Black Rock Lock Refurbished
After 100+ years of operation, the 650’ x 70’ Black Rock Lock needed to be refurbished. This included refurbishing the lock gates originally constructed of riveted plates and angles. BIDCO Marine worked with Robishaw Engineering in configuring a 140’ x 60’ x 7’ Flexifloat assembly to support their Manitowoc 2250 Series 3 crawler crane with 150’ of boom. The crane’s center pin needed to be positioned 30’ from the bow of the barge to lift the 175,000 lb. lock gate. Two perpendicular rows of floats were added to the stern and ballasted with approximately 480,000 lbs. of water to act as counterweight to the 300-ton capacity crane sitting on the bow. Along with providing stability calculations, Robishaw Engineering reviewed the hull stress caused by the large bending moment created by the opposing crane and ballast water. By using the S70 Quadrafloats and Duofloats in a brick work pattern, stresses on the locks and hull were determined to be well below allowable limits.
After a 4 month restoration, the locks were successfully placed back into service. In 2021, over 2,600 vessels and 60,000 metric tons of commerce passed through the lock. The Black Rock Lock continues to be safely and effectively operated by the U.S. Army Corps of Engineers.