MAN B&W S65ME-C8.2-GI-TII, Project Manual

Page: 351 / 395

MAN B&W 18.06
Page 3 of 6
MAN Diesel MAN B&W ME/MEC/GI engines 198 67 265.5
Bearing Wear Monitoring System
The Bearing Wear Monitoring (BWM) system mon-
itors all three principal crank-train bearings using
two proximity sensors forward/aft per cylinder unit
and placed inside the frame box.
Targeting the guide shoe bottom ends continu-
ously, the sensors measure the distance to the
crosshead in Bottom Dead Center (BDC). Signals
are computed and digitally presented to computer
hardware, from which a useable and easily inter-
pretable interface is presented to the user.
The measuring precision is more than adequate to
obtain an alarm well before steel-to-steel contact
in the bearings occur. Also the long-term stability
of the measurements has shown to be excellent.
In fact, BWM is expected to provide long-term
wear data at better precision and reliability than
the manual vertical clearance measurements nor-
mally performed by the crew during regular serv-
ice checks.
For the above reasons, we consider unscheduled
open-up inspections of the crank-train bearings to
be superfluous, given BWM has been installed.
Two BWM ‘high wear’ alarm levels including devia-
tion alarm apply. The first level of the high wear /
deviation alarm is indicated in the alarm panel only
while the second level also activates a slow down.
The Extent of Delivery lists four Bearing Wear
Monitoring options of which the two systems from
Dr. E. Horn and Kongsberg Maritime could also
include Bearing Temperature Monitoring:
4 75 261 Bearing Wear Monitoring System XTSW.
Make: AMOT
4 75 262 Bearing Wear Monitoring System BDMS.
Make: Dr. E. Horn
4 75 263 Bearing Wear Monitoring System PS-10.
Make: Kongsberg Maritime
4 75 264 Bearing Wear Monitoring System OPEN-
predictor. Make: Rovsing Dynamics
ME, ME-C and -GI engines are as standard spe-
cified with Bearing Wear Monitoring for which any
of the above mentioned options could be chosen.
Bearing Temperature Monitoring System
The Bearing Temperature Monitoring (BTM) sys-
tem continuously monitors the temperature of the
bearing. Some systems measure the temperature
on the backside of the bearing shell directly, other
systems detect it by sampling a small part of the
return oil from each bearing in the crankcase.
In case a specified temperature is recorded, either
a bearing shell/housing temperature or bearing oil
outlet temperature alarm is triggered.
In main bearings, the shell/housing temperature or
the oil outlet temperature is monitored depending
on how the temperature sensor of the BTM sys-
tem, option: 4 75 133, is installed.
In crankpin and crosshead bearings, the shell/
housing temperature or the oil outlet temperature
is monitored depending on which BTM system is
installed, options: 4 75 134 or 4 75 135.
For shell/housing temperature in main, crankpin
and crosshead bearings two high temperature
alarm levels apply. The first level alarm is indicated
in the alarm panel while the second level activates
a slow down.
For oil outlet temperature in main, crankpin and
crosshead bearings two high temperature alarm
levels including deviation alarm apply. The first
level of the high temperature / deviation alarm is
indicated in the alarm panel while the second level
activates a slow down.
In the Extent of Delivery, there are three options:
4 75 133 Temperature sensors fitted to main bear-
ings
4 75 134 Temperature sensors fitted to main bear-
ings, crankpin bearings, crosshead bear-
ings and for moment compensator, if any
4 75 135 Temperature sensors fitted to main bear-
ings, crankpin bearings and crosshead
bearings