There’s a lot to like about ammonia. This colorless fuel emits no carbon dioxide when burned. It’s abundant and common, and it can be made using renewable electricity, water, and air. Both fuel cells and internal combustion engines can use it. Unlike hydrogen, it doesn’t have to be stored in high-pressure tanks or cryogenic dewars. And it has 10 times the energy density of a lithium-ion battery.
So there is always a fly in the ointment of this sort of story…
Manufacturers and engineers must overcome key technical hurdles and safety issues in the design of ammonia engines and fuel cells. Port operators and fuel suppliers must build vast “bunkering” infrastructure so ships can fill ammonia tanks wherever they dock. And energy companies and governments will need to invest heavily in solar, wind, and other renewable-energy capacity to produce enough green ammonia for thousands of ships. Globally, ships consume an estimated 300 million tons of marine fuels every year. Given that ammonia’s energy density is half that of diesel, ammonia producers would need to provide twice as much liquid ammonia, and ships will need to accommodate larger storage tanks, potentially eating into cargo space.
So to fully replace oil you need 600 million tons, all produced artificially in new chemical plants. And then there is the ‘pungent’ odor and its solubility in water where it produces a strong alkaline Ph, the fact that it can cause breathing problems etc etc etc.
Not saying it is not an interesting approach but I really have to wonder how acceptable this would be. This seems like a question of ‘what kind of hell are you willing to accept to reduce CO2’ when the reality is that there are a lot of other things to do first and a lot better future directions to take. I like the idea of the age of windjammers returning…as in the last post.
Not so much for the wings + Wind Turbines + Solar Cells but because it is not one hull but Seven (7!) each one of those sub sections is essentially a barge with a rugged locking mechanism that creates a rigid sea going hull once engaged. This way the crew and propulsion section can drop off and pick up sections either all or one or two as they make their rounds and the expensive bit gets much more use as well as being smaller and less expensive, probably safer as well.
So the Naval Strike Missile, a middle weight anti ship missile will be mounted on an Amphib to provide integral defense and a little bit of offense capacity. The main purpose of this deployment is for experimentation with the fleet, to see if it changes the nature of the game when at sea. The Amphib is a big ship but is in essence a sea going ferry for the marines, a fast freighter. But these ships are big and impressive and sometimes used to show the flag. They have defensive weapons but nothing to ‘shoot the archer’ usually that is left to an escort. Having some rounds on board would change the dynamics and utility perhaps in a positive way.
While the preliminary deployment will have the missile amidships like a warship might. But the missile could be mounted on a truck that is being transported, just drive it out onto the flight deck, lock it down and shoot. With all sorts of truck mounted ordinance such as Hellfire, 155mm Cannons, HIMARS GPS Guided Rockets, there are a lot of options that this could provide for protection or force projection.
With the continued growing cost of specialized warships this sort of flexible tactical utilization looks like a good use of modern precision weapons. One can and should argue that it does not provide any kind of one for one replacement for a warship. But is a warship; a frigate, destroyer, cruiser… really what we need? Maybe its a combination of gnat weight autonomous missile slingers supporting heavy flex fighters like this Amphib.
So this seems crazy but in all honesty it has actually been a thing for a long time. It is mentioned in a lot of sixties/seventies SF not focused on space flight. It was seriously studied several times as a sort of replacement for parachute insertion of military force. And like most of those sorts of efforts there was a commercial concept to support the technology since the folks in the defense industry understood that military programs cannot support a robust industry on its own.
Just look at nuclear power, there was a reason that nuclear power stations evolved as the Navy came to realize they wanted nuclear ships. And there is a reason that small aircraft carriers and non nuclear submarines are anathema to certain parts of the Naval establishment. They know that if non nuclear CVs and SSs became common the industry required to support the nuclear fleet would become unaffordable.
People have already talked about the DoD buying Starships and using them as bombers / hypersonic weapons platforms. This is just turning the model above around.
Back in medieval times freighters and warships were the same thing, they just tacked on some fighting platforms and went at it with bows, crossbows, catapults, swords, etc. Even the Vikings probably started out as traders though always ready to ‘raise the black flag and slit a few throats’ if that looked like the right business strategy.
Anyway…sorry for the side commentary, it’s evening and I had a good dinner so I’m wandering a bit.
So, again anyway…if you look at it, a craft like the Starship, which has the performance as a single stage vehicle to haul 100 tons 10,000 miles in less than an hour has some attraction on its face….but in reality?
To my mind the most value dense time sensitive cargo is people but that’s years out at the least.
In the meantime are there cargos that are so time sensitive that something like a starship might make sense?
Couriered documents. Maybe
Mail. Does not seem like it.
Medical supplies only if the ship could land almost anywhere and take off again.
High value tech like chips? Maybe but 100 tons is overkill.
In fact most of the above are not 100 ton class cargos and frequency and flexibility of landing seem critical.
So dead on arrival? No there are customers who might pay for a a limited 100 ton capability. I think it would need to be anywhere in the world which is more than 10,000 miles but is probably within the capability of a modified Starship with more fuel and less cargo…or maybe an extended tank Starship could do 100 tons out to 18,000 miles (my wag of anywhere in the world from anywhere in the world.)
A somewhat smaller starship could do 10 tons 18,000 miles and probably land at just about any port or airfield as long as you can supply LOx and LNG, which is not that uncommon.
Go back to the start. If you burn a couple of hundred tons of LOx/LNG what is the cost? Does it make economic sense? Is it safe, is it going to be acceptable?
LOx/LNG are in the same $/ton range as Jet fuel, you are burning a couple of times the fuel since you have to haul up the oxidizer with you and pay for that as well so say 4x the fuel bill.
The hull is in line with a modern airline.
If you can do a trip a day or so with support costs in the same range as a jet, it would appear to me that for the right cargo you could make it work.
Is it safe?
Well not right now but once the tech is wrung out ?? I think so.
the big difference is much higher energies than a jet.
But…your exposure time is a fraction of that of a jet over the same range. Accidents in mid flight are rare but generally lead to complete loss. Exposure time is probably the most important difference…advantage Point to Point
Ok so the major threat time is when you are near the ground around take off and landing, Those are shorter for the Point to Pointer.
And to me the difference in energy involved is immaterial…dead is dead and most of the time accidents of any magnitude in those phases are not survivable.
Accidents on the runway often have survivors but that is eliminated in the Point to Point case…up and down…no in between…
Only time will tell, my guess is YES.
It will be a bit like the glamor days of the early airliners I would expect point to point for certain segments to be a real elite punch card
Especially as near earth space becomes an exotic but achievable location.
Natural gas fired Gas Turbines to get wind speed on the right ‘quarter’ and the combined wind speed provides a boost to get up to 60% fuel savings. All very well till you get in a real blow, it does look like it’ll be a bit of a handful in bad weather, it has big stabilizers like a sailing yacht so maybe it’ll work…anyway it’ll be a figment of computer simulation sthen tank testing for a few years yet.
I drove up to my parents the other day via a route I had not taken for a year, along the route a new wind farm had sprung up, dozens of multi MW turbines, apparently most went in over a period of only a few months once the tracks cables and bases were in place. Several a week being finished off. Now the support crew is something like twenty full time maintainers. Not sure if this is really the hope of the industrial heartlands, it’s not bad but heatedly the sustained work the towns these behemoths rise near, need.
Same with the sea based units, though the ports the support vessels sail from will get more than the maintenance base of a land based array.
Safe comfortable service offshore service craft are a very real need with the growth of offshore infrastructure. Bigger conventional hull forms hare being built but in reality bigger is not a good option for service craft. This is a traditionally, and rightly, conservative industry but its also one where big break throughs can ignite rapid change.
The proposed craft is what is generically called a SWATH( small waterplain hull) design, and the proposer has it right about the advantages. Though a SWATH is usually intended for best transit performance ( ride, efficiency, safety and speed) the proposed ability to change the ‘ride height’ is different, in line with some mored rigs ability to ballast down for best ‘ride’ in a particular area or sea state.
Regarding transit, I think the writer may have misunderstood the concept creator, fast ferries are generally catamarans and these days often SWATH or SWATHlike craft. I think the lower hulls would be brought up to some intermediate depth for high speed transit not retracted into a hull riding form, which is both rough riding and less efficient. Either that or there is some patent/IP gamesmanship going on…which would not be surprising.
Wired and others have been nattering about the Chinese carrier, it’s nascent flight wing, how crappy the hardware is, how hard the job is, etc, etc. working to defuse the China threat they think is being blown up by the Pentagon and congressional hawks.
Look at the two pictures above, the time from first flight to rational threat back ‘in the day’ was a few years, the big gun guys were laughing the whole time. That Fighter struggling off the Lianoning is a threat today if need be, and you do not have to impress an admiral to be able to sink his fleet. No it’s no realistic threat today but don’t make the mistake of equating little with none, the US capability with the capability required to be a threat, or today with forever. The US CVN capability is essentially static or downtrend, China is on the edge of asymptotic rise, with a century and millions of man years of prior experience across the world to pull up on. As other articles in have discussed, what really is a CV in the 21st century? So how long could it be till a Chinese CV threat is more than a wild card? Not long is my estimate.
Norwegian ship owner Myklebusthaug Management plans to become the first company to employ a direct current (dc) power grid on board a ship. A 5000-ton (4535-t) offshore platform support vessel will deploy ABB’s Onboard DC Grid, which ABB says will improve efficiency and reduce emissions for ships with electrified propulsion.
In existing electrical propulsion vessels, more than 80% of electrical power consumption goes to thrusters and propulsion drives. They use dc connections derived from an alternating current circuit.
Rather than converting ac to dc, the Onboard DC Grid optimizes propulsion by distributing power through a single dc circuit, according to ABB. ABB predicts that once ship owners see the benefits of electric propulsion, dc grids will see rapid acceptance. Myklebusthaug Management’s 93-m (305-ft) oil field supply and construction vessel is scheduled for delivery in the first quarter of 2013.
“We believe that by 2020, approximately 20% of ships will be electrified, and quite a bit of that will be dc,” said Heikki Soljama, head of ABB’s business unit marine.
One key reason the Onboard DC Grid saves power is that the ship’s engines no longer have to run at a fixed speed. Engine speeds can be adjusted to optimize fuel consumption.
At the same time, bulky transformers and switchboards can be eliminated, reducing the footprint and weight of the electrical system by up to 30%. The main ac switchboards and transformers are no longer needed.
However, ABB’s system extends the many dc-links used in all propulsion and thruster drives. That lets shipbuilders retain the dc generators, inverter modules, ac motors, and other proven products.
The grid can be used for any electrical ship application up to at least 20 MW. It operates at a nominal voltage of 1000-V dc. The power distribution can be arranged with all cabinets in a single lineup using a multidrive approach or it can be distributed throughout the vessel by short-circuit proof dc busbars. That gives designers more freedom for locating electric components, which can result in a more functional vessel layout.
Good synopsis of why DC and to some degree why electric…this is the future but as always the path is long and takes odd jaunts that will ‘drive men(proponents) mad.’