Anyone have any random nerdy facts?

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
AI won't help.
(Gasps in fear) now you’ve done it, you’ll be put on the big tech hit list for sure!! :headspinning:
Oh, my sweet summer child. AI won't help. Modern automation (which is not the same thing) may help. But even extremely optimistic views of what staffing will be required put that in the 50-80 people range for 100 MW-1 GW reactors. Since current large cargo ship crew sizes are on the order of 20-25 people, of whom perhaps 8-10 are in charge of the engineering spaces (and some of whom wouldn't be replaced if the diesels were), you're looking at doubling to quadrupling the crew size. Add to that the difficulty in finding crew who are (a) qualified and (b) willing to go on 4-month voyages, and you're looking at a ship that's extremely hard to staff.

And that's before you get to environmental issues. A nuclear ship (rightly or wrongly) would be barred from many of the world's ports. You also don't build hatches into your ship big enough to eject the warp core, and I don't think that you understand the scale of People Will Care if you do dump an overheating core into the ocean.
I guess that just making training in reactors part of regular training won’t happen unless there are nuclear ships that need crew, as for the environment, it seems to me that a good amount of traffic will be between nuclear nations (eg US and China) so no need to be concerned with proliferation. I wasn’t suggesting a hatch! A nuclear core will melt through the hull unless you try and stop it, make a spot for it to make a puddle and it’ll make its own hatch, I imagine you’d rather have a hole in your ship than have a puddle of hot uranium! As for the public’s irrational fear of nuclear stuff, the best way to get over your fear is to do it and have nothing bad happen! Also as I said it won’t be over heating for long and it’ll be relatively contained so you can can pic it up later If it’s in a bad place (eg a coral reef or a port).
 
(Gasps in fear) now you’ve done it, you’ll be put on the big tech hit list for sure!! :headspinning:
If I'm not on there already, they aren't paying attention. :D
I guess that just making training in reactors part of regular training won’t happen unless there are nuclear ships that need crew, as for the environment, it seems to me that a good amount of traffic will be between nuclear nations (eg US and China) so no need to be concerned with proliferation. I wasn’t suggesting a hatch! A nuclear core will melt through the hull unless you try and stop it, make a spot for it to make a puddle and it’ll make its own hatch, I imagine you’d rather have a hole in your ship than have a puddle of hot uranium! As for the public’s irrational fear of nuclear stuff, the best way to get over your fear is to do it and have nothing bad happen! Also as I said it won’t be over heating for long and it’ll be relatively contained so you can can pic it up later If it’s in a bad place (eg a coral reef or a port).
The real problem is that reactors have a unique set of weird stuff that you'd need to learn, which is useless if you aren't working on a reactor. There is a pool of nuclear technicians available though--they just all happen to work for the Navy right now. If they want to stay on a ship, they'll probably stay in the service, and if they want to get off a ship, they don't want to be on your crew. To recruit them, you'd need to really bump their pay up, which of course adds to the expense. That makes the cost-benefit analysis even worse.

As an exercise for the student, look at publicly available sources for what a 100 MW small reactor costs. Compare to a ~100 MW slow speed diesel from MAN or Sulzer. You should also be able to find fuel consumption for the diesel engine in tons/day or tons/hour. Assume 300 days/year of operation, look up the cost of heavy fuel oil, and work out what the fuel cost is per year. Assume a 20-year ship lifetime for a large container ship and look at the difference in propulsion system costs, even if you don't account for the cost of acquiring and disposing of nuclear fuel and the cost of additional crew. I think you'll find the difference illuminating.

In addition to rational and irrational environmental fears, there's geopolitical concerns. I can't imagine a Chinese or Russian nuclear powered ship getting a real warm welcome in a US port, and likely vice versa.

If you have a puddle of hot uranium that's able to burn through the bottom, you've already done it badly wrong. Among other things, your fuel rods are broken now so they'll leak all kinds of unpleasant isotopes out. Also, you'll get a nasty steam explosion when the first burnthrough happens and water starts flooding into the ship. That will wreak havoc on anyone or anything nearby--hopefully your crew has already abandoned ship.

Finally, you greatly underestimate both (a) the regulations governing throwing stuff over the side (nerdy fact: you aren't allowed to throw a ceramic plate over the side within 25 miles of shore unless you've broken into <1" pieces first!) and (b) how easy it is to recover multi-ton things from the seafloor, particularly when they are already broken by massiver thermal stresses. If you aren't nominally allowed* to throw a plastic garbage bag over the side in any ocean, the authorities are going to take a dim view of dropping a reactor core to the sea bottom. The world has treated the oceans as a garbage dump for millennia, and the various authorities are trying to reel that back.

* I know it happens; I'm just reading the regulations.
 
they can do that already, go steal a Russian ice breaker! :p
The real problem is that reactors have a unique set of weird stuff that you'd need to learn, which is useless if you aren't working on a reactor. There is a pool of nuclear technicians available though--they just all happen to work for the Navy right now. If they want to stay on a ship, they'll probably stay in the service, and if they want to get off a ship, they don't want to be on your crew. To recruit them, you'd need to really bump their pay up, which of course adds to the expense. That makes the cost-benefit analysis even worse.

As an exercise for the student, look at publicly available sources for what a 100 MW small reactor costs. Compare to a ~100 MW slow speed diesel from MAN or Sulzer. You should also be able to find fuel consumption for the diesel engine in tons/day or tons/hour. Assume 300 days/year of operation, look up the cost of heavy fuel oil, and work out what the fuel cost is per year. Assume a 20-year ship lifetime for a large container ship and look at the difference in propulsion system costs, even if you don't account for the cost of acquiring and disposing of nuclear fuel and the cost of additional crew. I think you'll find the difference illuminating.

In addition to rational and irrational environmental fears, there's geopolitical concerns. I can't imagine a Chinese or Russian nuclear powered ship getting a real warm welcome in a US port, and likely vice versa.

If you have a puddle of hot uranium that's able to burn through the bottom, you've already done it badly wrong. Among other things, your fuel rods are broken now so they'll leak all kinds of unpleasant isotopes out. Also, you'll get a nasty steam explosion when the first burnthrough happens and water starts flooding into the ship. That will wreak havoc on anyone or anything nearby--hopefully your crew has already abandoned ship.

Finally, you greatly underestimate both (a) the regulations governing throwing stuff over the side (nerdy fact: you aren't allowed to throw a ceramic plate over the side within 25 miles of shore unless you've broken into <1" pieces first!) and (b) how easy it is to recover multi-ton things from the seafloor, particularly when they are already broken by massiver thermal stresses. If you aren't nominally allowed* to throw a plastic garbage bag over the side in any ocean, the authorities are going to take a dim view of dropping a reactor core to the sea bottom. The world has treated the oceans as a garbage dump for millennia, and the various authorities are trying to reel that back.

* I know it happens; I'm just reading the regulations.
I guess so, I really hate it when one really cool and useful technology is prevented from growing because it’s competitor is old and everyone knows how to deal with it and don’t want to deal with new things.

I wonder how the navy deals with these problems (especially the ports, not having the right equipment)

Finally I apologize for not remembering about the fuel casing I should really know better!
 
I guess so, I really hate it when one really cool and useful technology is prevented from growing because it’s competitor is old and everyone knows how to deal with it and don’t want to deal with new things.
New tech gains adoption slowly until it's cheaper or otherwise more desirable than the legacy versions. If small nuclear proves cheaper on land, people might take closer looks at it for marine applications in the future.
I wonder how the navy deals with these problems (especially the ports, not having the right equipment)
They throw vast sums of money at the problem so that they have bases which are set up to handle reactors, refueling, and training infrastructure. It's worth it to them not to have to worry about refueling (as much for capital ships and subs).
 
Remember that sugar has something like half the specific impulse of APCP. It's probably one letter lower than you're thinking.

From the guestimated mass, the impression of altitude, and rather limited experience at estimating these things, I'd say F or G.

I've made nozzle-less rockets pressed into 3/4" diameter x 10" long cardboard tubes. The core is taperer with a belled end and formed with the same tooling one would press a clay nozzle with.Using fast burning BP made from a hotter burning charcoal and milled in the normal BP ratio resulted in the F range on a test stand. You can squeak a little more thrust using a cored motor and a nozzle, but then you have to use a slower burning BP mixture to avoid a CATO.

Nozzle-less motors using hotter burning compositions are fun, fast and can be quite reliable, but those mixes are rather sensitive and require a lot of care when using. I was experimenting using different ratios of BP with hotter burning fuels, with and without nozzles to create the thrust you need for a specific project, by those experiments stopped when my son was born. We were also testing a hot burning fuel pressed in 1" tubes with varying core lengths before they CATO. It became too hard to go somewhere where I could legally make and test the compositions. I'd really like to get back to those experiments some day.

One should learn how to make these compositions with a mentor at their side. Mistake could cost a limb or your life. They aren't allowed a Tripoli research launches. Manufacture, transportation, storage and use all require some different licenses. For someone who does want to learn this side of rocketry, you can learn and do it safely and legally at the PGI convention.
 
I guess so, I really hate it when one really cool and useful technology is prevented from growing because it’s competitor is old and everyone knows how to deal with it and don’t want to deal with new things.
New tech gains adoption slowly until it's cheaper or otherwise more desirable than the legacy versions. If small nuclear proves cheaper on land, people might take closer looks at it for marine applications in the future.

@NTP2, it's not mainly about the reluctance to deal with new things. That's there, no doubt, but note that @boatgeek's questions for the student were all about the prices. If money makes the world go 'round, it also makes the world stand still. Reluctance to deal with new things is quickly overcome when the new things cost less than the old ones.
 
@NTP2, it's not mainly about the reluctance to deal with new things. That's there, no doubt, but note that @boatgeek's questions for the student were all about the prices. If money makes the world go 'round, it also makes the world stand still. Reluctance to deal with new things is quickly overcome when the new things cost less than the old ones.
True but it takes money to make them cheaper! That was what a was referring to.
 
In the final episode of "Psych", the shadow of the drone filming the episode is visible as it flew over the cast.
 
Buckbeak the Hippogriff (in Harry Potter And The Prisoner of Azkaban) was the first CGI animal to defecate in a movie. Walking With Dinosaurs did have a pooping dino that appeared earlier, but it was on TV.
 
In the (US) Eisenhauer Interstate Highway System, there are five two digit highway numbers that are used twice for current, unrelated highways: 76, 84, 86, 87, and 88. Each of these is applied to one highway in the northeast or mid-atlantic, the other being distant, in the south, midwest, or west. The eastern highways of all except one pair (76) are wholly or partly in the State of New York. I-76 is in Ohio, Pennsylvania, and New Jersey (mostly Pennsylvania).
 
In the (US) Eisenhauer Interstate Highway System, there are five two digit highway numbers that are used twice for current, unrelated highways: 76, 84, 86, 87, and 88. Each of these is applied to one highway in the northeast or mid-atlantic, the other being distant, in the south, midwest, or west. The eastern highways of all except one pair (76) are wholly or partly in the State of New York. I-76 is in Ohio, Pennsylvania, and New Jersey (mostly Pennsylvania).
The lead digit in three-digit interstate highway numbers indicates whether the sub-highway is a "dead-end" spur or rejoins the main highway to form a loop. Odd numbers (eg I-395) are spurs, and even numbers (eg I-405, I-495) rejoin.
 
The lead digit in three-digit interstate highway numbers indicates whether the sub-highway is a "dead-end" spur or rejoins the main highway to form a loop.
Correction: The highway may constitute only part of a loop, and not join the main highway at both ends. For example, see I-287 in New Jersey and New York.
 
Isn't is also true that:
Even numbered highways go east-west
Odd numbered go north-south
and the lower the number the more western / southern they are?
 
For the two digit numbers:
  • Odd numbers are for highways going north-south, with lower numbers being in the west.
  • Even numbers are for highways going east-west, with lower numbers being in the south.
  • Numbers that are multiples of five indicate long haul highways, in theory from coast to coast or Canada to either Mexico or the sea. In reality, not all of them go all the way.
    • Some of the non-multiple of five highways are longer than some of the multiple of five highways. I-81, for example, goes from the Canadian border at the Thousand Islands bridge down to Tennessee, 855 miles, which is longer than both I-30 and I-85. There are others even longer, but 81 is dear to my heart.
  • There are a good number of exceptions.
  • Three digit numbers are related to the two digit highway indicated by taking off the leading digit, as @boatgeek indicated. Therefore, their directions are not related to their last digits.
The older US Highway system (which have black and white shields instead of the Interstate Highway system's color shields) use a similar system, but the low numbers are in the North and East. I-90 and US-20 are rather close together, as are I-70 and US-40, I-95 and US-1*, I-5 and US-101*, and others.

* US-1 and US-101 are both north-south long haul highways that are exceptions to the normal numbering.
 
Back
Top