Malleus, pg 385 describes the Essene, an "Isolde Pattern bulk clipper" as "...a space going cathedral three kilometers long."
Xenos, pg 162, gives the following scenario.
From Malleus, pg 281"The wait, which lasted 66 hours, was neither comfortable nor pleasant. We wore heat gowns and sat in the gloom above as, above us, the heretic fleet scowered Obol and its immediate zone for traces of us...
...after 40 hours, Lowink was confident he overheard the astropathic traffic exchanges indicating a fleet departure, shortly followed by a tremor in the fabric of the fathomless immaterium. But still we waited for the one thing I would take as convincing.
Just after the turn of the 66th hour, it came. An astropathic signal in Glossia: "nunc dimittis".
...The Essene, slow and majestic, moved in to meet us. Once the heretic fleet had left the system, Maxilla had emerged from hiding in the star's corona and sent his signal."
[/quote]I raised my weapon. She flew at me.
Her sheer bulk brought me down.
One spider limb stabbed entirely through the meat of my left thigh. Her steel fangs, like needles, snarled into my face. I saw her eyes, black and without limit or sanity.
She spat.
I wrenched my head around to avoid the corrosive spew, and fired my bolt pistol up into her.
The impact threw her backwards, all 400 kilos of wizened witch and bionic undercarriage.