Establishing Dry Dock/Vessel Communication

The Dock Master must obtain all information pertaining to the drydocking and undocking evolutions and have a clear understanding of the full scope of work to be accomplished during the lay period. It is important to establish of lines of communication between the ship, the dry dock, and any other organizations involved so that questions can be easily raised and answered.

When communicating with the ship or dry dock, the Dock Master should bear in mind that all parties have the common objective to dry dock the ship safely and efficiently. Secondary issues such as seniority or financial disagreements may disguise this common purpose. Under such circumstances, an important role of the Dock Master is to assure adherence to the primary objective and not to allow secondary issues to divert important resources or to diminish the ship-shipyard cooperation essential for achieving the best possible drydocking.

Other tools for open and clear communication are the Drydocking Notice and the Drydocking Conference.

Drydocking Notice

The Drydocking Notice is the first document sent to the ship. This document provides the schedule of the drydocking, a detailed discussion of the drydocking, drydocking procedure, regulations for a ship in the dry dock, services available, safety, etc. The Drydocking Notice should serve as the ship’s reference document for expectations for the ship’s preparation for drydocking and while in the dry dock. It is a detailed instruction document.

The Drydocking Notice should include:

– Time and location of the Drydocking Conference

– Docking Plans and intended docking position

– Acceptable ship trim, list and ship loading conditions

– Acceptable tank loading conditions

– Request of notification for any movements of weights aboard ship

– Storage of retractable underwater equipment

– Positioning of propellers and rudders

– Ship’s crew responsibilities for the drydocking

– Schedule of the ship is in the dry dock.

Drydocking Conference

The Drydocking Conference is a meeting with the ship at which the Dock Master can review with the ship the contents of the Drydocking Notice and answer questions. It also provides an opportunity to discuss the drydocking operation and to explain why some of the requirements are imposed upon the ship. In addition, the visit for the conference is a proper time to:

– Verify the drydocking position.

– Verify the current Docking Plan; review the ship’s copy of the docking plan, and the most recent drydocking reports.

– Obtain the latest information regarding special work to accomplish in dry dock or other special requirements.

– Obtain current data on expected drydocking list, trim, loading, and stability.

The professional expertise of the Dock Master in conducting the Drydocking Conference, and their ability to convey the shipyard’s commitment to providing an excellent drydocking are key elements in establishing the cooperative spirit and excellent communication between ship and Dock Master.

Following the formal conference, Dock Masters should make themselves readily available to the ship for further meetings. The Dock Master may require additional meetings with the ship if changes in the scope of the planned dry dock work.

Provided below are an example Drydocking Notice and an example Drydocking Conference Agenda. They are only examples. The conditions and responsibilities for each dry dock, shipyard, and ship can be different. Thus, the Drydocking Notice and Drydocking Conference will be modified to the unique situation.



Ref: (a) List any references

Encl: (1) Readiness for Drydocking Report

(2) Diver’s Checklist

(3) Record of Weight Change Report

  1. Purpose. To promulgate responsibilities, guidance, and procedures governing drydocking operations at DRY DOCK NAME .
  2. Discussion. The following is a summary of the responsibilities, services provided, sequence of events, and safety requirements for the drydocking of the SHIP scheduled for DATE with an approximate sill time of TIME . Docking position # and Docking Plan revision NUMBER & REVISION will be utilized for this evolution. The drydocking will be conducted in accordance with reference (a).
  3. Responsibilities of the DRY DOCK.
  4. Verify tugs and pilot are available to meet sill time and be on station at TIME .
  5. Provide all handling lines and wires for the dry dock.
  6. Provide pusher boat to pass inhaul line, and ship handling lines port and starboard.
  7. Arrange for divers to be on station and ready to dive at TIME .
  8. Provide ship with a brow to their port or starboard side fantail while in the dry dock.
  9. Provide ship services (power, firemain, potable water, etc.).
  10. Provide ship riders to spot lines and to assist in positioning of the ship.
  11. Conduct initial block inspection as soon as the blocks are clear of water.
  12. Provide a crane and man basket for personnel transfer in the event of an emergency, during the drydocking evolution.
  13. Responsibilities of the Ship.
  14. One day prior to drydocking, submit a report of all liquid soundings and completed Readiness of Drydocking Report (Enclosure (1)) to the Dock Master.
  15. After landing on the blocks, submit a report of all liquid soundings to the Dock Master.
  16. Maintain zero list prior to and during the drydocking of the ship. Any deviation must be discussed with, and approved by the Dock Master.
  17. Maintain acceptable trim, provided by the Dock Master, prior to and during the drydocking of the ship. Any deviation must be discussed with, and approved by the Dock Master.
  18. Place shaft(s) and screw(s) in docking positions, with rudder(s) locked in mechanical zero position. All retractable projections from the hull must be housed.
  19. Provide 10 line handlers onboard port and starboard sides to receive lines and grip hoist wires from the dry dock.
  20. Provide necessary personnel to coordinate and connect firemain so that ship’s generators can be shifted to emergency cooling.
  21. Provide necessary personnel to coordinate and complete all other pier service connections.
  22. Provide necessary personnel to arrange for transfer of phone services, and make connections on the pier.
  23. Provide security personnel with communications to the ship.
  24. Sequence of Events.
  25. Tugs and pilot will maneuver the ship from its berth to a position fair to the dry dock basin approximately 60 feet (20 meters) from the dry dock’s sill.
  26. The pusher boat will pass the inhaul line plus the #6 port and starboard handling lines to your fantail and then make up, bow towards the wind, to your stern.
  27. Tugs, pilot and inhaul lie will bring the ship across the sill to a position approximately 50 feet (15 meters) inside the dry dock and stop.
  28. When the first extremity of the ship crosses the sill of the dry dock, the responsibility and control of the ship will shift to the Dock Master.
  29. The dry dock crew will pass wire rope port and starboard sides from grip hoist to provide positive control of the ship during the inhaul procedure and to maintain centered positioning.
  30. As the ship continues into the dock, five more handling lines and two more wire ropes will be passed to the port and starboard sides. The Dock Master will determine the number of lines required at pre-drydocking ship visit, and the appropriate bitts and chocks will be marked accordingly.
  31. The ship will again be stopped at a point where the tug’s services are no longer necessary, and they may disconnect from the ship. The inhaul line will bring you to your final longitudinal position.
  32. Centering chains will be passed across your bow and stern, and the ship will be centered laterally.
  33. The ground strap is attached to the vessel to starboard side of ship.
  34. While the ship is centered, firemain will be passed from the dry dock to the ship, enabling the shifting of generators to emergency cooling.
  35. The dock dry basin water level will be lowered to a point such that the keel is approximately one foot (.3 meter) above the centerline keel blocking.
  36. Once the ship has shifted to emergency firemain, all machinery with suction from the sea must be secured. This must be accomplished prior to divers entering the water to verify centering of the ship. The Diver’s Checklist (Enclosure (2)) will be completed and passed to the diving supervisor prior to commencing diving operations.
  37. After final centering of the vessel is verified, the dry dock basin water level will be lowered two additional feet, thus landing the ship “one-foot hard on the blocks.” Divers will again verify centering and contact of each keel block with the ship’s keel prior to the hauling of side blocks.
  38. After ship lands on the blocks, the necessary shore power connections will be completed.
  39. Side haul blocks will all be brought to their final position against the hull.
  40. The divers will again check the centering of the ship and each side block contact with the hull. Divers will also check clearances of domes, fins, and propellers to closest part of the blocking.
  41. When all checks are satisfactory, the remaining dry dock basin water will be removed.
  42. The brows will be positioned and other services installed as directed by the Dock Master.
  43. Period of Ship-in-Dock.
  44. Record of Weight Change Report.

Record all weight changes and weight shifts of .25 tons or more. All weight changes must be recorded to ensure the ship’s stability has not been degraded.

Lifelines, Nets, and Kickboards.

All areas of the ship’s deck required for unlimited access by personnel during period in the dry dock must be enclosed with fixed stanchions, lifelines, nets, and kickboards.


All ammunition remaining onboard, while ship is in dock, is not to be moved without the expressed permission of the Dock Master.

Radios and Radars.

At no time while in dry dock will it be permitted to rotate or radiate any masts or antennas without the permission of the Dock Master.

Movement of Onboard Cranes and Machinery.

At no time in dry dock will movement of onboard cranes and machinery be permitted without the permission of the Dock Master.


Location Date

Drydocking Conference Agenda SHIP

– Drydocking planning meeting held at the LOCATION inside the dry dock compound. Attendees: Dock Master, shipyard services supervisor, shipyard Program Managers, ship representatives.

– Shipyard schedule crane for stop log removal and replacement.

– Shipyard schedules Pilot and three tugs.

– Ship schedules security boom removal.

– Ship schedules movement from Pier XX Berth XX to dry dock.

– Dock Master schedules divers for drydocking.

– Drydocking Conference held at the LOCATION inside the dry dock compound. Attendees: Dock Master, shipyard services supervisor, shipyard Program Managers, ship representatives.

– Ship provide tank sounding to Dock Master.

– Dock Master meets with pilot to plan ship entry operations.

– Dock Master meets with divers to plan diving drydocking operations.

– Dock Master conducts drydocking brief for ship line handling supervisors.

– Dock Master completes preliminary drydocking calculations.

– Dry dock crew brings out mooring lines, grip hoist and centering chains up at dry dock frames 115 and 515

– Block Inspection at the dry dock.

– Dry dock basin is swept clean and cleared of all equipment and debris.

– Dock Master conducts final inspection of dry dock blocks and dry dock basin.

– Environmental Inspection. No further entry into the dry dock basin allowed.

– Auxiliary generator placed on ship.

– Stop ship production work involving weight changes of .25 tons or more.

– Ship ballasted to zero list and one foot (or less) trim.

– No additional ship weight changes of .25 tons or more allowed.

– Final tank soundings and trim and stability condition sent by ship:

– Dock Master complete final drydocking calculations.

– Ship ready for drydocking. Retractable equipment stored.

– Dock Master weather check-maximum winds 15 kts.

– Dry dock crew pre-floods dry dock to 20 ft. and secures the dry dock.

– Ship diver tag-outs started.

– Commence flooding dock to sea level.

– 3′ tide height required for 1′ clearance over the blocks during ship movement into the dry dock.

– Crane and with man safety basket on station.

– Security boom opened for tug boats.

– Dock Master briefs line handling supervisors.

– Ship services and brow are removed.

– Line handlers on station. Communication checks.

– Line handlers remove guard rail.

– Pilot and tug boats make up to the ship at pier XX berth XX.

– Dock Masters, Pilot, ship and tug boats on Marine Band channel XX. Communication checks.

– Ship enters the dry dock stern first.

– Ship’s crew cast heaving lines to dry dock line handlers from the stern as they near dry dock sill.

– Tugs ease vessel into dry dock. Only bow tug will enter the dry dock.

– Ships crew cast heaving lines to dry dock line handlers from the focsle as they cross dry dock sill.

– Ship line handlers take in dry dock mooring lines and make up to the ship’s focsle.

– Vessel continues into position.

– Line handlers hold vessel in position.

– Pilot transfers to bow tug.

– Tug boat on bow disconnects and departs.

– Line handlers run lines to capstans and center and position vessel.

– Line handlers draw up centering chains.

– Ground strap and salt water services are installed onboard the ship.

– Secure ship generator.

– Ship diver tag out of equipment completed.

– Dry dock Crew dewaters dry dock to 21 feet.

– Divers inspect the blocks for interferences, check for center and position, and report to the Dock Master.

– Dry dock Crew resumes dewatering dry dock to 17 feet.

– Divers conduct final inspection.

– Resume dewatering the dry dock completely.

– Commence installation of all remaining services.

– Line handlers install dry dock guard rail.

– Dry dock is dry.

– Ship takes tank sounding after ship lands on blocks.

– Dock Master and ship Inspect hull and blocks.

– Service Ship’s Crew Shipyard

– Ground cable assist make up make up

– Install brows open hand rail crane/rigging

– Salt water make up to ship crane/rigging

– Shore power assist cable set up crane/rigging

– Fresh water assist hose lay out crane rigging

– Telephones assist make up make up

– CHT assist make up make up

– Cable assist make up make up

Physical Inspection of the Vessel

It is imperative that physical inspections/visits of the ship to be drydocked are conducted. At least two inspections are recommended.

The first inspection/visit should be carried out a couple days prior to the drydocking to mark the ship for placement of handling lines, grip hoist wires and other ground tackle, and to mark points forward and aft for centering the vessel in the dry dock. Marks are also to be made on the port and starboard sides of the vessel, which will be visible during the drydocking operation, to identify locations of hull appendages. This also will aid in positioning the vessel over the blocks by lining up these key points. Any dry dock personnel who will be onboard the ship during the operation should use this opportunity to identify themselves and establish communication with the ship’s personnel.

The second inspection/visit should be as close to the drydocking time and date as possible, and shall be directed at assuring that all previous arrangements and markings still exit and have not been obliterated or impinged. This visit should also be to make a visual determination as to the ship’s compliance with predetermined drafts, trim, and list for the entrance into the drydocking facility.

Listed Vessels

A ship should always be drydocked in a zero list condition if possible. In most cases, it is easy to remove any list from a ship prior to drydocking. The redistribution of liquids in the tanks, and/or the movement of other ship’s loads can change the ship to a zero list condition.

In some special situations, such as a damaged ship or especially loaded vessel, it may not be possible to obtain a zero list condition. In these cases, the list can be corrected by the addition of weight to the ship. The Dock Master should carefully check that the list is not associated with a poor stability (small or negative GM) prior to undertaking corrective action.

CAUTION: If weights are added to a ship to correct list, and the cause of the list is then corrected while the ship is in dry dock, the correcting weights must be removed prior to undocking so that the ship will not roll to a listed angle as she lifts off the blocks.

Usually, a safer method is to remove the ship’s list before the ship enters the dry dock. In rare situations where the ship must be drydocked with list, special precautions for rolling list out once on the blocks must be followed. Using buoyancy and/or pulling the list out with lines is possible, but risky.

It is never acceptable to have the ship sitting on the blocks in any appreciable listed condition.

Trimmed Vessels

Ships arriving for a drydocking should be as close to a zero trim condition as possible. Drydocking with trim in a dry dock that cannot itself be trimmed, results in a knuckling (sueing) reaction. The ship first lands on one keel block at the deep end of the ship resulting in a large point load. The ship then pivots about this keel block as the dock basin water is lowered until the ship comes to an even keel.

In planning the drydocking of a ship in an extreme condition of trim, the primary factors of concern to the Dock Master are:

– The difference in trim between ship and the dry dock that will need to be accommodated

– The bearing width of the ship’s keel on the blocks

– The location of the ship’s longitudinal center of flotation relative to the aft edge of the knuckle block and the ship’s MT1″ (MTcm) characteristics

– The length of the ship

– The characteristics of the keel blocks, and allowable block stress and load-deflection characteristics

Having this information, the relationships that are developed in this section may be used to establish that maximum allowable trim condition for any particular ship and dry dock combination. Assumptions to consider when determining the maximum allowable trim are:

– The values of MT1″ (MTcm) and of LCF

– The knuckle (sueing) reaction between the ship and the keel blocks can be assumed to act at the after end of the knuckle (sueing) block.

– The maximum stress will occur when approximately one-half of the original trim has been removed during the process of dewatering the dock.

Problems drydocking with trim include:

– The knuckle reaction causes a loss in stability (loss in virtual GM). In the case of ship with large trim and low GM, the ship may become unstable before the landing draft.

– The knuckle block loads may be so large as to prevent a safe drydocking.

If stability is a problem, the usual steps to improve stability should be considered: remove high weight, add low weight, and eliminate free surfaces. In addition, an effort should be made toward reducing trim.

Trim can be changed appreciably only by moving large weights fore and aft in position. Shifting of liquids will normally provide the most practical means of adjusting trim. The use of peak tanks and other large capacity tanks far removed from amidships maximize the trimming moment for a given weight transfer. Alternatively, shifting or removal of anchors and chains can correct trim. Dry cargo, stores, and ammunition are also candidates, but usually are less convenient to handle and more commonly of lesser weight than liquid loads.

For small ships, the addition of weights on deck may be an effective way of reducing trim. However, such weight additions raise the center of gravity and what is gained in decreased trim may be offset by an unacceptable loss in stability.

A ship with a large amount of irremovable trim presents a special situation to the Dock Master. Floating and other dry docks with trimming capabilities result in an acceptable ship/dry dock relative trim. In other dry docks where the trim cannot be adjusted, adjusting the dry dock’s blocking build-up heights can reduce the effective trim between ship and dry dock.

In addition to knuckle block loading limitations, the ship’s trim should not exceed the ship’s length divided by 100. A ship that exceeds the maximum allowable trim calculation should not be dry docked.

The Dock Master normally has to deal with a ship with relatively small amounts of list and/or trim. However, they may on occasion require the ship to modify the list and/or trim of his ship to insure a safe docking situation. When such action is necessary, it is important for the Dock Master to know the implications of the requirements he is imposing and how they can be met.

Drydocking Check-off Lists

It is strongly recommended that any dry dock facility prepare and utilize check-off lists. Generic check-off lists are provided in the Work Book.

Systems in Support of the Docking/Undocking Operation:

Concurrent with the detailed preparations, discussed in Chapter 2 and earlier in this Chapter, the entire dry dock system must be ready to undertake the drydocking. This means that all of the dry dock systems that support the drydocking operations, as well as those systems that will be required to provide support for the ship in the dry dock must be in proper working order.

In this regard, the importance of having all systems fully functional must be emphasized. An occasion will arise when a drydocking must be conducted with a bad pump or one indicator tagged out because of derangement or repair. Recognize that these are abnormal and potentially dangerous situations. Dry dock systems are designed to be redundant to accommodate an unexpected failure of a component or a system. When any part of a system is deranged, the design redundancy of the system is reduced or even eliminated. This results in the decreased safety of the entire drydocking operation. The Dock Master must be aware of the physical readiness of his dry dock and be fully cognizant of the effects of such reduced readiness and problems that could therein arise upon drydocking operations.

The Dock Master is primarily responsible for continually insuring that the dry dock is ready for drydocking operations. In view of the comments above, the Dock Master must keep the shipyard management advised regarding the implications of machinery and equipment derangements and their potential impact on the operating condition of the dry dock.

The Dock Master should review readiness in the following areas as he plans a drydocking:


Pumps can become air bound and will fail to take suction unless the air is removed from the system. To accomplish this vacuum, priming systems are normally installed as an adjunct to the main ballast pumping system.

For a floating dry dock, the main ballast tank system, including piping, valves, and pumps, is designed to afford the Dock Master a capability to selectively pump or flood ballast tanks or groups of tanks from a central control station such that the dock can be raised or lowed to provide:

– control of trim

– control of list

– control of water level in the basin

– control of load distribution on both the dry dock and ship

The common aim in the design of ballast tank systems for all modern floating dry docks is to provide a system that will allow the Dock Master maximum flexibility in adjusting ballast. The systems are normally designed to provide the following basic capabilities:

– Transfer ballast water within certain dry dock’s ballast tanks.

– Flooding of water from sea to all tanks either individually or in groups.

– Transfer of water from the individual ballast tanks or groups of ballast tanks to sea.

The principal features of the Ballast Control Station are:

– Remove control of valves and pumps.

– Valve position and pump operation are shown by indicator lights.

– Tank water levels are indicated.

– List and trim angles of the dock are shown.

Line Handling Systems

Ships to be drydocked are often brought into position, and held in position, by tugs just outside the dry dock sill. Before the ship enters the dock, lines are rigged from the dry dock to the ship. Hauling the ship into the dry dock commences and as the first extremity of the ship crosses the sill, and then the Dock Master takes over control and responsibility for the safety of the ship until the last extremity of the ship crosses the sill during the undocking process.

Considerable skill and good judgment are required to properly handle drydocking lines to guide the ship safely into dock and to position the ship in the desired location within the dry dock. Years of experience with handling ships into dry docks have established the proper positioning of capstans, cleats and/or bollards needed for the line handling operation. The number, position and power of capstans along with the number, size and position of cleats will vary with each dry dock and ship.

Capstans. Since most ships coming into dry dock are dead ships, that is, propulsion power cannot be used, and with near zero speed, rudders will not provide steerageway, it is necessary to use docking lines for maneuvering and capstan power to haul a ship into dry dock.

Cleats. Cleats for securing and controlling guide and snubber lines are spaced at intervals along port and starboard wing walls. The space of cleats is such that line handlers can shift lines singly while the line immediately forward or aft maintains control using a cleat until the line being moved has a proper lead from a cleat to provide control by running or snubbing the line as necessary. Cleats can provide control only when a line is in tension. Always remember the basic axiom of line handling: “YOU CANNOT PUSH ON A LINE.”

Centering and Alignment System

Any one of numerous techniques can accomplish monitoring the transverse centerline position of the ship relative to the block system centerline:

Centering chains or wires. Chains or wires hang, suspended between the dry dock’s walls. A mark in the forward chain is used to match the center point of the last keel block for transverse centering of the vessel’s bow. A mark in the after chain is used for transverse centering of the stern and longitudinal placement of the vessel over the blocking.

Transits or suitable telescopes. Optical devices can be mounted on the dry dock to coincide with the block system’s centerline plane. These can be used to monitor the ship’s centerline plane. Vital Note: When using this technique, both the dry dock and the ship being drydocked must be maintaining alignment in a perfectly upright zero list condition.

Battens. Visual cues like battens can be mounted on the dry dock to define the block system’s centerline plane. The ship’s stern, transom and/or suitable targets mounted topside are then maintained and aligned with the plane established by the dry dock battens.

Centering tackle can use a variety of mechanical devices that provide significant mechanical advantage or purchase power while at the same time provide a veneer control and a positive means of holding a selected position. Chain falls, wire rope block and tackle, “come-a-long” wire power hoists, ratchet driven turnbuckles, etc., are examples of equipment that can be used for this purpose.

Wire or chain should be used with such centering systems to avoid stretch or surge conditions that could result in an unstable positioning system.

Pairs of centering tackle are rigged from the dry dock to the ship, port and starboard. Just prior to the ship landing the tackle is tensioned as required to maintain the ships’ centerline plane coincident with the block system centerline plane. Similar pairs of tackle can be rigged that tend fore and aft to maintain the ship accurately in the proper longitudinal position relative to the block system.

Communications System

The docking process involves the coordination of a relatively large group of people including personnel located on the dry dock, on the ship being docked, and on the tugs that assist in the drydocking operation. In addition, the drydocking operation often must be carried out during inclement weather conditions and at time when visibility is poor.

Considering these factors and the length of dry dock basins and the spacing between dry dock sides, over which distance communications must be accurately relayed, it is clear that a reliable and convenient communication system is an essential ingredient in the docking process.

The hallmark of an efficient and well-trained docking crew is the noticeable absence of frequent and loud communications. The discipline and format of communications is well established and often simple hand signals have been developed for use by the Dock Master and the line handler supervisors that achieve the transmittal of the desired instructions.

The reliability of sold state portable radio transceivers provides a convenient and flexible means of communication for the Dock Master to contact the ship being docked, the tugs involved in the docking operation and the dry dock crew members conducting the drydocking.

It is essential that the communication system to be used during a drydocking be carefully described as to the extent and purpose of its use during the Drydocking Conference. Any special communication format or nomenclature associated with the docking process should be clearly established.

Ship Support Systems

The best time to install most ship support systems to the ship from the dry dock is after the ship has landed on the blocks. For example, installing heavy power cables before you land can create a list in the ship, resulting in ship centering and landing issues. Installing smaller services like a fire-main line may not affect the ship’s list and can be accomplished before the ship lands on the blocks.


It is essential that all arrangements be made prior to drydocking to establish the type of electric power, amount of power, and method of hookup. The ship may need this service in order to maintain lighting, communications, vital auxiliary machinery, etc. The use of AC electric power is almost universal aboard modern ships. To meet the needs of drydocking all types of ships, dry docks serving these ships should have installed a generator on the dry dock or on the ship, or have tie lines with shore power sources.

The dry dock must have available adequate portable electric cables to make the necessary attachment to the ship’s shore power connection point prior to installing and/or energizing shore power cables, the dry dock must first attach hull ground straps to the ship in dock to insure a satisfactory path to ground circumventing the insulating effect of the dry dock blocking.

Vital Note: Grounding cables from the ship to the dock must be installed prior to energizing any shore power service to the ship.

Piping Systems

The basic function of piping systems is to transport and control the various liquids and gases that are required for the operation of the ship or may be a part of the ship’s cargo. Certain piping systems that support the operation of the ship must remain in service while the ship is in dry dock for reasons of safety or crew habitability. These systems must be identified prior to the drydocking and arrangements made to provide support via the dry dock or adjacent pier facilities to permit their continued operation. Example systems include:

– Fire Protection Systems

– Flushing Systems

– Cooling Water Systems

– Fresh Water Systems

– Sewage and Drainage Systems

– Steam Systems

Vital Note: It is very critical that the Dock Master discuss and emphasize to the ship the importance of maintaining careful records of tank levels immediately prior to the drydocking and after landing on the blocks for comparison with tank levels for the undocking. The liquid weights aboard ship while in dry dock should also be a matter appropriate for careful discussion at the Drydocking Conference.


Crane service is essential for materials handling within the dry dock basin and to transfer materials from an adjacent pier, ship, or barge to the dry dock work site. The lifting capacity and out-reach of cranes are tailored to match the dimensions of the dry dock they serve. It is strongly advised to have at least one crane on each side of the dry dock arranged such that the cranes can move the full length of the ship in the dry dock, therefore supporting requirements throughout the length of the dry dock. Crane service must support ship work and also work on the dry dock itself. Therefore, it is necessary that the Dock Master establish and enforce priorities for crane service and ensure that clear lines of communication are defined for obtaining and coordinating crane service.

Emergency Systems

There should be emergency systems for casualties that occur in the dry dock. Example systems include:

– Emergency power systems

– Firefighting facilities

– Damage control facilities

– Flooding alarms

Readiness of Gear

Overall material readiness of the dry dock was previously discussed in this section. A variety of special gear must be checked for readiness:

Special positioning equipment – transits, battens, positioning chains, etc., should be checked at the time of basin checkout.

Punts for transfer of lines and of personnel should be available. (A pusher boat is normally used for the transfer of lines and for assistance in controlling the stern of the ship during drydocking/undocking operations.)

Readiness of Drydocking Support Services

The support services usually required for a drydocking include:

– Tugs

– Pilot

– Divers

As these services are provided by cooperating groups, timely notification of scheduled requirements and immediate notification of schedule changes are essential.

Line Handling 

General line handling concerns and commands are provided in this section.

  1. Line handlers should wear line handler attire through the entire ship handling operation:
  2. Kapok or self-inflating life jackets/personal floatation devices
  3. Steel-toes safety shoes
  4. Hard hats
  5. They should remove any jewelry
  6. Commands to Line Handlers                                                                                               (…more)
1. Line and Line Stations: Stand by your lines This means all personnel designated for each line or line station man their lines and be ready to take line handling direction from the line handling supervisor.
2. Let go, or Let go all lines This directs the line handlers to smartly slack off of lines to permit lines tending on a pier, tug or ship to be cast off.
3. Send the lines over This will be the command when lines are to be passed to a ship, tug, or pier, and will normally be accomplished by use of a heaving line or messenger. Care must be taken that the correct end of the line, most usually the end of the line with the eye to be placed over the bit or bollard, is the end of the line that is sent over.
4. Hold what you’ve got This means to hold the line as it is.
5. Check your line Means to slack your line just enough to let it ride with a heavy strain off a bit, cleat or bollard.
6. Shift your line This means to remove your line from the bit or cleat where it is working now and move it to another attachment bit or cleat, as directed by the line handling supervisor.
7. Cast off your line This command will be given when you are to let your end of the line go, to either fall in the water, or to be retrieved by persons handling the opposite end of the line.
8. Single up Take in all bights and runs of extra lines so that there only remains one strand or run of line.
9. Double up Pass additional runs of the line to the corresponding attachment points of the single run line.
10. Take in all lines This order will normally be given at the end of an operation when line handling will no longer have an effect on the evolution. The lines will be brought to your station.

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