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Relative size of combatants

"Hell's Gate" and "Hell Hath No Fury", by David, Linda Evans, and Joelle Presby, take the clash of science and magic to a whole new dimension...join us in a friendly discussion of this engrossing series!
Re: Relative size of combatants
Post by Jonathan_S   » Mon Jul 13, 2015 9:00 pm

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phillies wrote:Fortunately, we are not aware of a portal that formed, say, 30 miles up. It would happily have sucked much of the air out of the multiverse for a long distance.

Not quite so disruptive as draining off all the air, but image a portal connecting the (underwater) continental shelf with someplace above ground.

A miles wide fire hose draining the ocean into another world! :shock:

Mil-tech bard wrote:Jonathan_S,

You might want to read the following, then revise and extend those remarks.

See:
The Massawa-Asmara Cableway

https://en.wikipedia.org/wiki/Asmara-Massawa_Cableway

From a quick looks that has a total elevation change of twice the height of the cliff. But that rise of 2.3km was over a distance of 71 km, with large numbers of supporting towers.
For that matter a little googling turned up this page which says that even so it had to be split into nearly 30 separate cable sections, with the cars transitioning between them, and supported by nearly 500 tower. So any given cable has an average elevation change of about 77.4m (254 feet) and an average length of 2.5 km (oh, and a tower on average every 465 feet)



However, critically, unlike an elevator cable it doesn't have to support the weight of that length of cable because the weight is spread across the multiple supporting towers. So the suspended weight between any two towers in the current cable-car load + just the weight of the cable between them.



So again, that type of system works up the slope of the Traisum side but I still don't see that it changes things on the 1km vertical cliff that's the Karys side.

You could build a multi-stage elevator down that face, but it's take a number of transfer stations each of which would need to provide power for it's cable segment. And of course, until you drive the Arcana's back, it's vulnerable to magic attacks since it'd be sticking out onto their side of the portal. So its a fixed target that should be easy for them to target; and therefor just not possible until you'd secured a 'beachhead' around the cliff face. But at that point just use the railroad and access road that parallels it. <shrug>

Now if they end up digging into a stalemate on that portal I could potentially see a cableway system on the Traisum-side slopes to move ammo, relief troops, and supplies up to maintain lookouts, AA, and mortars up near the ridgeline.
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Re: Relative size of combatants
Post by Mil-tech bard   » Mon Jul 13, 2015 9:34 pm

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Consider this --

Not a hurricane if the portal is large enough and unobstructed. I suppose all the universes linked along the way would either add to this influx of air or reduce it depending on relative pressures of all those universes and the associated universes tied into that chain. The same would be said about the impact of air flow into Karys.

All in all Howard's suggestion for RFC to avoid the issue altogether is a wise one.


...and why "Hell's Gate" might have been named that by the author.

Hell's Gate's weather has to be highy...different...given how much humid/dry air was ported into and through a relatively small area.

As in, eight different multiverse chains worth of varying multiple planetary partial pressures connected through one world ecology.
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Re: Relative size of combatants
Post by Mil-tech bard   » Mon Jul 13, 2015 9:57 pm

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With this passage --


So again, that type of system works up the slope of the Traisum side but I still don't see that it changes things on the 1km vertical cliff that's the Karys side.

You could build a multi-stage elevator down that face, but it's take a number of transfer stations each of which would need to provide power for it's cable segment. And of course, until you drive the Arcana's back, it's vulnerable to magic attacks since it'd be sticking out onto their side of the portal. So its a fixed target that should be easy for them to target; and therefor just not possible until you'd secured a 'beachhead' around the cliff face. But at that point just use the railroad and access road that parallels it. <shrug>


You show you are missing the point.

As long as less mass is going up to the tops of the cliffs than down the 1km drop, GRAVITY PROVIDES THE ENERGY.

And some of that potential energy lost as waste heat from the cableway's brakes can be converted to useful work in the form of electricity or moving mechanical belts/geared axles or causing compressors to fill pneumatic tanks for power tools.

You can fill the baskets/cable cars at the tops of the cliffs with loose rocks and soil, and so long as it is less mass than what is going up, the Rope/Cableway has a power source.

And this thread has pretty much established that the portal edge is back some distance from the Cliff edge.
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Re: Relative size of combatants
Post by Astelon   » Tue Jul 14, 2015 4:06 am

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It's not about the energy to run the the system, it's about being able to build it in the first place. You have a three thousand yard drop off a nearly vertical cliff. You simply can not place the nineteen or twenty weight bearing towers you would require just to reach the ground in Karys.
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Re: Relative size of combatants
Post by Jonathan_S   » Tue Jul 14, 2015 7:20 am

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Astelon wrote:It's not about the energy to run the the system, it's about being able to build it in the first place. You have a three thousand yard drop off a nearly vertical cliff. You simply can not place the nineteen or twenty weight bearing towers you would require just to reach the ground in Karys.

One correction, I believe it's a roughly 3000 ft drop; not 3000 yard.

But otherwise yes.
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Re: Relative size of combatants
Post by bkwormlisa   » Tue Jul 14, 2015 7:37 am

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It's three thousand feet, not three thousand yards, and the cliff isn't quite vertical. At least, there was a lot of erosion at the top, so I am assuming the entire cliff is eroded back some most or all of the way down. There is probably enough space that the elevator wouldn't protrude into Karys, though we don't know that near the bottom and it doesn't really matter since this would have been before they knew the Arcanans existed.

Despite that, I agree with you more than Mil-tech Bard. The height would require multiple supports for the cables, and the cliff is steep enough to make building them extremely difficult. The cliff is close enough to vertical that it would be an elevator, not a cableway, and Wikipedia says that today's longest elevator is 1,654 ft: https://en.wikipedia.org/wiki/Burj_Khalifa. That's maybe than half the distance we're talking about, and using materials the Sharonians almost certainly don't have. Basically, the cliff is too close to vertical and far too tall for a cableway as we usually use the term if there is any chance of intermediate supports.

The longest unsupported cableway we have ever made:
Feldmoos-Chli-Titlis Aerial Tramway was an aerial tramway in Switzerland. It was built in 1979 by the Swiss company Habegger between Feldmoos and Chli Titlis for the erection of a communication facility on Chli Titlis. The aerial tramway was used for transporting goods with a weight up to 3.8 tons also for transporting up to 20 people. It used only a single vehicle. After completion of the facility the aerial tramway, which remained property of Habegger, was dismantled in 1986.

The aerial tramway had five towers and a total diagonal length of 4675 metres. The support rope was installed on four towers, the upmost tower was only used for the return rope, in order to avoid its collision with the suspension ropes. The most important feature of this aerial tramway was that it used the longest span of all aerial tramways ever built with a length of 3467.1 metres [2.17 miles]. For this span field special markings were required: every 100 metres, there was a red coil and every 500 metres an aircraft warning light. For their power supply a wind generator buffered by accumulators was used, which made technical problems at the beginning. The diameter of the both suspension ropes was 46 mm, that of the push rope was 38 mm.

The drive was done by a DC engine with 301 kW in the valley station. The maximum speed of the gondola was 6 m/s to 10 m/s. https://en.wikipedia.org/wiki/Feldmoos-Chli-Titlis_Aerial_Tramway
This was made of what was at the time modern materials, which were (I am assuming) about a century advanced over the Sharonians.

The steepest grade cableway allowed today is 45 degrees (citation: a cnn news article, which is hardly very accurate). If we assume the cliff is a nice round 3000 ft high, that makes for an unsupported cable at leat 4242 ft long, which is a little less than a mile, or just under half the length of our longest unsupported length. So we could probably make a cableway for the cliff, assuming we could get all of the materials to the ground to receive it, but I seriously doubt the Sharonians could. In addition, the longer the cable, the more of its capacity is taken up by its own weight, so they would be seriously limited as to the mass such a cableway could haul, not to mention being very low speed. Definitely major restrictions if it could even have been built. And note, this would definitely take it into Karys.

Mil-tech Bard: Yes, they could use gravity to power such a cableway, though the effort of hauling all of those rocks would probably make building a steam plant for it more practical. But do you have any textev for saying they could recapture some of the potential energy of the drop? I don't think we even tried doing that until we were much more advanced than they are, and even today we usually don't. Besides, they don't have much electricity and they don't use pneumatic power tools (at least, Shaylar was thinking they didn't when she watched Arcanans using them).
Astelon wrote:It's not about the energy to run the the system, it's about being able to build it in the first place. You have a three thousand yard drop off a nearly vertical cliff. You simply can not place the nineteen or twenty weight bearing towers you would require just to reach the ground in Karys.
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Re: Relative size of combatants
Post by phillies   » Tue Jul 14, 2015 10:03 am

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Astelon wrote:It's not about the energy to run the the system, it's about being able to build it in the first place. You have a three thousand yard drop off a nearly vertical cliff. You simply can not place the nineteen or twenty weight bearing towers you would require just to reach the ground in Karys.


You drill the towers into the side of the cliff, and run the cableway parallel to the cliff.

An alternative is called "tunnelling". This would include the tunnel that is a notch in the side of the cliff with one side open.
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Re: Relative size of combatants
Post by Mil-tech bard   » Tue Jul 14, 2015 11:31 am

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Lets look at this --

Despite that, I agree with you more than Mil-tech Bard. The height would require multiple supports for the cables, and the cliff is steep enough to make building them extremely difficult. The cliff is close enough to vertical that it would be an elevator, not a cableway, and Wikipedia says that today's longest elevator is 1,654 ft: https://en.wikipedia.org/wiki/Burj_Khalifa. That's maybe than half the distance we're talking about, and using materials the Sharonians almost certainly don't have. Basically, the cliff is too close to vertical and far too tall for a cableway as we usually use the term if there is any chance of intermediate supports.


You have missed several points that push the plausibility of Sharonan ropeways to support the cut.

1. There was an overwhelming need to get large amounts of work crews, draft animals, explosives and steam engine powered equipment to the bottom of the cliff to support the Traisum cut's construction, and

2. The TTE civil engineering capability was effectively a generation or more beyond any turn of the 20th century technology we knew, particularly in terms of steam engines (See the Bison snippet text), and

3. Sharona has telekinetic talents capable of making cliff side construction both far faster and far safer (Think about the motion pictures of workers moving of hot rivets in 1920-30's skyscraper construction...and now replace with T-K Talents)

4. Finally, you really need to go back and read this link closely --


http://www.lowtechmagazine.com/2011/01/ ... sport.html


This was the range of capability of ropeway/cableway technology circa 1911:

Length, speed and capacity of the lines

Length and capacity of aerial tramways gradually increased throughout the century. In 1911, aerial ropeway lines were typically 1,000 to 15,000 feet (305 to 4,600 metres) long, with a daily cargo capacity of 15 to 200 tons and speeds of around 2 to 5 mph (3,2 to 8 km/h). Some gravity powered installations were faster, with speeds around 15 to 30 mph (24 to 48 km/h), but higher speeds were considered to be a negative influence on wear and tear. Weight of the individual loads varied from 25 to 375 kilograms.

Motive power, if applied, was generally from about 2 to 15 HP. The fall was between zero (almost horizontal lines) and 4,000 feet (1,220 metres). Working staff amounted to 2 to 5 people. Some lines were built parallel to each other in order to increase cargo capacity (the maximum capacity of a single ropeway was about 800 tonnes per day). Some early ropeways were longer and more powerful. The Usambara ropeway in Africa was 5.6 miles (9 kilometres) long and transported tree trunks weighing up to one tonne each (picture above). At its highest point, the ropeway was 130 metres above the ground.


and

Transport infrastructure


Ropeway towers could be constructed from timber or iron and were generally between 100 and 300 feet (30 to 90 metres) apart, although much longer spans were possible if necessary. In bicable ropeways the tension in the track cables was produced by weights applied at one of the terminal stations. However, in longer lines it became necessary to apply additional tension at intermediate points.

For this purpose tension stations were built at distances of about 3000 to 6000 feet. The cars passed from one section of the cable to the next by means of intervening rails - so that no interruption occurred in the continuity of the track. This means that there are no limits to the length of a ropeway: each (longer) ropeway consisted of multiple sections that could be considered as separate ropeways.

The same technique was applied to "angle stations", which were used to make a curve in a ropeway (tension stations and angle stations could be combined - see the illustration above, right). The largest drawback of an aerial tramway, also relevant today, is that it can only be built in a straight line. Every angle in a ropeway requires the erection of an angle station, which raises capital costs. However, in general, few angle stations are needed because ropeways can be constructed above most obstacles.


If you are using rappelling, then elevators, in stages down the cliffs. You can build multiple platforms out the sides of the cliffs -- First for those rappellers and, then later, for elevators.

Then you drill/blast/cement support foundations for metal structures out from the sides of the cliffs, in stages, all the way down.

Finally, you construct a zig-zap pattern of ropeways down the cliff side with a series of combined tension stations and angle stations at the zig or zag end with towers in between the "T&A stations" to keep the tram cars from entangling/scraping the cliff sides.

Considering that the Swedish the 96 km (60 miles) long Norsöj aerial tramway had 514 towers and 25 tension stations and was built in 370 days in the late 1930's/Early 1940's. I think the TTE civil engineering crew could easily match that, simply from three generations of increasingly larger capital equipment investment.

And even if the TTE could not match the Sweds of the late 1930's, this circa 1905 Mina La Mejicana tramway they certainly can. And in a great deal less than the two years it took to build. After all, they are only looking to go to the bottom of a cliff.

http://translate.google.com/translate?h ... rev=search

...it was built between 1903 and 1905 one cableway linking a distance of 34.3 km and a difference height of 3510 meters.

The cableway was composed of eight sections, joined by 9 stations each of which provides traction to the next stage by steam engines fed with wood, and an additional section that connected the station II with the casting of Santa Florentina. The total laying including this section is 35,128 meters.



and


The cableway had the following characteristics: the speed was 2.5 m / s , 450 trucks had separated from each other by about 112 meters, each with a load of 500 kg and a capacity of 0.3 m³ . In some places the height above the ground reached 450 m.

Each station is linked to the next by a wire and cable supporting traction, supported by towers placed at regular intervals. On arrival at each station, the trolley wire is unhooked traction and was coupled to the next station. The support wire is 32 mm and the pulling of 23 mm, both of steel with hooks lead between cable runs. In total, there are 262 towers have a height between 1 and 50 meters; They were used 140 km of steel cable, 100 km of booking.

Besides bulk cargo, there were special wagons for transporting water, fuel, food, construction and demolition materials, and people. There was also a special grease and varnishing of trolley wires leading to a person, a lubricant reservoir and a hand pump that allowed such a task as each section is walked.

For the construction of the cableway they worked around 1,600 people and pack animals were used as means of transport, particularly donkeys and mules , on average 90 asses to transport foods and 600 mules to transport construction materials. In the last phase of construction, the Argentine Army facilitated 200 mules of its body of artillery , coming at that time to deal with some 1000 animals.

The inauguration of the first sections was the 4th of July of 1904 and launched on January 1 , 1905.
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Re: Relative size of combatants
Post by Castenea   » Tue Jul 14, 2015 8:07 pm

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Mil-tech bard wrote:Lets look at this --

Despite that, I agree with you more than Mil-tech Bard. The height would require multiple supports for the cables, and the cliff is steep enough to make building them extremely difficult. The cliff is close enough to vertical that it would be an elevator, not a cableway, and Wikipedia says that today's longest elevator is 1,654 ft: https://en.wikipedia.org/wiki/Burj_Khalifa. That's maybe than half the distance we're talking about, and using materials the Sharonians almost certainly don't have. Basically, the cliff is too close to vertical and far too tall for a cableway as we usually use the term if there is any chance of intermediate supports.


You have missed several points that push the plausibility of Sharonan ropeways to support the cut.

1. There was an overwhelming need to get large amounts of work crews, draft animals, explosives and steam engine powered equipment to the bottom of the cliff to support the Traisum cut's construction, and

2. The TTE civil engineering capability was effectively a generation or more beyond any turn of the 20th century technology we knew, particularly in terms of steam engines (See the Bison snippet text), and

3. Sharona has telekinetic talents capable of making cliff side construction both far faster and far safer (Think about the motion pictures of workers moving of hot rivets in 1920-30's skyscraper construction...and now replace with T-K Talents)

4. Finally, you really need to go back and read this link closely --


http://www.lowtechmagazine.com/2011/01/ ... sport.html
Mil-tech, I think you are overestimating the number of personnel needed at the far end of the cut, however this cannot be done with no personnel, those personnel need supplies and to get there, thus a rope way until the cut is complete enough to bring them their supplies through the cut. That ramp would have been built from the Karys side not the Salby side of the portal. Note: I expect that there is a shack near the portal at the side of the tracks for a Voice to shelter while awaiting messages from down chain, while being just a short walk to send the message up chain.

Thus the reason that I would expect that there is a warehouse in Salbyton with the supplies needed to build a ropeway sufficient to support guns dug into the side of the mountain that can command the approach ramp for the cut. Just building the ropeway to get to the bottom of the cliff will require several tons of rope, and additional tons of other supplies to build the T&A towers.
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Re: Relative size of combatants
Post by Astelon   » Tue Jul 14, 2015 9:45 pm

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phillies wrote:You drill the towers into the side of the cliff, and run the cableway parallel to the cliff.


Mil-tech bard wrote:If you are using rappelling, then elevators, in stages down the cliffs. You can build multiple platforms out the sides of the cliffs -- First for those rappellers and, then later, for elevators.

Then you drill/blast/cement support foundations for metal structures out from the sides of the cliffs, in stages, all the way down.


What you end up doing is hanging a temporary platform with heavy (steam powered) equipment and work crews, over the side of the nearly vertical cliff. You are running huge risks with weather, accidents, and tipping over your crane. Then you would have to find suitable locations to place each permanent platform, and finally lower a really big crane down to the new platform to do it again. I don't see this project as possible, without heavy aerial lift capacity (helicopters).

If you dump enough debris over the side of the cliff (as you blast and dig out the cut) you will eventually have a makeshift ramp. It would not be something you would want to build train tracks over, however, it could (with some improvement) get the crews needed to make a permanent ramp into Karys.
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