Crossrail: Eleanor Street & Mile End Road Shafts

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CEEQUAL Excellent (87.2%) – Whole Project Award
Version 4.1, November 2017 | London

Client:  Crossrail Ltd
Designer: Jacobs Engineering Group
Contractor: Costain Skanska Joint Venture

Assessors: Mike de Silva & Michael Whitehead (Crossrail Ltd) Simon Taylor (Constain Skanska JV),  James Ennis & Jessica Kennedy (Arup)

Project summary

Crossrail is delivering the Elizabeth line – a new railway for London and the South East. When it opens through central London from December 2018, it will transform travel in London.

As Europe’s largest infrastructure project, Crossrail is delivering 42km of tunnels, 10 new stations and improving 30 more. The finished railway will be an accessible route of 41 stations from Reading and Heathrow in the west to Shenfield and Abbey Wood in the east. When the railway is fully operational in 2019, the Elizabeth line will increase London’s rail capacity by 10 per cent, reduce journey times, offer more choice and bring an additional 1.5 million people within 45 minutes of London.

Costain Skanska Joint Venture (CSJV) are Principal Contractor for the Crossrail Eleanor Street & Mile End Shafts – Civil Works project which commenced in 2012.

The project comprises the construction of Crossrail intermediate shafts, adits (to link the shafts to the main running tunnels), head houses and associated enabling works at Mile End Park and Eleanor Street shaft sites. These two sites are both located in the London Borough of Tower Hamlets.
During the fourth quarter of 2015, CSJV was awarded a supplementary package of works to fit out shafts, construct head houses and complete associated packages of works at three additional Crossrail shaft sites. These sites were Limmo Peninsula in the London Borough of Newham, Stepney Green in the London Borough of Tower Hamlets and Fisher Street in the London Borough of Camden. CSJV took over the three additional shaft sites as Principal Contractor at intervals during February and May 2016.

The intermediate shafts at all sites provide access to the running tunnels for firefighting, emergency access/egress and general maintenance. At Eleanor Street and Stepney Green sites, the shafts host fans for tunnel ventilation as well as a drainage system. Mechanical, electrical and public health services will be provided in each shaft to enable these primary functions to operate effectively.

When complete, the C360 project will be an essential part of the operational railway. When the railway is fully operational in 2019, the Elizabeth line will increase London’s rail capacity by 10 per cent, reduce journey times, offer more choice and bring an additional 1.5 million people within 45 minutes of London.

Challenges and achievements

Project Strategy

In order to meet the agreed terms of the Crossrail works contract, Costain Skanska Joint Venture were required to prepare and implement Management Plans addressing a number of Environmental topic areas before commencement of the works. The Management Plans for Sustainable Transport were communicated in staff training and displayed on dedicated noticeboards at each of our sites. The Site Waste Management Plan was actively updated along with a live online version which tracked active targets, waste duty of care arrangements and removal figures. The Ecology Plan was updated whenever the ecology consultants were employed to manage these aspects on our sites and to take account of their findings. The Energy Plan was updated with details of various initiatives that were trialled on our sites and found to be successful in energy saving so that the initiatives could be considered for our sister sites. The main Environmental Management Plan was used as a key reference document for our Work Package Plans and was reviewed & updated throughout the six year programme on a minimum six monthly basis.

People and Communities

The project sites are located in London and stretch from Holborn in the centre of London to Canning Town in the east. Each of the project sites has the potential to impact on local communities as they are located in very sensitive areas in close proximity to residential properties, businesses and recreational areas used by the public. For example, the Eleanor Street site is adjacent to a traveller community; the Mile End site is located adjacent to a sports centre in Mile End Park which is one of very few green spaces available to residents in East London; Stepney City Farm, a park, residential properties and a school surround the Stepney Green site; Fisher Street is located in the densely populated London zone 1 and is surrounded by businesses and residential premises, and the Limmo Site is adjacent to the River Lea with residential flats across the River.

The project team understood that as they were going to be located on each of our construction sites for a number of years we would become part of the local community. As a result, having a good relationship with the community was immediately identified as an important aspect if the project was to be a success. C360 employed a dedicated community relations manager to oversee this.

The senior management, including the Community Relations Manager, reviewed details of the catchment area (as a minimum all properties within 100 metres of the works) including residents’ groups, ward councillors, community centres etc. This enabled the team to select who the main stakeholders are in the area, those who should receive information regarding the construction works and its program, and also if any specific groups require unique ways of disseminating the communication materials i.e languages spoken, or a sensory impairment. As part of the wider benefits of the C360 project to the local community, examining the location of the works and the catchment area also enabled the team to explore areas for opportunity to invest in the local community and assist in funding local projects and activities. This led to the development of C360s community liaison investment plan (CLIP).

The engagement with the local residents resulted in the low number of complaints received by the project. This meant that the local authorities were confident in consenting a request to increase working hours on all our sites. The likelihood of disturbance from our works on local residents was greatly reduced, due in part to early notification of works, and a site team who were well trained on nuisance reduction.

Other ways C360 have benefitted the local community are by using local charities to supply the food and meeting rooms for training and meetings. This meant that CSJV have ensured that money stays in the local community. The project has also employed a number of local companies and suppliers to carry out work on site.

The site team have conducted numerous site visits and open days for local primary and secondary schools as well as colleges and universities. C360 has also teamed up with a local girls school (Ursuline Academy) and the company Woman in Construction to inspire more females into the construction industry. The C360 STEM female graduate engineers took the lead on these days. One student in particular took note of day she attended. Following an interview, this student was formally offered a place on Skanska’s Graduate Program.

An engineering program, being led by the C360 STEM team, is being set up at St John Cass School adjacent to Stepney Green site, to try and inspire more future engineers and construction workers.

C360 have partnered with Enabling Enterprise who are a not-for-profit social enterprise. With the help of C360 they hope the sites visits will equip young people with the skills, experiences and aspirations they need to succeed in life.

CSJV staff have set up a ‘Book Buddy’ volunteer reading scheme at the local Cayley Primary School. Every Thursday each week during term time, 4 CSJV staff spent time reading with 4 pupils. C360 chose Cayley Primary School as Ofsted said that ‘the school is much larger than the average-sized school with most pupils being of Bangladeshi heritage. The proportion of pupils known to be eligible for free school meals is well above that found nationally. The proportion of pupils who speak English as an additional language is well above average and many who join the school are at the early stages of learning English’.

C360 has partnered with London Community Rehabilitation Company who supports ex-offenders to find employment. C360 have employed a number of people including a Graduate Quantity Surveyor and a Safety administrator through this initiative.
The staff on C360 organise a number of fundraising days throughout the year for local charities and organisations including: Cancer research UK, St Josephs Hospice, London Air Ambulance, SERV Bloodbikes and Spitalfields Crypt Trust.

The Historic Environment

In order to ensure that noise from construction of a Floating Track Slab (FTS) didn’t adversely impact local residents, a temporary acoustic enclosure had to be constructed at the Fisher Street site. However, as the site offices used by CSJV at Fisher Street are a Grade II listed building with a basement, CSJV were required to install temporary props within the basement of the listed building to support the weight of the equipment, acoustic shed and CSJV materials on the roof of the shed. As agreed with London Borough of Camden heritage advisor, a method which negated the need for drilling was used. This enabled zero impact to the historic fabric of the building.

The use of Filcor 125 (expanded polystyrene) beneath the pump slab further protected the building and basement through weight reduction. Filcor 125 spread the load more evenly over the basement, and reduced the vibration from the pumps. As Filcor 125 is a breaker, it offered damping properties, effectively leaving the slab floating on top due to the cantilevered construction. Vibration monitoring was carried out at the site which showed there to be no exceedance of the parameters 100% across all monitoring events.

Ecology and Biodiversity

Mile End site abuts Mile End Park, one of very few green spaces available to local residents. Eleanor Street site is an urban environment providing limited habitat. Whilst Crossrail and CSJVs principles are to continuously push for sustainable improvements in construction, complex construction designs and space restrictions left limited scope to mitigate biodiversity loss. However, the aforementioned conditions created an intensified need to protect and enhance biodiversity and support the surrounding communities.

The biodiversity measures taken at these two sites include a wildflower grassland mound covering the headhouse with climbing plants covering the wall at Mile End, and incorporation of a sedum covered green roof on the headhouse and planting of trees and wildflower grassland at Eleanor Street.
Mile End mound was formed using Lytag – an aggregate manufactured from coal power station waste. The wildflower meadow mix comprised 35 different species. 3 trees of moderate value were felled during enabling works. CSJV engaged with London Borough of Tower Hamlets (LBTH) Park Development Officer to ensure the location and species of replacement trees were in line with the parks design and LBTH Biodiversity Action Plan (BAP). 5 native Franz Fontaine and 2 pollinator encouraging fruit trees (Malus Elstar) were planted.

19 low growing, self-regenerating, and drought resistant sedum species on top of a substrate comprising of recycled crushed brick, topsoil and composted recycled material made up the green roof at Eleanor Street. The substrate stored rainwater for plant growth and helped alleviate flooding. As hawthorn, is a target species in the LBTHs BAP, this is used for security planting between the head house and local road.
This project increases two of LBTH’s BAP priority habitats (open mosaic via green roofs and neutral grassland via wildflower turf roof) as well as encouraging birds, invertebrates including Brimstone butterfly, Common Blue butterfly and every species of bumblebees, the latter three of which are listed as priority species in LBTH BAP.

The rooftops recycle CO2 into O2. They lock up airborne pollutants, which improves air quality and generates a healthy micro-climate around the building for colonisation by neighbouring flora and fauna. The mass on the green structures have sound-absorbing properties to create dramatic dB reductions, provides aesthetic benefits including adding natural colour to the local area and encourages the public to understand wildlife value. Finally, CSJV aimed to return Mile End Park to its original character and maintain any green corridors, footpath and cycle connections.
One aim on this project is to achieve no net loss of biodiversity. Assessments were carried out using the DEFRA tool to quantify this. 88% and 62% increase in biodiversity post-construction for Mile End and Eleanor Street respectively, thus exceeding the project aim.

Physical Resources – Use and Management (Energy, Water, Materials, Waste)

C360 has been donating the excess materials to local not-for-profit organisations such as the Stepney City Farm and Friends for Tower Hamlets Cemetery Park. Materials such as concrete, paving stones, bricks, top soil, semi mature trees, scaffold boards and old PPE have been donated. These materials have been used for edged pathways to help make the route easier for people with visual impairments, a new concrete base for the pig pen and a new paved area in one of the gardens, allowing access for those in wheelchairs and pushchairs at the farm. C360 also arranged with the farm and the cemetery park for staff to volunteer installing these items as well as on several other occasions.
C360s waste timber is collected by a charity called Community Wood Recycling. This charity collects the wood and either reuses or recycles the wood depending on quality. In 2016 CSJV as a collective has helped to rescue, reuse and recycle more than 15,000 tonnes of waste timber. This has created more than 500 potentially life-changing job and training opportunities for marginalised people which includes underprivileged, ex-offenders or people with learning difficulties.

At the Fisher Street site, C360 constructed a temporary acoustic enclosure to ensure that noise from construction of a Floating Track Slab (FTS) didn’t adversely impact local residents. The team designed the enclosure with deconstruction in mind to ensure that all materials were used and disposed in the most sustainable way possible.

Once the shed was no longer needed, all materials as part of the enclosure have either been reused or recycled thus 0% of waste went to landfill. The Soundex mats were reused by Costain Thames Tideway project, the metal structure was dismantled and given back to Envirofab for recycling or reuse, and the slab sections taken away by Tarmac for recycling as road aggregate.

The lifting eyes were cast into the reinforced concrete slab. The benefits of this include time savings (deconstruction of the slab will be 60% faster than using traditional methods via breaking up); better relationships with adjoining properties as it is a lot quieter than other demolition methods; lower risk as de-construction will not leave any parties susceptible to possible flying debris and carbon efficient as it removes the need for plant to carry out the slab break up.

The C360 project had little interface with the non-sewerage water environment, except at Limmo Peninsula worksite, where our works were in close proximity to the Bow Creek area of the River Lea. As our site operated a temporary works discharge into the river under consent from the EA, we set up a robust filtration and treatment system for water being removed from the tunnel shaft. This system operated fail-safes and shut-offs for suspended solids and pH variance, and was inspected regularly to meet the conditions of our consent. We ensured that our direct impacts on the water environment were effectively isolated by operating a barriered ten metre border zone between the worksite and the river bank, which for a long stretch was demarked by a double layer of fencing to ensure that there was no uncertainty about the restricted work areas.

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