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.
Engineers Bell Book
The Engineers Bell Book, NAVSHIPS 3120/l, is a
record of all bells, signals, and other orders received by
the throttleman for movement of the ships 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
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
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
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