Water vs Hydrogen discussion

[BytePro]

Very eloquently put!

Yeah, tech usage rarely ever makes use of optimal designs of efficiency, cost, or safety due to social and historical reasons.

Here's a few examples little more down to earth than rocket science:

- Gasoline cars. (This is almost a perfect analogy to L-Hyd vs Water in Traveller!) Proliferate in large part due to egos that clashed over standardizing on DC and AC, naval requirements during WWI and the development of the electronic starter and gas infrastructure. We transport an explosive liquid in tankers and store in neighborhoods in small containers, under our seats and in retail facilities run by minimum wage paid folks with almost no required or certified knowledge - not to mention in large tanks near refining facilities invariably located near populated areas.

- LNG for electric power generation. Electrical power is readily available from wind, water, and sunlight - yet we transport LNG around the world. (Talk about non-optimal fundamental safety issues!)

- Computer chips. The combined costs of inefficiencies of growing wafers in a gravity well and the phenomenal expense required to minimize vibration in fab could arguably have financed huge orbital industrial facilities by now. (Not to mention, CPUs being digital and tied to clock cycles, instead of being analog and each operation optimally taking its own time, and then there is the whole optical issue...)

- Fiber optics. Politics related to Cable TV left us today largely still stuck with speed limited, energy wasting copper to the bulk of (American) households and decades long stalling of optical technologies from processing to holographic storage.

- Power transmission and wireless data communications. Refer to Tesla.
​

Markets aren't driven by efficiency - rather by ROI. They are not limited by safety concerns - rather by 'acceptable economic risks' (related to ROI). ROI invariable involves time and expense. If something is already available, however inefficient, costly, unsafe, etc. - if money can be made with some tech, in short enough order, then it will likely be adopted.

The imperatives of wars and military buildups are arguably the most common ways new and better tech comes into being and usage. But, military applications have their own set of natural priorities in which market concerns, not to mention long term environmental damage and resource usage are of lower priority.

[P.S. - ClF5 aboard spaceships and water instead of LH - hehe, excellent RP options! :devil:]

 

[rancke]

All the arguments about how L-Hyd is the better choice in a lot of cases miss the point that it is not the better choice is ALL cases. If there's no enforced-by-nature reason why carrying around hydrogen in the form of water doesn't work, it should be an option.

This is especially so in a set of generic rules, but even in the OTU alone the explanation that the no-water option became the established technology is up against the fact that the technology was invented independently eight times. And, as I said, that's just for the OTU. What about alternate TUs?

Finally, there are applications where L-Hyd just doesn't work, where it's not a question of doing it a little less efficiently, it's a question of not doing it at all.


Hans

 

[BytePro]

Is there a place in the RAW where it is not an option?

Sure, its not in the design rules. In all actuality, you could just use water IYTU in place of L-Hyd. Refined just being purified. Suspect even if you used a marker to scratch out every place in canon that L-Hyd was specifically mentioned, the marker would be virtually brand new when done.

IMTU, 'snagging' water into the tanks and making a quick getaway has always been an option. Of course, I added my own D mix requirements, meaning they couldn't fully fuel (reduced jump in most cases and duration if that mattered). And, I added issues with impurities (especially salts). I added these 'balancing' factors despite not even using the OTU or most of canon. These were all just for RP goodness, though, in a fictional setting one could envision these being non-issues (since the water could be readily purified when taking it on - i.e. via instant steam and chilling process for example, which would also work for ice...).

Conversely, as far as L-Hyd 'not working' in a particular case - that is not really an issue in a fictional setting unless one choices to arbitrarily make it so.

 

[Enoki]

Very eloquently put!

Yeah, tech usage rarely ever makes use of optimal designs of efficiency, cost, or safety due to social and historical reasons.

Markets aren't driven by efficiency - rather by ROI. They are not limited by safety concerns - rather by 'acceptable economic risks' (related to ROI). ROI invariable involves time and expense. If something is already available, however inefficient, costly, unsafe, etc. - if money can be made with some tech, in short enough order, then it will likely be adopted.

The imperatives of wars and military buildups are arguably the most common ways new and better tech comes into being and usage. But, military applications have their own set of natural priorities in which market concerns, not to mention long term environmental damage and resource usage are of lower priority.

[P.S. - ClF5 aboard spaceships and water instead of LH - hehe, excellent RP options! :devil:]

Actually, it is usually driven by the most commonly adopted technology. We use Windows instead of Unix, Linix, Apple etc., for most smaller computer applications simply because it became the most common one in use. It wasn't "the best" or "the most adaptable" but rather simply the one everyone used so it became the standard.

The same goes for military products. Bolt action rifles continued in manufacture long after semi-automatic and automatic rifles that could be mass produced showed up simply because the cost of switching was too high. Most militaries recoginzed in a war that having two different rifles in production was a mistake and switching simply wasn't going to happen. The bolt action was "good enough" so it stayed in service.

The US military still uses what are obsolesent radios in many cases simply because they can't afford to replace literally billions of dollars worth of equipment suddenly.

So, what usually occurs in the market is that a product gets into use because it is good enough to do what the market's users need it to do. Switching becomes expensive and difficult with mass use so, the rate of change is slow. It is only when a much better product comes along that is cheap enough to replace the existing one does change occur.

 

[aramis]

As I pointed out above, refining fuel on demand is only feasible for power plants. For Jump fuel, the equipment is too big, and unrefined presents a notable risk. It's not really a cost issue, just a space issue. (FPP's are one of the cheapest components per ton on a starship.) You can easily install equipment to refine a jump's worth of fuel in 8-16 hours, but not in the 2/3 hour needed for jump fuel use (presuming it's not all used in 10 min or less, which is implied in later editions - in MGT, it takes 10-60 seconds to jump).

 

[BytePro]

Actually, it is usually driven by the most commonly adopted technology. ...

That is putting the cart before the horse.

In the case of Windows - it's market dominance was largely a matter of cost (goes back to the ROI of the business customers). It was adopted by business which later helped fuel its adoption for home use. Another commonly missed fact is that Windows development thru W95 was completely funded by IBM (via tech and license costs for OS2). This gave MS an ROI advantage over its competitors which translated into lower market cost (though it didn't have to - good marketing and Bill's shrewdness not to be downplayed).

Your other examples all speak to ROI. Both from a consumer and a provider standpoint.

 

[McPerth]

I guess most of those arguments would only work if some innovation is done in a place (and so subject to those external pressures) and exported to the others (who adapt this technology, as it is cheaper than developing by themselves).

I the case of JD/fusion in OTU, it has been discovered by several races, and (as written) all adopted the same solution (LHyd tanks instead of water tanks to be converted to Hyd). I find quite improbable they were all subjected to the same pressures (as it could be when the Vilani were the only JD producers and most others that have it copied from them), so I guess there would be some efficiency/seccurity/whatever you want reasons to make LHyd better than water.

I still keep thinking that the fact that rules don't reflect it does not mean there are no reasons for it to be, just the reasons are assumed to be known by everyone (or at least everyone who matters: technicians, designers, researchers, etc) in the OTU, even if not told to the players.

 

[BytePro]

Well, sure, the reasons are obvious - the authors didn't think of it :rofl:

Of course, neither have any of my players in ~30 odd years (well, odd and even). And I've made use of the dangerous handling characteristics of L-Hyd in plenty of adventures (both aboard ship and port-side). Mind, doing so adds drama that is more appealing then 'realism' for most, and players eventually figure out that they can set-off L-Hyd leak alarms to their own advantage on highports and even other vessels.

There is one aspect, though, that makes having the option, at least, to use L-Hyd very reasonable - the relative availability and easily found nature of hydrogen from gas giants. Some systems will simply lack liquid water oceans - meaning water only fuel would have to be obtained from frozen sources which would likely be highly contaminated, not to mention require detection first and potential risk in acquiring (ice-slides, explosive or toxic gases embedded in the ice, etc). Accounting for these aspects taking more time to deal with than for hydrogen can make the risks and economy of L-Hyd justifiable.

 

[saundby]

Something I've done for fun is having external leaks generate thrust. While still in the jump bubble it doesn't have any apparent effect, but when emerging from jump it is found to have had the effect of changing the ship's relative velocity such that they may find themselves emerging from jump with a very undesirable vector relative to anywhere they'd like to get to while the PP still has fuel enough to power the M-Drive.

As to hydrogen handling--it's so awful now (I'd rather work with almost any propellant than LH2, TBH--even Silane or TEAL/TEB), that I presume that technology has reduced it somehow to a sort of "Gas Station" level of safety, perhaps a little less so when scooping your own (we usually RP out the scoop, unless that's already happened enough times in the present campaign that it'd be a drag on the action.)

I do like to present some nonstandard local variations on technology and let the characters get a bit down and dirty with it. I've used hypergolic storables, metallic propellants, the different sorts of nuclear propulsion, etc. for local in-system use. In some places the locals are trying to spread their technology to other systems as an adjunct to or replacement for the standardized stuff, with varying levels of success. It varies by campaign, too. My usual campaign isn't a standard OTU.

 

[BytePro]

Something I've done for fun is having external leaks generate thrust. While still in the jump bubble it doesn't have any apparent effect, but when emerging from jump it is found to have had the effect of changing the ship's relative velocity such that they may find themselves emerging from jump with a very undesirable vector relative to anywhere they'd like to get to while the PP still has fuel enough to power the M-Drive.

Hehe, that's a dirty trick - I like it! :devil:

I've setup adventures where PC could use outgassed L_Hyd for a very weak form of emergency thrust. Also, gas filled fuel bladders to raise a sunken ship to get to cargo.

 

[warwizard]

Having just read the entire thread, I have some comments from the prospective of a T4 user.

In T4 Mass counts, we have to account for mass when calculating the ship's acceleration, if the ship designer throws in larger capacity m-drives to maintain that 1 G capability when fully loaded, I have no problem with utilizing whatever compounds the crew cares to use to store H2 not needed for jump.

For Example the TL=10 HEPlaR m-drive uses H2 as a rocket fuel. The drive is a large capacity rocket using plasma accelerated via electric fields. H2 is just the most efficient working fluid producing the highest velocity exhaust. The drive can run on water or benzene or whatever you care to throw out the back, the only change is the KN you get per mt of fuel and M/W of power. That being said I'd shoot a missile designer that tried to fuel it's HEPlaR with water, I want my missiles to go fast!

I've done many TL=9 designs in FF&S II, where we do NOT have HEPlaR. the cost of even providing 1g of thrust is easilly 10 times the cost of the rest of the ship. So our TL 8 rocket scientists, are adverse to putting anything besides LH2 in a spaceship does not come as a surprise to me.

A society that goes through developing spacecraft at lower technologies will generally utilize the lightest species in it's plasma rockets, thereby establishing the use of LH2 in it's space industry before developing the jump drive, leading to the use of LH2 for jump fuel storage, cause that's what they know how to carry the hydrogen.

 

[atpollard]

I agree that using a Reaction Drive of any kind in your spacecraft renders volume a trivial concern compared to mass. Unfortunately (or fortunately) most versions of traveller employ Reactionless Drives where volume is king and mass is trivial.

As an aside, I find it amusing that even the systems that choose to use reaction drives and mass, get the rocket equation wrong. This is not a criticism. I fully understand that choosing to crawl at a snails pace (0.001G) to the jump limit using a high efficiency-low thrust drive or using 80% of your ship for reaction mass are not particularly enjoyable alternatives. I just get a chuckle from 'soft science of a different flavour' posing as hard science.

 

[BytePro]

Yeah - this is why I stayed with a limited set of CT and more recently Mongoose.

To each his own, but I'll accept hand-wavium science fiction over out-right bad science, squatting amid fiction, any day of the week, especially when it comes at a cost to playability. :nonono:

 

[warwizard]

ATPOLLARD, There ARE reactionless drives in T4, and also reaction drives that are quite good and fuel efficient vs the ion drive and the chemical rocket. Each one has a different problem that it poses to the designer. Suffice to say decent performance can be had with good fuel efficiency, but they do have other drawbacks. This thread is a discussion of hydrogen storage and discussion of maneuver drives is just a side discussion wherin some rule systems does count the mass vs thrust.
I am pointing out that a H2 as water fuel storage system that while more volume efficient, may be nine times the mass, for a given amount of LH2 and maintaining a set arbitrary level of thrust/mass performance will cost more volume in maneuver drives and or power plants, and not maintaining the performance levels may add minor additional travel times to the jump point.
Just adds an additional calculation for when you determine your return on investment, ship either costs more, needs more crew, or it's slower getting to market with the increased payload.