K Line is blaming May's Houston Ship Channel crash and oil spill on a BW Group-controlled VLGC, court papers show.

Subsidiary K Line Energy Ship Management filed a complaint Tuesday in Galveston federal court alleging that the 82,400-cbm Genesis River (built 2018) was forced to change course repeatedly by the erratic movements of BW's 82,300-cbm BW Oak's (built 2008). That led to a crash with a Kirby-owned flotilla, the Japanese shipowner alleged.

The crash closed the Houston Ship Channel for three days, while 9,000 barrels of reformate spilled and one of Kirby's barges sank.

"[T]he positions and movements of BW Oak impaired the navigation of Genesis River," wrote Dimiti Georgantas, K Line's lawyer at law firm Royston, Rayzor, Vickory & Williams.

"For instance, BW Oak failed to properly allow Genesis River to proceed at a sufficient distance away from the bank of the Houston Ship Channel, and BW Oak improperly transited in too close of proximity to Genesis River during the course of these events."

The complaint was filed by K Line Energy and the Genesis River's registered owner, FPG Shipholding Panama. The BW-controlled ship, registered owner BW VLCG and manager BW Fleet Management are named as defendants.

Kirby Inland Marine, a subsidiary of Houston-based Kirby Corp, first filed suit against K Line and FPG in June. That complaint alleged the Genesis River change direction twice before colliding into a Kirby-owned tug and two of its barges, spilling hundreds of thousands of gallons of reformate.

K Line's complaint makes similar allegations against the BW Oak, accusing the ship of travelling too quickly in an improper area, forcing the Gensis River to manoeuvre out of the way.

In Kirby's initial lawsuit, the company claimed damages stemming from the crash, sinking and the clean up.

"The incident referred to is presently the subject of on-going investigations and hearings by the USCG and the NTSB in Houston and proceedings have been initiated in the United States District Court for the Southern District of Texas," BW LPG said in a statement.

"Accordingly, in these circumstances it is inappropriate for BW LPG to make any comment in response to the various allegations raised in the article."