Yokogawa CMZ-700 Gyrocompass
YOKOGAWA DENSHIKIKI CO., LTD.
Refurbished
The YOKOGAWA CMZ-700 Series Gyrocompass is a marine navigation system developed to provide stable and accurate true-heading information for ships and distribute that heading to connected bridge equipment.
The CMZ700 family includes documented variants:
CMZ700B
CMZ700S
CMZ700D
with the main compass assembly identified as:
MKM022 Master Compass.
The photographed SM MARINE SERVICE™ unit clearly shows the characteristic CMZ700 master-compass enclosure with the gyro/container assembly exposed inside and the front operation section marked:
GYROCOMPASS
GYRO HEADING
RUN
EXT
FAIL
The product is part of the legacy Yokogawa Denshikiki Co., Ltd. / YDK marine-navigation family.
A gyrocompass determines true north using a rapidly rotating gyroscope together with the effects of gravity and the Earth’s rotation.
Unlike a magnetic compass, it is not primarily dependent on Earth’s magnetic field.
This makes the gyrocompass an essential reference source for many bridge systems.
The CMZ700 supplies heading information to equipment such as:
Yokogawa literature describes the CMZ700 as a marine gyrocompass designed for stable heading measurement, improved follow-up performance and distributed heading output.
The three major documented configurations should be treated separately.
CMZ700B is the basic configuration.
Manufacturer literature describes the B version as driving repeater systems directly from the master compass without requiring the larger control-box arrangement used in other configurations.
The basic system centers around:
MKM022 Master Compass
with optional supporting units according to vessel requirements.
CMZ700S uses additional control/interface equipment and supports expanded input/output requirements.
Technical/service documentation identifies:
MKC320 / MKC321 Control Box
with CMZ700 installations.
This configuration is useful where the vessel needs more heading distribution, external-sensor integration or additional interface functions.
CMZ700D is the dual-gyro configuration.
A dual installation provides additional redundancy by using two gyrocompass systems.
This is particularly valuable where heading availability is mission-critical.
The suffix should always be verified from the vessel documentation or equipment nameplate before ordering replacement components.
The primary master compass for the CMZ700 family is:
MKM022
Yokogawa service documentation explicitly identifies:
Master Compass – MKM022.
The master compass contains the key:
gyro/container assembly
anti-vibration mechanism
follow-up mechanism
heading sensing/control components
required to generate and track ship heading.
The photographs supplied by SM MARINE SERVICE™ show the internal gyro/container assembly clearly inside the MKM022-type cabinet.
One of the most important replacement items associated with CMZ-700 is the:
KT005 Gyrosphere
also searched as:
KT005 Gyro Sphere
KT005 Sensitive Element
A related exchange-service reference is:
KT005E.
SM MARINE SERVICE™’s existing technical catalogue identifies:
CMZ-700 → KT005 / KT005E Gyrosphere
while distinguishing the CMZ-900 family’s MKT007/MKT007E sphere.
This distinction is important because CMZ700 and CMZ900 gyrospheres should not be mixed simply because the gyro cabinets look similar.
The KT005E designation is used in marine-market documentation for an exchange gyrosphere associated with the CMZ500/CMZ700 family.
For exchange-basis supply, buyers should provide:
existing sphere type
gyro model
serial/nameplate information
condition of the old sphere
before shipment.
The gyrosphere operates inside the gyro container assembly.
A documented Yokogawa engineering change introduced a redesigned container for CMZ700 in 2005.
Yokogawa’s engineering-change document states that the newer complete container assembly could replace the original container as a whole, but warns that old/new upper and lower components should not simply be mixed individually.
That is an important servicing point:
replace according to the approved container combination, not by visual similarity alone.
Marine gyrocompasses must tolerate continuous vessel vibration and shock.
The CMZ700 documentation describes an improved anti-vibration structure using elements including:
universal joint
outer bellows damper
rubber isolator
bellows damping
to protect the gyro assembly and maintain heading performance.
This was an important design feature of the CMZ700.
The CMZ700 uses a lighter container design to reduce the load on the stepping/follow-up mechanism.
Yokogawa documentation reports a heading follow-up performance of approximately:
30°/second
compared with a slower earlier CMZ500 design.
This allows faster heading tracking during sharp vessel turns.
One of the key CMZ700 advantages is direct ship-battery operation.
Technical specifications give a standard main supply of:
24VDC
with an operating input range around:
20–30VDC.
This is useful because gyro heading can remain available from the vessel’s DC/navigation supply even if normal AC mains power is interrupted, depending on shipboard power design.
The documented optional AC adapter is:
MKR027
This allows the gyro system to be powered from AC mains.
CMZ700B documentation lists AC supply options including:
100VAC
110VAC
115VAC
230VAC
50/60Hz
when the optional adapter is used.
For replacement, the exact AC adapter input voltage must be verified.
Another important related unit is:
MKR024 Link Unit
The link unit expands system functionality and is associated with additional heading/sensor interfaces.
Technical documentation identifies it as part of the optional CMZ700B system configuration.
Useful buyer-search phrases include:
CMZ700 Link Unit
MKR024 Yokogawa
MKR024 gyro interface
When the appropriate optional interface/control equipment is installed, CMZ700 can perform automatic speed-error correction.
The system can use:
ship speed data
and
latitude data
to compensate for gyro speed/latitude-related heading error.
This is particularly useful for vessels operating over large latitude ranges.
A valuable CMZ700 feature is the ability to accept an external heading source.
Compatible external heading may come from equipment such as:
magnetic compass interface
GPS / satellite compass
and can be distributed to repeaters/connected equipment as a backup heading source.
This provides useful operational redundancy if the primary gyro heading becomes unavailable.
The CMZ700 system can also monitor the difference between:
gyro heading
and
external heading.
The optional link arrangement can generate a deviation alarm if the difference exceeds the configured limit.
This helps bridge personnel identify heading-source disagreement.
Heading from the master compass can be distributed to repeater compasses.
CMZ700 technical documentation identifies digital repeater output using a serial system related to:
RS422 / RS485 electrical characteristics
with heading data transmitted at:
4800 bps.
The serial data format is based on:
IEC 61162-1.
The CMZ700 documentation lists supported serial heading formats including standard marine navigation sentences.
This allows the gyro heading to be integrated with other bridge equipment such as radar, autopilot and navigation computers.
Therefore useful technical search phrases include:
CMZ700 NMEA heading output
CMZ700 IEC61162
CMZ700 RS422 heading
The CMZ700 family also uses the:
MKR050 Repeater Compass
as a related heading repeater.
CMZ700 technical documents list MKR050 separately as an approved repeater-compass component.
This is an important spare for bridge wings, steering positions and other locations requiring visible gyro heading.
The CMZ700 includes a built-in restart timer.
The documented timer can be set from:
1 to 99 hours.
This feature supports planned restart/operation behavior after power-related events according to system configuration.
A marine equipment reference for CMZ700B gives performance figures of approximately:
±0.25° static error
and
±0.75° dynamic error
for that configuration.
Actual onboard accuracy depends on installation, correction settings, maintenance condition, ship motion and operating environment.
CMZ700 technical documentation states compliance with the IMO gyrocompass performance standard:
IMO Resolution A.424(XI)
and associated Japanese standard requirements.
This is one reason the series was widely used aboard commercial ships.
The CMZ700 supplies true-heading data for:
Merchant vessels
Tankers
Bulk carriers
Container ships
Offshore vessels
Passenger vessels
High-speed vessels
and other ships requiring gyro heading for bridge navigation systems.
Marine radar uses gyro heading for functions such as:
true-motion display
target tracking
course stabilization
bearing calculations
An incorrect gyro heading can therefore affect radar presentation.
ECDIS relies on correct heading information to orient the vessel symbol and navigation display.
A faulty or unstable gyro can lead to heading discrepancies between the ship’s actual orientation and electronic chart display.
The autopilot uses heading feedback as one of its primary control inputs.
If CMZ700 heading becomes unstable, the autopilot may steer poorly or generate heading-source alarms.
AIS and VDR systems may also receive heading information from the ship’s gyro network.
Maintaining reliable CMZ700 heading output can therefore affect several bridge systems simultaneously.
Check:
24VDC input
navigation battery supply
breaker/fuse
power switch
internal power supply
AC adapter if fitted
before replacing the master compass.
Allow the gyro proper startup time and confirm that the container/gyro motor has started correctly.
If the system remains outside normal running condition, investigate internal power, gyro/container and control electronics.
A FAIL indication can be associated with several causes.
Check:
gyro/container condition
internal PCB status
power supply
follow-up mechanism
sensor connections
before assuming the gyrosphere itself has failed.
Possible causes include:
worn gyrosphere / sensitive element
incorrect supporting-liquid condition
mechanical container problem
follow-up fault
incorrect speed/latitude correction
The correct troubleshooting sequence should follow CMZ700 service documentation.
Check:
gyrosphere condition
container mechanics
latitude setting/input
speed-error correction
follow-up system
Gradual drift does not automatically mean the entire master compass must be replaced.
Inspect:
repeater output circuit
RS422/serial wiring
MKR050 repeater
link/control unit
output configuration
before disturbing the master gyro.
Check:
serial output
IEC61162 configuration
cable continuity
interface unit
heading sentence format
The master gyro can be operating correctly while an external heading-output circuit has failed.
If external-heading monitoring is configured, compare:
gyro heading
with
external magnetic/GPS heading.
A large deviation may result from either heading source, not necessarily the CMZ700.
Inspect the:
stepper/follow-up mechanism
gyro container freedom
mechanical damping system
motor/control electronics
The CMZ700 was specifically designed for smooth high-speed follow-up, so abnormal sluggishness warrants inspection.
Common replacement requirements can include:
MKM022 Master Compass
KT005 Gyrosphere
KT005E Exchange Gyrosphere
Gyro Container Assembly
MKC320 Control Box
MKC321 Control Box
MKR024 Link Unit
MKR027 AC Adapter
MKR050 Repeater Compass
MKN016 Connection Unit
Power Supply Modules
Inverter Assemblies
Control PCBs
Interface PCBs
Follow-Up Components
Cables & Connectors
The exact part number and revision should always be matched before installation.
Yokogawa CMZ700 and CMZ900 belong to related marine gyro families, but components should not automatically be considered interchangeable.
One particularly important distinction is the gyrosphere:
CMZ700 → KT005 / KT005E
CMZ900 → MKT007 / MKT007E.
This is a valuable buyer-search distinction because many ships maintain both generations across different vessels.
The CMZ700 was developed with improved follow-up characteristics compared with the earlier CMZ500 generation.
CMZ700 documentation reports approximately 30°/s follow-up versus around 12°/s for CMZ500.
Some exchange gyro references overlap the CMZ500/700 family, but full-system parts should still be checked individually.
SM MARINE SERVICE™ supports worldwide sourcing and supply of YOKOGAWA CMZ-700 gyrocompass systems and spare parts.
Depending on availability, equipment may be offered as:
New / New Old Stock
Used Tested Working
Refurbished
Reconditioned
Exchange Basis
Typical requirements include:
Complete CMZ700 Gyrocompass
CMZ700B / CMZ700S / CMZ700D
MKM022 Master Compass
KT005 / KT005E Gyrosphere
Gyro Container Assembly
Control Box
Repeater Compass
Link / Interface Units
Power Supply / AC Adapter
PCB Assemblies
SM MARINE SERVICE™ already maintains a dedicated YOKOGAWA CMZ-700 Gyrocompass product page and a separate CMZ-700 & CMZ-900 Gyrosphere technical page.
The CMZ700 remains installed on many vessels because it provides a complete conventional gyro heading solution with:
24VDC operation
heading distribution
external heading backup
speed-error correction options
repeater integration
stable marine gyro technology
When the existing bridge installation remains serviceable, replacing a gyrosphere, container, PCB or master unit can be significantly simpler than replacing the entire vessel heading architecture.
Marine service specialists continue to support CMZ700 repairs and spare parts, alongside CMZ900 and other Yokogawa gyro systems.
The CMZ-700 is a marine gyrocompass system used to generate and distribute true-heading information aboard ships.
The documented CMZ700 Master Compass is MKM022.
Documented variants include CMZ700B, CMZ700S and CMZ700D.
The principal replacement reference is KT005, with KT005E appearing as an exchange gyrosphere reference.
No. CMZ700 is associated with KT005/KT005E, while CMZ900 is associated with MKT007/MKT007E.
Standard operation is from 24VDC, with technical documentation giving approximately 20–30VDC input range.
Yes, with the appropriate optional AC adapter such as MKR027.
MKR024 is a related Link Unit used to expand CMZ700 interface/correction functions.
MKR050 is a Repeater Compass associated with the CMZ700 system.
Yes, this function is documented when the appropriate optional link/control equipment and ship-speed/latitude inputs are provided.
Yes. External heading from equipment such as magnetic or GPS-based heading sensors can be used as backup in configured systems.
Yes. CMZ700 documentation includes IEC61162-1 serial heading output and RS422/RS485-type transmission.
The documented timer can be set from 1 to 99 hours.
Yes, but engineering-change documentation shows that old/new container designs must be handled according to the approved complete-container replacement configuration.
SM MARINE SERVICE™ supports worldwide sourcing of CMZ700 complete systems, master compasses, gyrospheres and related spare parts subject to stock availability.
YOKOGAWA CMZ-700 Series Gyrocompass is a marine true-heading system available in documented CMZ700B, CMZ700S and CMZ700D configurations. The system uses the MKM022 Master Compass, with the KT005 / KT005E Gyrosphere as an important sensitive-element replacement reference. CMZ700 supports 24VDC ship-battery operation, digital repeater heading distribution, IEC61162 heading output, optional automatic speed-error correction, external-heading backup and a 1–99 hour restart timer. Related equipment includes MKC320/MKC321 Control Box, MKR024 Link Unit, MKR027 AC Adapter and MKR050 Repeater Compass. SM MARINE SERVICE™ supplies complete Yokogawa gyrocompasses, gyrospheres and navigation spare parts worldwide in new, used, refurbished and reconditioned condition.
SM MARINE SERVICE™
Marine Automation & Navigation Equipment Supplier
Available Condition:
• New Equipment • Used Equipment • Refurbished Equipment • Reconditioned Equipment
Stock Location:
• Bangladesh • China
Services:
• Worldwide Shipping • Technical Support • Spare Parts Supply • Marine Equipment Sourcing
Contact Information
SM MARINE SERVICE™ Samir Market, DT Road, Pahartali, beside CDA Market, Chattogram, Bangladesh
Mobile / WhatsApp / Viber: +88 01818 929292
Email: info@smmarineservice.com
Website: www.smmarineservice.com
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