International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

A MATERIAL DISTRIBUTION SCHEDULING FOR RIGGING SHIP-HULL BLOCKSWITH PIPESK Noda, S Shindo, and H Kimura, Kyushu University, JapanSUMMARY
In the precedence rigging of shipbuilding, most of the man-hour of rigging consists of piping work. Therefore it isimportant how the rigging of pipes is performed efficiently. Currently, all pipes which rigged in the engine room aredistributed on the same working space in the target shipyard. There are two problems; One is the distributed pipesoccupy a wide space to stock until installation, the other is it takes long time to find target pipes from distributed pipes.
We propose a new system which divides the pipes into several groups considering the assembling order that skilledworkers adopt. The number of the groups depends on the period of the piping works. Our system enables to reduce theburden of workers, reduce temporary space which placed pipes, and improve efficiency of the piping work. We show ademonstration of the proposed system through simulation using real ships’ data.
1.

INTRODUCTION

In the precedence rigging of shipbuilding, most of theman-hour of rigging consists of piping work. Therefore it
is important how the rigging of pipes is performed
efficiently. Since there are about 1,000 pipes only in anengine room, the rigging of shipbuilding need training
and experience. It takes about six days to assemble pipes
in a target shipyard, and all pipes which rigged in theengine room are distributed on the same working space.
Therefore, large space to put pipes and long time to findan objective pipe is needed.
In previous works, an assembly simulation system ispresented [1]. Workers can confirm procedure ofinstallation with animation on a computer display. Then,
we can extract some problems of installation and checkthe procedure of the installation in advance. His system
improves work efficiency in comparison withconventional works using only pipe drawings. However,in the assembly simulation, order for piping is still
generated manually. For that reason expert knowledge isstill necessary.
Y Wei and U Nienhuis developed an automatic
scheduling system of outfitting process planning [2]. Inthis system, components’ position, material, weight, size,productivity and strategy is considered.
In this paper, we introduce a new system which divides
the pipes into several groups considering assemblingorder that skilled workers adopt, and we show ademonstration of the proposed system through simulation
using real ships’ data.

2.

REPRESENTATION OF PIPES

We used piping data extracted from CAD data of
shipbuilding design system "MATES" used in Oshima
Shipbuilding Co. in this study. Figure 1 shows anexample of the data format, and corresponding 3-D formof the pipe is shown in Figure 2. The pipes are illustrated
by a “main pipe” and “branch pipes”. The data for one
pipe gives coordinates of the start point, the end point,© 2013: The Royal Institution of Naval Architects

the point(s) of bend(s), and outer diameters of both ends
of main pipe and end points of branch pipes. When thepipes penetrate deck, the coordinates of the penetration
points and the types of the penetration are included in thedata.
PipeN = 48
YD027 2405.5

211950.00 -5800.00 9141.17 バカ穴貫通着目点
KeiroN = 1, TenQt = 311568.60 -5800.00 9154.30 40
11799.90 -5800.00 9154.30

Type ofpenetration

12550.60 -5800.00 9088.63 40
KeiroN = 2, TenQt = 211679.90 -5800.00 9154.30

Root No.

11679.90 -5800.00 9277.41 40
・・・

The numberof the points

Figure 1: Example of pipe data

Figure 2: Figure of a pipe

3.

3D-EXPRESSION OF THE PIPES

We developed a data converter that loads pipes’ data andgenerates X3D file. It enables us to understand easily
what shape the pipes are, where they are and how toassemble them. X3D files are available with X3D viewer
for free (e.g. Flux Player). We added functionally fordisplaying the data of the pipe on which is clicked on thescreen. Figure 3 shows an example of the pipes with FluxPlayer.

International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

Figure 3: 3-D display of all pipes and data of a pipe
4.

ORDER FOR ASSEMBLING PIPESThe order for assembling pipes is a little different
depending on the pipers. The rough outline of thedecision is following [3]:Priority1: Pipes penetrating /fixed on deck
Priority2: Pipes located lower
Priority3: Pipes with 80-200 mm in outer diameter
Priority4: Pipes with 65 mm or less in outer diameter
In precedence rigging, construction work is carried out
with the block flipped upside down. The pipes locatedlower have higher value of Z. The pipes with over 250
mm in diameter are usually assembled last. Howeverthese are distributed other space for considering the casethat these pipes cannot be assembled because of otherpipes. Pipes with 80 mm or over in diameter is assembled
earlier than the ones with 65 mm or less in diameterbecause these pipes with 80 mm or over in diameter isassembled with cranes.
We developed the scheduling program loading pipes’
data, dividing the pipes with the way that pipers decide
order for assembling, and displaying the divided pipes.
Figure 4 shows the flowchart of our system and Figure 5
shows divided pipes in a block of the underside of anengine room and Figure 6 shows enlarged views of them.
There are 809 pipes in the engine room.
The supplementation of Figure 5 and Figure6 is asfollows:
Blue pipes: Installed pipes
Red pipes: Pipes which attached at the current step
Transparent pipes: The pipe which attached at thesubsequent steps
Green spheres: Points of penetration

Figure 4: The flowchart of our system© 2013: The Royal Institution of Naval Architects

International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

Figure 5a: Material distribution 1/4

Figure 5b: Material distribution 2/4

Figure5c: Material distribution 3/4

Figure 5d: Material distribution 4/4© 2013: The Royal Institution of Naval Architects

International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

Figure 5e: More than 250 mm diameter pipes

Figure 6a: Material distribution 1/4

Figure 6b: Material distribution 2/4

Figure 6c: Material distribution 3/4

Figure 6d: Material distribution 4/4© 2013: The Royal Institution of Naval Architects

International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

5.

INTERFERENCE OF PIPES

Figure 7: Problem of workability
In Figure7, order of piping is 1-2-3-4 following the way
introduced in the section 4. However, When Pipe-2 isassembled earlier than Pipe-3, there is a risk that Pipe-3
cannot be assembled with cranes due to geometric reason.
These pipes should be grouped into the same distribution
in order to change assembly order manually. We addedfunctionally for detecting interference between pipes
during the transference of the pipes. This function isbased on the assumption that pipes are installed by cranes.
That allows considering the 3-D interference problem as
a 2-D problem by projecting pipes on the X-Y plane. In
this function, we approximate pipes with rectangles as
Figure 8. Then this function judges interference by thepositions of the sides of the rectangles. The result ofinterference judge of the engine room introduced in priorsection is shown in Figure 9. Red pipes are interferedpipes.

Figure 8: Approximation of a pipe

mentioned in the section 4, the order for assembling
pipes is different depending on the pipers, andunexpected problems may occur. Therefore it is difficult
to decide detailed assembly order automatically. In oursystem, we consider that dividing pipes following order
estimated roughly allows improvement of work
efficiency without degrading on-site flexibility.
In the section 5 we approximate pipe with rectangles. For
that reason parts of bends cannot be approximatedaccurately. However, it is no problem because on-site
workers deal with the problem that pipes are a little
interfered.
As a demand of the target shipyard, when thecompartment is complete except for only one pipe, it ispreferable to assemble the pipe regardless of its height(Figure7).

Figure 10: Problem of productivity
On-site supervisors in the target shipyard gave us quite
positive comments. They judged that this system is so
useful that they want to try it in practice and to confirm
usefulness.
7.

CONCLUSION

In this paper, we introduced the system which divides thepipes into several groups considering the assemblingorder that skilled workers adopt.The evaluation of thissystem in practical use is a future work.
8.

Figure 9: Interfered pipes
6.

DISCUSSION

We tested our system with another data that has 1020
pipes.
Y Wei and U Nienhuis developed an automatic
scheduling system of outfitting process planning. In theirsystem order for piping is decide clearly. However, as© 2013: The Royal Institution of Naval Architects

ACKNOWLEDGEMENTS

The authors would like to acknowledge support andinformation provided by Oshima Shipbuilding Co..
This paper is the result of work sponsored by the Japan
Society for the Promotion of Science (JSPS) Grants-inAid for Scientific Research (B) 23360388. This support
is gratefully acknowledged.
9.

REFERENCES

International Conference on Computer Applications in Shipbuilding, 2013, Busan, Korea

1.
Y Okumoto, ’Shipbuilding Technology &Production System’, Seizando-shoten publishing, 2009 inJapanese2.
Y Wei and U Nienhuis, ‘An Automatic
Schedule Generation System of Outfitting Process inShipbuilding’, International Conference on Computer
Applications in Shipbuilding (ICCAS), 20093.
S Shindo and H Kimura, ‘A Material
Distribution Scheduling for Rigging Ship-hull Blocks
with Pipes’, Conference Proceedings of the Japan
Society of Naval Architectures and Ocean Engineers,
2013 in Japanese
10.

AUTHORS BIOGRAPHY

Kazumasa Noda holds the current position of M.A. inthe Department of Maritime Engineering, Graduate
School of Engineering, Kyushu University.
Shohei Shindo holds the current position of M.A. in theDepartment of Maritime Engineering, Graduate Schoolof Engineering, Kyushu University.
Hajime Kimura holds the current position of Associate
Professor at the Department of Maritime Engineering,
Kyushu University. His previous experience includes
optimization in shipbuilding.

© 2013: The Royal Institution of Naval Architects