Under contract to the Philadelphia Regional Port Authority Urban planned and designed a layberth for berthing and mooring two LMSR ships, part of nation’s “Ready Reserve Fleet,” for deploying U.S. Ground Forces overseas in the event of war. LMSRs are 950 feet long, 106 feet wide, and 90 feet high. LMSRs provide lift capacity for equipment to support U.S. Military Units throughout the world. The creativity and ingenuity in the structural arrangement and structural design resulted in reducing the overall cost of the project from an estimated $6.0 million to $4.0 million.

The layberth was to be designed for a sustained wind speed of 74 mph and a river current speed of 2 knots. Positioning the ships in a nested configuration as opposed to an inline configuration resulted in reduced total design loads (due to shielding) and reduced number of structures to be designed and constructed. The nested configuration and cantilevering the ships 416 feet upriver of the wharf edge minimized the expensive wharf space occupied by the ships and allowed the normal wharf activities to continue, generating revenues for the port. A quasi-static analysis of the nested configuration indicated that a total of 44 mooring lines tied to 22 mooring points (bollards), with a lateral load capacity of 150 tons each, would be required to safely moor the ships at this berth.

The use of high early strength concrete; similar and repeated design and detailing of concrete footings, concrete pile caps, and steel triangular truss walkway; allowing the contractor to pour the 7’-0” thick concrete dolphin caps in two lifts of 1’-0” thick as first lift and using it as a formwork for the second 6’-0” thick lift resulted in reduced labor costs and a saving of $500,000. This $4.0 million project was designed in 5 weeks and constructed in 4 months.