Load/Path

In July, Dutch engineers found that the steel in the arch of the Merwedebrug, a 1960s motorway bridge on the A27 near Gorinchem, was weaker than they had thought. Lorries and coaches were banned. NL Times says about 18,000 vehicles a day used to cross.

The road agency Rijkswaterstaat then closed the bridge from 24 September and replaced its asphalt with a thinner, lighter layer. That cut about 400 tonnes of permanent weight, known as dead load. The bridge reopened on Saturday evening, ahead of schedule, with a 70 km/h speed limit. It has to last until a new bridge is finished, which is planned for 2031.

The only rail tunnel between New Jersey and New York's Penn Station opened in 1910. This week, the first tunnel boring machine (TBM) for a new tunnel alongside it was launched in North Bergen, New Jersey. The old tunnel will then be repaired. A TBM is a giant rotating drill that digs and lines a tunnel as it goes.

This one has a cutting head 8.7 m across and weighs about 1,525 tonnes. Its first drive is about 1.5 km through hard rock under the Palisades cliffs. It should advance at around 10 m a day. Railway Gazette says the first drive is expected to take a year, which allows for stops and slower stretches. Four machines are planned in total. More than 200,000 rail passengers a day travel on this corridor.

Small modular reactors (SMRs) are nuclear plants designed to be built from factory-made parts, so they should be quicker and cheaper to put up. On 29 September, US regulators (the Nuclear Regulatory Commission, NRC) gave the Tennessee Valley Authority (TVA) a permit to build one at Clinch River, Tennessee. TVA says it is the first US utility to get such a permit for this design.

The reactor is a 300 MW GE Vernova Hitachi BWRX-300, a boiling-water design: water boils inside the reactor and the steam drives the turbine directly. TVA says it is about a third the size of a traditional nuclear unit. The NRC's review took 14 months, four months ahead of schedule. TVA has not set a start date, and it still needs a separate licence before it can load fuel.

Racks of AI chips now draw so much power that operators want to feed them at 800 V DC (direct current) instead of today's lower voltages. For the same power, higher voltage means less current, so thinner cables and smaller losses. But every rack then needs compact converters to step 800 V down to 48 V or 12 V. Further stages bring it down to the roughly 1 V the chips use.

Japan's Renesas launched a gallium nitride (GaN) power transistor for that job on 30 September. GaN switches faster and wastes less energy than silicon. Renesas says its 8 × 8 mm package, cooled from both faces, has a footprint 57% smaller than the 10 × 15 mm package widely used today. Mass production starts in mid-2027.

Modern TVs and cinema projectors can show a wider range of colours than older screens. But viewers don't all see those colours the same way. Colour vision varies from person to person, and the lens of the eye yellows with age. About 1 in 20 men has deuteranomaly, a common red-green colour deficiency.

Researchers at UCL built a model of these differences and tested it on 16 displays, from TVs to professional monitors and projectors. In Optics Express they show that tweaking the exact shade of light a screen's red, green and blue emit could make colours look closer to the same for different viewers. Industry calibration methods would need updating first.

Seven Chinese government bodies have published a plan for the country's battery industry up to 2030, released on 28 September. By 2030 it wants long-life lithium batteries to last 15,000 charge cycles. That's one full charge a day for 41 years.

It also wants leading manufacturers' defect rates down to a few faulty cells per billion made. And it wants the first large-scale use of all-solid-state batteries, which replace the liquid inside a cell with a solid. These are targets, not products yet. They tell battery makers what they will be designing for over the next five years.

Concrete floor slabs account for about 40% of a building's embodied carbon (the CO₂ released making and building it), the University of Stuttgart says. Timber floors are greener, but they usually need beams and more columns, so they end up deeper. A Stuttgart-led team has made a flat timber-concrete slab that is the same 36 cm thickness as a concrete one.

It spans in both directions between columns, using glued timber segments laid along the paths the forces take. A full-size test piece spanning 8 × 4 m carried 20 tonnes plus its own weight and bent only 12 mm. It uses about 66% less reinforced concrete than a standard slab. The first pilot building is planned in Oberkochen, Germany.

The Airbus A350F, a freighter version of the A350 airliner, flew for the first time on 29 September in Toulouse. A crew of five kept it airborne for 4 hours 10 minutes, reaching 25,000 ft (7,600 m) and an airspeed of 340 knots (about 630 km/h).

It can carry up to 111 tonnes and has what Airbus calls the largest main-deck cargo door in commercial aviation. Airbus claims up to 40% less fuel burn per tonne carried than older freighters. Next comes a ten-month campaign of about 400 flight hours, which should end with certification by the European Union Aviation Safety Agency (EASA).

NASA's SpaceX Crew-13 mission docked with the International Space Station (ISS) on 1 October, 7 hours 55 minutes after launch. NASA says that is the fastest launch-to-docking by a US spacecraft in the station's history.

The trip isn't set by rocket speed. A spacecraft has to match the station's orbit and catch up with it, and the timing of that chase sets how long it takes. On board are NASA's Jessica Watkins and Luke Delaney, Canada's Joshua Kutryk and Russia's Sergey Teteryatnikov.

The US Navy is buying 30 medium-sized uncrewed surface vessels, ten each from three builders, trade press reports. One winner, HII, says its ROMULUS boat steered itself 420 nautical miles (778 km) in 28 hours during a 13-day trial.

The hard part is not the hull. The boats must follow COLREGs, the international "rules of the road" that stop ships colliding, with almost no human input. The next phase asks for vessels up to 90 m long that can run for at least ten days uncrewed.

Mercedes has brought its biggest upgrade since May to this weekend's race at Sepang in Malaysia. F1 is racing there for the first time in nine years. A document from F1's governing body, the FIA, lists seven changed areas on the W17, Mercedes' 2026 car, mostly the floor and the rear of the car. The aim is more downforce (the air pressure that pushes the car onto the track) and better traction out of slow corners, one of the W17's few weak spots.

The most visible change is the sidepod, the body section beside the cockpit. It now ramps down steeply towards the rear wheels, to guide air along the car without letting it peel away from the surface. Simulations predict about three tenths of a second a lap, The Race reports. RacingNews365 puts the downforce gain at about 4%, with no extra drag. Both are estimates until the car runs.

Formula E has named Bridgestone as its only tyre supplier from the 2026/27 season, replacing Hankook. The deal runs to 2029/30, and the new season starts on 18–19 December in Jeddah, Saudi Arabia. The tyres have to cope with the new Gen4 car. Formula E says the Gen4 car produces up to 600 kW (815 bhp), reaches 100 km/h in 1.8 seconds and has permanent all-wheel drive.

Bridgestone will supply a main dry tyre (a slick, with no tread), the Potenza Gen4, and a separate heavy-rain tyre called Typhoon Tyre. Earlier Formula E cars used a single all-weather tyre, Grande Premio notes. Bridgestone says 65% of the material is recycled or renewable. That includes carbon black (the filler that strengthens rubber) made from oil produced by heating scrap tyres without oxygen, and silica from rice husks. These are company claims.

University of Michigan engineers have built a steering wheel for semi-autonomous cars. It lets the driver disagree with the car before it acts. Two patches on the rim, at 10 and 2 o'clock, swell to show which way the car plans to turn. The driver can squeeze a patch to say no and suggest a different move.

In lab driving tests, drivers using this two-way system drove smoother paths and braked more confidently than with one-way warnings. They reported less effort and frustration, and regained trust faster after the system made an error. The catch: some drivers trusted the system too much after the car had accepted their input. Toyota Research Institute funded the work, published in Human Factors. The team is looking for commercial partners.

MIT engineers have built a small swimming robot driven by real muscle cells. Its skeleton is a gel film about half a millimetre thick. On top sits a layer of muscle, thinner than a hair, made from cells engineered to contract when light shines on them.

Flash light on one fin and only that side moves, so the team can steer it through a water maze. It swims at about four body lengths a minute. In the group's earlier, iris-shaped design, the muscle moved only about 0.1 mm. A stiffer gel and grooves that line up the cells made the difference. The work is in Advanced Functional Materials.

Today's mRNA vaccines must be stored at −20 to −80 °C, which is hard in hot countries with weak power supplies. An MIT team has made versions that stayed stable for up to a year at room temperature, and for two months at about 37 °C.

They screened nearly 50 ingredients already approved for medicines and picked five. A machine-learning model then chose the best mixtures over a few rounds of experiments. So far the vaccines have only been tested in mice. Published in Nature Biotechnology.