Athens-class escort frigate

"Noisy, slow and unreliable? Why does the UNSC even bother with such an old ship?"

- Anonymous ensign, on the Athens-class frigate.

The Athens-class escort frigate (hull classification symbol: FFE), mockingly dubbed the Pancake Frigate by sailors, is an ancient line of light-tonnage combatants utilized by the UNSC during the Human-Covenant War. Introduced towards the end of humanity's golden age, the Athens-class frigate was never a popular vessel even in its heyday. Renowned for being slow, poorly armed and later unreliable, they nevertheless found advantages with their powerful sensor systems, low RADAR cross-section, and incredible durability for a ship of its size. It is because of this latter advantage that saw the ship being kept in service for the better part of seventy years, outliving many of its more fragile replacements.

The Athens-class frigate was first introduced by the up-and-coming Reyes-McLees Corporation in 2483, to supplement and eventually replace its predecessors. Failing to find popularity from its intended customers, these frigates would be deployed in colonial backwaters, which demanded ruggedness from escort ships operating there. Thankfully, the unexpected escalation that characterized the early Insurrection would keep these ships in production. Their crew-inefficiency and durability were crucial to preventing many ships of the class from being stolen, expanding their manufacturing time up until 2501. It was at this point that ships based around the revolutionary Magnetic Accelerator Cannon became at their most popular, pushing the Athens ever-closer to extinction. Eventually, the discovery of a lethal reactor defect in 2518 would see the entire class scheduled for decommissioning and scrapping.

Fortunately, the sudden loss of entire colonies from an alien conglomerate would see all previously-decommissioned ships being pulled back into the fleet. A massive refitting campaign was conducted to bring every non-scrapped vessel back up to modern standards, which included the Athens-class. Unlike most other ships, the Athens actually proved capable of resisting multiple plasma torpedo hits, allowing it to support larger cruisers for longer in combat. Because of this, production was restarted, and they would proudly serve as capable escort vessels, although even they would fail to stem the tide of the encroaching Covenant fleets. While production was once again stopped in 2543, enough were made that they would remain a common sight towards the war's end. Once the war ended, the class continued to serve for only a few years before being scrapped to usher in the UNSC's next generation of escort ships.

Development
"I've always emphasized the importance of durability. It's a great psychological threat, undermining your enemy's confidence that they can beat you. From a business standpoint, it offers the customer a higher-quality product, one which can be constantly reused, and reused. I don't think a company that adopts the disposable mentality will amount to anything more than a waste of lives and resources if we ever fight a real threat."

- Dr. Robert McLees, on his preferred design doctrine

The Athens-class escort frigate traces its origins back to 2479. Although less than a decade old, RMC had expanded massively not by trying to claim new markets in the colonies, but by instead utilizing existing infrastructure within the Sol system. This tactic, helped further by the merge of its predecessor companies, allowed them to create a powerful industrial base that would lead to a string of excellent freighter releases that restored Mars' reputation for excellent ships.

Propulsion and powerplant
One thing which has given the Athens-class frigate its terrible reputation is the low-quality of its original power generation equipment. These frigates were first fitted-out with an old Hanley-Messer Mark I Deuterium fusion reactor. It is notable for being one of the last reactors to still utilise pressure-cooked hot fusion for power, whereas nearly all other examples including their replacements rely on laser-ignited cold fusion principles. As a result of this, this particular model is plagued by fuel inefficiency and low output, being rated at only six percent of the output of modern equivalents. In addition, the Mark I only had a single small chamber for power generation which occupies only a quarter of the reactor's total volume. This is woefully insufficient to power the propulsion systems up to even the average speeds but is sufficient to maintain power to the rest of the frigate thanks to the designers' cleverly choosing components that did not require much energy to function. Instead, the bulk of the volume is dedicated to a thick layer of dense yet cheap ceramics, reinforced with industrial Sapphire to maintain the pressure needed for nuclear fusion. Unfortunately, it is because of these attempts to cut corners that would lead to the reactor's unreliability and dangers to the crew. The insufficiently-strong Sapphire supports were required to be replaced at a frighteningly-frequent affair or risk a slow reduction in output. Even worse, the cheap materials and obsolete safety systems would result in the release of dangerous radiation and, on at least one occasion, cook the ship's interior to a crisp.

Because of these complaints, the reactor was the very first thing to be changed when the class was brought back into service. Now, all Athens-class frigates are powered by three Dormant-123 DFRs. Named after their manufacturer, the Dormant Corporation, these new systems are smaller, more fuel-efficient and magnitudes more powerful than the Mark Is they replaced. They are arranged in a triangular pattern pointing towards the ship's bow, with one located in the center, with further connections surrounding them in a circular pattern. This not only increases the pressure within the central chamber, but it also creates a latent magnetic field that intersects with those produced by the reactors, greatly increasing energy production. They are more than capable of replenishing the MAC capacitors and sustaining the full potential of its engines, all while doubling or even tripling the previous distance it can travel before refueling.