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Terraformer

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From: The Fortunate Isles

Registered: 2007-08-27

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Carbon-Free Propulsion Using Articulated Tug and Barge Technology

Carbon-Free Propulsion Using Articulated Tug and Barge Technology -- Maritime Executive

A tug of 3,500 to 4,000-horsepower is able to propel a barge tow of 4-barge widths by 10-barge lengths.

Railways moving the same tonnage and or volume as 40-barges would require groups of locomotives generating 30,000 to 40,000-horsepower to pull several trains.

We're not the only ones thinking along these lines:

Recent advances in liquid air energy storage could form the basis of tug propulsion. The tug could operate on heat-of-fusion stored thermal energy and recharge at coastal nuclear power stations.

A wide range of technologies have future potential to provide carbon-free propulsion for maritime vessels and might include:

- Liquefied Air: Initiatives are underway in England to develop grid-scale energy storage using super-cooled liquefied atmospheric air that has a density of over 80% that of liquid water. It has been successfully tested as propulsion in a small car and has potential to being adapted for ship propulsion where a geared turbine or positive-displacement rotary engine would drive a propeller. The combination of liquefied air stored inside well insulated containers and a source of stored thermal energy aboard a mega-size tug could theoretically propel a barge for distances of 600 to 1,000 n. m.

- Iron-Air Battery: The iron air battery occupies the space of a standard size shipping container (40-feet length). Small-scale testing indicated negligible deterioration of battery chemistry after 20,000-full depth drain cycles and is able to deliver steady output for a duration of up to 100-hours. An array of 2-levels of 8-wide by 4-lengthwise of iron-air battery containers (64) carried aboard super tug of 300-ft length by 70-ft width would deliver over 4,000-horsepower for 100-hours, making the technology suitable for tug-barge operation along inland waterways. Coastal operation and Great Lakes service would require larger versions of the tug.

- Stored Thermal Energy: Modern solar-thermal power stations continue to generate electric power after sunset, generating steam from thermal energy stored in mixtures of molten salt such as 80% lithium hydroxide and 20% lithium fluoride. There may be scope to modify coastal nuclear power stations to include a dock, where a tug may be moored to replenish its thermal energy supply. The tug would use a geared steam turbine or suitable positive-displacement rotary engine to provide propulsion while pushing and navigating barge trains along inland waterways or single barges in short-haul coastal service.

Presumably barges on canals and rivers will not have to deal with the sort of wave conditions faced by coasters? Maybe we could do far more articulation there then... Tom Pudding

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Use what is abundant and build to last

tahanson43206

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Registered: 2018-04-27

Posts: 19,427

Re: Carbon-Free Propulsion Using Articulated Tug and Barge Technology

This post is reserved for an index to posts that may be contributed by NewMars members...

Best wishes for success with this interesting new topic....

This is the first time I've seen the idea of combining the thermal store and liquefied air in one transport system.  This solves the problem of having to scavenge thermal energy from the atmosphere or from the water.

I'm hoping our members with mechanical system design skills will show how this concept could be implemented at various scales.

I remain interested in a small scale energy storage system able to deliver 20 amps at 120 VAC for an hour in a remote work setting.

Members of this forum have speculated about use of compressed air for this purpose, but so far all we have is hand waving.

Hand waving is good, but I'd like to see the speculation resolve to drawings that can be put into Real Universe use.

(th)