Washboard Effect

The entire volume of the Shackleton Expanse has strange gravimetric distortions and ripples in space-time that can be a danger to vessels traveling at warp speeds. The overall phenomenon is known as “The Washboard.” Near the edges of the Expanse, vessels at warp have their warp field compressed and expanded as space-time distorts around the vessel, making the crew feel as though the ship was accelerating and decelerating, or swaying from side to side. This effect is so pronounced that warp systems from the 23rd century and earlier were prevented from operating in all but the furthest reaches of the Expanse, damage often occurring to the warp systems of the vessels. This restricted most exploration of the area until the 2360s.Even with modern warp systems capable of adapting to the subspace and gravimetric distortions, this effect can still be felt at high warp velocities, and becomes stronger the closer a vessel comes to the Washboard Triplets, the cause of this effect.
One of the first Federation starships to enter the Shackleton Expanse was U.S.S. Umbra, a Miranda-class vessel, in 2308.With the scale and danger of the Washboard then unknown, Umbra did not slow its warp velocity when it detected a Class-M world. Logs show that as the vessel turned toward the system, it began cutting against the gravimetric shear and suffered immediate catastrophic damage to its warp nacelles. The vessel dropped out of warp half a light-year from the planet, with most of its power systems burnt out. After drifting under low impulse power for 1.5 standard years, the survivors of Umbra made planetfall on the world they called Finally, unwillingly becoming the first Federation colonists in the Expanse. Finally is used as a waypoint and for shore leave, the decedents of Umbra having built a small Starfleet outpost on the shores of Lake Here’s Fine.