ISS Crossfield

The 'ISS Crossfield (') was a Terran Empire starship, the science vessel prototype in Imperial Starfleet service in the 2250s decade. (SS STO (From the Desk of Starfleet Intelligence))

Service history
The Crossfield was developed as science vessel in the 23rd century, but ended up re-designed to employ weaponised mycelial technology. Development and construction fell under the aegis of Commander Jason Reyes at the Bureau of Imperial Special Weapons Field Research of the Emperor's Special Projects Division aboard, and the Honorable Commodore Peter McGillis at the Bureau of Appropriations and Allocations of the Starship Development Review Board at $𝜇$, respectively. On stardate 1191.9, Commander Reyes dispatched a memorandum to McGillis to inform him how the mycelial spore-based technology required radical changes to the Crossfield's spaceframe, and that Reyes had secured support by astromycologist $𝜇$. (SS STO (From the Desk of Starfleet Intelligence))

The class was in service by 2256. 

In 2410, Lieutenant Commander Kyla VanZyl of Starfleet Intelligence/USS Voyager learned of the development history of its Terran Empire counterpart to the Federation's own prototype, the USS Crossfield. (SS STO (From the Desk of Starfleet Intelligence))