Contractors working on HS2 have begun excavating the first of five shafts that will provide ventilation and emergency access to the ten-mile long tunnels they are digging under the Chiltern hills.

Once complete, the 78m deep shaft near the village of Chalfont St Peter will be topped with a headhouse inspired by nearby barns and other agricultural buildings to help it fit into the surrounding landscape.

Below ground level, the shaft will reach down to the twin tunnels, with fans and other equipment designed to regulate air quality and temperature, remove smoke in the event of a fire and provide access for the emergency services.

The structure was designed by HS2 Ltd’s main works contractor Align JV – a team made up of Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick – working with its design partners Jacobs and Ingerop-Rendel, and the architect Grimshaw and landscape designers, LDA.

A 120 tonne drilling rig with a specialised cutting head was used to excavate the walls of the shaft, before concrete was poured in to form each of the 16 wall panels. Now, with the walls complete, the team are excavating the chalk from inside the shaft to reveal the full depth of the structure.

The two HS2 tunnel boring machines (TBMs) – named Florence and Cecilia – are expected to reach the shaft next year and complete their 10 mile journey in three years’ time. Once the TBMs have passed through, the team will build the internal vent shaft structures, basement works and install the equipment.

Around 18,000 cubic meters of material is expected to be excavated from the shaft, with the chalk set to be reused to landscape the site once construction is complete, taking trucks off locals roads and helping to create new chalk grassland habitats. 

Rohan Perin, HS2 Ltd’s Project Client Director said:  “The excavation at Chalfont St Peter shows how much progress we have already made in delivering the Chiltern tunnels. Topped with a headhouse inspired by the style of local barns and agricultural buildings, the shaft is one of the few elements of the tunnel which will be visible above ground level and shows just how seriously we are taking our responsibility to protect the landscape and natural environment.

How the site will look once work is finished

Daniel Altier, Align Project Director added: “I am delighted with the progress we have made with the Chalfont St Peter shaft and the fact that we have been able to put in place measures to limit disruption to the local community.

“We are very conscious to ensure that any permanent structures on the project fit into the surrounding landscape and the Chalfont St Peter headhouse is no exception.”

Before the start of construction, a temporary access road was built to link the site with the A413, Amersham Road. This has allowed construction traffic to avoid the centre of Chalfont St Peter and stopped heavy goods vehicles (HGVs) driving past Robertswood School and the Epilepsy Society.

A new temporary marshalled lorry holding area has also been established on the A413 near Gerrards Cross. HGVs can be held in this newly surfaced layby until their approach to the vent shaft site is clear – helping to reduce congestion and eliminate queueing at the site entrance.

Industry leaders have called for the acceleration of rules relaxing requirements for Covid-19 self-isolation for double-vaccinated construction workers.

The Construction Leadership Council is warning that sites will “grind to a halt” amid the pingdemic.

On August 16 regulations on self-isolation will be relaxed across the economy when anyone who has been double-jabbed will be able to continue to work if they are notified that they have been a contact of someone that has Covid-19.

But ahead of the change, construction businesses from merchants to manufacturers and consultants to contractors are being severely hampered as staff are having to stay home after being identified as a contact of a Covid-19 case, even if they are fully vaccinated.

The issue is further exacerbating existing difficult trading due to materials and staff shortages.

The CLC proposes that the 16 August relaxation be brought forward as soon as is possible.

CLC co-chair Andy Mitchell said: “We have reports from across the industry of plants, sites and offices having to wind down activities as staff have been asked to isolate.

“This is putting very significant pressure on the sector, risking project delivery and even the viability of some firms.

“Where staff are already fully vaccinated, and recognising that such people will be free to work from 16 August anyway, we are asking the Government to bring forward this
date for essential industries like construction, ensuring that the industry doesn’t grind to a halt.”

Did you miss our previous article…
https://www.clarkeconstructioncreations.com/?p=81

Construction companies are backing calls from business chiefs to end the pingdemic of workers being forced to self isolate.

Tony Danker, CBI Director-General, said: “The current approach to self-isolation is closing down the economy rather than opening it up. This is surely the opposite of what the Government intended. Businesses have exhausted their contingency plans and are at risk of grinding to a halt in the next few weeks.”

“What is now needed is a well-balanced approach to reopening the economy, rather than the awkward compromise that currently exists.”

Build UK is supporting the CBI’s approach as pressure grows to bring forward the August 16 deadline for easing self-isolation rules.

Danker said: “We can end the pingdemic by bringing forward the date by which all those who have been double-jabbed no longer need to self-isolate if not infectious and introducing a test & release scheme.

“Then, with infection rates rising, mitigations should also be put in place. The vast majority of businesses today are already behind this approach – demonstrating to employees and customers their diligence on Covid safety and this approach should be extended to other settings.

“We must also ensure workplaces have access to an effective, accessible testing regime. With workplace testing due to end in a matter of days, firms need urgent clarity on how community testing will work in practice.

“Ultimately, the country needs a new settlement for our society if we are to confidently live with the virus. It’s not just about the next three weeks, but the next 6-12 months – come what may in the winter ahead. The CBI will be working with businesses to explore what they need in the coming days and will set out our proposals on a new settlement.”

Did you miss our previous article…
https://www.clarkeconstructioncreations.com/?p=56

The Department for Education has named the next wave of 50 schools for the Prime Minister’s ten-year rebuilding programme.

Over the next decade, the School Rebuilding Programme is due to deliver 500 projects.

The rebuilds and refurbishments will create modern education environments, providing new facilities from classrooms and science labs, to sports halls and dining rooms.

New school buildings will be designed to be net-zero carbon in operation, helping meet the Government’s net-zero target.

The 50 projects build on the existing programme bringing the total number of schools being upgraded to 100.

The DfE is also launching a consultation to gather views on how to prioritise schools for the remainder of the programme.

Funding for individual projects in the School Rebuilding programme will be determined when the scope and delivery plans at each school are developed. Projects will range from replacing or refurbishing individual buildings through to whole school rebuilds.

The most advanced projects from the first round of the programme will begin construction in autumn 2021.

Did you miss our previous article…
https://www.clarkeconstructioncreations.com/?p=50