St Pancras International (Transport - ESP)

St Pancras International is a key London interchange and the very definition of a ‘destination station’. Managed by Network Rail High Speed Ltd this buzzing regional, national and international travel hub has been part of Britain's railways heritage for the better part of 150 years.

Designed by William Barlow in 1863, it gained instant fame for its “Barlow Shed” train shed arch that spans 73 metres and is over 30 metres high at its apex; at the time, the largest enclosed space in the world. The Grade 1 listed red brick Gothic landmark façade fronting the station was the result of an architectural competition in 1865 and became the Midland Grand Hotel. In 1935, the hotel was closed and the building became railway offices, renamed as the St Pancras Chambers.

One of the largest transport hubs in Europe, St Pancras International now has 13 platforms, six of which are around one kilometre long and serve the international Eurostar services. The station also incorporates 47 retail outlets and designer boutiques, plus stylish Eurostar arrivals and departure lounges, and a further ten shops on the station platform level. It also boasts a daily farmers' market and, at 90 metres, the longest champagne bar in Europe. However, thanks to careful attention to detail and a sensitive understanding of the architectural importance of the National Heritage building, St Pancras International remains one of the greatest Victorian buildings in London.

Recently named one of the UK's most used stations with around 50 million people visiting the station each year for travel and retail experiences, safety of staff and passengers is of the highest importance.

Following a site safety upgrade, the Eurostar terminus at St Pancras International in London bristles with the latest high-performance fire detection and alarm technology, including no fewer than 5,000 Hochiki ESP – Enhanced System Protocol – analogue addressable devices, installed throughout the site. A variety of Hochiki devices were selected, each chosen for its proven ability to combat fire risks in the huge multi-activity station. They included optical smoke sensors for back office and main passenger concourse areas; multi-sensors for more challenging environments such as plant rooms and workshops; heat detectors in kitchens and toilets; audio visual devices and base sounder beacons.

They are all automatically re-calibrated every 24 hours to compensate for any environmental contamination and to ensure that they continue to operate reliably at the specified sensitivity. Indeed, a key factor cited by the installer for the decision to opt for the Hochiki solution was the flexibility of the devices to be compatible with other products already installed. For example, Hochiki's ESP protocol devices are configured to share system information and event details on a highly fault-tolerant secure network.

The success of the installation can be judged by the fact that the same solutions were also adopted to protect two other stations on the UK side of the London-to-Paris rail link. The Ebbsfleet International Station near Dartford in Kent, and the Stratford International Station near the City and Canary Wharf that was also central to the 2012 Olympic transport strategy, with forecasted passenger volumes of 25,000 a day to and from the Olympic Games' venues.

However, technical performance was not the only consideration with which the installer had to contend

“We had to take great care when installing the fire detection equipment, as it was vital to minimise any adverse aesthetic impact on the highly decorative Victorian architecture. Another major challenge was the need to install the new system in a station that was to remain open and be used daily by thousands of passengers. So, the fire safety system had to be always fully functional.”

Error-free detection

The life safety installation is managed in the station's main control room where, around the clock, a 1.2-metre LCD screen displays the entire station and its fire detection system. This provides an overview of the whole installation, or a drill-down, showing various levels of detail; if necessary, pinpointing information on any specific device. If, for example, a fire is signalled, the precise location can be viewed on screen, where devices can be interrogated. The screen can even display the best evacuation routes.

With huge numbers of people converging on the station's platforms at peak travel times, and the travelling public's ever-present concerns regarding terrorist activities, ensuring the minimum disruption from false alarms was a paramount consideration. In the event of a confirmed fire, the system directly controls and monitors the station's voice evacuation system, which is audible in all the station's public areas. However, in places where high levels of ambient noise may make it difficult to hear voice alarms, such as toilets, Hochiki beacons were also fitted.

Famous for helping to reduce false alarms, Hochiki's ESP protocol uses a combination of sophisticated algorithms that reduce data corruption. Additionally, with parity and checksum error detection principles applied to every set of data, unwanted external “noise”, such as EMC interference is eliminated.

Hochiki optical smoke sensors are designed for both efficient detection and the virtual elimination of false alarms. The sensor's chamber incorporates uniquely angled baffles which allow air and smoke to circulate within the chamber but reduce the ambient light entering the chamber, thus improving the response of the optical elements. The sophistication of the sensing elements in the chamber enables it to also sense a wider range of fire types, so providing a more balanced response to different types of smoke particles. This is an Hochiki-developed technology that the company calls its “high-performance chamber”.

The sensitivity of each device is set to match the prevailing conditions, additionally, to allow the most suitable sensing mode to be adopted for a particular environment, the multi-sensors can be set to heat only, smoke only or a combination of both sensing elements working together to determine a real fire.

An Integrated Solution

The main control panel was designed and engineered to meet High Speed 1 requirements. It incorporated 196 fire zone indicators, and several firefighters' control switches to allow the plant to be managed anywhere in the network via Hochiki loop output relays. A repeater panel, with an emergency fire telephone, was incorporated into the system for use by the fire brigade should an emergency condition occur within the main control suite.

Summarising on the St Pancras International project the installer said:

“Over the years we have used many different fire detection devices and we can truly say that Hochiki has time and time again proved to be the most reliable and best performing of them all”.

Explaining in more detail:

“The key elements that we look for in a fire system are reliability, flexibility, good quality control, high performance and false alarm management. The last thing we need on a site such as St Pancras International is unwanted false alarms. Hochiki have delivered superior product performance and hands-on technical support.”

Just as Eurostar trains speeding out of the rejuvenated St Pancras International have established Britain's credentials in world-class high speed rail travel, so too has a new European benchmark for railway station fire safety been established.

The Transport sector has a duty of care for its passengers and staff as well as having to provide constant protection of its property and assets from the threat of fire.