The historic structure of The
20 世紀の歴史的構造物

20th century"Steel Citadel" TEKKO KAIKAN— Evolutional architecture with advanced various steel material —Teizo Amano NIKKEN SEKKEI Construction Management, Inc. Mitsuo Uchida NIKKEN SEKKEI LTD.
In 1966 (Showa 41), Japan’s population topped one hundred million. Its economy grew out of post war
economic recovery and aimed to make a further breakthrough following great nations. Interestingly,
in the same year, two buildings were completed: Keidanren Kaikan-the “castle” of Japan Business
Federation), which promoted reconstruction and restoration of Japan’s economy –and TEKKO KAIKAN“Steel Citadel” of steel industry, which always led industries. In particular, TEKKO KAIKAN was builtwith the latest constructional materials, such as large diameter tube truss steel structure, stainless steel,which was a new building material in those days, anticorrosion steel applied for everywhere. It was likean exhibition pavilion of steel. The details of the establishment of TEKKO KAIKAN and the points ofthe design and construction of the building is introduced by NIKKEN SEKKEI’s Mr. Teizo Amano and
Mr. Mitsuo Uchida, who were in charge of the design and supervision of TEKKO KAIKAN.
The full view of
TEKKO KAIKAN

1. Detail s of the Establishment of
TEKKO KAIKAN
The former managing director of TEKKOKAIKAN, Haruhiko Kozakai, stated about
the details of the establishment of TEKKOKAIKAN;“Steel industry, which led the post war
economic growth, grew and developed further
in 1955 (Showa 30). In 1959 (Showa 34), various
industrial activities were taken. As a result,they found ”Kozai Club Building” small andstarted to consider about a new steel complex
building.
Based on the decision of the board of
directors of Kozai Club (present-day The Japan
Iron and Steel Federation), they decided to build
a new steel complex building, which would
be a new place for cooperation of industry
and an appropriate place for steel industry, on
the site of “Kozai Club Building”. In order topromote the construction, “Kozai Club Building
Governing Board” was founded, and it wasstarted toward the realization at the center ofthis Governing Board.
Later, in 1961 (Showa 36), “TEKKO KAIKAN

1F Elevator hall

7F Lobby

9F Lobby1

20 世紀の歴史的構造物
The historic structure of the 20th century

Ltd.” was founded. The study was
made under “TEKKO KAIKAN
Construction Promotion Committee”
and later “KAIKAN Construction
Committee” from the planning andthe drawing up of the building to
the completion in 1966 (Showa 41).
It was supposed to aim to build abuilding which is appropriate as a
Steel Citadel with the best facilities.
M r. Yo sh i h i ro I naya ma , t he
managing director (at that time) of
Yawata Iron & Steel Co., Ltd, who
was the administrative director of
Kozai Club at that time and the firstpresident of TEKKO KAIKAN is
said to have had a great eagerness
and contribution to the constructionof TEKKO KAIKAN.”
NIKKEN SEKKEI was in chargeof the design and the supervision of
TEKKO KAIKAN and SHIMIZUCORPORATION was in charge ofthe construction.
2. Drift of the Design
The design of TEKKO KAIKAN
was based on the basic conceptthat this is a common facility

for steel industry and that thebuilding itself symbolizes steel andis an architectural building thatspecifically shows it. They aimed tobuild a building which can be used
for multi-purposes such as businessoffice, conference room, restaurant
and parking area in an L-shaped
area alongside a narrow three-sided
road with a strict setback regulation,
realizing functionality and planningwith convenience and high service
performance, appropriate facility
desig n, and interior desig n for“place for industry cooperation”.
In particular, by design in which
the features of steel materials
mainly made of iron and stainlesswere utilized, they aimed to build
a distinguishing building which isappropriate for the name of TEKKOKAIKAN.
In production and construction,w it h col la bor at ion w it h st eel
i ndu st r y, t hey u nder t o ok t heproduction and construction with thelatest steel materials and methods at
the time. One of the characteristic
was in that steel production, such as
stainless, was used not only for the

Overview of TEKKO KAIKAN(1) Overview of the building
Location
Construction period
PurposeSquare measure
Structure

Outside wallRoof

3-2-10, Nihonbashi Kayabacho, Chuo-ku, Tokyo
Commencement, March 1964 Completion, April 1966
Business office, conference room, restaurant, parking
area
Site area 1,509 m2, building area 1,330m2, total floor
space 14,112 m2
Deep foundation, steel—frame reinforced concrete
structure (9th floor, lozenge shaped grillage beam roof
structure consisting of heavy tubular steel with large
diameter steel tubes), three-story basement, nine-story,
four-story tower
Stainless curtain wall, stainless doors and windows,
weather resistant steel panel
Asphalt water-proof protective concrete(2) Overview of the facilities

Electric facility

Loop powered method, contract power 1200kW, electric
power plant 500kVA
Air-conditioning facility
Thermal source/2 turbo freezing machines 240RT,
2 1.5h/t steam boilers, air-conditioning system/airconditioning equipment 7-system, conference room zone/
dual duct, business office zone perimeter/fan-coil unit
systemSanitary facility
Water supply/elevated water tank system, central hotwater supply system, firefighting equipment
Elevating facility
3 passenger elevators, 1 service elevator
Machinery parking facility 2 double banked flat circular lots
OthersRenovations were taking place following the updated planin the midterm in 1997 and the renovation plan2

structure but also for the exterior,
the interior, the facility, the furnitureand the decorations.
3. Point of the Architectural
Plan
Meet i ng requ i rement s f r om
Constriction Committee, it was
the point of the construction plan
to make a planning that can beused for multi-purposes and can beused as a common facility for theindustry.
3.1 Floor Plan. Creating an Astylar
Large Space by Large Diameter
Steel Beam

From 1st to 5t h f loors havebusiness offices for the industryrelated groups. From 6th to 8th
floors have small-size, middle-sizeand large-size rent conference rooms.
The 9th floor has restaurants andsalon. From the 3rd basement to the
1st basement have parking area andmachine rooms. One feature is thatthe 1st floor has a wide lobby andthe conference rooms were designed
to be used for many purposes, suchas business conference, lecture
workshop, t ra i n i ng workshop,social party and wedding party.
In particular, the restaurant is an
astylar large space with 465m2,
showing lozenge shaped grid beams
made with large diameter steel
tubes.

3.2 Exterior Plan. A New Facadeby Stainless Panels

For the exterior, which is the faceof TEKKO KAIKAN, they adopted
a stainless curtain wall. In making
this curtain wall unit, they needed
to avoid distortion resulting fromwelding, uniform hairline finish,
ensure water-proof performanceof the jointed parts. And also, theexpression of rounded windowsfeatures a design to provide theimage of the latest all-stainlesstrains.

3.3 I n t e r i o r P l a n . V a r i o u s
E xpressions by Making theBest Use of Stainless

As for the interior, they had aninterior plan appropriate for each

The historic structure of the 20th century

use of the room. They also usedmaterials in various ways; stainlesscopper plates were processed to give
expression to the material and used
to finish main parts. In particular,
they used stainless copper plates forthe decorative panels for the lobby,
the hall and the conference rooms,
the door and inside panels of theelevators, the decorative frame oflighting equipment, decorative relief
with polishing, etching, folding inorder to make interior have various
expressions in the use of hightechnologies in those days, aiming athigh quality construction.

Figure 1
Piled-up pipe steric moment frame plan in the second plan

4. Overview of Structural Plan
T hey m a de c h a ng e s i n t hestructural plan three times anddecided on the final plan, which isthe present one.
According to t he f irst pla n ,taking the location conditions into
account, they proposed a three-story
basement and nine-story reinforced
concrete structure in a conventional
method which is a combination of
new steel materials only with shapesteel of iron frame material (roleH-shaped steel, T bur, honeycomb
H- shaped steel). I n rega rds tot h i s pl a n , T E K KO K A I K A N
Construction Committee made thefollowing requirement. “The building
should be innovative and symbolicof new steel materials, while it isappropriate for the name of TEKKO
industry, which is the founder.”For this requirement, the second
plan was made, considering about
the form of expression of steel fromvarious perspectives. As a result,large diameter steel tubes as a single
tube, which conventionally had
not used at construction industry,
were used to make moment framewith piled-up pipes and the plan
was proposed to the Construction
Committee (Figure 1). The plan
was to aim to disperse stericallyt he st ress t h rough t he use of
torsional stiffness of the pipes andalso to use steel tubes as a facility

Figure 2
Working drawing and roof steel framing planduct. However, although the costof this plan was expected not so
different from the conventional SRC
structure, it took inevitably longer
time than that of SRC structure in
construction period because housesaround the site were located close toeach other and there was no vacantlot. Therefore, the plan was applied
to take back to the Construction
Committee.
H o weve r, t h e C o n s t r uc t i o n
Committee appreciated the potentialof the plan and proposed to keep atleast the part of the top floor as atest case. Consequently, as the thirdplan, they decided an innovative
construction, in which the first plan
was adopted for the 8th floor below,
and steel moment frame with large
diameter steel tubes was adopted forthe 9th floor following the second

3

Figure 3
Unitization of 9th floor erection plan

plan (Figure 2). Moreover, the 9th
floor is set back to meet setback
reg ulation for f ront road . The
following description explains about
the actual plan.
4.1 Overview of the Structural Plan
4.1.1 StructureF r o m t h e 3 r d ba s e m e nt t o
2nd basement , the f loors were
reinforced concrete structure. The
1st basement was SRC structure.
The outer perimeter of from 1st
to 8th floors and the common corepa r t were SRC structure. The
inside beam was S structure with
fireproofing protection. The 9th
floor was pipe steric moment framewith fireproofing protection. The
material of the pillar is 555.8φ×
16 and the material for the beam is609.6φ×12.7. The materials meetthose JIS at that time. The core of

20 世紀の歴史的構造物
The historic structure of the 20th century

the tower was RC 4-story structure.
Lightweight concrete was poured
on the S structure part of thefloorboard, which was VA-shaped
deck plate Oshima ballasting, andfield connection was performed with
JIS high-strength bolts (F9T). The
pipes were welded as full penetration
welding joint whether they were
weld at that site or at factories.
4.1.2 Used Steel Materials for the
Structure

Reinforced thin bars met current
SR235. Main reinforced bars met
current SD345, which was acceptedby the minister at that time. For
steel mater ia ls were used C T
and T bar, for steel panels wereused current SM490A, for beamhoneycomb H were used SS400, andfor pipes were used current STK400.

4.2 Overview of the Constructionof Pipe Structure in 9th Floor

Steel materials in the part ofpipe structure in the 9th floor wereused current STK400. The total
amount was approximately 100t.
As shown in Figure 3, they weremade at factories in consideration of
the unitization for erection plan. In
making them, they carefully planned
the unitization and the welding
details and controlled the accuracyof the production.
Additionally, construction of pipe
structure in the 9th floor was done
to minimize the errors arising fromerecting steel frame to the 9th
floor and avoid interfering with theupper pipe construction because
erection was performed on the floor
beam at the 9th floor. Particularly,
they needed to be careful about thelozenge shaped grid beam structurewith large diameter steel tubes,
which did not have any previous
example.
4.2.1 Pipes Weld Joint

They made the joint of the pipes
easy. Unit had the maximum length
and width for transportation. They
tried to minimize the number of
weld joint at the site. Also, panel
unit for the construction was width

Figure 4
Welding details of each material

3.0m and length 13.0m, taking into
account of the site conditions andthe size possible to transport in thenight time. The unitization is asshown in Figure 3 described above.
Fig u re 4 shows t he welding
details of each material where
structural pipes are joined, 30mm
clearance were provided for smoothsettling and high quality of welding
operation.
4.2.2 Plumbing Unit and Welding
at the Site

Each material was applied either
vertically or horizontally. The detailof J-A weld joint in Figure 5 shows
an example of applying a material
vertically. It is possible to adjust
the vertical or horizontal erection
depending on the angle of the insert
ring as the backing metal.
For instance, when it is appliedvertically, insert ring as backing
metal is attached to the circle of theupper side of a pipe and the insert
ring is attached to the circle of the4lower side of a pipe as well. The
30mm space between them in the
figure is clearance dimension for
the erection. A backing metal as
spacer for the space is inserted into
the space before site welding so thatthe site welding of the circle of steel
tube can have continuity.
In the detail drawings of single
material joint in Figure 5, insteadof attaching an insert ring to abracket, which is a triangle shapewhen viewed from a main pipe, theinsert ring is attached to the upper
pipe to drop from above. The 10mm
clearance is taken into account here
as well. The actual erection andsite welding took approximately one
month as shown in Figure 6.
A lso , t he weld ing mater ia ls
met JIS D4303 (lime titania type).
B ecause t he site welding wa s
performed in July and high humidity
season, they were dehumidified(same action as preheating) with agas burner to prevent weld cracks
occurring during high humidity

The historic structure of the 20th century

underside of the steel tubes (welding
position was overhead welding
position). Naturally, various defects
were found at erection.
4.2.3 Error Correction Method for
Welded Parts

Figure 5
Detail drawings of simple material, oblique pillar base, etc.

Picture 1/Qualification test for welding
engineer at Noda factory of Kawasaki
Heavy Industries（1）40mm 以上の場合

completely.
Total inspection was performed
during the site welding control atthat time in order to avoid various
defects.
Also, in regards to welded partsof steel tubes , X-ray sa mplinginspections (ultrasonic inspection
was not available at that time) were
performed with a focus on the（2）40mm 以下の場合（3）相貫継手部継手線の場合

加
工
組
立
溶
接
塗
料
仮
組
発
送
建
方
現場溶接
現場塗装
作業台除去

New materials shown in Figure
7 (1) were used for 3 areas whereroot gaps were over 4 0 mm ofaccumulated error. If the error was
no more than 40mm, padding (called
buttering) was carefully performed
from one side as shown in (2) andthen final welding was performed atregular gaps of root.
Also, as shown in (3), line heatingc or rec t ion wa s per f or med on
unsatisfactory parts on joint lines ofintersecting joint parts. If the gap
did not fit or was too big, as shownin Ro part ( ロ ), a baking metal was
attached or padding from the sideof a main pipe was performed tocorrect a detail dimension, and thenfinal welding was performed.
The most common defect swere "disparity" of root gap onintersecting joint part. The cause ofsuch disparity of root gap accuracy
was due to the accumulation of alot of accuracy configuration, suchas accuracy of circularity of pipematerial, and finishing of pipe cutter,accuracy of removing weld line on
spiral steel tube, erection accuracy
and welding distortion accuracy.
Their effort was tried for a better
solution of this structure type in the
future through this experience as
one step.

5月
10 20

6月
10 20

7月
10 20

8月
10

Figure 6
Work schedule from erection to site welding

Figure 7
Correction method for site welded parts

5

20 世紀の歴史的構造物
The historic structure of the 20th century

4.2.4 Quality Control of ProductDimension

Quality control of product size anddimension is to minimize machining
e r r o r o f e a c h c o n n e c t i o n bymeasuring dimension accuracy andcircularity of rough pipe itself. In
regards to cutting with an automatic
pipe cutting machine, it is obviousthat the accuracy of intersected
form depends on a circularity ofprocessed material. However, thepipes were cut on the tentative
assumption that the steel tubes were"perfect circles" within the allowableerror range. Additionally, the JIS
allowable tolerance of diameter ofthe spiral steel tube supplied for thisconstruction was ± 0.5%D (3mmfor a diameter of 60cm). Therefore,
dimensional adjustment or correctionof cross-section shape with some
grinder finishing was performed toa certain extent after cutting pipes
with an automatic pipe cutting
machine.
As stated above, the dimensional
quality control of product unit
at factories, such as the proper
check on intersected joint parts offinal steel tube products, was also
performed thoroughly.
4.2.5 Welding Control and Welding
Workmanship Additional Test

In the welding department at thattime, since it was the time without
current ultrasonic test method, toJIS qualified personnel of the steel
tube, which the Japan Welding
Engineering Society certified, in
accordance with the provisions of theparticular specifications in Nikken
Sekkei, performing the welding
workmanship additional test of thewelding engineer, and the selectionof the welding engineer, the number
of welding engineer with high skill
was ensured for a factory and for aconstruction site.
4.2.6 Steel Frame Manufacturing
Factory for Steel Tubes

Steel frames for steel tube were
manufactured at Noda factory of
Kawasaki Heavy Industries Ltd.,There were not many factories

wh ich cou ld ma nu f act u re t hesteel tube structure at that time.
Kawasaki Heavy Industries Ltd.,
which was in charge of steel frame
manufacturing, had developed an
automatic gas cutting machine which
could numerically control both endsof pipe at the same time. However,the diameter of steel tube was too
big for the automatic gas cutting
machine to handle. Therefore, they
improved the automatic gas cutting
machine to handle large diameter
steel tubes.
5. Inherited New Structural
Steel Products and New
Construction Methods at
That Time
5.1 New Structural Steel Products

New pr o duc t s u s ed f or t he
TEKKO KAIKAN construction arelarge spiral welded steel tube, large
H-shaped steel, honeycomb H-shaped
steel, high-strength bolt, high-tensile
deformed steel bar, deck plate,weather resistant steel plate, various
surface treated steel plate and thelike. The characteristics of the main
products are as follow:• Honeycomb beam H -shapeds t e e l : H o n eyc o m b b e a m i s

a be a m m a t e r i a l . To m a ke
this beam material, a web of
H-shaped steel is cut unevenly,
then one cut piece is rotated
180 degrees and the protruding
pa rts of both cut pieces a rewelded. For the construction of
the building, H-shaped steel wasused for structure material of thepillars and beams, however thishoneycomb beam was used formost parts of joist. It was used
not only for weight saving of
the building but also for the airconditioning duct, electric system,
piping of water and sewage andthe like.
• High-strength bolt: High-strength
bolts had not been used muchat the time of the constructionof the building because weightof steel f ra me building wa s
light. However, high-strength
6bolt has more advantages thanconventional bolt or rivet has,and approximately 37t of highstrength bolt was used for theconstruction.

• High-strength deformed steel
bar: Approximately 40% of steel

bar for reinforcing bar used forthe construction of the building
is high-tensile deformed steel bar
and it was used mainly on thefoundation and the like.
• Steel deck : New deck plateproduct was used for flooring on
the 2nd-9th floors and rooftop.
Shortening of the construction
period at the factories and weight
reduction of the building wasachieved by using the deck plates.

• Weather resistant steel plate:

Weather resistant steel plate is asteel material with new functions.
One disadvantage of steel, rust,is instead utilized to provide thesteel plate with a characteristicof high corrosion resistance inthe air whereby the base materialis actually protected by a layerof fine rust. It was used for thepenthouse louvers, handles on therooftop, upper wall surface of theparking space entrances and thelike of TEKKO KAIKAN.

• Stainless steel plate and various
surface treated steel plates:

Stainless curtain wall was used
for the building exterior. To
fit with the exterior, stainlesssteel was used for many parts,
such as the first floor lobby andelevator hall on each floor asinterior material. On the other
hand, surface treated steel plates,
such as steel plate with printed
patterns and enameled iron plate,were used as interior material
in t he f i r st f lo or lobby, forpartitions between hallway andeach business office and the likealthough they were not used asmuch as stainless steel plates.

5.2 New Construction Methods

N ew c o n s t r uc t i o n m e t h o d sused for the TEKKO KAIKAN
c o n st r uc t io n were S he et pi leThe historic structure of the 20th century

Picture 2/Large space created withspiral large diameter steel tubes

excavation support method, Caisson
Pile Foundation Method, rhombicmesh steel tube structure, curtain
wall with stainless panels, pouring of
concrete using a pumping machine,trowel direct finishing of concrete
floor (Monolithic Method), using
metal form (steel plate form) andsteel tube scaffolding (prefabricatedscaffolding) and the like. The major
new construction methods were as
follow:• Rhombic-mesh steel tube
structure: This structure was a

new construction method usedon the 9th floor, the top partof T E K KO K A I K A N . A rch
structure was commonly used forlarge spaces, such as gymnasium,using small diameter steel tubes
at that time. However, the arch
structure was not suitable fornormal building construction
because space above the arch
structure could not be used as
rooftop and there was height
limitation. Therefore, engineers’groups from both companies,
wh ich were i n cha rge i nthe desig n and construction,
advanced the research with steel
manufactures and developed theworld's first "rhombic-mesh steel
tube structure".
• St ainl e s s cu r t ain w al l : Thec h a r a c t e r i s t ic o f s t a i n le s scurtain wall is in that it cancreate beautiful and brilliant
appearances in addition to theexcellent strength and durability.
A lso , a lt hough it is more
expensive than normal ferrous
materials, it has a good economic
performance when taking into

Picture 3/High-strength bolts to enable
the rationalization of site connection

Picture 4/Stainless curtain wall (hanging)account low maintenance factors.

performance of the structure at thetime of the construction surpassedt he s t a nd a r d f o r e a r t hqu a ke
resista nt desig n a f ter 19 81 inJapan and the durability, safety,
functionality, excellent appearance
and the like have been maintained
thoroughly. The proven functions of"TEKKO KAIKAN" built as a steel
citadel are still being used widelyand steadily.

• Caisson Pile Foundation Method:

Caisson Pile Method which wasa new method at that time wasadopted for the foundation work.
In this method, total of 35 roundholes with diameters of 1m-1.8m
are made in foundation. Then
excavation is performed down
to bedrock while retaining walls
are built on the periphery andthe holes are filled with concrete.
By applying this method, groundsubsidence and the like can behandled very well.

• Pouring of concrete using a
pumping machine: As a new

attempt of concrete pouring, apumping machine (concrete pump)made in West Germany was used.
Ready mixed-concrete was placed
down to the basement level, fromwhich it was pumped up to therooftop through a pipe and thenpoured on each floor.

6. Conclusion

Reference document
1) " Twenty-f ive yea r's history of TEKKOKAIKAN" published in 1987

Nikken Sekkei Construction Management, Inc.

Teizo Amano<Career Summary>1960 Joined present-day NIKKEN SEKKEI LTD.
2006 Joined NIK K EN SEK K EI Cons truc tion
Management Inc.
2010 S e n i o r p l a n n e r o f M a n a g e m e n t
Department in the company<Current External Activities>• Vice -president of General Conditions ofConstruction Contract Committee• Chief of Agreement Working Group of The
Japan Institute of Architects.NIKKEN SEKKEI LTD.

Now, even when viewed standing
in front of the TEKKO KAIKAN
whe r e 4 4 ye a r s pa s s ed a f t e rcomplet ion a s a de sig ner, t hestainless panel curtain wall has theunchanged beauty and brightness.
I am deeply moved because I know
the time that people involved in theconstruction to create the building
together. General renewal of TEKKOKAIKAN, such as renewing interior
and facilities which degraded overtime or passed the service life, hasbeen done. However, the seismic7

Mitsuo Uchida<Career Summary>1965 Joined present-day NIKKEN SEKKEI LTD.
2005 Joined NIK K EN SEK K EI Cons truc tion
Management Inc.
2010 A ssociate direc tor of Administration
Department at NIKKEN SEKKEI<Current External Activities>• Managing Director, Supporting Association for
Building Steel Structural Technology• Chi e f o f Su p e r v i s o r y Su b c o m mi t t e e o f
Technical Commit tee of Japan Structural
Consultants Association＜ Journal of Japanese Society of
Steel Construction “JSSC ” (Summer 2010) ＞