12 Maintenance Inspection

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http://www.liebherr.com Offshore Division

12th North Sea Offshore Cranes &

Lifting Conference 2007

Maintenance, Inspection, Temporary

Cranes & Crane upgrades

Part 1 Maintainability of Cranes, Access to Components,

Standardisation of Component InterfacesPart 2 Condition Monitoring, Lubricant Analysis,

Oil Flow Monitoring

Part 3 Data Logging/Recording/Monitoring

Analysis and Value of Recorded Data

Part 4 Temporary/Mobile Cranes

What has to be considered?Part 5 Crane Upgrades

A real example

Version 1.0, dd. 17.04.07




Maintainability

Due to more stringent rules (i.e. exhaust emissions),

increased maintenance intervals, decreased size etc.,

installed components to cranes become more and more

complex. Maintenance and repair to the component on

site has become more difficult. Special tools and specific

knowledge is required and in most cases the environment

needed can not be achieved offshore. In addition, down

time of the crane shall be kept at a minimum.

New philosophies in regards to maintainability have

therefore to be considered for the latest generation of cranes.

Part1 Maintainability of Cranes




Standardise interfaces of componentsI.e. Standardised instrumentation via Can-Bus of diesel engine one

plug only. Access to main components by maintenance crane allows

replacement without another crane.


Un-park

maintenance crane

Lift engine to deck

Remove radiator

and hoodEnginereplacement

Slew gearbox

replacement




Standardise interfaces of componentsSimplified and standardised interfaces allow a quick and

problem free replacement of the whole component.

I.e. Standardised winch flanges with four pins. No special

tensioning equipment required. Winch is installed to allow

exchange without major lifting equipment.


Remove bolted diagonals Replace winchRemove pins from winch

flange




Condition Monitoring

Mainly external measuring equipment like vibration

analyses, noise analyses or oil sampling are considered

as condition monitoring.

All this monitoring is prone to failure, oil samples might be

taken from the wrong port or are not taken at all.

However, they are a tool for evaluating the condition of

any component and in some cases the only option for a in

situ evaluation.

It is therefore important to implement in line monitoring

without any interaction of the operator/user.

Part2 Condition Monitoring




Lubricant Analyses

Lubricant analyses are a good and simple measure for

condition monitoring but when not carefully taken a

completely wrong result can be created.

The latest control systems are offering monitoring without

any interaction of the operator/user assuring the exact

same measurement/sampling method.

I.e. In line flow monitoring, allows constant monitoring

of all hydraulic components. Together with a machine

data recorder (refer to part 3 of this presentation) adatabase of the leak oil development is created.





In Line Oil Flow MonitoringThe leak oil is a direct indication of wear which gives a

good and reliable indication of the current condition of all

installed hydraulic motors and pumps. No additional

measurements are required.


Principle Layout for a hydraulic flow monitoring system.

00,5

1

1,52

2,53

3,54

4,55

5,56

6,57

7,58

D ES C RI P TI O N a u x. h o is t

m o t o r n o . 1

a u x . h o ist

m o t o r n o . 2

m a i n h o i s t

m o t o r n o . 1

mai n h o i s t

m o t o r n o . 2

l u f f i n g m o t o r s l e w i n g g e a r

m o t o r n o . 1

s l e w i n g g e a r

m o t o r n o . 2

L e a k O il ( m a x . ) L e a k Oil

L e a k O i lM e a s u r e me n t( l e a k o i l p e r m in u t e w it h 1 0 0 b a r s y s t e m p r e s s u r e )

A m o u n t i n L i t re s P e r U n it

D at e o f R un ni n g D ES CR IP T IO N T yp e I de nt . No . M a x. A ll ow a bl e A ct u al D if fe re nc e

In sp ec ti on H ou rs Le ak Oil (m ax . ) Le ak Oil in %D at e o f R un ni n g D ES CR IP T IO N T yp e I de nt . No . M a x. A ll ow a bl e A ct u al D if fe re nc e

In sp ec ti on H ou rs Le ak Oil (m ax . ) Le ak Oil in %

a ux . h oi st mo to r n o. 1 A 2F 80 5 102 29 614 2 ,0 0 0 ,0 0% a cc ep ta bl e

au x . h ois t m o to r n o . 2 2,00 0, 00% acc ep ta bl e

m ai n h oi st m ot or no . 1 A 2F 12 5 5 102 29 714 3 ,0 0 0 ,0 0% a c ce pt ab le

m ain ho i s t m o tor no . 2 3,00 0, 00% acc ep ta bl eluf f ing m ot or A 2F 90 2,50 0, 00% acc ep ta bl e

s le wi ng g ea rm ot or no . 1 A 2F 45 5 102 29 514 1 ,5 0 0 ,0 0% a cc ep ta bl e

s le win g ge ar mo to rno .2 A 2F 45 1, 50 0, 00% ac cep ta bl e




Existing Data Logger Limited information such as time, average weight of lift is

recorded. The information content is very limited.

Part3 Data Logger

date load cycle time start time end

TT.MM.JJ No. hh:mm:ss hh:mm:ss

24.03.1998 0 09:38:13 09:39:55

24.03.1998 1 09:41:46 09:42:41

24.03.1998 2 09:44:24 09:45:36

24.03.1998 3 09:48:03 09:48:23

24.03.1998 4 09:55:59 09:57:08

24.03.1998 5 09:59:25 10:00:35

24.03.1998 6 10:01:45 10:02:44

24.03.1998 7 10:04:12 10:06:0224.03.1998 8 10:07:33 10:09:03

24.03.1998 9 10:10:42 10:12:03

24.03.1998 10 10:13:52 10:14:40

cy cle time average load max load

average load

plus dead weight

22t

utilization

hh:mm:ss (t) (t) (t) (%)

00:05:15 18,7 50 40,7 115,6

00:03:33 7,9 40,4 29,9 93,2

00:04:51 13,7 43,2 35,7 99,8

00:08:16 4,8 33,6 26,8 77,7

00:04:35 10,6 44,8 32,6 103,5

00:03:30 5,9 47,2 27,9 109,1

00:03:26 7,8 45,1 29,8 104,1

00:05:11 17,7 49 39,7 113,100:04:39 7,3 51,9 29,3 120

00:04:31 14,2 44 36,2 101,6

00:07:35 5,9 38,6 27,9 89,2




Machine Data Recorder (MDR)

What is a MDR?

MDR is the permanent measurement and recording of

machinery conditions using the existing instrumentation.

The recording contains loading spectrum and maximum

values for main components of the crane.

Unlimited information which can be used for

maintenance, condition monitoring without guessing and

assumptions.

Gives data for all installed components.

Part3 Machine Data Recorder




Data recorded via existing instrumentation

- All rights reserved - E. & O. E -

Master

CPU

Ethernet/RS232

CAN 1...4





Maximum Value Recorder 10 maximum values inclusive of date and time are

recorded.

At the same time when maximum value arises, also

additional parameters will be recorded to describe the

environmental field

Load Spectrum Recorder The monitored process variable (i.e. load) is subdivided

into categories.

During operation the process variable usually passes

through several categories in which the time of stay will

be summed up.





utilization MDE [%]

start time 31.05.2001 15:54:28stop time 30.08.2001 08:44:54

date time utilization MDE [%] outreach LML [m] operation mode load l.m.l. [to] slewing angle [°]

%MD1.73 %MD1.24 %MD1.8 %MD1.18 %MD4.18

MDutilizationMde MDoutreachLML MDoperationMode MDloadLML SDVslewingAngle

31.07.2001 10:26:01 106.81 38.70 8 55.00 131.54

05.07.2001 20:47:58 106.59 36.55 8 59.25 72.45

07.08.2001 04:43:10 106.36 42.99 8 47.48 79.97

05.07.2001 21:32:02 105.64 38.64 8 54.51 73.44

30.07.2001 09:19:53 105.49 38.96 8 53.80 64.67

26.08.2001 09:19:00 104.98 40.62 8 50.61 49.10

20.06.2001 03:29:21 104.95 38.34 8 54.74 44.33

20.06.2001 03:10:29 104.26 37.05 8 56.82 48.51

08.07.2001 00:02:42 104.14 36.95 8 56.99 96.21

09.07.2001 03:46:11 103.02 38.98 8 52.50 144.86

10 maximum valuesof recorded process variable


Maximum Value Recorder 10 maximum values inclusive of date and time are

recorded.

At the same time when maximum value arises, also

additional parameters will be recorded to describe the

environmental field




monitored

process variable

summed up

time shares


Load Spectrum Recorder The monitored process variable (i.e. load) is subdivided

into categories. During operation the process variable usually passes

through several categories in which the time of stay will

be summed up.




Possible use of MDR data, results

Recorded Stress

Cycles

Stress Cycle

Spectrum

Expected RestLife Time of

Component

Classification

according to FEM





Results from recorded data:

Power Spectrum


Power Spectrum per Speed

Speed Spectrum




Ø Multi Dimensional

Analyses

Ø Exact details about

Load Spectrum

Ø Preventive

maintenance based

on real and actual

utilization/usage of

each installed

component


Results from recorded data:

Slewing angle versus loadSlewing angle versus load




Summary of Machine Data Recording:

The machine data recording is permanently recording data of the

condition of the crane. The data recorded and analysed will be

supportive for the evaluation of the condition, utilisation and theoretical

calculated remaining life time of components.

The data recorded supports and is used for

establishing major maintenance and service intervals accordingto FEM, DIN, BS or equivalent standards

establishing of strategic and preventative maintenance

remaining life time calculations

analyses of crane data, i.e. heavy load and overload situations

- All rights reserved - E. & O. E -





Temporary/Mobile Cranes used offshore! What has to be considered?

In the recent past, we have been approached more and more to use mobile/crawler

cranes as temporary lifting aids offshore.

Part4 Temporary Cranes

However there is a big

difference between such a

standardised land based

machine compared with an

offshore crane.

Since the offshore standards

have become more and more

stringent, many points have to

be considered before such a

crane can be used offshore.





Rough comparison

Offshore Cranes Land based mobile/crawler crane

- Certified material and welding - Material certification not traceable

- Failure Mode Charts required - Free standing machine not connected

to platform structure

- AOPS/MOPS required - AOPS/MOPS not installed, hoisting

speed not sufficient

- Big cabins with specific access - Small cabins used, required exits and

requirements access size not according to offshorerules

- Emergency lowering required - Emergency Lowering not installed

- Dynamic load charts considering - Land based load charts only

offshore wind speeds, off- and side

leads and heel/trim considered

- Emission standards - New machines will fulfil requiredemission standards, but certification

is generally not available





Other issues

The maximum allowed deck loads to be considered, crawlers

and other free standing machines are generally quite heavy

(counter weight). Edge loads implemented to the deck are

therefore quite high which requires a heavy structure

distributing the forces to the deck.

Cabin is positioned very low which causes many blind lifts.

For cranes designed for an onshore environment, corrosion

protection has to be specifically checked (i.e. slew pinions

outside).

Conclusion

Based on the above, a lot of effort is required to allow using

a crawler/mobile crane for an offshore application (off site

lifts), still requiring a lot of compromises. In many cases it is

more practical to use an offshore crane on a suitable frame

or a temporary pedestal as a temporary solution.

The minimum component weight for the installation has been

found to be similar for both offshore and crawler/mobile

cranes.




Part5 Crane upgrade

Why to upgrade an existing crane:

Changes of requirements

Higher reliability Unavailability of spare parts (obsolete)

Shorter delivery time as a new crane

Difficulties replacing entire machine (restricted lifting aids, access, etc.)

It is more cost efficient (existing crane in very good condition, crane is very big, etc.)

Possible upgrades:

Power pack

Control system

Load Indicator / Moment Limiter

Increase of Lifting Capacity

Upgrade of man riding capability

Upgrade to suite new rules

Boom extension

More speed




Part5 Crane upgrade

Basis of such a Project:

Review/Availability of Crane Documentation

Review of requirements/ownersspecification/scope of work

Crane survey (if required)

Example:

Crane Model: Monarch 6032

Capacity: 21,8to at 8m, 2-fall operation

Requirements:

Replace of existing winches with wet running

drive splines and additional brakes

Install a new hydraulic open loop system

Install a new LML/SLI (Mipeg 2000 Type)

Install new electrics as required (Including winchrotation indicators)




Existing Winch

New Winch

Part5 Crane upgrade

Requirements:

Replace hoisting and luffing winch against new winch

New winch with

wet running drive splines

additional brakes (suitable for man riding)

winch frame




Part5 Crane upgrade

Requirements:

Install a new hydraulic open loop system for hoisting and luffing circuit and a separate

closed loop for the slewing circuitNew pumps and hydraulic motors

New radiator and filtration system

New Joysticks

Use existing tank and under floor piping from tank to pumps




Part5 Crane upgrade

Requirements:

Install a new LML/SLI

Mipeg 2000 recording

New load cell and angle sensor

New rope sheave to suite new load cell

Install new electrics

Winch rotation indicators

Control panel




Thank you for your attention.

12 Maintenance Inspection

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