long term viable fuel source, it is nasty stuff. It's basically tar. It has to be kept heated to about 70c less it become to viscous and can't be pumped anymore and heated even more before being used in the engine.