Chapter 40: Running Out of Oil

The investigation of the wrecked ship concluded successfully. No skeletal sailors or ghostly wraiths were found, but the five sisters seemed entirely satisfied. That night, they were so excited they couldn’t sleep, clinging to Commander Eve until Ringo stepped in to scold them—a rare experience for all involved. Eve wasn’t spared from Ringo’s reprimands either, though Ringo later profusely apologized for including her.

The wrecked ship was subsequently towed to The Tree. It served as a valuable source of research material, and its cannons and other iron resources were slated for recovery.

While this matter was resolved, it highlighted another pressing issue: the need to detect approaching ships early. Given the anticipated technological level of potential adversaries, total annihilation of an encroaching fleet could theoretically keep The Tree's existence a secret. However, such actions risked catastrophic consequences.

For instance, there was no understanding of this world’s "magic" systems. Existing knowledge was effectively negative due to biases from scientific paradigms. So far, intelligence from Telek Harbor suggested no long-range communication technology. Still, there was no guarantee that a more advanced nation couldn’t employ magical long-range communication.

Sinking a ship approaching The Tree, only to have its home nation alerted to the attack, would spell disaster. Being branded as a hostile entity would severely limit operational freedom. Ideally, peaceful negotiations would be pursued.

For Eve, "peaceful" didn’t necessarily mean without weapons—it meant without direct conflict. Gunboat diplomacy was very much on the table.

"Ocean current research should be a top priority. It’s a relief that the situation in Telek Harbor has stabilized," Eve remarked.

"Yes, ma’am, Commander. The patrol network there is largely established, and the area has been stable for several months. We can reallocate some resources to oceanographic surveys," Ringo confirmed.

Resources dedicated to Telek Harbor’s defense and development were scaled back to allocate more toward surveying the waters around The Tree. This included deploying additional solar-powered reconnaissance drones (Swift) and replacing their equipment for current mapping. Deploying buoys for more detailed measurements was considered but ultimately rejected; no information, however trivial, could risk falling into the hands of other forces.

"Satellites... still out of reach, huh. The launch site isn’t even under construction, and rocket manufacturing resources are scarce..."

"Yes, ma’am. There are also unresolved technical issues. We’ve made no progress investigating the upward resistance observed at altitudes above 5 kilometers," Ringo reminded.

"Oh, right. That was a thing..."

Early tests with high-altitude planes revealed abnormal deceleration during ascension. Existing stockpiles of rocket boosters remained, but manufacturing more was currently impossible. Additionally, launching satellites safely would require extensive testing—a challenge given their lack of knowledge about this world’s space environment.

For the foreseeable future, reconnaissance relied on the solar-powered Swift drones.

"But Swift has severe payload limitations," Eve pointed out.

"Correct, ma’am. Due to its design, most of the drone’s weight comes from its motor, battery, and solar panels," Ringo explained.

The Swift drones, designed for sustained solar-powered flight, had strict payload and energy constraints. Batteries needed to be recharged during the day to sustain overnight operations, leaving only a small margin for onboard systems.

"Hmm... We’ll need larger aircraft," Eve mused.

Large propeller planes were ideal due to their fuel efficiency, as jet aircraft were too fuel-intensive. However, operating large aircraft required runways, which The Tree currently lacked.

"The flying boat design is nearly complete. Should we prioritize resource allocation for testing?" Ringo suggested.

"Yes, adjust the resource plan to prioritize the flying boat’s development. Also, we really need a solution for fuel supply," Eve said.

At present, no petroleum resources had been discovered. While reserves existed, they were depleting. The addition of aircraft operations would significantly increase consumption.

"Hydrogen doesn’t have enough energy density for aviation fuel..." Eve muttered.

"As the saying goes, desperate times call for desperate measures," Ringo offered.

"Right. So, practically speaking, what’s the situation?"

The Tree had surplus energy that could be diverted to hydrogen production, potentially replacing petroleum-based fuel.

"Hydrogen’s energy density is approximately 13 megajoules per unit volume. By comparison, jet fuel is around 37 megajoules. While it’s difficult to make a direct comparison between gases and liquids, it’s safe to say hydrogen’s energy is roughly one-third of jet fuel," Ringo explained.

"That means our operational range would also shrink to a third," Eve deduced.

"Yes, ma’am. While specifics could vary, that’s a reasonable assumption. Hydrogen combustion results in lower range and output compared to jet fuel."

"Are there alternatives to combustion?"

"Yes, ma’am. Fuel cells can convert hydrogen into electricity for propulsion," Ringo said, displaying data on fuel cell output and motor efficiency.

Eve focused on the manufacturing and maintenance costs.

"Fuel cells are expensive upfront and require high maintenance," she noted.

"Correct. High-performance materials are used for electrodes, separators, electrolytes, and control systems. Electrodes degrade with use and require periodic replacement," Ringo elaborated.

"High-performance materials... Rare metals and specialized compounds. Even if we can fabricate the compounds with the molecular printer, this is..."

The cost of sustaining fuel cell operations rivaled that of directly investing in petroleum exploration. It seemed more practical to allocate resources toward finding oil fields rather than mass-producing fuel cells.

"For ships, large gas turbines can be adapted for hydrogen fuel. However, aircraft face stricter constraints, making fuel cells more viable overall," Ringo concluded.

"Ugh... This is a tough one," Eve sighed.

While rare metals could be extracted from seawater at low efficiency, the current production levels couldn’t support widespread fuel cell use. Reducing the number of operational aircraft would hurt exploration efficiency.

"This won’t work. For now, aircraft will continue using petroleum. Ships can transition to hydrogen turbines. Does that sound feasible?"

"Yes, ma’am. Limiting petroleum use to the flying boats should suffice for now. Meanwhile, we’ll explore oil fields or alternative energy sources," Ringo confirmed.

Existing trade ships were equipped with diesel engines. As their fuel needs grew, plans to retrofit these ships with hydrogen turbines were initiated. Aircraft development shifted toward energy-efficient designs to conserve The Tree’s petroleum reserves.

"If only we could build large-scale facilities, we could solve so many problems," Eve lamented.

"Large facilities require massive amounts of iron, so construction isn’t feasible yet," Ringo replied.

"If only the ground was stable..."

"Even in shallow waters, the surrounding area is entirely ocean. Laying foundations alone is incredibly challenging. Under current conditions, our best option is..."

"...To construct platforms for seabed mining. With no land-based mines, the seabed is our only hope," Eve finished.

"Yes, ma’am. Given current projections, it’s the most viable path forward," Ringo affirmed.