The Dockmasters Journal - Volume 2, Issue 1
January 2025
Editor: Waleed (Wally) Sayed, P.E., M. ASCE
A publication focused on Dry Docks presented to Dock Masters, Dry Dock Engineers, Operators, and Owners.
Our mission is to focus on the diverse world of dry dock facilities, showcase their successes and unique capabilities, disseminate industry specific knowledge, and share lessons learned from dry dock incidents with a positive presentation.
In this month’s edition:
⦿ A Note from the Editor
⦿ Questions for the Editor
⦿ Main Article: Dry Dock Certification Standards-What is Dry Dock Certification Standards-What is United States Department of Defense Standard Practice, Safety Certification Program for Drydocking Facilities and Shipbuilding Ways for US Navy Ships, MIL-STD-1625?
⦿ Community Highlight
⦿ So, this one time, I was on a dry dock...
A Note from the Editor:
Happy New Year! 2025 is already shaping up to be a busy year for the maritime industry. We hope to see you at the Dockmasters Conference in Providence, RI, on June 4-5, 2025.
“A ship in dry dock is safe, but that’s not what ships are meant for.”
Questions for the Editor:
Q) Why does my floating dry dock pitch fore and aft during docking operations?
A) In short, it shouldn’t. The stability of a vessel is a function of the hull form and tank arrangements. Unlike a traditional ship, the stability of a semi-submersible floating dry dock significantly decreases when the pontoon is fully submerged leaving only the wing walls to provide the dock’s righting moment. The overturning moment is based on the ballast levels in the individual tanks accounting for free surface from any slack tanks. In a floating dry dock design transverse and longitudinal stability must be assessed. If a dry dock were to roll from port to starboard uncontrollably it would be due to transverse instability. If a dry dock pitches fore and aft uncontrollably it is due to longitudinal instability which is generally attributed to narrow wing walls and long ballast tanks.
If a marginally stable floating dock is arranged with one or two center tanks and separate wing tanks, one method for reducing the free surface is to press up the center tanks and manage only the wing tanks. While this may work in commercial dockings, it should be noted that USCG SFLC STD SPEC 8634 has a specific rule prohibiting non-proportional ballasting (Refer to para. A2.8.2.1, Proper pumping plans). For narrow wingwalls a potential solution is to extend the wing walls, designed as cantilevers extending beyond the length of the pontoon.
Dry Dock Certification Standards-What is United States Department of Defense Standard Practice,Safety Certification Program for Drydocking Facilities and Shipbuilding Ways for US Navy Ships, MIL-STD-1625?
MIL-STD-1625 provides detailed instructions for certifying drydocking and launching facilities for US Navy Ships only. This comprehensive certification program is a publicly available document and is administered by US Naval Sea Systems Command (NAVSEA) only. As a certification program, this is an in-depth process that is intended as a long-term arrangement to dry dock and/or launch US Naval vessels. While 3rd party engineering firms such as Triton Dry Dock assist shipyards in designing their facilities, developing their certification program and Facility Certification Reports, and providing 3 rd party control inspections, only NAVSEA is authorized to certify facilities to this Standard.
Note that US Navy Naval Ships’ Technical Manual (NSTM) Chapter 997, Docking Instructions and Routine Work in Dry Dock, is a restricted document and is not publicly available.
Documentation is always the main ingredient with any dry dock certification. The major documentation components for MIL-STD-1625 compliance are lengthy and are given as a high level overview. The program first addresses general requirements which are applicable to all drydocking facilities, with further specific requirements for each type of drydocking facility (floating docks, graving docks, marine railways, vertical lifts, and transfer and launch ways). The major document is a Facility Certification Report which consists of eight separate Enclosures as follows:
Enclosure 1: Historical Data
Enclosure 2: Design Data
Enclosure 3: Operational Limitations
Enclosure 4: Manning Procedures
Enclosure 5: Maintenance Program
Enclosure 6: Operating Procedures
Enclosure 7: Protection of Ship During Lay Period
Enclosure 8: Survey Results
One major component of the Design Data that differs from other certification programs is the explicit seismic requirement. Newly designed facilities must meet the seismic requirement while existing facilities must investigate and document the seismic capability of the facility. The seismic requirement is dependent on the location of the facility when referencing seismic acceleration maps.
Within the Maintenance Program is the most crippling requirement, Periodic Gauging, which when it was first implemented significantly reduced the number of MIL-STD-1625 facilities certified to dry dock USN vessels. This requirement involves extensive Ultrasonic Thickness (UT) gauging of all steel structures including floating dry docks and caissons. While this requirement is triggered based on the age of the facility, the actual condition of the facility is irrelevant when determining the necessity of this costly activity.
Another major component of the Maintenance Program are the inspection checklists. These are intended to be extensive and explicit by identifying every individual structural, mechanical and electrical component. For the checklists to be implemented also requires every identified component on the checklist to be clearly labelled with an individual reference ID. This allows for inspectors, auditors and maintenance personnel to identify each component correctly.
Manning requirements are given for the Facility Operations Supervisor (FOS), or Dockmaster. The Dockmasters requirements are given explicitly, and extensive documented experience is required. It should be noted that when a Naval vessel is in dry dock, the FOS must be within 1-hour travel of the dry dock. Dry dock and vessel stations and functions should be included with the dry dock operating procedures and each station identified should include a qualified manning assignment as well as training documentation.
Triton Dry Dock is a premier dry dock engineering firm with extensive experience designing, modifying, analyzing and certifying dry dock facilities. You can trust Triton Dry Dock to provide your shipyard with the most effective and efficient dry dock solutions.
Community Highlight
Nathan Power is a maritime professional with a career focus on the operation, repair, and construction of naval combatants and logistics ships. He has experience as a deck officer on oceangoing naval support vessels, merchant marine training vessels, commercial bulk articulated tug and barges, and sea trials of naval combatants, among others.
He has worked in shipyards for 10 years, starting in material control and logistics management.His shipyard tenure laid the groundwork for his advanced maritime roles.
Since returning to the waterfront as dockmaster and waterfront operations manager, Nathan has managed and executed projects ranging from maintenance dredging, waterside infrastructure construction and rehabilitation, ship’s husbandry and support, commercial diving operations, launching and operational testing of vessels, and docking and undocking vessels from floating dry docks. He currently commands a 28,000LT capacity drydock.
So, this one time, I was on a dry dock...
So, this one time, I was on a dry dock…during a graving dock operation. The graving dock blocks were set as a fixed build (no hauling block capability), and the vessel had wide propellors. The tide and vessel draft were such that it was not possible to bring the vessel down the center of the blocks. Instead, the vessel was hauled in along one side of the graving dock and then translated over the blocks into its centered position. Several checks were made to determine the amount of clearance the vessel would have over the blocks. The block heights, vessel drafts and clearances are all based on a single reference point. In this case the operator indicated the dock drafts on the walls were referenced as 5-ft above the dock floor, or the top of a keel block. All reference points must be known prior to dock flooding as all these components disappear underwater and are no longer visible or easily reachable. The dock was pre-flooded, and the operation went smoothly enough with the vessel hauled in and over the blocks, the gate seated, and the graving dock dewatered. As the water level in the dock decreased to where we should be able to see the tops of the dock blocks, there were no visible side block caps on the port side and there were no blocks floating in the basin. As the water levels continued to lower, the sound of wood splitting became evident. As we hurried down into the basin it became apparent that all of the port side blocks were gone. Calls were made to immediately reflood the dock. As we were exiting the basin it was noted that the zero draft mark was referenced from the dock floor and independent of any keel block height. Instead of positive clearance, there was negative clearance, and the port side blocks were knocked off and became wedged under the bilge keel. As the old saying goes, trust but verify.
Next edition:
✅ Floating Dry Dock Deflection Monitoring
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📩 Reach out to Wally at wally@tritondrydock.com—we’re looking forward to hearing from you!
Disclosure: Waleed Sayed, P.E. is a co-author of “ASCE Manuals and Reports on Engineering Practice No. 121, Safe Operation and Maintenance of Dry Dock Facilities” and a co-author and voting member of “ASCE/COPRI Standard 77-22, Dry Dock Standard”. Mr. Sayed is not compensated for presenting any information related to these publications. This publication was developed and produced without any assistance from Artificial Intelligence (AI).
Disclaimer: The information provided in this publication is general in nature and not prescriptive to any specific dry dock facility. Always consult a qualified professional when developing any site-specific plan.
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