No Tube Required

"...Power source for the lift engine," Claire said, reviewing the final climb section's specifications. "You mentioned wanting continuous heat from the Demon Realm's lava pools. Walk me through the actual setup."

"I was picturing the engine sitting up on the surface," Arista said, sketching a rough concept, "with a tube running down into the Demon Realm specifically to draw heat from a lava pool, feeding it back up to the boiler."

Claire studied the sketch for a moment, then frowned slightly. "...That's a considerable distance for heat to travel. How deep does that tube need to run?"

Arista checked her own measurements against the established depth of the Demon Realm below the surface, and felt the problem land before Claire even needed to point it out.

"...Kilometers," she admitted. "The same rough depth as the original tunnel, more or less. That's an enormous span for heat to travel through a tube before it ever reaches a boiler at the top."

"Right. And every single meter of that tube bleeds heat into the surrounding rock along the way, unless it's insulated considerably better than anything we've built before. By the time whatever's flowing through that tube actually reaches the surface, you'd likely be working with a fraction of the lava pool's original temperature, nowhere near efficient enough to justify the engineering complexity of building a multi-kilometer heat-transfer line in the first place."

Arista sat with that, already seeing the obvious flaw now that it was actually pointed out. "...I overcomplicated this. The climb section, the actual part that needs the engine, that's already sitting in the Demon Realm. It's not up on the surface at all. There's no reason to pipe heat up to an engine, when I could just build the engine down there, right next to the lava pool itself."

"Exactly," Claire said. "Same principle as the swing ride's own steam engine. You didn't pipe lava heat anywhere for that project either. You built the boiler directly where the heat already was."

"...I don't know why I defaulted to overcomplicating it this time," Arista admitted, mildly sheepish, already crossing out the tube concept entirely. "Force of habit, maybe. Assumed the engine needed to sit at the top of the climb for some reason, instead of just... being wherever the heat actually is."

"Old instinct, probably, from projects where the power source and the mechanism needed separating," Claire said. "This one doesn't need that. The lift engine and the lava pool can simply be neighbors."

Arista redrew the design properly this time, a modest boiler house built directly alongside one of the Demon Realm's naturally occurring lava pools, close enough to draw continuous heat without any transfer losses at all, the cable mechanism running directly from there up through the final climb section.

"...Much simpler," she said, satisfied. "No tube, no insulation losses, no unnecessary engineering complexity. Sometimes the answer really is just 'put the thing where the thing it needs already exists.'"

Beelzebub, when consulted about the boiler house's placement, approved without hesitation, delighted at the prospect of another small piece of his realm's infrastructure quietly supporting Arista's latest project.

"Any pool you like," he said, gesturing at the Realm's considerable geothermal abundance. "We have no shortage."

"This one, I think," Arista said, marking a modest, easily accessible pool close to the climb's base. "Close enough to the track that heat loss between boiler and lift mechanism stays minimal too."

Claire reviewed the finalized placement, satisfied. "Continuous, reliable, zero unnecessary transfer distance. This should run indefinitely, same as the metro's own network has for two years running."

"There. That works," Arista said, grinning, relieved to have caught the overcomplication before actually wasting weeks digging an unnecessary heat-transfer tunnel. "Turns out the simplest answer really was sitting right there the whole time."

You could be reading stolen content. Head to the original site for the genuine story.

With the prototype finally finished and the engine's placement properly settled, the crew turned their attention to an entirely different problem, one that had been quietly waiting in the background the whole time.

"...Wait," Bram said, studying the finished cart prototype, then glancing up toward the distant Celestial anchor point, four kilometers overhead. "How exactly are we getting the carts up there? Nobody's carrying one up a mountain, and I doubt Thoth wants to make repeated cargo runs hauling steel carts one at a time."

Arista sat with the question, genuinely not having thought that far ahead. "...Huh. Good point. That's not a small logistics problem."

"You could disassemble them, carry the pieces up, reassemble at the top," Claire suggested, though even she sounded unconvinced by her own idea.

"That works, but it's tedious, and it risks introducing assembly errors at altitude that we wouldn't catch as easily as we would down here at ground level."

Bram considered the problem a while longer, then brightened slightly. "...What if we don't carry them up at all? What if we mount the cart directly onto the track in the Demon Realm, right at the base of the final climb, and just let the cable haul it up the same way it's meant to during actual operation?"

Arista blinked, then grinned, delighted by the sheer, obvious elegance of it. "...That's genuinely perfect. We don't need to solve a separate transport problem at all. The climb mechanism already exists specifically to move a cart from the Demon Realm up toward the Celestial anchor. We just use it for exactly that, before the track's even fully operational."

"And it doubles as our first real test of the catch hook system," Claire added, already seeing the full advantage. "We've tested the mechanism in isolation, on the scale models, and on the static test track sections. This would be the first time we actually run it under full, real-world conditions, full cart weight, full climb distance, genuine cable tension the entire way."

"Two birds," Bram said, satisfied. "Solve the logistics problem, and get a genuine functional test out of the same action."

Arista was already sketching the plan properly, cross-referencing the cart's catch bar dimensions against the hook mechanism one final time. "...Okay. We mount the cart at the base of the climb, engage the catch hook manually to start, same way it'll happen automatically once the whole loop's connected, and let the cable haul it the entire four kilometers up to the Celestial anchor point."

"If it makes it the whole way without incident," Claire said, "we've proven the single longest, most demanding stretch of the entire cable system in one test."

"And if it doesn't," Bram said, "we find out considerably earlier and considerably more safely, mounting one empty cart, rather than discovering a problem the day Michael and Beelzebub are actually sitting in it."

"Exactly the kind of test I want to run," Arista agreed, already directing the crew to prepare the first cart for transport down into the Demon Realm.

They lowered the cart down through the existing tunnel access the following day, settling it carefully onto the track at the climb's base, catch bar aligned precisely beneath the waiting lift hook.

"...Engaging," Claire called, watching the mechanism carefully as the hook swung into position, catching cleanly against the cart's reinforced bar with a solid, satisfying click.

[Catch Hook: Engaged]

The boiler, freshly built beside its lava pool, hissed steadily to life, the cable drawing taut, and slowly, smoothly, the empty cart began its ascent.

"...It's moving," Arista breathed, watching the cart climb steadily away from the Demon Realm's depths, cable running clean through every guide point along the way. "Let's see if it holds the whole way."

They tracked its progress carefully, checkpoint by checkpoint, the cart maintaining a slow, steady pace the entire distance, cable tension holding consistent, no snags, no stalls, no unexpected resistance anywhere along the climb.

Nearly two hours later, word came back from the crew stationed at the Celestial anchor point.

[Private Message from: Colm]"Cart's arrived. Cam rail engaged properly, hook released clean, cart rolled to a stop exactly where it should. First full-distance test: success."

Arista let out a long, relieved breath, grinning at the news. "...It worked. The whole climb, full distance, first real test, and it worked perfectly." Arista glanced at the elapsed time, already making a mental note. "Deliberately slow, too, this time, just to actually watch it properly. Full operational speed should cut that considerably once we're confident enough to actually push it."

"Two problems solved at once," Bram said, satisfied. "Cart's where it needs to be, and the cable's proven itself over the single longest stretch it'll ever actually need to manage."

"Now we just need enough carts up there to actually run full operations," Claire said, already calculating how many more trips the same method would require. "But at least we know, now, that getting them there isn't going to be the hard part."

Arista studied the distant, cloud-obscured summit where her very first cart now sat waiting, patient and proven, at the top of a four-kilometer climb she'd built from nothing but steel, adamantium, and a lot of careful, patient engineering.

"...One cart down," she said, grinning. "A few more trips, and we'll have enough to actually open this thing properly."