It is a Site of Special Scientific Interest and designated part of a Special Protection Area. The new tunnel, which is a total of 1.2 miles long, is the longest non-estuarial tunnel in the United Kingdom. The maximum depth below ground, measured to the top of the tunnel, is about 200ft.

A full technical submittal on Elta Building Services Division proposals was required by ventilation contractors, James Paget Services, along with a formal letter of life expectancy for the units. Orders for the specially manufactured units, were then placed in April and May 2010. The first part of the order comprised two sets of long-cased, axial ‘run & standby’ fans with matching stainless steel ancillaries for ventilation of the void in the low-point sump.

After Elta sought confirmation from the motor supplier that it was possible to do so, each fan is set to work for 12 hours then switch to standby mode. They then operate in the opposite direction, switching again after each 24-hour period. “Windmilling” losses for standby fans, along with the control logistics of forward/reverse operation were decisive factors in the model selection process.

The second part of the order was for four bifurcated, cylindrically cased ATEX axial fans with matching ancillaries. Manufactured by the Fareham based Applied Technology Division of Elta these were designed to meet specific site requirements when supplying air and extracting gases from the drainage impounding sump. The bifurcated fans are quality, direct motor driven units, specially developed for handling hostile conditions of hot, dust-laden air, corrosive fumes or gases. The units are designed so that the gases by-pass the motor in order to eliminate any detrimental effects.

Two temperature options are available in either a cylindrical or conical casing. Elta manufactures a range of fans to meet the European Union (EU) directive ATEX (ATmosphÌÄå¬res EXplosibles) which coordinates various technical and legal conditions throughout Europe. This new and evolving standard ensures safety of equipment installed and operated in potentially dangerous atmospheres by reducing the explosion risk through established design methods.

The new, twin-bored road tunnel is an important part of the £371 million Hindhead project, one of the major schemes in the current Government’s programme of road works. The tunnel is part of the 4 milelong dual-carriageway currently under construction to replace the last remaining stretch of singlecarriageway. It will complete the 68 mile link between Portsmouth and the capital, removing a major source of congestion on a busy route (which carries over 28,000 vehicles per day) and improving road safety as well as air quality in the area. Work on the main tunneling works started in February 2008.

The tunnel features cross-passages every 100 metres along with state-of-the-art safety and communications systems. Secretary of State for Transport, Mr. Philip Hammond opened the Southbound bore to traffic on Wednesday, 27th July 2011, the first vehicles being escorted through the tunnel in convoy. Northbound traffic was introduced to the new road a few days later. It was opened within budget and on schedule.

Elta is part of the £85 million Elta Group, a family of businesses with operations in six countries on four continents which, together with a network of international distributors, provides quality fans and related air movement equipment to customers worldwide.

The LC Range is an extensive selection of robust, long-cased axial fans, fitted with adjustable-pitch, aerofoil-section, bladed impellers and offers performance with strength, durability and corrosion resistance.

The fans were produced in a collaborative project between the Fareham and Kingswinford manufacturing facilities of fan specialist Elta, for the pressurised ventilation system at the new station. Supplied and fitted by Elta’s Building Services division customer Advanced Smoke Technology Limited, experts in the design and installation of smoke control, extract and pressurisation systems, the units are mounted in pairs on purpose-built frames on the ceiling of the station building above the west and east stairwells. They are wired into the master control panel of a pressurisation system, which incorporates an automatic changeover facility should the duty fan fail to switch to ‘standby’ mode. In this way, constant ventilation and a positive pressure are maintained within the stairwells of the station.

Advanced Smoke’s spokesman, Brian Lockton commented: “We have had a good working relationship with Elta for some time now. This job involved various exacting stipulations because of the sensitivity of fire hazard in stations. We have always found that by working closely with them, we are able to overcome any technical difficulties with comparative ease.”

Finished in RAL 7001 matt grey to the specification of the customer (London Underground Limited – LUL), the units and accessories supplied meet the requirements of Section 2 Materials Approval as defined in the Fire Precautions Act and LUL Standard Fire Safety Performance of Materials Specification. The LUL requirement is associated with the paint finish of the units, which is specially formulated for areas requiring low smoke and low, toxic-fume emission. It is also graffiti resistant.

Specialised, electrical cabling within the fans from the motors to the external terminal boxes also complied with Section 12 of the LUL Specification – being heavy duty, enhanced oil-resisting, flame retardant with low smoke and zero halogen-gas emissions.

Main contractor for the Dalston Junction Railway Station project is Mansells Construction with engineering services supplied by Briggs & Forrester.

Although the original station closed over two decades ago on 27 June 1986, along with the railway line it served, the neighbourhood retains its name, with road signs and bus stops alike still referring to the area as ‘Dalston Junction’.

Located at the corner of Kingsland High Street and Dalston Lane, the station first opened on 1 November 1865 as part of an extension to Broad Street on the North London Line. Remains of the former station were cleared in early 2005 and the station is on schedule to re-open in May 2010 – initially as the temporary northern terminus on the Chelsea-Hackney Line route between Wimbledon and Epping, as part of the London Overground East London Line extension.

The new station is 250 metres from an existing station, Dalston Kingsland, but future railway maps will show the two stations as a single interchange.

For more information on our products or services please contact Elta Building Services on +44 (0)1384 275800 or Elta Applied Technology on +44 (0)1489 566500. Alternatively please visit our website eltauk.com

Elta is part of the £85 million Elta Group, a family of businesses with operations in six countries on four continents which, together with a network of international distributors, provides quality fans and related air movement equipment to customers worldwide.

Contractor Balfour Beatty, working on behalf of the Highways Agency, has already taken delivery of its temporary ventilation for the Hindhead bypass, which will provide a dual carriageway link from London to Portsmouth. The 1.4 metre diameter contra rotating fans were designed and manufactured at Elta in Fareham and their purpose is to extract machinery fumes and dust to provide fresh air whilst the tunnel is under construction.

After taking into account ecological and environmental considerations, Elta’s technical expertise has ensured that the manufactured units are sympathetic to wildlife at the Hindhead National Trust site and ensuring nearby residential houses are unaffected by the continual running of the fans. The units have been constructed utilising heavy attenuators and by housing the fans inside acoustically lagged containers, noise pollution has been successfully kept to a minimum.

Work is also due to commence later this year at Elta on a £150,000 contract to supply ventilation for three underground tunnels housing high voltage electric cables in the City of London. The EDF Energy and National Grid tunnels require specialist ventilation to remove the heat produced by the electric cables along with being required for smoke clearance in the event of a fire.

Elta’s smoke ventilation ranges is specifically developed for general ventilation plus emergency smoke extract and the company has recently extended its EC-Certification for smoke related fan units with BSI, making it one of the largest certified standard product ranges available within Europe, as Allan Hurdle, managing director of Elta, Fareham explains;

“It’s an ideal project for Elta to become involved with as we have a wealth of knowledge and expertise in this required field. The fans needed for the tunnel sites in London need to remove hot smoke in the event of an emergency and must be constructed in such a way so that they do not ignite any gas that may be present.

Acoustic lagging is a specific feature of these applications as sound levels are important as the main vent shafts are in residential areas in London. As one of the leading suppliers in the industry our customers are assured of consistently high product quality by encompassing the very latest standards.”

Elta is part of the £85 million Elta Group, a family of businesses with operations in six countries on four continents which, together with a network of international distributors, provides quality fans and related air movement equipment to customers worldwide.