ltw mk15 operation manual_vol 2 rev c

8/10/2019 LTW MK15 Operation Manual_vol 2 Rev C

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Light Weight Taut Wire Mk 15B Operation Manual

2

Documentrevisions

Written by Checked by Approved byRev.Date Sign. Date Sign. Date Sign.

A 21/9-04 SL 25/9-04 HT 30/9-04 SL

B 14/5-08 SL 15/5-08 HT 26/5-08 SL

C 29/10-08 SL 30/10-08 HT 31/10-08 SL

D


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Table of contents

1 INTRODUCTION..........................................................................................................5

2 ABBREVIATIONS ........................................................................................................6

3 TECHNICAL DATA .....................................................................................................7

3.1 Operational Specifications ........................................................................................7

3.2 System Accuracy.......................................................................................................7

4 TECHNICAL DESCRIPTION..................................................................................... 9

4.1 Principle of Operation .............................................................................................23

4.2 Hydraulic System .................................................................................................... 12

4.3 Winch System..........................................................................................................13

4.4 Tension Compensating System ...............................................................................13

4.5 Control System........................................................................................................13

4.6 Heating System........................................................................................................14

5 OPERATION................................................................................................................ 15

5.1 Setting in Operation................................................................................................. 17

5.2 Parking..................................................................................................................... 21

5.3 Adjusting Wire ........................................................................................................23


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Document History

Rev AInitial Issue

Rev B Revised fig. 5.2 Optional Remote Control Panel and table 5.2 Remote

Control Panel Button Functions both available from SN BAN-090.

Rev C Revised chapter 5, Operation; due to change of operation terminal.


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1INTRODUCTIONThe Taut Wire is a position reference system intended for a

deck-mounted, starboard or portside position, on most surface vessels.

The purpose of the Taut Wire is to give accurate input data, related to

vessel movement, to the vessel's data processing system to calculate

vessel position corrections.

The purpose of this manual is to provide the user a general

understanding of the principles, and instructions for operation of the

MK15 Taut Wire System.

Note All technical description, information and specification given in thismanual are subject to change without further notice.


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2ABBREVIATIONS

Abbreviation Explanation

DC

DP

KM

LTW

PLC

TB

Direct Current

Dynamic Positioning

Kongsberg Maritime

Light Weight Taut Wire

Programmable Logic Controller

Terminal Board

TW Taut Wire

UPS Uninterruptible Power Supply


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4TECHNICAL DESCRIPTION

4.1 Principle of Operation

The purpose of the Taut Wire is to give accurate input data, related to

vessel movement, to the vessel data processing system to calculate

vessel position corrections.

The Taut Wire system is fundamentally electro-hydraulic-pneumatic

and requires electrical and air supply from the vessel.

The wire rope, although thin to reduce the "offsets" caused by

underwater current disturbance, is strong enough to heave the weight

with a safety factor of 400 percent. Control of the system is effected

from either of two control panels; main control panel (local) or optional

bridge control panel (remote).

The wire rope is tightened against the depressor weight (on the seabed)

with a constant tension by means of a pneumatically and servo electric

"mooring" control system. Any movement of the vessel in either or

both of the X (alongship) or Y (beam) co-ordinates, will cause a

deviation of the tensioned wire rope from the vertical. This deviation

activates potentiometers mounted in the gimbal (sensor) head and

produce changes of analogue data directly proportional to the X-Y

inclination of the gimbal head.

The analogue wire length measurement is obtained from a measuring

device driven by the moving wire.

The DP system contains an accurate model of the dynamics of the

vessel which simulates the vessel's response to various forces e.g. wind,

wave and current disturbance.

Deviations in the specified position of the vessel (detected by changes

above analogue input parameters) will be processed by the software

model to generate appropriate corrective commands to the vessel's

propeller and rudder system.


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FeedForward

GainOptimum

Wave and CurrentDisturbance

Wind

WeightDepressor

RudderPropeller/

Command

+

+

StateMeasured

Taut Wire

Figure 4.1 Principle of DP System Operation


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Figure 4.2 Taut Wire Main Parts


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4.2 Hydraulic System

The Hydraulic System operates the boom between the parked and theoperating position.

The system is powered by a small hydraulic power unit, and is

automatically controlled and operated by the PLC system.

The hydraulic system gear pump is driven by a 3-phase, 440 V, 60 Hz,

1.5 kW AC motor IP class 56.

Hydraulic oil tank has a capacity of 10 litres Mobile DTE 13 M or

equivalent

Figure 4.2 Cabinet Door Removed


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4.3 Winch System

The winch lower and hoist the depressor weight to and from the seabed.

The winch is powered by a electrical powered servomotor, and theservo system is equipped with a fail-safe magnetic brake located

between the servomotor and the gear.

The system is automatically controlled and is operated by the amplifier

and the PLC.

Electrical power are from the vessels own supply.

A MDFRARS 132 Mx4 IP 66 Special Asynchron Servomotor, giving

84Nm at 2030 rpm/18 kW powers the winch drum. Max. moment is

168 Nm.

The SEW gear system (gear ratio 1:12) is bringing the maximum torqueup to 1200 Nm.

4.4 Tension Compensating System

The system activates the electrical powered servomotor whenever the

wire tension is deviating from the set-point in mooring mode.

Compensating cylinders air pressure is manually set and automatically

controlled by the pressure regulator. Actual pressure is indicated on the

manometer. Wire tension is directly related to the cylinder air pressure

i.e. increased pressure gives increased tension and visa versa.

Pressurised air is from the vessels own supply.

Wire tension is recorded by the load cells (2) located under the wire

angle compensator and visualized on a gauge located on the local

operating panel.

4.5 Control System

The hydraulic and winch drive systems are automatically controlled

and operated by a Telemecanique TSX Micro PLC system.The local control panel, is situated on the taut wire cabinet R/H side

and has the following equipment

Main power switch

PLC terminal

Mooring indicator lamp

Mooring tension indicator (optional)

Joystick for manual hoisting and lowering


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5OPERATION

Figure 5.1 Local Operator Panel

Button Display Action

Hoist Wirelength: 0 m

TW Control Hoist Hoisting weight.

Stop Wirelength: 0 m

TW Control TW Stopped

Activating brake.

Lower Wirelength: 0 m

TW Control Lower Lower weight.

Boom In Wirelength: 0 m

TW Control Boom In Boom to parked position.

Boom Out Wirelength: 0 mTW Control Boom Out Boom to operating position.

WireAdjust

Codeword: 0

New Wire : 0 m

Adjusting wirelenght after cutting and newwire installation.

LocalControl

TW Control TW Ready LTW manually controlled from local panel

BridgeControl

Bridge Control TW ready LTW manually controlled from bridge

ResetAlarm

Resetting alarms

Alarm

Page

Alarm history

Table 5.1 Local Control Panel Button Functions

Local

Control

BandakDate Time

Wirelenght Out (m)

0

TW READY

Hoist

Stop

Lower Boom In Boom

Out

Wire

Ad ust

Bridge

Reset

Alarm

Alarm/Warnin


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Figure 5.2 Optional Remote Operator Panel

Button Display Action

F 1 Wirelength: 0 mTW Control Hoist

Hoisting depressor weight.

F 2 Wirelength: 0 m

TW Control TW Ready

Activating brake.

Controlled braking

F 3 Wirelength: 0 m

TW Control Lower

Lower weight.

F 4 Bridge Control TW Ready Bridge Control Selected

ENTER N/A N/A

ESC N/A N/A

Table 5.2 Remote Control Panel Button Functions


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Figure 5.3 Operational Mode

The starting procedure is for safety reasons solely effected from the

Taut Wire Control Panel, but the Taut Wire Control may be transferred

to the Bridge Control Panel (option) where it remains throughout the

positioning operation.

Note Hydraulic power will only be available when BOOM OUT, or BOOMIN mode is activated, and 10 seconds after


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STEP PROCEDURE COMMENT

1 Check air lubricating system Fill up with Mecman oil if necessary

2 Drain and pressurise tensioncompensating system.

3 bar is theoretically corresponding to 200 kptension (appox. 4.2 bar = 300 kp)

NOTE!

Do not exceed recommended pressure limits asthis may result in damaged gimbal head andloss of depressor weight.

3 Check wire rope for proper alignmentwith regard to wire guide wheels etc.

4 Set MAIN SWITCH to "ON" CONNECTING is displayed throughout the PLCself test program.

WARNING!

Do not operate buttons or joystick before TWREADY is displayed.

5 Press HOIST Check that weight is stabilised in weight catcher.

WARNING!

Never activate Stop prior to operating the boom. Ifdoing so, the brake will be activated and the boomin/out movement will most likely cut the wire.

NOTE!

With reference to the warning above, its vital thattaut wire is still in HOIST mode during boom in/outoperation to allow wire to be paid off the drum.

6 Check that WIRELENGTH 0 m is displayed before

proceeding to next step. Please see table 5.3.3.


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5.2 Parking

For both practical and safety reasons this procedure is effectedsolely from the local panel.

Note This procedure should always be carried out at completion ofevery operation before attempting to move the vessel to a new

operational area.

WARNING Due to the boom over-centre position when parked, theDepressor Weight is part of the boom locking system and

must not be removed unless the boom is mechanically

secured.

Figure 5.4 Parked Mode


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1 Press Local Control TW CONTROL is displayed.

2 Press "WINCH HOIST" Winch starts hoisting.

Hoisting speed reduces to 0,3 m/s the last 3 metre.

NOTE!

"WINCH HOIST" can be overridden by the joystick.

For safer hoisting and better weight control it isrecommended to stop weight a few meters belowthe water surface and manually hoist the weight up

to the weight catcher. Note also that the lastmeters of hoisting have reduced speed.

Check that weight is secured in catcher beforeproceeding to next step.

If joystick is used to override the hoist function,stop mode is activated when joystick is released.(Zero position)

WARNING!

Before BOOM IN, ensure that taut wire is inHOIST mode.

3 Press "BOOM IN" NOTE!

The boom can be stopped in any position

4 Operate the joystick and manuallylower the weight into the basket.

WARNING!

For safety reasons, use manual lowering only.

5 Turn MAIN SWITCH to "OFF" position

6 Close and secure panel door

7 Drain water from air reservoir and airpressure regulators

NOTE!

In case of long operation stops, depressurise airsystem.


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5.3 Adjusting Wire

NOTE!

This procedures are used for resetting wirelength whenever new wire is

installed/cut or if the wirelength displayed differ from the actual situation.

5.3.1 Installing new wire


1 Turn MAIN SWITCH to "ON" Wait till "T W READY" is displayed.

2 Using joystick unwind old wire Disconnect wire both from depressor weight andwiredrum.

3 Spool on new wire using Joystick

Keep a tension of 100-150 kp when spooling onwire to prevent the wire from penetrating the layerson the wiredrum.

4 Connect wire to the depressor weight

5 Pull in the slack and hoist the weightinto the weightcatcher and then lower itback to the cradle.

It might be an usefull safety action to lower theweight into the sea till the last layer is visible on thewiredrum and then pull it up again.

6 Press Wire Adjust Keep pressed till new menu is displayed.

7 Insert code 7533 and enter

8 Press New Wire Keep pressed till new menu is displayed

9 Insert new wirelength 500 alternatively 700 meters

10 Press Main Returning to main menu.


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5.3.2 Cutting wire

NoteThis procedure is calculating remaining wire on the drum after cutting.


1 Turn MAIN SWITCH to "ON" Wait till "T W READY" is displayed.

2 Using joystick, unwind wire

3 Cut off necessary length of wire and re-attach wire to weight

4 Using joystick, pull in wire slack.

5 Press Wire Adjust Keep pressed until new menu is displayed.

6 Insert actual m cut and press enter

7 Press Main Returning to main menu

5.3.3 Wirelength 0-point reset


1 Press Wire Adjust Keep pressed till new menu appears

2 Press Reset Wirelength


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ltw mk15 operation manual_vol 2 rev c

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