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Saudi Arabia

Tallest Flagpole In The World

The Jeddah Flagpole has been officially recognised by The

Guinness Book of World Records as the world’s tallest, at

171mhigh. It is located on the Tariq Ben Zayed Roundabout

in central Jeddah, Kingdom of Saudi Arabia and carries a

flag approximately 30 x 60 m weighing up to 1 tonne.

Byrne Looby Partners have been involved on this land-

mark project from start to finish. Employed by the design

and build contractor, Al Babtain LeBLANC Technologies

FZCO, Byrne Looby planned and supervised the initial site

investigation, designed the piling and foundations and pro-

vided site supervision throughout the construction.

The Byrne Looby project team consisted of John Byrne

leading the geotechnical input, Richard Thiemann heading

the structural element, Sam Peet undertaking all the com-

puter modelling while Ian Pearcy and Aidan Commerford

were responsible for the drafting. Byrne Looby had three

people on site throughout the different stages of the


The ground comprised coralline limestone over sand-

stones, siltstones and mudstones and it required sixteen

piles 25 m long and 1200 mm in diameter to support the

foundation block. The foundations include 95 t of rebar

and 450 m³ of concrete.

As well as resisting the high moments and shear from

wind loads on the flagpole the foundations needed to

provide sufficient stiffness to avoid build-up of resonant


The foundation comprised an octagonal reinforced

concrete base 16 m across and 2 m deep with a 2.5 m high

plinth on top.

To resist the very high oscillating loads under the flag-

pole base a C45/55 concrete was specified for the plinth

whilst the base was reduced to C32/40.

Despite the high concrete strengths the basewas tanked

to provide adequate durability against the aggressive soils.

The high concrete strengths meant high potential tem-

perature during curing of the concrete. Careful design of

the mix was required together with batching using iced wa-

ter and cooling of the aggregate.

To ensure the precautions were adequate a 2 x 2 m test

cube was poured and temperatures monitored. The foun-

dation was poured in two sections, the base and the plinth.

The flagpole is a tubular steel structure tapering from

5 m diameter at its base to 2 m at the top. It encloses an

access stair and the flag raising mechanism.

The flagpole was erected in segments and bolted to the

foundation with 168 pretensioned bolts fixed to a double

anchor ring within the base.

Byrne Looby staff were resident on site throughout the

works to confirm that works were constructed in accord-

ance with specifications and to provide full records of the

works carried out.

Byrne Looby

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Contractors World International Vol 6 No 1