As there would be a vast amount of money saved because there would be no power and propulsion unit required, and that space would be available for more containers, I would hope that some of that money would be put into the ship (sea barge?!) design to deal with just the sort of issues you mentioned.
I am unconvinced that the savings would be vast.
The issue is that if you have two vessels weighing, say, 100,000 tonnes each, separated by a towing cable of, say, 100 metres, in bad weather conditions fluctuating wind and wave forces on the two parts will be sufficiently different that sometimes the cable will be slack, and sometimes the vessels will be separating with a relative speed difference of, say, one knot when the cable becomes taut. At that point, something breaks. Making the cable more elastic (say, by putting a spring in it) reduces the peak load in that instance but then introduces more dynamic instability the rest of the time.
Another way to look at it is to compare a harvestman with an elephant. Mass goes with L cubed, strength with L squared.
When tugs tow drilling rigs from one place to another, or towing anything else for that matter, they proceed very slowly, only a few KPH, and there's usually a long heavy cable that hangs down in a broad U and is seldom, if ever taut. The weight of cable in the U acts as the spring you're suggesting. Other ships are warned to keep clear.
Table 2 in the following link shows that for powerful tugs with bollard pulls in excess of 90 tonnes, towline lengths of just under
1km (909m) are required.
Yup. Now imagine trying to operate a multi-barge "train" like that.
Why use flexible couplings? They would in any case be rather dangerous for "barges" moving at 20 knots if they had to be stopped (how could they be stopped, in fact? Droppable transverse keels, perhaps, acting as sea brakes). Towing bars like this, adapted and scaled up, should give marine engineers something to think about!
How the sterns and bows would have to be strengthened to deal with tow bars like that I can only wonder. But would it be impossible - or impossibly expensive?
I think the consensus is, and I agree, that saving a few pence on propulsion units is not worth the risk of breakage. Container ships are already at just about optimal size.
It will if you remove the reactor first
In fact, passenger jets actually travel slower than they did in the
1960s. Cruising speeds of commercial airliners today are around 480-510 kts, compared to the 525 kts of a Boeing 707. The lower speed gives better fuel economy with modern jet engine designs.
Obviously they throttle back near coasts
While I don't doubt that sort of system would be fine in calm inland waters, the St. Lawrence seaway, the Great Lakes, the Amazon, the Rhine, I cannot conceive of it being anything like capable of withstanding an Atlantic hurricane or Pacific typhoon. Those types of storms can rip single ships apart, let alone whole strings of them.
Concorde was never economically viable.
The reason the US never developed supersonic planes was because it would have needed massive government investment. And as we saw with Concorde supersonic travel is really a playboy thing.
To be fair the US *did* pump just as much money into the Apollo programme. Although in total miles per passenger, Concorde probably wins.
Concorde WAS economically viable for a niche market. But its apples and oranges. That capital cost and comfort were much higher and lower.
No, the reason is that over continental america the booms would have been unacceptable
Not sure about the great lakes!
I can't help but feel the anti boom movement was really an anti-non US tech movement. The average USian must have hated not being #1 in such a prestigious - and globally noticed - field.
Jethro_uk <jethro snipped-for-privacy@hotmailbin.com wrote
Mindless stuff. It wasn?t allowed to go supersonic over europe or the middle east etc either.
In article <sf142s$htl$ snipped-for-privacy@dont-email.me, Jethro_uk <jethro snipped-for-privacy@hotmailbin.com writes
+1In article snipped-for-privacy@mid.individual.net>, %% <%%@gmail.com> writes
It was an incredible business tool.
Overland. Another factor was that the initial demo flights were using the prototype engines which were much noisier.
Having flown on it from Nice to Heathrow I can tell you it was an incredible experience.
It became profitable when used on these types of journeys. Transatlantic also became profitable when they realised that the people flying didn't actually reserve their own seats and didn't know the cost, thinking it was about twice the actual, so BA doubled the fare.
In article <setsp9$oda$ snipped-for-privacy@dont-email.me, "Brian Gaff (Sofa)" snipped-for-privacy@blueyonder.co.uk> writes
Didn't save the Titanic.
un-crewed remotely driven ships will outfox the pirates
If there's no crew to hold to ransom and with no means to directly steer the ship into some rogue port to unload the cargo, extracting any value from the cargo will be next to impossible, even if you do disable the remote control
as a hermetically sealed tube it's not surprising that it's a hell of a task getting the reactor out in one piece.
not so in a ship that has potential of an open route to the top of the ship
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