What a turn on

For ten weeks of each year Blackpool becomes the place to visit in England. The Lancashire town continues to be a booming tourist mecca at a time when the UK's other seaside resorts are closing for the winter. What is the attraction? The now world-renowned illuminations: six miles of decorative street lighting running the length of the seafront promenade.

Visitors are led by strings of festoon lighting through avenues of giant plastics features secured high on reinforced streetlamp poles. Over 500 individually designed features are arranged in 20 themed sections, from alien spaceships to jelly sweet monsters, which culminate in a series of giant tableaux on the cliffs of the Fylde coastline. "Its like a theatrical performance – you have the warm up then build towards this climax at the end," exclaims Richard Ryan, illuminations manager. The entire display encompasses over 100 miles of festoon lighting, 200 miles of cables and wiring and over one million lamps. It uses around £50 000 of electricity over the 66 night switch on period.

Ensuring the display's success is a full-time job. A 45-strong team including artists, electricians, joiners, mechanics, painters and engineers works year round designing, repairing, installing and dismantling the features. The staff is generally split into three departments: maintenance, new features and EOD – erection, operations and dismantling. The numbers in each team vary throughout the year according to the workloads, as most members are multi-skilled.

Everything is designed and built in house and only specialist work, such as laser displays, is contracted. All of the lv electrical installation is carried out by the in-house team: "There are no outside contractors. We looked at it, but there was very little interest," explains Ryan. The hv supply is subcontracted out under an agreement for the control, operation and maintenance, since the Blackpool team does not have these skills.

Staff run the show from five cavernous workshops just behind the town's main entertainment strip. In these real life Aladdin's caves, piles of coloured lamps sit alongside lamp post features three metres high and tableaux that reach the ceiling and stretch several metres long. When the dismantling begins immediately after the lights go out on 2 November this year, the features will gradually be brought back to these warehouses over an eight-week period. Here each part will be inspected, tested and any repairs made before the installation process begins again in April.

Every year there are new features to design and manufacture. "We can't change everything each year as its economically and practically impossible, so we change 20-25% ," explains Ryan. The solution to keeping the overall display fresh includes moving each themed section to another area in the route and updating existing features for new displays. Each section is the same length, stretching the distance between 12 lamp posts, around 400 m, which simplifies the reorganisation. "The whole thing is about contrast – in terms of different types of lights and tableaux scenes," explains Ryan.

The advantages of prefabrication are not lost on the illuminations team: the display is erected in modular sections and a "curly wurly" device has been created to reduce the installation time of the festoon lighting, which loop thrice between lamp posts. Small pieces of coiled wire are positioned at regular intervals on the strings of lights in the warehouse; these are looped onto a support wire and simply pulled along, reducing the workload by two-thirds. And with 65 000 staff hours needed to run the display, any time saved is invaluable.

This year two new road sections have been created and on the cliff top there are two new tableaux: top topiary and the flagship haunted hotel. Get up close and the effort to complete these three-dimensional features in the limited time available is obvious. The top topiary itself stretches over 100 m. This is primarily constructed from timber, with low voltage, surface-mounted lighting giving the appearance of shaped hedges. The haunted hotel is the first tableau to incorporate live-action video, which is projected onto the feature. This tableau stands 7 m high and 25 m wide and includes high tech lighting, sound and mechanically-operated trees.

To satisfy the changing expectations of the public and demands for a more interactive experience, the illuminations have partnered with Sony. Two portable trailers have been fitted with the firm's latest technology: the Eyetoy, and Dance:UK, an interactive Playstation dance mat, which is being launched at the illuminations. "This is the first interactive display to this degree," states Ryan.

Distribution/power supply
The best designs in the world are nothing without a reliable electricity supply and equipment. "We can't just tap into the streetlights, it's too big for that," stresses Ryan. Instead, a dedicated mains distribution system powered directly from the Grid runs the length of the promenade. This feeds seven substations containing stepdown transformers and switchgear that are spread along the length and serve feeder cabinets running north and south from the substations by underground cables. From the cabinets a three-phase supply is distributed to the lamp posts, where it is split and used as single-phase for the features. Each lamp post can be individually isolated by means of an mcb or fuse at its base. The feed to the features is via three 32 A sockets on the lamp posts on the West (sea) side of the road. To feed the east side, a 4 mm, harmonised, three-core rubber cable is tripped across the road at height. The whole display is controlled by a Scada system. Each feature has its own electronic controllers to operate the local switching of lights. "It's the only practical way to do it," says Ryan.

A heavy mains cable is run to the cliffs to supply the tableaux. The distribution from this has to be redrawn each year and new cabling installed due to the varying needs of each display. Ryan explains: "If you're moving a tableau that uses a lot of current you have to rebalance the phases."

One of the biggest problems for the illuminations team is the location of the display. "It's a great environment to test a product but not an ideal place if you're not sure about your product," states Ryan of the exposed coastal position. Everything must be designed to withstand severe climatic conditions: wind and the corrosive salt sea spray being the biggest dangers. "We've had IP68 plugs that have got water into them," he stresses.

This factor has played a major role in the conversion of the illuminations to a low voltage system. "Low voltage is very safe: safe for staff to work on and reliable," states Ryan. "Basically if you're below 50 V, you're a lot safer and a lot more reliable, and you don't have to earth it," he adds. Ryan is an advocate of low voltage equipment, having been inspired over 30 years ago on a childhood trip to a Skegness amusement park. He explains: "On some rides they used to have fluorescent tubes and health and safety basically told them to take them off. They replaced them with 24 V lamps. When I came to Blackpool I said: 'this is what we've got to do, I've seen it work'. They can stay lit in any weather – you can soak them in salt water and they'll stay lit."

The low voltage theory was tested on sections of the display before the gradual conversion. A 24 V separated extra low voltage system is being used after a "brief flirtation" with 12 V showed that the voltage drop between features was unsuitably large; 48 V worked but the lamps are more expensive.

The festoon lighting is fed by 2·5 V cable running between two lamp posts, across the road then parallel to the original run in a U formation. This eases installation. The 2·5 V cable is strong and will carry sufficient current – a 75 m run with lamps at 1 m intervals is possible with no voltage drop. The cable has a life of around seven years and, as with the features, is rotated annually.

The 15 W festoon lamps of the past have been replaced with 5 W versions, giving a significant saving in electricity use; the standard version is a 24 V, B22 filament lamp. These are specially imported from the Far East, which is not always a simple task, but is necessary as no standard products are available in the UK and, Ryan states: "No British lamp manufacturer would make them for us. We ordered 50 000, but they didn't think it was worth getting out of bed for." Political or economic instability are standard risks of a foreign source, but this year's batch was delayed by something quite different: the SARS virus. The lamps eventually arrived to site only three days before installation was due to begin.

Other lamp sources used include fluorescents, gobos and non-neons. Neon lamps are not used as they are unable to cope with the conditions. "I've never found a neon that will work. If you don't keep it clean, the salty deposit on the outside will catch fire," explains Ryan.

Switch on this year was on 29 August, but there is no time to rest for the illuminations team: plans for next year have already begun. Apt for a seaside resort, designer Graham Ogden gets his main inspiration from his holidays. This year he ventured to Hawaii, so look out for surfers in the coming years!