The BT Tower - A Connected World
Going Global
Going Global
Changing the logo at the top of the Tower is a massive task, which involves expert scaffolding and a real head for heights. The photo opposite shows the first 'wrap around' backdrop of the (then new) static BT lettering.

Opposite: Building the new lightbox in March 2004. All photos © Light Straw Archive.
| EXIT | Going Global | Glossary & Links |
A Connected World

Developed for BT by Wolff Ollins, the "connected world" globe was originally used exclusively as the logo for BT Openworld. However, on 7th April 2003, this logo was adopted as the new BT corporate image. But it was not until 29th March 2004 that a representation of the logo appeared at the top of the Tower. The realisation of the project involved many months of planning and implementation...

"The complete circumference of the Tower will be in-filled with signage bearing three 2.5 metre-high, back-illuminated BT initials. At night the seven colours of the Connected Earth globe will be front projected onto the sign. It won't be static. All the colours will be present at once, but they will slowly fade from one to another, giving a sense of movement."

Rufus Leonard the creative agency, together with design and events team Imagination Plc, took on the daunting task of transforming the image(s) at the top of the tower. The tower is iconic to BT, so the realisation had to visually convey the new global theme, while retaining the well known BT lettering.

Going Global
Yellow Globe
At the start of the project, consulting engineers, Buro Happold Façades Group, traced the history of the tower's signage to help establish how best the new concept could be matched to the 1960s architecture.  The challenge was to create a 360º representation of the logo, using programmed colour-changing sequences to reflect the complex shape and colours of the global image. At this stage, Imagination's architectural lighting design team contacted AC Lighting's special projects division on account of their specialist knowledge of exterior colour changing systems. They were to supply the lighting and control solution for the building's new logo. Of the light fixtures available, Martin's Exterior 200 was found to offer the best overall performance of beam spread as well as closely matching the 7 Pantone colours of the Connected World logo.
Blue Globe
Scaffolding was erected between the 35th and 37th floors of the tower and many microwave dishes had to be relocated to enable the work to take place. On level 36, Interior Plc extended the existing steel framework of the 3 lightbox fascias to create a continuous signage box, measuring 5 metres high with a perimeter length of 60 metres. The flexface skin which was then stretched over the steelwork produced a seamless 360º front projection panel incorporating the familiar blue 'BT' lettering, which is lit externally from below. To produce a 'wall-washing' beam of light around the fascia required 48 IP65 rated Martin Exterior 200 CMY luminaries which were attached to the outside of the tower.
Red Globe
Tony Rimmer (Imagination): "The fixtures were positioned at the bottom of the signage using custom brackets, 360 degrees all the way around with about a one degree elevation from vertical, so it’s a very sharp incline, almost vertical." To operate the 48 fixtures required a control system with DMX capability, an astronomical clock and the ability to easily switch between various pre-programmed lighting sequences for special events. AC's projects division used their knowledge of architectural lighting controllers to specify an ETC Unison system and Chroma-Q™ Magic Box DMX distribution solutions. AC was also responsible for the installation and full programming of the system.
Green Globe
The lighting sequence is triggered one hour after sunset and goes off one hour before sunrise. The main sequence divides the fixtures into seven groups of light scenes, with each scene equating to a different colour in the logo at any point in time. By fading the scene colours in and out whilst simultaneously rotating the groups in a set order, this gives the impression of the globe seamlessly rotating around the tower's crown.
Glossary & Links

IP Rating is described by 2 digits. The first digit relates to dust protection, the second digit relates to water protection. Luminaires with higher degrees of protection will keep internally cleaner which ensures reflectors are maintained in good condition. IP65 gives a dust tight rating (6) and is protected against water jets (5), both of which would affect the performance.

CMY - Cyan, Yellow, and Magenta.
DMX (Digital MultipleXing) is a standard which allows the control of 512 dimmers in a daisy chain fashion.
ETC - Electronic Theatre Controls

Note: Text abridged from press releases by the companies named below.

The Pantone name is known worldwide as the standard language for colour communication from designer to manufacturer to retailer to customer.

Creative Agency: Rufus Leonard
Implementation: Imagination Plc (design & events company)
Lighting Specialists: AC Lighting
Lighting Supplier: Martin Professional
Lighting Contractor: Interior Plc
Consulting Engineers: Buro Happold Façades Group

Design, images and text compiled by © Light-Straw. With thanks to M.Knight.
Page last updated June 2015 revision. Checked May 2021.

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