Posted by : sanjay swain Saturday, October 26, 2013
· the major event
· preparing the vessel for the next 30 months
DRYDOCKING MAINTENANCE ALTERNATIVES
· traveling squads
· shore assistance
· compare with shipyard
· heavy work involving high lifts transportation
· lowest cost
DRYDOCKING SPECIFICATION (most important document)
· description of all jobs
· compiling the specifications as early as possible
DRYDOCKING SUCCESS FACTORS (knowing the vessel)
· good and complete specification
· controlling the yard
· adequate resources
DRYDOCKING THE SUCCESSFULL DD
· the specification to cover between 80-90% of all work
· no major extra cost
· within the stipulated time and estimated cost
DRYDOCKING PREPARATION FOR ENTRY
· vessel to be free for hot work and enclosed places to be ventilated as required
· bunkers / f.water / ballast etc. be suitably distributed to achieve suggested trim.
· works in specification identified / marked.
· supervision duties decided and agreed to.
· a list of all items to be surveyed is kept ready
· list of all certificates expiring is ready
· list of conditions of class to be dealt with is clear
· list of new applicable regulations to be attended to is available.
· modifications /fabrications if any as per new regulations should already
· be in the scope of repairs
· liase with the surveyor and agree on the scope of inspections / duration of inspections.
· to keep surveyor informed about the docking surveys and get a list of recommendations at the earliest for completion of statutory certificates.
· get surveyor’s approvals for the scope of repairs involving class.
PRE DOCKING SURVEYS
• get the gauging reports verified and establish the scope of steel repairs.
• agree with surveyors’ action plan for crediting of cargo /ballast tanks for (intermediate/special) surveys
• agree on testing procedures / repair procedures if any and press test of tanks as per requirements.
• it is advantageous to plan to credit all tanks prior to docking, the trading pattern permitting.
• to credit max possible CSM items prior to docking.
DRYDOCK WORK SCHEDULE
• ship staff and yard jobs are clearly understood / planned and carried out without interference
• yard jobs (in process and completion and testing) are properly supervised
• spares supplied to yard by vessel / arrival of new spares etc are properly recorded and monitored
• decision makings are properly delegated
• onboard timings are suitably altered to get max productivity.
• shipboard meetings are properly timed to continously monitor the situation.
• repair teams if any are to be properly utilised and effectively monitored
dry docking safety
• safety meetings involving yard and ship staff to be properly timed and well attended
• violations of yard guidelines are to be strictly discouraged (hotwork in engine room etc.)
• tank entries etc. are to be done strictly according to procedures and personnel to be doubly careful while closing openings
• importance to be given to attire.
• extreme care to be exercised while turning engines/operating steering gear/starting blowers/switching on electrical breakers/prior trials etc.
• systems are to be properly deactivated and rendered safe (depressurise hydraulic lines/empty oil lines/drain sea water lines etc)
• boundaries of fuel oil tanks are properly marked
• the tank drain plugs are properly marked / identified and protected from inadvertant opening.
• frame nos are suitably marked on deck/sides and bottom.
• vent pipes are suitably marked/identified.
• repairs done through afloat workshops are always cheaper
• most of the specialized jobs are done thru subcontractors or representatives of OEMs with a surcharge.
• a repair team will always be cheaper if the materials can be organized cheaply.
• you will loose a fortune if you need to do tank cleaning inside a yard.
• all additional work will be charged at a very high rate.
• the smaller the fabrication jobs/steel jobs on deck--the more uneconomical it becomes.
• quantities of steel work/pipe work/hull painting etc are to be determined with respect to conditions in tariff like
• minimum kgs per location
• minimum meters per location.
• charges for inway and access work
• minimum surface (blasting)
• minimum no of points per location (gauging)
• WATCH OUT FOR THESE DANGER AREAS
transport to workshop
ventilations / bilges / services.
• it would be cost effective to take a quote for the following
- unshipment of rudder
- renewal of carrier bearing with yard material
- renewal of pintle bearing with yard material
- standard tariff for o’haul of motors (kw basis) /pumps (kw basis)/pipes (meter basis)/ testing of pipes (meter basis) /testing of welds (meter basis) / supply of skilled and unskilled manpower (hourly basis) magnaflux / radiography and other tests / staging (tower and block/buildup of pits/reweld bottom plates
• best economy is an outcome of a tight specification
the following important aspects are covered by the contract document
• time of completion
• discount offerred
• penalty clauses
• repair specifications
• repair specifications
• payment schedule & redelivery of vessel
• owners rights
• yards responsibilty and limitations
• engagement of subcontractors and surcharge.
• work done certificates
• authority and owners representative
• cancellation clause / terms
• facilities to be provided to owners representatives
• change of scope of repairs
• spares and stowage
• pilotage tugs etc for shifting for yards convienience
• the owners enquiry contains the conditions of the owners
• the yards offer contains the yards rules and conditions
• the conditions in the yards offer stand valid even if they are
contradictory to owners request once the vessel has been stemmed
• the areas of contradictions are to be agreed upon / thrashed out prior stemming the vessel.
drydocking technical - corrosion protection
- choice of the correct type and quantity of anodes.
- replenishing of electrodes for impressed current systems if fitted.
- protection of anodes while painting
- correct placing of anodes under guidance from supplier.
- removal of old anodes
• steel work
- inspection of weld quality / fitups
- keep track of the dimensions and locations (for commercial reasons)
- bush clearance
- sealing 0 rings for the taper surface of the pintles
- proper cementing of palm bolts
- water box closing plate water tightness
- jumping bar /clearance
- key ways
- push up and pull up hydraulic pressures (push up curve)
- key ways
• anchors and chain-
- gauging and reversal if reqd
- cleaning of chain locker and insp
- gauging of stiker plates
- build up of pits
- wee out/gouge and build up weld seams of bottom plates
- inspection of drain plugs
drydocking technical (machinery)
• cleaning of coolers and heaters
• o’haul of large electric motors
• balancing of rotating equipments as reqd.
• o’haul of machinery as reqd
• recheck alignments of machineries if disturbed.
• remove deficiencies in automation and control equipmen as reqd.
drydocking instrumentation and navigating equipments
• callibration of electrical switchboard meters/other electrical and mechanical measuring devices
• o’haul of main breakers and callibrating safety trips.
• rectify deficiencies in navigating instruments
• rectify deficiencies in safety systems if any.
drydocking prior flooding(important items prior flooding)
- all tank drain plugs are inspected and vacuum tested after fitment
- all anodes are functional
- sea chest gratings etc are secured
- correct ballast is taken.
- inspect rudder (water box) / propeller /rope/ guard
- all cargo/ballast tanks are clean from remnants of steel work
- cargo lines etc pressure tested / pumps are tried out
- all tank valves (if remote operated) are tried out
- hatch covers etc and other type of cargo gear are tried out and properly secured
- all sea chests are properly purged of air
- all equipment in engine room are tried out
- main engines/boilers are preheated and ready for trials
drydocking sea trials
• sea trials
- engines are run to required speed, movements are checked.
- steering is confirmed to be performing satisfactory
- stern tube oil is checked for maintaining level.
• the vessel may proceed to sea on satisfactory completion in some cases