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.
Contractors World International Vol 6 No 1