Photo: Sandy Joseph/ULA

The investigation is ongoing as to why the MV Delta Mariner  collided with the Eggner Ferry Bridge on the Tennessee River in Kentucky last Thursday night, taking out over 300′ of the span, but reportedly, the ship was in the wrong channel.  It apparently was in a recreational channel where the bridge had a lower clearance rather than the  shipping channel where the clearance would have been adequate. Sam Sacco, a spokesman for Foss Maritime, said the ship made the trip many times in the past 10 years and had an experienced captain and local river pilot on board.

The Delta Mariner is a 312-foot long roll-on roll-off ship designed to carry rocket components from the Boeing factory in Decatur, AL to either Cape Canaveral in Florida or to Vandenberg Air Force Base in California, via the Panama Canal.  When the ship collided with the bridge, it was carrying carrying one Atlas 5 rocket and several other components to be used for two upcoming launches from Cape Canaveral, FL, including one slated to blast off April 27.  The rocket and components were not damaged in the collision.

Decatur, AL is roughly 300 miles from the Gulf of Mexico. How did an ocean-going ship end up colliding with a bridge in Kentucky 500 miles from the Gulf and 200 miles north of Decatur, AL, where it was loaded?  There are two ways for the Delta Mariner to reach the Gulf of Mexico.  It can travel on the Tennessee River to the Tennessee–Tombigbee Waterway, then south to the Tombigbee River, and into Mobile Bay and the Gulf, a distance of about 550 miles.  The minimum depth of the Tennessee–Tombigbee Waterway, however, is 9 feet whereas when fully loaded the Delta Mariner can have a draft of 14 feet. In those cases, the ship can travel on the Tennessee River to the Ohio River, then down the Mississippi to the Gulf of Mexico a voyage of over a 1,000 miles.  The Delta Mariner was on this longer northern route when it collided with the Eggner Ferry Bridge in Kentucky.