Conrad nears completion of double-ended ferry for Texas
Conrad Industries , Morgan City, La., is putting the finishing touches on a new 263’3″ × 62’11” × 15’6″, 500-passenger, 70-vehicle ferry for the Texas Department of Transportation (TxDOT).
The John W. Johnson will be the sixth vessel in the fleet of ferries that operates on Galveston Bay between Galveston Island and Port Bolivar. The free ferry service is the only way motorists can cross the waterway between the Bolivar Peninsula and Galveston Island, a 2.7-mile trip.
The new ferry will be capable of carrying eight 18-wheel trucks weighing 80,000 lbs. each. Like the other five ferries in the fleet, the John W. Johnson is double-ended with a pilothouse on each end.
Four of the five ferries in the fleet feature Voith Schneider cycloidal propulsion systems. Vertical cycloidal propulsors at both ends of the boats provide excellent maneuverability.
The John W. Johnson , however, has conventional, ducted propellers powered by a diesel-electric system that features a RACCI -designed variable frequency drive with Siemens equipment. Primary power consists of two GE V228 Tier 2 diesel engines. The engines each produce 1,728 hp at 900 rpm and drive the AVK alternators that supply juice to electric propulsion motors – two on each end. Lufkin gearboxes turn shafts with 5-bladed, Kaplan-style Rice wheels in nozzles. The new ferry’s running speed is 13.5 knots.
“This vessel is a radical departure from the Voith Schneider vessels,” said Mark Rodriguez, TxDOT’s engineer/maintenance supervisor in Galveston. “The Voith Schneider vessels are very maneuverable, but the maintenance costs are much higher.”
To improve maneuverability, three high-aspect-ratio rudders will be used on either end of the new ferry.
Houston-based Alan C. McClure Associates and Schuler & Allan handled the design of the John W. Johnson .
“This was our first ferry for the state of Texas, so we partnered with Schuler & Allan,” said Darrel Harvey, Alan C. McClure’s vice president. “They were very prominent during the initial phase, and we hope our collaboration with them on this project is the first of many more to come.” – Ken Hocke