Universal Crane Model for the Ship Design System E4...model for the ship design process, In order to...

1 Copyright © 2014 by ASME

Proceedings of the ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering

OMAE2014

June 8-13, 2014, San Francisco, California, USA

OMAE2014-23499

UNIVERSAL CRANE MODEL FOR THE SHIP DESIGN SYSTEM E4

Hendrik Vorhölter*

Mareval AG Hamburg, Germany

Email: [email protected]

Jakob Christiansen HeavyLift@Sea GmbH

Hamburg, Germany Email: [email protected]

Hannes Hatecke Hamburg University of Technology (TUHH)

Hamburg, Germany Email: [email protected]

* Address all correspondence to this author

ABSTRACT For the ship design system E4 a universal crane model was

developed. With the help of this model the design of crane

vessels and cranes can be harmonised better and lifting

operations can be analysed more precisely. The model is able to

handle any type of cranes which are used in the shipping and

offshore industry and provides the input for every simulations

method within E4 which needs to consider crane operations.

Special focus was given on keeping a common user interface

both for the designer of a crane vessel and the planning

engineer for lifting operations independently of the type and

functionalities of the crane. Such a universal crane model has

not been implemented in any other ship design software until

now.

In this article the motivation for the development of the

model is described together with the requirements for a

universal crane model. The principle of the model explained

and its functionality is demonstrated in several examples.

Keywords: Ship Design, Software, Offshore, Lifting, Crane

INTRODUCTION In recent years more and more heavy lifting crane

operations in the offshore industry have been performed by

floating vessels. On the one hand, the oil and gas industry is

exploring deeper water depth where the use of jack-up or fixed

platforms is not feasible any more. On the other hand, the

offshore wind industry requires cost efficient solutions for

heavy lifting operations. In order to increase the usability and

the operational range of floating crane vessels new ship designs

have to be developed and the reliability of the prediction of the

operational capability for lifting operations has to be increased.

In most cases the crane and the vessel on which it is

installed are designed independently from each other. This is for

several reasons: Very often the crane and the vessel are

designed from independent companies or the crane shall be

suitable for the installation on different ship types and vice

versa. Hence, the crane is very often incorporated into the ship

design process only by its required space, weight and a load

chart. But if the operational capability of a crane vessel in

offshore lifting operations shall be driven to its maximum, ship

and crane have to harmonised in their dynamic behaviour. This

requires an integrated crane model for the ship design process,

which most ship design systems do not have.

In order to overcome this problem a universal crane model

was developed as part of the joint research and development

project “HoOK” for the ship design system E4 [2]. The aim of

the HoOK project is to provide an integrated simulation tool for

lifting operations with ships for the early ship design as well as

the planning of lifting operations offshore and inshore (see also

[3]). The aims of the HoOK project are described below. This is

followed by a description of the ship design system E4 and its

underlaying philosophy. After defining the requirements for a

universal crane model the implemented crane model is

described. The article concludes with some application

examples and an outlook on future work.


FIGURE 1. PLATFORM LIFTING WITH FLOATING SHEER LEG MATADOR 3

FIGURE 2: INSTALLATION OF A TIDAL TURBINE WITH A CONVENTIONAL HEAVY LIFT CARRIER SIETAS TYPE 183 (COPYRIGHT SAL HEAVYLIFT GMBH)

R&D PROJECT HOOK There are a large number of different tools for the

simulation of different aspects of transport and installation

operations. But, there is a lack of comprehensive, fast and

reliable simulations tools that are suitable for the early design

and planning phase. In order to fill this gap, the research and

development project “Hochsee-Operationen mit Kranen”

(Offshore operations with cranes) – in short “HoOK” – has

been started in spring 2013 (see also [3] and [7]). It aims at the

development of new simulation tools for offshore lifting

operations. The project consortium consists of the ship design

office HeavyLift@Sea, the Institute of Ship Design and Ship

Safety of the Hamburg University of Technology (TUHH) and

the marine consultancy office MAREVAL as project

coordinator. In this consortium, the different strengths of the

three partners are combined: MAREVAL’s experience in

offshore operations and offshore technology, HeavyLift@Sea’s

experience in the design of heavy lift vessels and the

competence of TUHH in the development of software for

dynamic ship simulations. The project is scheduled for a three

year period and is funded by the German Federal Ministry of

Economics and Technology in its program “Maritime

Technologien der nächsten Generation” (“Next-Generation

Maritime Technologies”).

SHIP DESIGN SYSTEM E4 E4 is a ship design system especially developed for the

early design phase. The early design phase in the ship building

industry is characterized by extremely short lead times for a

rather complex task. Within a few days or weeks all key

elements of the ship and its major systems have to be analysed

with respect to their functionality, weight and space

requirements as well as costs. This can only be achieved by the

coordinated work of experts from various disciplines.

Therefore, the main features of E4 are multi-user functionality,

the use of a common data base for all embedded tools and the

use of first principal based direct simulation methods already

for the early design. The design of the common data base

follows the philosophy that only the original data is stored. Any

information which can be derived from the original data quickly

is generated only if it is required.

The embedded tools in E4 can address all topics which are

part of the traditional work of a project department or design

office, e.g. hull form development, loading conditions, intact

and damage stability as well as speed power performance. But

manoeuvring, dynamic positioning and sea keeping analysis

both in frequency and in time domain can also be performed

with E4.

Until now no explicit crane model exists for E4. Crane

operations can only be analysed by modifying the light ship

weight distribution and the loading conditions manually. This is

for some hydrostatic analysis sufficient but with low

performance. And for dynamic analysis it is inadequate. The

crane model to be developed shall provide the common data

base for the description of cranes and crane loads for any

analysis tools used in E4. Additionally the crane model shall

comply to the needs of tools to be developed in the future. For

instance, within the HoOK-project a module will be developed

which allows the chronological description of lifting operations

including water ballast operations.

REQUIREMENTS FOR A UNIVERSAL CRANE MODEL The first step for the development of a universal crane

model is to define the requirements for the model. Most of the

requirements are a consequence of the above described

philosophy of E4 and the aspired use of the model. The

requirements identified by the project consortium are as

follows:

The model shall be suitability for the early design

phase which requires simple modelling of the basic

cases like a single hook operation of one crane and the


possibility for fast modifications of the key parameters

like the load or outreach.

Advanced simulations require more detailed

information about the velocities and limits of the crane

components, which need to be provided.

It must be possible to handle all types of cranes used in

the shipping and offshore industry, like pedestal crane

and A-frames, cylinder and wire luffing cranes,

knuckle-boom and gantry cranes.

The necessary input must be restricted to data, which is

available for the ship designer, i.e. no internal know-

how from the crane manufacturer should be required.

The definition of a crane and crane load with its

functionality and geometry must be quick via a user

interface.

The model must be suitable for modelling and

handling multiple cranes or hooks lifting operations.

Data transfer from one project to another must be

possible like the replacement of the crane information

within one project.

The model must be able to compute the equilibrium

condition for the free hanging load with the resulting

loads for the crane(s) and tugger winches.

For advanced high-performance time domain

simulations it maybe necessary to generate adopted,

simplified models automatically from the available

information.

The model must provide mass, COG and mass moment

of inertia as well as upper block position and free rope

length at any time during a lifting operation for time

domain simulations.

There should be different modes for the control of the

crane, e.g. direct control by defining geometric

properties like a luffing angle or indirect control by

defining a lateral position on and a height above the

deck for the hook.

Fulfilling these requirements implies that the crane model

consists of a data basis and a set of basic functionalities. These

functionalities are for instance used to compute the equilibrium

condition for the free hanging lifting gear.

DEVELOPMENT OF THE MODEL In order to be able to develop a universal crane model

which can be adapted to different crane types and lifting

operations one has to ask oneself what the common definition

of a crane is. The dictionary says that a crane is “a device for

lifting and moving heavy objects, typically consisting of a

moving boom, beam, or gantry from which lifting gear is

suspended” [5]. The definition implies that in order to be able

to model a crane one must be able to model one or several

bodies, which can be manipulated in their alignment with

respect to other bodies or the ship. Furthermore, one needs to

model lifting gear and further gear for the manipulation of the

bodies. Whereas the lifting gear consist of pulleys, which of

course can be multi-reeven.

As the model should not be used as a crane design tool, the

crane bodies and wire ropes are handled as rigid for a start. The

consideration of the stiffness of the crane would require detailed

information about the crane structure. But this information is

usually not available for a ship designer or operator. And for the

largest part of possible lifting operations neglecting of the

stiffness is acceptable as long as the precise modelling of the

moment of lift-off and touch-down is not required.

In the following the key elements of the crane model are

described, which are the kinematic model, the actuators for

manipulating the model, the solution scheme for the

determination of the equilibrium condition as well as the

controlling mechanisms.

Kinematic Model

The kinematic model of the crane is set up by rigid bodies

which are coupled to each other. Each body of the crane has one

parent body, which can be the ship, and each body can have

multiple child bodies. Each body has its one local coordinate

system. The COG and moment of inertia of the body and further

vertices as well as the geometry are defined in this local body

frame. A geometry description is used for the visualisation and

for the determination of wind loads. The position and

orientation of the child body is defined relative to a vertex of

the parent body via translatory and rotatory offsets in the local

body frame. The offsets can either be fixed, or manipulable, or

the respective degree of freedom (DOF) can be free. If a DOF is

fixed between two bodies, this results in a coupling force or

moment in the respective axis direction. With this model the

kinematics of a single crane can be described. If multiple hook

operations on one load should be possible it is required that one

body can be coupled to multiple bodies. These additional

couplings result not only in coupling forces but also in

kinematic constraints. This will be explained with the following

example.


Body 1 Body 2

(Parent)

Body 3

(Child)

Defining Vertex

Vertex 1Vertex 2

Vertex 3

Vertex 4

Kinematic offset and kinetic coupling

Kinetic coupling and kinematic constraint

x

y

z

x

y z

x

y z

FIGURE 3: BODY WITH COUPLING TO TWO OTHER BODIES

Figure 3 shows the model of a spreader bar (body 3)

hanging on the hooks of two different cranes (bodies 1 and 2).

In this case body 2 shall be the parent body of body 3 in the

kinematic model. Thus, the kinematics of the rigid body 3 is

defined by the rotation of the body frame of body 2 into the

body frame of body 3 and the offset vector between the vertices

2 and 4. For the kinetic coupling between body 2 and 3 it is

assumed that the translatory DOF are suppressed whereas the

rotatory DOF are free. The second coupling of body 3 is

between vertices 1 and 3. For this coupling also the translator

DOF shall be suppressed whereas the rotatory DOF shall be

free. The sum of the number suppressed DOF from the two

couplings must be less or equal six, which is given in this case.

Otherwise the load balance for the body would not be solvable.

As the kinematics of body 3 is already defined with respect to

body 2, the second coupling between vertices 1 and 3 leads the

already mentioned kinematic constraint. This requires that thile

seeking the equilibrium position of body 3 not only the load

balance must be fulfilled but also the offset between vertex 1

and vertex 3 must be kept as defined by the user.

The modelling scheme is similar to models used in the

analysis of multi-body systems in the robotics. Further details

can be found amongst other by Woernle [9]. As the model is

rigid precautions have to be made that the model cannot be

overdetermined, as mentioned above in the example.

Actuators

As stated above the offsets between the bodies can be

manipulable. For these manipulations actuators are defined. For

a start three types of actuators are included in the model. These

are pulleys, cylinders and slewing gears, which are described in

detail below. Dynamic simulations require also information

about the allowable speed for the actuators. The maximum

allowable speed is defined depending on the actuator load, as

most heavy lift cranes are restricted in this way.

Pulleys consist of a rope with a start and an end point. The

start and end point are either thimble or winches. The rope can

be reeven around multiple sheaves. Each sheave or winch is

defined by a vertex in a body, an axis and a diameter. The

definition of the thimble requires only the body and vertex. The

enlacement of the rope around the sheave follows the right hand

rule around the defining axis. As the position of the vertices is

known from the kinematic model the mass and COG of the

pulley can be determined with a weight per length of the rope.

Figure 4 shows a pulley starting from the winch touching three

sheaves and ending at a thimble.

Body 1

Body 2

Sheave 2

Thimbel

Winch

Sheave 1

Sheave 3

Defining Vertex

Defining Axis

FIGURE 4: MULTI-REEVEN PULLEY WITH WINCH, SHEAVES AND THIMBLE

For some types of crane like offshore knuckle-boom cranes

not every sheave is touched by the rope at any time (see also

Figure 9 and Figure 10). These sheaves need to be identified

automatically. The load acting on the pulley is computed from

the load balance of all bodies (see the following section also).

Therefore, the pulley’s load is considered in the balance at

every thimble, winch or sheave in the direction of the rope. For

the sheaves it is considered twice: at the point of arrival and at

the point of departure.

The catenary of the ropes or chains is neglected, as for

usual crane configurations the catenary is small during

operations.

Cylinders are defined as a link between two vertices of

two bodies. The cylinder is acting as a coupling force between

these two vertices.


Body 1

Body 2

Cylinder

Defining Vertex

Defining Axis

FIGURE 5: DEFINTION OF A CYLINDER BETWEEN TWO BODIES

Figure 5 shows the definition of a cylinder between two

vertices of two bodies. The axis of the cylinder is defined by the

actual position of the two vertices. The diameter of the piston

rod and barrel are only required for the visualisation.

Slewing gears are modelled as a moment of force acting

on the two coupled bodies. The axis of the moment is defined

by the plane of the slewing gear.

Determination of the Equilibrium

The most essential part of the crane is the lifting gear. The

lifting gear consists of one or several hooks which are lowered

by a pulley from a upper block which is attached to a beam. The

distance of the hook to the beam is controlled with the pulley.

But the rotational DOF of the hook with respect to the beam are

usually free within certain restrictions. The hook aligns itself in

the equilibrium condition. For a single hook lift, i.e. one piece

of load attached to one hook, the static equilibrium is defined as

the position in which the combined centre of gravity of the load,

the hook and the lifting gear is below the upper block in the

direction of gravity. In case of multiple hook lifts, i.e. several

hooks of one or multiple cranes are attached to one load, the

computation of the equilibrium can be more complicated. This

is especially the case if tugger winches are used as well as

diagonal pull or varying heel and trim conditions need to be

considered.

A solution for the above described problem for the static

condition lies in solving the load balance for the multi-body-

system. Therefore, for each body the load balance is set up in

all six DOF. The balances are combined in one equation system,

which than can be solved. The coupling forces and moments as

well as the actuator loads are the free variables. During the

generation of the crane model care has to be taken that the

system is not under-determined. Over-determination has to be

considered due to the usually high number of free DOF.

Furthermore, the non-linearity of the pulleys needs to be

considered. A pulley can only bear tensile loads, compressions

loads are not possible. If this should be considered, non-linear

solving schemes need to be used and the user has to be warned

of slack lines.

The equations system is solved for the actually defined

kinematic description of the multi-body-system. If the crane

system is not in the equilibrium, this results in a defect for the

solution. This is also the case if the kinematic constraints for the

bodies attached to multiple bodies are not fulfilled. By

performing an outer iteration in which the not fixed kinematic

couplings are varied, the load balance is equalised. With this

solving scheme the static equilibrium for any crane system

defined with the model described above can be found.

Controllers

The various types of crane which are used in the heavy lift

and offshore industry allow different types of operations. A way

has to be found that these different types of operations can be

modelled easy in the ship design or lifting operations planning

process. A simple example for this problem is that in the

kinematic model the position of the hook is defined by the

distance between the hook and the upper block on the jib. The

designer or operator usually does not want to define this

distance but for instance the height of the hook above the deck.

Therefore, controllers are introduced in the model. The

controllers regulate the actuators depending on reference

quantities. These references quantities can be for example the

height of the hook above deck or the angular deflection of a

spreader bar with respect to the ship’s axis. It is also possible to

define controllers which act on several actuators depending on

the same number of reference quantities.

APPLICATION OF THE MODEL In the following four examples for the application of the

model are presented. The first example is a simple model for

the early design, followed by a detailed crane model for a heavy

lift vessel and the model of a knuckle-boom-crane of an

offshore construction vessel (OCV). The last example is a

multi-hook operation with a floating sheer leg while lifting an

offshore platform.

Simple Model for the Early Design

The effort which can be spend in the early design phase for

modelling is very restricted. Therefore, it is absolutely

necessary to have a model with limited input parameters. But,

still all required computations for instance with regard to ship

stability or longitudinal strength must be possible. A simple case

for the early design could be for example a wire luffing,

revolving crane with a single hook, as this is the most common

crane in the shipping industry. The model of the crane would

consist of four bodies, which are the crane column, the crane

house, the jib and the hook. If the crane is adapted from a

previous project only the following input would be required.


Height of the crane column and crane house as well as

length of the jib

Weight and COG of the four bodies

Weight and COG of the load

Geometric properties and drag coefficients, if wind

loads need to be considered

The crane has two single reeven pulleys one for the jib and

one for the hook. Controllers are defined for the regulation of

the three actuators depending on the slewing angle, the outreach

and the hook height above deck. But, these parts of the model

remain probably the same for each project, and can therefore be

adapted. Figure 6 shows the visualisation of the crane model.

For the each body the defining vertices, the COG and the body

frame are shown. The data for the crane is given in the Annex.

FIGURE 6: SIMPLE CRANE MODEL FOR THE EARLY DESIGN

With this crane model the reaction forces and moments at

the crane base can be computed for different positions of the

crane and varying floating conditions. Figure 7 shows the

reactions forces and moments depending on the slewing angle

for the crane with a load of 160 t and a luffing angle of 45°. The

necessary input data for the crane is shown in the annex. The

reactions are computed for a floating condition with 5° heel to

port side and 5° trim on the bow. The x-axis is pointing towards

the bow, the y-axis to port side and the z-axis upwards. A

slewing angle of 0° is pointing towards the bow and 90°

towards port side. The origin is at the base point of the crane

column.

-10

12

34

56

-40

-30

-20

-10

010

20

30

0 90 180 270 360

Re

acti

on

forc

es

[MN

]

Re

acti

on

mo

me

nts

[M

Nm

]

Slewing angle [°]

Mx My MzFx Fy Fz

FIGURE 7: REACTION FORCES AND MOMENTS DEPENDING ON THE SLEWING ANGLE

It can be seen that the reaction forces are independent from

the slewing angle whereas the moments vary with a phase shift

of 90° as it was expected. The x-moments are not zero for 0°

slewing and the y-moments for 90° slewing due the heel and

trim of the vessel.

Detailed Model for Heavy Lift Vessel

If the capabilities of a crane vessel shall be utilised to the

maximum for a heavy lifting operation, simulations performed

in beforehand must be as precise as possible. This requires

more detailed models of the crane, as described in the example

above. The second example is such a detailed crane model for

a Sietas Type 183 heavy lift vessel [4] with two NMF DK IV

Heavy cranes with 1000 t lifting capacity at 16 m outreach [6].

The cranes have two hooks, one main hook and one auxiliary

hook, which can be manipulated independently from each other.

The complete reeving of the cranes is considered in the model.

Thus, the correct loads on the ropes can be computed for any

lifting configuration.

Figure 8 shows the situation during a lift operation when a

load, which is longer as the distance between the two cranes, is

slewed inboards.


FIGURE 8: SLEWING LONG LOAD INBOARDS WITH SIETAS TYPE 183 VESSEL

OCV with Knuckle-Boom Crane

For offshore operations a wider spectrum of cranes is used.

Very often knuckle-boom cranes are used. One advantage of

knuckle-boom cranes is that they allow to keep the distance

between the jib tip and the water surface constant within a

certain outreach range. Therefore, the hoist ropes is usually

guided by two sheaves at the tip of the jib as shown in Figure 9.

Depending on the alignment of the second jib the hoist rope

touches only one or both of these sheaves.

FIGURE 9: OCV KNUCKLE-BOOM-CRANE AT HIGHER OUTREACH

This is shown in the third example which is the knuckle-

boom offshore crane of the OCV BOA Sub C [1]. Figure 9 and

Figure 10 show the crane in two different positions. The

outreach is varied by unfolding the beams without varying the

hook height as it is done typically for knuckle-boom cranes. It

can be seen that depending on the outreach the sheave which is

last touched by the rope varies. It has to noted, that this is done

automatically without user interference.

FIGURE 10: OCV KNUCKLE-BOOM-CRANE AT LOWER OUTREACH

Multi-Hook Operation with Floating Crane

The forth example is for demonstrating the full

functionalities of the new developed crane model. Therefore,

the lifting of the topside from an offshore platform with the

floating sheer leg “Matador 3”[8] was remodelled. The lifting

operation was performed on the North Sea in spring 2013 and is

shown in Figure 1. The crane model itself consists of 15

different bodies for the A-frame, the span bracing, the flying jib,

and the four hooks and the blocks for the pulleys. For the lifting

operation two spreader bars have been used to regulate the

distance between the two main hooks and the two hooks on the

fly jib respectively. These spreader bars, the platform and the

shackles are modelled as additional bodies which are coupled to

the hooks and the platform. The grommets are modelled as

pulleys without sheaves. In the model the luffing angle for the

A-frame and the flying jib as well as the hook height for each of

the four hooks can be controlled independently.


FIGURE 11: TOTAL VIEW OF THE SHEER LEG MODEL WHILE LIFTING THE PLATFORM

FIGURE 12: DETAIL VIEW OF UPPER BLOCKS OF THE SHEER LEG MODEL

CONCLUSIONS AND OUTLOOK Harmonising the capabilities of crane vessels and cranes in

the ship design requires a crane model for the ship design

software. The needs from the ship design process and the

planning process for lifting operations lead to requirements for

such a crane model. In the presented work a universal crane

model was developed for the ship design system E4, which

fulfils the defined requirements. The model delivers the

necessary input for the simulations tools within E4 whenever

crane operations need to be considered.

Future work within the HoOK project will focus on the

development of simulations tools for complete lifting operations

in time domain. Therefore, loads and movements caused by

waves, current and wind will be considered. Concerning the

model it has to be evaluated whether the stiffness at least of the

ropes needs to be considered.

NOMENCLATURE COG Centre of gravity

DOF Degree of freedom

Fi Reaction forces at the crane base in direction i

Mi Reaction moment at the crane base around

axis i

OCV Offshore construction vessel

ACKNOWLEDGMENTS We would like to thank our co-workers in the R&D project

HoOK with special thanks to Prof. Dr.-Ing. Stefan Krüger.

Furthermore, we would like to thank the German Federal

Ministry of Economics and Technology which provided funding

for the R&D project in its program “Maritime Technologien der

nächsten Generation” (“Next-Generation Maritime

Technologies”).

REFERENCES

[1] BOA, 2009. “BOA Sub C”. Boa Group. Trondheim.

Norway.

[2] Bühr, W., Keil, H., Krüger, S., 1988. “Rech-

nereinsatz im Projekt“. Jahrbuch der Schiffbau

Technischen Gesellschaft 82. p 352 et seqq. Springer-

Verlag. Berlin, Heidelberg. Germany. (in German)

[3] Shipbuilding Tribune, 2013. “Germany: Research Pro-

ject HoOK Underway“.

http://shipbuildingtribune.com/2013/05/23/germany-

research-project-hook-underway/ [Online; accessed

20-November-2013]

[4] SAL Heavylift, 2013. “MV LONE Ship’s Particulars”.

SAL Heavylift GmbH. Hamburg. Germany.

[5] The free dictionary, 2013.

http://www.thefreedictionary.com/Crane [Online; ac-

cessed 25-11-2013]

[6] TTS NMF, 2010. “Heavy Cargo Crane Super Lift

DKSL 1000016”. TTS-NMF GmbH. Hamburg. Ger-

many. (not published)

[7] Vorhölter, H., Günther, J.-H., 2013. “Direct Simula-

tion of Offshore Lifting Operations”. Offshore Wind,

Vol IV, No 04 October 2013. pp 34-38. Rotterdam.

The Netherlands.

[8] Vuyk Engineering, 2007. “Matador 3 Capacity Dia-

gram”, Bonn & Mees. http://www.bonn-


mees.com/36/matador-3.html / [Online; accessed 25-

November-2013]

[9] Woernle, C., 2011. “Mehrkörpersysteme – Eine

Einführung in die Kinematik und Dynamik von Sys-

temen starrer Körper”. Springer-Verlag. Berlin, Hei-

delberg. Germany. (in German)

ANNEX A: DATA FOR SIMPLE CRANE MODEL

TABLE 1: DESIGN DATA FOR SIMPLE CRANE MODEL

Dimension Value

Column height 10 m

Column COG 5 m

Column weight 50 t

Crane house height 20 m

Crane house COG 10 m

Crane house weight 150 t

Jib lenght 20 m

Jib COG 10 m

Jib weight 75 t

Hook weight 5 t

Sheave diameter 0.5 m

TABLE 2: LOAD CASE PARAMETER

Dimension Value

Luffing angle 45°

Distance hook jib tip 20 m

Load mass 160 t

Heel 5°

Trim 5°

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