HS2 construction teams start to make their mark
MAJOR civil engineering projects are already beginning to make their presencefelt alongthe routeof HS2Phase1 as preparations for the constructionof the new railway gearup.
At what will eventuallybe the southernportal of the 10- mile-long Chiltern Tunnels, a 17-metrehigh headwallhas been constructed ready for the arrivalof two giant tunnel boring machines( TB Ms) later this year.
Specialiset ngineersled by H S 2' sm a in works contractor AlignJV have excavated more than 160,000sqm of material over the last seven months to createa levelsurfacefrom which the pairof 2,000-tonne,17-metre long machineswill launchin early-2021.
Tunnel ling is expected to take threeyearsT. hetwo TBMshave been named Florence a, ft er Florence Nightingale, and Cecilia in recognitionof pioneering astronomerand astrophysicist, CeciliaPayne-Gaposchkiwn,ho wasborn in Buckinghamshire.
Soilnails
Morethan 636'soil nails'someup to 20 metres long - havebeendriven into the headwalland connected to a concretelining to hold the groundand the surfaceof the headwallin placewhen the TBMsbeginto breakthrough. A much more public sign of progress appeared near Solihull on August9 when a new
65-m modular bridge was installed across the M 42 motorwayin just two days. The2,750-tonnebridge structure was carried along the motorwayon a self-propelled, 448- wheel transporter, which tookjust 105minutesto move the bridge span 1 SO metres from construction site to its final position.
Thework wascompleted 22 hoursearlierthan planned, allowingthe busyroadto reopen.
Roadclosures
Traditional construction methodswould haverequired severalweeksof roadclosures, followed by additional weekend and overnight closures.
Furtherwork in preparationfor the arrivalof HS2isscheduled to take placearoundthe Birmingham Airport Interchange station laterthis year.
In west London,a Balfour Beat ty V IN C IS Y ST RA joint v en tu re(BBVSt)ookpos session of the entire Old OakCommon Interchange construction site on July27.
The movefollows morethan two yearsof enablingand clearanceworksat the site, including demolishing the former Great Western Railway locomotivesheds.
Initial work at Old Oakwill includepiling worksfor the foundationsof the new station, with around £350 million of contracts expected to be awardedoverthe nexttwo years for preparationwork alone.
■ HS2Ltd haslauncheda £523mtenderfor a specialist contractor to deliver high voltage power supply systems for Phase1 and Phase2a. Thewinner will be responsiblefor the design, manufacture, supply, installation, testing, commissioning and maintenanceof HVpower supply sys te msi,nc lu ding aroundSOtraction sub-stations betweenLondonand Crewe and a dedicatedHVnon-traction power networkfor stations, tunnel shafts, portals, de pots and railwaysystems.
A shortlist is expectedto be announced next year, with the contract awarded in 2022.