he  or  she  relinquishes  command.  Completed  pages  of the  log,  filed  in  a  post-type  binder,  are  numbered consecutively.  They  begin  with  the  first  day  of  each month and run through the last day of the month. When the commanding officer (or engineer officer) directs a change or addition to the Engineering Log, the person directed must comply unless he or she believes the proposed change or addition to be incorrect. In that event, the commanding officer or engineer officer will personally enter his or her comments and sign the log. After the log has been signed by the the commanding officer,  it  may  not  be  changed  without  his  or  her permission  or  direction. Engineer’s Bell Book The Engineer’s Bell Book, NAVSHIPS 3120/l, is a record of all bells, signals, and other orders received by the throttleman for movement of the ship’s propellers. Entries are made in the Bell Book by the throttleman (or an assistant) as soon as an order is received. Entries are usually made by the assistant when the ship is entering or  leaving  port,  or  engaging  in  any  maneuver  that  is likely to involve numerous or rapid speed changes. This procedure  allows  the  throttleman  to  devote  his  or  her undivided attention to answering the signals. The   Bell   Book   is   maintained   in   the   following manner: 1.   A separate bell sheet is used for each shaft each day, except where more than one shaft is controlled by the same throttle station. In that case, the same bell sheet is used to record the orders for all shafts controlled by the station. All sheets for the same date are filed together as a single record. 2.  The  time  of  receipt  of  the  order  is  recorded  in column number 1. 3.   The   order   received   is   recorded   in   column number  2.  Minor  speed  changes  (generally  received  via revolution   indicator)   are   recorded   by   entering   the number  of  rpm  ordered.  Major  speed  changes  (normally received via engine order telegraph) are recorded using the  following  symbols: a.   1/3-ahead 1/3 speed b.   2/3-ahead 2/3 speed C.    I-ahead standard speed d.   II-ahead full speed e.   III-ahead  flank  speed f.   z-stop g.  B1/3-back  1/3  speed h.  B2/3-back  2/3  speed i.  BF-back  full  speed j.  BEM-back  emergency  speed 4.   The  number  of  revolutions  corresponding  to  the major  speed  change  ordered  is  entered  in  column  3. When the order received is recorded as rpm in column 2 (minor speed changes), no entry is made in column 3. 5.   The   shaft   revolution   counter   reading   (total revolutions) at the time of the speed changes is recorded in  column  4.  The  shaft  revolution  counter  reading-as taken hourly on the hour while underway-also is entered in column 4. For   ships   and   craft   equipped   with   controllable reversible pitch propellers, the propeller pitch in feet and fractions  of  feet  set  in  response  to  a  signaled  speed change,   rather   than   the   shaft   revolution   counter readings, is recorded in column 4. The entries for astern pitch are preceded by the letter B. Each hour, on the hour, entries  are  made  of  counter  readings.  This  helps  in calculating  engine  miles  steamed  during  the  time  the propeller pitch remained constant at the last value set in response  to  a  signaled  order. On ships with gas turbine propulsion plants, a bell logger provides an automatic printout each hour. This printout  is  also  provided  whenever  propeller  rpm  or pitch  is  changed  by  more  than  5  percent,  when  the engine   order   telegraph   is   changed,   or   when   the controlling station is shifted. Provision must be made for manual logging of data in the event the bell logger is out of commission (OOC). Before going off watch, the EOOW signs the Bell Book on the line following the last entry for his or her watch. The next officer of the watch continues the record immediately thereafter. In machinery spaces where an EOOW is not stationed, the bell sheet is signed by the watch  supervisor. NOTE:  A  common  practice  is  also  to  have  the throttleman sign the Bell Book before it is signed by the EOOW or his or her relief. The Bell Book is maintained by bridge personnel in ships  and  craft  equipped  with  controllable  reversible pitch  propellers  and  those  in  which  the  engines  are directly  controlled  from  the  bridge.  When  control  is shifted to the engine room, however, the Bell Book is maintained by the engine-room personnel. The last entry made in the Bell Book on the bridge shows the time that control is shifted. The first entry made in the Bell Book 1-2