report is a general statement of when the ship arrived, why it is in drydock, the work the shipyard did on it, and any problems not resolved. When work in the drydock has progressed to the point  that  its  completion  can  be  accurately  forecast,  the ship is scheduled to be undocked. The docking officer directs   all   arrangements   for   undocking.   When preparations are complete, the docking officer orders the dock flooded to a point that lacks about 2 feet of lifting the ship from the blocks. Flooding is stopped. Each shop that worked on underwater parts of the ship checks its work for tightness, and the ship’s personnel make an overall check of the watertight integrity. Reports of satisfactory condition are made to the docking officer before he will resume flooding. The docking officer is in direct charge of the undocking until the bow crosses the sill. INCLINING  EXPERIMENTS We will explain inclining experiments at this point because they are often done when the ship is floating steadily  in  a  flooded  drydock.  These  experiments  also may   be   done   in   any   calm   water   where   heavy weight-moving equipment is available. The experiment consists  of  moving  known  weights  certain  specified distances across the deck and recording the angles of heel produced. The data are then used to calculate the vertical position of the center of gravity. When a ship is constructed, all components used in construction  are  weighed  and  the  data  are  used  to calculate  the  vertical  position  of  the  center  of  gravity. The data are then confirmed by an inclining experiment carried out on the first completed ship in the class. The experiments  are  then  repeated  periodically  on  typical ships of that class throughout the life of the class. NAVSEASYSCOM orders inclining experiments on certain ships to learn whether the center of gravity has shifted since the ship was commissioned, and why. The purpose is to determine any rise in the center of gravity due to added weight over a period of years and to  compute  the  effect  of  this  rise  on  the  stability characteristics  of  the  ship. DOCK AND SEA TRIALS The section on Ship Trials that appears later in this chapter  gives  more  information  on  trials.  We  will discuss dock trials and sea trials here because they are normally carried out following most major repairs or alterations. The  ship’s  CO  directs  the  engineer  officer  to conduct a dock trial as soon as possible after repairs or alterations have been completed. The purpose is to determine  the  condition  of  the  electrical  and  main propulsion plants. The ship superintendent witnesses the trial. If there are any problems, the ship superintendent must have them corrected and hold another trial. They repeat  this  process  until  all  problems  are  resolved. A sea trial is held as soon as possible after the dock trial  has  been  completed  if  the  shipyard  commander  (or SUPSHIP) and the ship’s CO consider it necessary. The ship’s CO conducts the sea trial on those repairs or alterations he feels should be tested. A sea trial includes a full-power trial unless the ship’s CO wants to wait until new machinery parts have been run in and crew training will support the trial without fear of damage. READINESS FOR SEA The  TYCOM  normally  allots  the  ship  a  readiness for sea (RFS) period immediately after the overhaul is completed. The ship’s force uses this time to return the ship  to  unlimited  operational  status.  The  RFS  period normally will be less than 7 days, and it may be omitted if there is an immediate operational need for the ship. The  shipyard  may  not  use  this  time  to  complete unfinished  overhaul  work.  If  the  shipyard  needs additional  time,  it  must  ask  the  TYCOM  for  an extension, and it must finish the work before the RFS period  begins. DEPARTURE REPORT The  planning  department  of  SUPSHIP  or  the  naval shipyard submits a departure report within 60 days after an overhaul is completed. This report tells all interested activities what overhaul work was scheduled, how much was completed, and what it cost. A departure report serves the following purposes: (1) The ship can correct records showing its material condition (2) TYCOM can evaluate the overhaul and adjust accounts allotted to its administration,  and  (3)  the  responsible  SYSCOM  can learn what alterations were done and what they cost. SHIP  TRIALS The Navy requires ship trials to determine such things as performance characteristics, readiness for service,  the  extent  of  needed  repairs,  the  adequacy  of completed repairs, and the most economical rate of performance  under  various  conditions  of  service.  This information on ship trails is quite broad. If you expect to  take  part  in  any  of  the  trials,  study  the  general 9-19