Load/Path

Over the weekend of 24 October, HS2 finished sliding the second of two steel viaducts across the M6 near Birmingham. The motorway stayed open throughout.

Each viaduct is 320 m long. Instead of lifting the deck into place with cranes, the contractor, Balfour Beatty VINCI, built it in sections behind one end. Strand jacks (hydraulic jacks that pull on steel cables) then hauled it forward over the road, a stage at a time. The last push moved the deck 76 m in nine hours. A nearby link road was shut as a safety zone and reopened 25 hours early. The two decks sit side by side, 100 mm apart. The east deck, finished in 2025, will carry trains towards London. The new west deck carries them towards Birmingham Curzon Street and the north.

On 23 October, about 211 households were moved out of three residential towers in Canning Town, east London, in the early hours. Newham Council says the property's management company reported "serious structural problems". Residents have been told not to go back until further notice.

The council has not said what is wrong. The trade paper Construction Enquirer reports that letters to residents flagged problems with the transfer slab, and a structural investigation is under way. A transfer slab is a thick floor that collects loads from the walls and columns above. It passes them to a different set of columns below. It is often used where flats sit over a car park or shops. The towers were finished in 2017.

On 20 October, crews in south-west China broke through the second bore of the Jinyang Tunnel, a 12.18 km twin-tube road tunnel on a new expressway. At its deepest, there is 1,723 m of rock above it.

That much rock squeezes hard. The Tunnelling Journal reports horizontal stress in the rock of about 54 MPa. Stress that high can make rock burst violently from the tunnel walls. Groundwater pressed on the tunnel at up to 3.5 MPa. About 85% of the rock was rated poor or very poor (grades IV and V). Over the whole dig, about 160 million m³ of water flowed in. Crews drilled and blasted for 2,132 days. They lined the tunnel with two layers of steel-fibre concrete and drilled relief holes to let stress out of the rock before it burst.

Inter-array cables link each wind turbine to the others and to the substation that sends power ashore. This week the contractor Seaway7 finished laying all 95 of them at East Anglia Three, off Suffolk. Together they run more than 240 km.

The wind farm will have a capacity of 1.4 GW, from 95 Siemens Gamesa turbines of 14 MW or more. It is the first UK offshore wind farm with 115 m blades. It costs £4bn and is owned by ScottishPower Renewables and Masdar. The cables still have to be tested, connected and buried, and turbines are still going in. Full operation is targeted for the end of 2026.

Fusion machines need huge, fast pulses of electrical power, and those need special power electronics. On 22 October the US Commerce Department signed letters of intent to give up to $389m to four companies working on power chips and chip materials. Two of them are fusion firms.

The biggest share, up to $175m, goes to Helion, for high-voltage power chips to drive the magnets in its pulsed fusion machine. Commonwealth Fusion Systems could get $85m for heating and control electronics, Vertical Semiconductor $73m for gallium nitride power chips, and Sibelco $56m for ultra-pure quartz. In return, the government takes a small, non-voting share in each firm. These are letters of intent, not final deals.

Gallium nitride (GaN) chips switch power with less waste than silicon. Infineon is aiming them at AI data centres, energy infrastructure, electric vehicles and robotics. This week the European Commission approved up to €319m of Austrian state aid for Infineon to make them on larger wafers at Villach.

Infineon plans to spend about €1.1bn by 2034, inside its existing cleanrooms. Moving from 200 mm to 300 mm wafers gives 2.3 times as many chips per wafer. Production should start by the end of 2027. In return for the aid, Infineon must give start-ups and universities access to kits and labs, run skills training and share some profits with Austria.

A good solar material has to do two things. It must absorb light strongly, and it must keep the charges that light creates long enough to collect them. Usually, materials good at the first are poor at the second.

Physicists at the University of Oxford found that thin films of bismuth sulfide break this rule. The charges drop into a lower-energy "reservoir" that slows their loss. At room temperature, the team estimates the rate at which charges are lost falls by about 75%, compared with materials that absorb as strongly. The paper is in Nature. It explains a mechanism. Nobody has built a better solar cell from it yet.

When rain falls between a satellite and a dish on the ground, the signal gets weaker. Haofan Dong, a PhD student at the University of Cambridge, uses that loss to work out how hard it is raining along the path.

He tested the idea on 40 satellite links in southern France, against weather radar, over 25,398 rainy samples. The work won him the Young Engineer Prize at the European Microwave Conference in London. The hard part is separating the effect of rain from other weather and from the receiver itself. The university did not publish an accuracy figure.

Silicone is in baking trays, baby-bottle teats and sealants, and it is hard to recycle. New silicone starts with silicon made from quartz sand, at about 2,000 °C.

Chemists at TU Berlin found a way to break used silicone back down to dimethyldichlorosilane, the basic building block for making new silicone. They use a catalyst plus phosgene, a toxic gas, which they add in a safer solid form. The reaction runs at 80 degrees. With one type of product, up to 99% came back after 24 hours. With a mix of old cupcake pans, teats and lids, the figure was 86%. The paper is in Nature, and a patent has been filed.

Before a new battery cell leaves the factory, it goes through "formation". These first slow charges build a thin protective layer inside the cell. Formation takes about a third of production costs, a quarter of the factory floor and about a quarter of the plant's electricity.

Engineers at Cornell University, working with battery firm C4V, watched the layer form in real time using light and electrical measurements. They found a slow charge builds a good layer, and the discharge can then go faster. The cell's resistance settled after just 1.5 cycles. Their new routines cut formation time by more than half, and matched C4V's normal process in tests. C4V estimates that a factory making more than 10 GWh of cells a year could save up to $100m a year.

In 2022, NASA crashed its DART spacecraft into the small asteroid Dimorphos, to test whether we could nudge an asteroid off course. The European Space Agency's Hera mission is going to inspect the result.

This week ESA released Hera's first image showing Dimorphos and its larger partner, Didymos, as two separate objects. It was taken from 1,280 km away. Dimorphos, 151 m across, shows up as about one pixel. Didymos is 780 m across. The pair are about 197 million km from Earth. Braking burns have slowed Hera to 20 m/s relative to them. Close-up images are due on 25 November.

Tesla says it has started early production of Optimus, its two-legged humanoid robot, at its factory in Fremont, California. On its earnings call, the company said most of a production line able to make a million robots a year is installed. It also said reaching that rate would take "a year, maybe longer". Musk said first deliveries to customers are likely towards the end of 2027.

For scale, the International Federation of Robotics says nearly 7,000 humanoid robots were bought worldwide in 2025, out of 603,000 robots of all kinds. None of Tesla's figures has been independently checked.

Most prosthetic limbs read muscle signals with sensors on the skin. Those signals fade, pick up nearby muscles and are thrown off by sweat.

A team at MIT measured the muscle itself. Three people with below-knee amputations had pairs of 3 mm magnets, coated in gold and plastic, implanted in up to four ankle muscles each. Sensors on the skin track the magnets from up to 6 cm away. The gap between two magnets shows how long the muscle is, and how fast it is changing. In a test steering a cursor on a screen, MIT says this gave more accurate and stable control than the usual methods. No numbers were given, and nobody has yet used it to drive a real prosthesis.

Engineers at ETH Zurich built an implant that removes excess glucose from the body using a catalyst instead of a drug. The catalyst is graphite felt coated with tiny particles of gold and platinum. It turns glucose into gluconate, which leaves the body in urine.

A glucose sensor on the arm sends readings to a phone or watch. When sugar is too high, the phone switches the implant on, and power arrives wirelessly. It switches off at the target level. In diabetic mice over six weeks, it kept glucose under control and caused no tissue damage. It has not been tested in people. The paper is in Science.