- S E L F -P R O P E L L E D - M I N E - C O U N T E R - C H A R G E -

 

Self propelled Mine Counter Charge
1. General characteristic

Self propelled Mine Counter charge is used to identify and destroy naval mines. Its target can be located at least 300m from a launch point. Typical mission profile calls for identification and destruction of a target detected by other means. Normally it will be detected by means of mine hunter's bow sonar. Missions against targets stored in data bases is also very likely.
SMCC is a disposable, torpedo like, small remotely operated vehicle. It carries mine disposal equipment to detected and classified target. While target is identified by vehicle sonar and TV camera this equipment is used to initiate mine explosive. Specific feature of one of SMCC versions is vertically oriented shaped charge. For the shaped charge or semi armor piercing (SAP) gun, an aiming procedure is required. This is achieved using SMCC maneuvering abilities and laser aiming device. While properly aimed, the device is triggered by means of coded signal sent from operators console. Accidental triggering of a mine fuse also means mission success.
If the disposal device is not triggered by the operator, during a defined time, the SMCC computer neutralizes the fuse and is able to flood its pressure hull with sea water.

SMCC is available in two versions. Version armed with a mine counter charge, is a disposable, single mission device. Training and reconnaissance version of SMCC is identical, with exception for lack of the charge. It is recovered after a training or reconnaissance mission has been finished.

2. Navigation

Mine counter mission consists of a few distinguished periods. It starts with a short launch phase followed by transition to target area. Constant tracking of SMCC position is critical in transition phase. Tracking is accomplished by means of acoustic transponder/responder. It is fixed to vehicle body and responds to ultra short base line navigation system or ships mine hunting sonar. Relocation phase in friendly environment lasts a few minutes. While struggling with strong currents it can take 15 minutes for the SMCC to reach a target area. To facilitate operator work in this phase, an automatic control procedure can be selected. This integrates data from tracking system, vehicle data and navigation data of the mission platform (ship). Together with environmental information (currents) these data allow for calculation of optimum path and vehicle parameters. During next mission phase, the target must be found using vehicle sonar and TV camera.. Auto heading and auto depth/altitude are usually utilized but manual control is compulsory in this phase.. This is also true for the following identification and aiming phases.

3. SMCC system completion

Basic set delivered is composed of the following elements:

SMCC (armed) in transporting case 10 pcs
SMCC (training) in transporting case 2 pcs
Operators console 1 pc
Launcher in transporting case 1 pc
Launcher winch 1 pc
Launcher lifting cable 1 pc
Recovery net 1 pc
Hydroacoustic navigation system
antenna 1 pc
Maintenance equipment set 1 pc
Spare parts set 1 pc

4. Technical specification

Operating depth: 200 m
Maximum speed: 3 m/s
Range: 500m
Mission duration time (total maximum) 30 minutes
Mine disposal device:
1. Shaped charge with 2kg of explosive, vertically or horizontally mounted
2. Qinetiq's SAP projectile gun
3. Other devices up to 8kg mass
External dimensions of SMCC:
-length total : 1,400m (1,600m armed with SAP gun)
-width with stabilizers: 0,360m
-height with stabilizers: 0,360m
Mass: 45,0kg
Buoyancy: +1,0N to 2,0N
Propulsion:
-four, 3 blade screw propellers in horizontal plane, electrically driven, 50 W power each
-single vertical thruster, electrically driven 3 blade screw propeller in a tunnel, 50 W power

Energy source: Lithium ion accumulator battery
nominal voltage: 24V
nominal capacity:16Ah C1

Controls: Remote, computer aided, using single optical fibre of 2000m length
Mass of SMCC and optical fibre dispensers
in transporting case: 60,0 kg

Basic components of SMCC

4.1 Mine disposal devices
SMCC is prepared to carry two types of mine disposal devices. They are located in vehicle bow section. Less expensive is shaped charge. It is metal lined to increase capability to initiate mine explosive charge. Depending on target specification, shaped charge is pointed horizontally or vertically. Vertical charges are used against moored and partly buried mines. Qinetiq designed SAP projectile gun is installed as alternative. It is understood that the gun is more effective against non sensitive explosives and mines buried in sediments. Charge type and orientation is being selected according to local conditions.


4.2 Observation and navigation equipment
To achieve high navigation accuracy, SMCC system uses comprehensive set of navigation equipment. Different devices are of prime importance during mission phases defined below. USBL hydroacoustic navigation system leads vehicle during transition to a target area. Diving depth and altitude are measured simultaneously. While in the area, scanning sonar and TV camera provide required information. Complete set mounted on the vehicle consists of:

1. Two B&W TV cameras
2. Three lamps
3. Scanning sonar
4. Two laser aiming devices
5. Magnetic compass with pitch and roll sensor
6. Echosounder as altitude meter
7. Pressure sensor as depth meter
8. Transponder/responder for hydroacoustic navigation
4.3 Pressure hull
Majority of SMCC vehicle components are installed inside a single pressure hull. It consists of cylindrical body closed by bow and stern, covers. The covers provide all pressure penetrations and support all internally mounted devices. This way components are divided between two interconnected units that can be mounted after completely assembled. Bow section contains battery and mine counter charge while rear is devoted to control computer and propulsion motors. The pressure hull is streamlined externally with plastic covers that are built around sonar head and optical fibre dispenser.

4.4 Vehicle Controller
Vehicle control system consists of several components both inside and onboard the ship.
The vehicle part is composed of: SMCC on board computer
Signal multiplexer
Arming and safety module
The on board computer collects sensor data and sends information to operator's console. The console returns commands that are used to govern speed of propellers and other actuators.

4.5 Pitch control
SMCC is basically neutrally trimmed. This condition is checked before packing. During transit phase of a mine counter mission, required pitch is achieved by means horizontal propellers thrust control. To allow accurate aiming, large pitch angles may be required. This is accomplished by means of internal ballast, that changes vehicle centre of gravity. Accumulator battery, moved by stepping motor, is used for this purpose. Angles of up to 30 are achieved steplessly.

5. Operator's console
SMCC is controlled by trained operator. He uses navigation data, sonar and television image . To allow operator to concentrate on a single screen, most important data are overlayed on TV signal. His work is further supported by navigation computer that integrates data from the hydroacoustic navigation system and platform's (ship) navigation sensors. It can also run several automatic procedures and use information from a ships mine hunting sonar. SMCC can be controlled using two types of consoles. Both are build of the same modules and runs the same software.

 

5.1 Permanently installed Operators Console
Operators Console is designed to be permanently mounted in ships operating room. It is integrated with ships command and navigation system. Console's steel enclosure is composed of several modules with external dimensions that allows transport through 600mm door openings. Modules located above control panel contains four 12”
LCD displays, Trackpoint II command module and TV signal management equipment. Two screens are used for TV signals from SMCC and launcher or deck. Two other screens accept SVGA signals from sonar and navigation computers.
A single screen console is also available. It uses large size high resolution LCD to display four scalable windows. Membrane keyboard can be replaced with a touch sensitive configurable LCD panel

Console contains the following computers in separate enclosures:
1. Control computer
2. Sonar computer
3. Navigation computer
4. Built-in trainer simulator computer
5. Sonar head simulator (optional)
6. Second TV image simulator

 

Single screen operators console

The following devices are
mounted on a control panel
and used to command the
system:
! Control keyboard
! Sonar control terminal
! Two axis joystick A
! Single axis joystick B
! Arming and firing unit

Selected command function can be switched to the portable controller to help in deck operations.

5.2 Portable operator's console
Portable operator's console can be mounted on ship of opportunity, helicopter or ashore. Four 10” LCD screens are used to reduce size and weight. The built in trainer computer has been removed for the same reasons. Functions of other components are the same or similar.

Basically operator's console case contains:
1. Control computer 2. Sonar computer
3. Navigation computer 4. Optical communication components

The permanently mounted console contains command module of hydroacoustic navi-gation system, video recorder, remote control unit receiver and UPS. In a case of portable system, these components are supplied as separate units. This allows easy arrangement of required components in confined spaces.

5.3 Remote controller
Portable remote controller is a part of operator's console. It is a convenient device, used by deck personnel to control SMCC while floating at the surface. Principally it is utilised to lead the training vehicle into the recovery net. It is also very helpful during pre-dive and post-dive check procedures. The remote controller contains a radio transmitter. It sends signals read by microprocessor from two joysticks and buttons. Components are enclosed in a sealed, fibre reinforced plastic box. Receiver within operator's console transfers control signals to computer system, using RS232 wire link.

5.4 Vehicle movement control
Two analogue joysticks and a keyboard is used to control the SMCC in water space. Settings are read by console control computer, processed and sent to vehicle computer via RS232, implemented on fibre optic link. The on board computer controls all the vehicle functions including propulsion electric motors and stepping motor driving a ballast weight.

5.4.1 Control in transition phase
During transition at relative speed of 2m/s to 3 m/s, SMCC movements are articulated by means of changes of speed of propellers. Vertical thruster and trimming ballast are not in use. To change thrust vector of propulsion propellers operator uses single two axis joystick (A) located on right side of the console. Automatic guiding procedure can replace operator in this phase of a dive.

5.4.2 Control during approach, identification and aiming
High demands to maneuvering abilities during these phases calls for use vertical thrusters and trimming ballast. Their operation is executed manually by means of buttons (ballast) and left side mounted joystick. Vehicle trim can be changed statically, using movement of ballast weight (battery) or dynamically, adjusting thrust of propulsion propellers. 5.6 Launch
SMCC is launched using dedicated equipment. It consists of a SMCC launcher and an electro-mechanical winch. The winch is used to lower the launcher with suspended vehicle close to a sea bottom. The launcher uses electrically operated catchers to firmly hold the vehicle. Launch procedure can be monitored by operator by means of launcher mounted TV camera. While free from the launcher the SMCC swims to a target area carrying one of the optical fibre dispensers. Other fibre dispenser is fixed to the launcher. A fins are mounted at down stream end of the launched body. The fins direct launcher against a current, to assure the SMCC is always launched with a current. The solution was selected to protect optical fibre against damage, caused by waves and sea currents and platform (ship) movements.

 

5.6 Launch
SMCC is launched using dedicated equipment. It consists of a SMCC launcher and an electro-mechanical winch. The winch is used to lower the launcher with suspended vehicle close to a sea bottom. The launcher uses electrically operated catchers to firmly hold the vehicle. Launch procedure can be monitored by operator by means of launcher mounted TV camera. While free from the launcher the SMCC swims to a target area carrying one of the optical fibre dispensers. Other fibre dispenser is fixed to the launcher. A fins are mounted at down stream end of the launched body. The fins direct launcher against a current, to assure the SMCC is always launched with a current. The solution was selected to protect optical fibre against damage, caused by waves and sea currents and platform (ship) movements.

5.7 Recovery
It is assumed that training and reconnaissance version of SMCC is recovered after a dive. To allow this operation, without use of a boat, a recovery net is provided with the system. This is suspended on a ship's crane and lowered to water surface. The net frame floats on the surface, while the net itself, forms a bag. To assure required shape net edges are ballasted with chain, Deck operator drives the vehicle into the net using portable control unit. With the vehicle inside the bag, the net and is lifted to the ships deck.

 

5.8 Cases for transport and storage
Components of the SMCC system are delivered and stored in dedicated protective cases. The cases are strong enough to be stacked in several layers. Each SMCC, enclosed in air tight polyethylene bag, rests on the a supporting frame that can pulled off after its case cover is opened and removed. It gives easy approach to any vehicle stacked in warehouse, ship's hold or on open deck.

 

GDANSK UNIVERSITY of TECHNOLOGY, FACULTY OF OCEAN ENGINEERING & SHIP TECHNOLOGY,
DEPARTMENT of SHIP DESIGN and SUBSEA ROBOTICS
80-233 Gdańsk, ul.Narutowicza 11/12, Poland
ph. (48 58) 347 19 91, fax: (+48 58) 347 26 99, e-mali: sek8oce@pg.gda.pl