In early June, 2020, CMC performed a Stability Test on the USNS 2nd Lt. John P. Bobo (USNS Bobo). This is a 673 foot MSC T-AK Class Pre-Positioning ship that was completed by General Dynamics Quincy Shipyard in 1985. Prior to the test, CMC spent many weeks surveying hundreds of spaces throughout every part of the ship.
The process of documenting a detailed list all of the weights to be added, subtracted, and relocated in painstaking and very time consuming. I would tell my wife, Kay and young Naval Architects to not let it overwhelm you, just take it one piece at a time. Below is a photo of one typical space that requires us to document all weights and CG locations of every item in the space that is not part of the lightship.
I quickly learned that on a 35 year-old ship like the USNS Bobo, the many Chief Engineers that served over that period of time saved many pumps, valves, cables, and other heavy parts as spares in order to make repairs in remote locations as the ship would fulfill its mission.
The inclining experiment portion of the stability test was performed on the day after the walk-through of the deadweight survey with the ABS surveyors. This normally would require at least three teams, each with a Naval Architect, MSC representative, and ABS surveyor. Unfortunately, the COVID pandemic was raging (pre-vaccine). Travel and Covid Testing restrictions for the shipyard and ship presented many challenges, but the work had to be done. Both the deadweight survey and inclining were performed by CMC with only two people (me and my wife, Kay). The deadweight survey report is a spreadsheet that had over 2,000 line items.
CMC had previously surveyed two other T-AK sister ships at Detyens Shipyard. One of these, the USNS Lummus, had a successful Stability Test that was performed pier-side using a similar test procedure that CMC developed using the ship’s cranes and test weights available at the shipyard.
A detailed test procedure was developed by CMC and approved by MSC and ABS.
This stability test was quite challenging for everyone involved, CMC, the shipyard, ABS, MSC, and the crew of the USNS Bobo. It required many hours of hard work and some very long days. Fortunately, we all came together, and it was successful Stability Test that led to having a new ABS approved Stability Book that accounted for a significant weight and CG change due to many years of modifications made to the ship.
This was also the last major project that CMC worked on for MSC and Detyens Shipyard just before I made the decision to retire.
