The Spinnaker Tower is a –high tower in Portsmouth, United Kingdom. It is the centrepiece of the redevelopment of Portsmouth Harbour, which was supported by a National Lottery grant. Its shape was chosen by Portsmouth residents from a selection of concepts. The tower, designed by local firm HGP Architects and the engineering consultants Scott Wilson and built by Mowlem, reflects Portsmouth's maritime history by being modeled after a sail. After several years of delays and cost overruns, it was opened on 18 October 2005.
The tower represents sails billowing in the wind, a design accomplished using two large, white, sweeping steel arcs, which give the tower its spinnaker sail design. The steelwork was fabricated by Butterley Engineering. At the top is a triple observation deck, providing a 320° view of the city of Portsmouth, the Langstone and Portsmouth harbours, and a viewing distance of . The highest of the three observation platforms, the crow's nest, has a wire mesh roof, allowing visitors to be in the elements. Windows extend to above head height, so it is not possible to get a view unobstructed by glass. The glass floor is the largest in Europe. The tower has a design lifetime of 80 years.
The project was over budget, with an overall cost of £35.6 million for the tower alone. Taxpayers were not meant to fund the tower, but Portsmouth City Council eventually contributed £11.1 million towards construction.
In March 2004, Portsmouth Council leader Leo Madden resigned after a highly critical report of the council's handling of the project and failure to exploit revenue opportunities, such as the Millennium. Barry Smith, the project's legal advisor, also retired after being suspended on full pay, mostly due to controversy over the contract with the builders, which at one point would have cost the council more to cancel than to complete.
The tower has been beset by health and safety issues, including large cracks beneath the observation deck and a malfunctioning external glass lift. Fathers 4 Justice campaigners and base jumpers have infiltrated the tower, leading to security concerns.
The tower was dedicated on 16 October 2005 and opened two days later. On opening day, the Tower's project manager, David Greenhalgh, and representatives for Mowlem and Maspero were stranded in the tower's malfunctioning external lift (built by Maspero) for an hour and a half. Abseiling engineers were called to rescue them. Some, including the franchise's chief executive, felt it was rather fitting that these particular people were trapped.
Once open, the tower attracted crowds in excess of expectations, despite only the internal lift working since opening, with over 600,000 people visiting the tower the first year. Observation towers in Canada have been similarly successful (for example, Toronto's CN Tower, the Calgary Tower, Niagara's Skylon Tower), as has the UK's Blackpool Tower.
In June 2006, the local press raised a concern that the tower may be forced to close. All public buildings in the UK require disabled access under the 1995 Disability Discrimination Act. With the external lift inoperative and only the internal lift for disabled access, the tower did not meet this requirement, and the tower operators could be sued under the act. This problem was rectified by investing in an evacuation chair, and training for staff to use it. In the event of evacuation, should the internal lift be inoperable, those unable to navigate the 570 steps can use the evacuation chair.
The original date given for the external lift to be operational was the end of January 2007, although as of August 2008 the lift is not in service.
In 2006, the tower won the RICS Project of the year award and the RICS Regeneration award.