210 Fun Facts About Construction

The Great Pyramid was the world's tallest structure for more than 3,700 years until what kind of building overtook it?

A cathedral: the spire of Lincoln Cathedral in England, finished around 1311, is usually credited with passing the pyramid; it blew down in a storm two centuries later and was never rebuilt.

Roughly how many large stone blocks were quarried to build the Great Pyramid?

2.3 million blocks is the usual estimate; the fine white casing stone came by boat from the Tura quarries, trips recorded in the logbook of an official named Merer that was found in 2013.

The Empire State Building took the world's-tallest title from which rival?

The Chrysler Building had snatched the title itself with a trick: its steel spire was built in secret inside the tower, then hoisted into place in about 90 minutes.

Ironworkers from Kahnawake, near Montreal, who helped build the Empire State Building belonged to which Indigenous nation?

Mohawk ironworkers took up high steel in 1886, when a bridge was built across the St Lawrence at Kahnawake and the builders hired local men, who soon made a name for working at height.

At its 2010 opening, Dubai's tallest tower was renamed Burj Khalifa in honour of the ruler of which emirate?

Abu Dhabi: the tower was called Burj Dubai until opening day, when Dubai's ruler renamed it for Sheikh Khalifa, whose emirate had just lent Dubai billions to cover its debts.

Which Chicago firm designed the Burj Khalifa, having earlier designed the Sears Tower?

Skidmore, Owings & Merrill gave the tower a Y-shaped plan in which each of three wings braces the other two through a six-sided central core, the stiffness that lets it stand so tall.

Hoover Dam sits in the Black Canyon of which river?

The Colorado: before any concrete was poured, crews drove four tunnels through the walls of Black Canyon to carry the whole river around the dam site.

Under the Roosevelt administration, what was Hoover Dam called until Congress restored its name in 1947?

Boulder Dam: once Hoover left office in 1933 the Interior Department avoided his name, and it took an act of Congress in 1947 to put 'Hoover Dam' back.

Workers saved by the movable safety net under the Golden Gate Bridge formed a group with what name?

The Half Way to Hell Club was formed by the nineteen men Joseph Strauss's net caught; eleven others died, ten when a scaffold tore through it on February 17, 1937.

What did the US Navy suggest for the Golden Gate Bridge before Irving Morrow chose International Orange?

Black and yellow stripes were the Navy's idea for making the bridge visible to passing ships; architect Irving Morrow chose instead an orange inspired by the red primer on the steel.

Who led France's failed 1880s attempt to dig a Panama canal, years after his triumph at Suez?

Ferdinand de Lesseps began digging in 1881, but disease and accidents killed an estimated 22,000 workers and his canal company went bankrupt before the decade was out.

Locks lift ships on the Panama Canal up to which artificial lake, the largest in the world when it was created?

Gatun Lake was made by damming the Chagres River, flooding a valley so that ships sail across the middle of Panama high above the sea instead of through a far deeper cut.

The Channel Tunnel's French terminal at Coquelles lies on the edge of which port town?

Calais: tunnellers from each side met under the sea on 1 December 1990, when Englishman Graham Fagg and Frenchman Philippe Cozette broke through with the cameras watching.

What is the Channel Tunnel's smaller third bore pressurised to keep out?

Smoke: the service tunnel between the two rail tunnels is the escape route, so it is kept at higher pressure and a fire in a rail tunnel cannot push smoke into it.

Which Roman building holds the world's largest unreinforced concrete dome?

The Pantheon's dome, finished under Hadrian around 126 AD, spans 43.3 metres and thins toward the top, with lighter pumice aggregate used higher up.

Research published in 2023 credits Roman concrete's ability to self-repair cracks to what?

Lime clasts in the mix: a 2023 MIT study found hot-mixing with quicklime left small reactive lime lumps that dissolve into cracks and recrystallise, sealing them.

Why did Joseph Aspdin name his 1824 cement after the building stone of Portland in Dorset?

It set to a similar colour: Aspdin, a Leeds bricklayer, was borrowing the name of a prized building stone, the pale limestone used for St Paul's in London.

Concrete is the second most used substance on Earth after what?

Water is the only substance people use more of than concrete, and making the cement that binds it produces around 8% of the world's carbon dioxide emissions.

A French gardener's 1867 patent for iron-meshed plant tubs was an early step toward which building material?

Reinforced concrete: Joseph Monier found that clay pots broke and wooden tubs rotted, so he cast planters in cement around an iron mesh, and later patented pipes and bridges built the same way.

Why does steel rebar work so well inside concrete as temperatures change?

The two expand at similar rates, so heat and cold do not tear the bond between them apart; the concrete's alkalinity also protects the steel inside from rust.

The Bessemer process, patented in 1856, made steel cheap by blowing what through molten pig iron?

Air: oxygen in the blast burned off excess carbon and silicon in about twenty minutes, cutting the price of steel so far that it replaced wrought iron for rails.

Which 1885 Chicago tower is often cited as the world's first skyscraper?

The Home Insurance Building let a metal frame, not its walls, carry the load, so the walls could be thinner and hold far more windows than a masonry tower of the same height.

Elisha Otis's 1850s invention, which made tall buildings practical, did what to an elevator?

Stopped it falling if the cable broke: a spring snapped catches into toothed rails the moment the rope went slack, and after Otis showed it off at New York's 1854 world's fair, orders followed.

E. W. Bullard's 1919 'Hard Boiled Hat', often called the first hard hat, was modelled on what?

A soldier's steel helmet: Bullard came home from the First World War and copied his army 'doughboy' helmet in steamed canvas, glue and black paint, replacing the leather caps his father's firm sold to miners.

High scalers at Hoover Dam made their own hard hats by dipping cloth hats in what?

Tar: the homemade hats set so hard that men struck by falling rock suffered broken jaws but no fractured skulls, so the contractor bought factory-made hard hats for the whole workforce.

Which US president signed the act creating OSHA into law in December 1970?

Richard Nixon signed the Occupational Safety and Health Act on December 29, 1970, when about 14,000 American workers were dying on the job each year, roughly 38 a day.

Which machine did a Kansas farmer and a draftsman build onto a tractor in 1923?

The bulldozer began as a bolt-on: James Cummings and J. Earl McLeod patented it simply as an 'attachment for tractors', meant mainly for filling in pipeline ditches.

The nail gun was designed by Morris Pynoos for work on which famous aircraft?

Howard Hughes's Spruce Goose: Pynoos's gun tacked the birch fuselage together while the glue cured, and the nails were then pulled; pneumatic nail guns went on sale in the 1950s.

Which wood panel did an Oregon box factory first show off at a 1905 world's fair, launching a new industry?

Plywood: the Portland Manufacturing Company brushed glue onto softwood veneers and pressed them with house jacks; door and trunk makers at the fair placed orders, and an industry was born.

Drywall panels are made from which mineral, sandwiched between paper?

Gypsum holds water locked inside its crystals, and in a fire that water is driven off as steam, soaking up heat and slowing the flames, which is why drywall lines fire-rated walls.

Which tape began in 1943 as a factory worker's idea, sent to Roosevelt, for sealing ammunition boxes?

Duct tape: Vesta Stoudt, who had two sons in the Navy, saw the pull-tabs on paper-taped cartridge boxes tear off, leaving troops struggling to open them, and Johnson & Johnson was asked to make her cloth version.

Which ancient civilization's temple builders were first to swap ramps for cranes, in the late 6th century BC?

Greece: cuttings for lifting tongs and lewis irons appear on Greek temple blocks from about 515 BC, the earliest evidence of cranes taking over from ramps for raising heavy stone.

What is the long horizontal arm of a tower crane, which carries the load, called?

The jib carries a trolley that runs the hook in and out, while a shorter counter-jib behind the tower holds concrete blocks to balance the load.

The Three Gorges Dam spans which Chinese river?

The Yangtze: the dam's reservoir flooded all or part of 13 cities and more than a thousand villages along the river, and well over a million people had to be moved out of its way.

In 2005, NASA calculated water behind the Three Gorges Dam lengthens Earth's day by how much?

0.06 microseconds: NASA's Benjamin Fong Chao worked out that lifting so much water shifts mass away from Earth's axis, slowing its spin by a hair and making the planet very slightly rounder in the middle.

Which engineer effectively supervised the Brooklyn Bridge's completion after her husband was left bedridden?

Emily Warren Roebling relayed her bedridden husband Washington's instructions and mastered the engineering herself; the bridge opened in 1883 and P. T. Barnum marched 21 elephants across in 1884.

Men digging the Brooklyn Bridge's foundations in pressurised chambers got a mystery illness that project physician Andrew Smith named what?

Caisson disease is what divers call the bends: men who climbed out of the compressed air too quickly had gas bubble out of their blood into their joints, and several died.

Which British architect co-designed France's Millau Viaduct with engineer Michel Virlogeux?

Norman Foster's practice shaped the bridge that engineer Michel Virlogeux conceived to end the summer traffic jams in Millau, where the road from Paris to Spain used to drop into the Tarn valley.

Which landmark did Jørn Utzon quit in 1966 and never see finished?

The Sydney Opera House: Utzon walked out when the state government stopped paying his fees, Australian architects finished the interiors, and he died in 2008 without ever seeing it complete.

Marc Isambard Brunel's first successful tunnelling shield dug under which river in 1825?

The Thames: Brunel's shield let miners dig in protected cells while the brick lining followed; the Thames Tunnel opened in 1843 after 18 years of floods and delays.

The giant tunnel boring machine 'Bertha' began digging a highway tunnel under which US city in 2013?

Seattle: Bertha set off in July 2013, broke down that December and could only be repaired after crews dug a rescue pit down to it; it finally broke through in April 2017.

What is the non-load-bearing outer skin hung from a skyscraper's steel frame called?

A curtain wall carries only its own weight and hands the push of the wind on to the frame, so it can be made of thin glass and metal instead of thick masonry.

Lego takes its name from a Danish phrase meaning what?

Play well: 'leg godt' in Danish, a name coined by Ole Kirk Christiansen, whose woodworking shop turned to wooden toys in 1932 when the economic crisis left him short of customers.

In Bob the Builder, Bob asks 'Can we fix it?' and gets which reply from his crew?

Yes, we can! The line also crowns the show's theme song, which became the UK's Christmas number one in 2000 and outsold every other single in Britain that year.

The Empire State Building's mast was originally meant as a docking station for what kind of aircraft?

Airships: passengers were meant to step off a moored airship and ride lifts down into Manhattan, but winds at that height made docking too dangerous and the plan was dropped.

To stop the diseases that had plagued France's Panama Canal attempt, American doctors waged war on which carrier?

Mosquitoes: army doctor William Gorgas had pools drained or oiled to kill the larvae, which cut the diseases back far enough for the canal to be finished.

Which US president signed the 1977 treaties that handed the Panama Canal over to Panama at the end of 1999?

Jimmy Carter signed the treaties with Panama's Omar Torrijos, and the Senate approved each by 68 votes to 32, a single vote more than the two-thirds they needed.

Which two leaders set up the 1981 working group behind the Channel Tunnel?

Margaret Thatcher and Francois Mitterrand agreed to study a privately funded link; Thatcher had expected a road for cars, but the scheme that was built is a rail tunnel.

Krupp's Bagger 288, the world's heaviest land vehicle when it was finished in 1978, is what kind of machine?

A bucket-wheel excavator: built to strip soil from a coal mine, it crawled 22 kilometres to a new mine in 2001, a three-week trip across a motorway, a river and a rail line.

Which number is a common British site nickname for a tracked excavator?

360: the cab and arm can swing a full circle on top of the tracks, so UK sites call tracked excavators '360s'; wheeled ones are 'rubber ducks'.

Which ancient water-lifting device, a pivoting pole with a counterweight, is often called the first crane?

The shaduf lets one person raise a full bucket with little effort because a counterweight on the pole's other end does the lifting; farmers in Egypt and India still use it.

A jackhammer combines a hammer directly with which tool?

A chisel: compressed air from a separate compressor drives a piston down onto the chisel and back again many times a second, far faster than anyone could swing a pickaxe.

Which site test fills a metal cone with fresh concrete, lifts it away and measures how far the pile settles?

The slump test: the drop in the pile's height once the cone is lifted shows how stiff or runny the mix is, a quick way to check that every truckload is the same.

In tube-and-coupler scaffolding, what are the vertical load-bearing tubes called?

Standards carry the scaffold's whole weight to the ground, so each one stands on a base plate that spreads the load; ledgers run along the scaffold and transoms cross it.

Bamboo scaffolding has long been particularly common in China, India and which city?

Hong Kong: its scaffolders lash bamboo poles together by hand, even around high-rise towers, and the same craft builds the temporary bamboo theatres used for Cantonese opera.

A wheelbarrow, with the load between the wheel and the handles, is which kind of lever?

Second-class: the wheel is the fulcrum and the load sits between it and the handles, like a nutcracker, so the person pushing lifts only part of the weight.

Traditional Chinese wheelbarrows differed from Western ones in what way?

A central wheel carried the whole load: the big Chinese wheel sat in the middle, so the operator only balanced and pushed and could move several times the weight of a front-wheeled barrow.

Why is a spirit level so called?

Its vial liquid is commonly alcohol, a 'spirit': alcohol will not freeze on a cold site, so the bubble keeps moving freely.

Builders square a corner by measuring a triangle with sides of 3, 4 and 5 units, applying whose theorem?

Pythagoras: because 3 squared plus 4 squared equals 5 squared, a triangle with those sides must contain a right angle, so a tape measure is all it takes to set out a square corner.

The 'plumb' in plumb bob comes from the Latin word for which metal?

Lead: Latin plumbum, the root of plumber and plumbing too, because the bob was a lead weight; Egyptian builders used plumb lines to check verticals.

Sun-dried mudbricks, far older than fired bricks, were traditionally mixed with what to stop them cracking?

Straw: its fibres hold the mud together as it dries, so the brick shrinks without splitting; such bricks were in use thousands of years before anyone fired clay in a kiln.

In masonry, why is mortar deliberately weaker than the bricks it binds?

It is the sacrificial element, cheaper to repair: a weaker mortar lets movement crack the joints rather than the bricks, and repointing a joint is far easier than replacing masonry.

What has been the most common binder in mortar since the early 20th century?

Portland cement: it sets faster and harder than the lime mortars it displaced in the early 1900s, though lime mortar is preferred for repointing historic brickwork because it is softer and breathes.

What is asphalt concrete commonly called in the UK and Ireland?

Tarmac is short for tarmacadam: surveyor Edgar Hooley patented it in 1902 after noticing a smooth, dust-free stretch of road where a spilled barrel of tar had been covered over.

On an I-beam, what are the horizontal elements called?

Flanges: the two horizontal plates sit far from the neutral axis, where bending stress is highest, so they carry most of the bending load.

What do builders call the beam that spans the top of a door or window opening?

A lintel carries the wall above across the gap; Stonehenge's horizontal stones are lintels too, locked onto their uprights with joints borrowed from woodworking.

The word 'adobe' reached English via Spanish from which language?

Arabic: Spanish adobe comes from Arabic al-ṭūb, 'the brick', itself borrowed from Coptic and ultimately ancient Egyptian; mudbrick building goes back thousands of years.

Which Italian city's vast brick dome did Filippo Brunelleschi raise without a supporting wooden frame?

Florence: Brunelleschi laid the dome's bricks in a herringbone pattern, which held each fresh course in place as the dome rose, so nothing had to prop it up from below.

A construction system based on posts and beams rather than arches is called what?

Trabeated comes from the Latin for a beam: Greek temples are built this way, and because a stone beam can only bridge a short gap, their columns have to stand close together.

In a truss, what are the joints connecting the members called?

Nodes: a truss joins straight members at its nodes, usually in triangles, so each member is only pushed or pulled along its length and never bent.

Which steel arch bridge, opened in 1932, is nicknamed 'the Coathanger'?

Sydney Harbour Bridge was built out from each shore as two half-arches, held back by steel cables anchored in tunnels until the halves met in the middle.

In traditional timber framing, what is a cantilevered overhang called?

A jetty: each upper floor juts out over the one below on projecting beams, so a medieval townhouse gained room upstairs without taking any more of the street.

What is the open circular hole at the apex of a dome called?

An oculus, Latin for 'eye', is left open to the sky in ancient Rome's best-known dome, so rain falls straight through and runs away down drains in the floor.

Which Gothic support carries a stone vault's sideways thrust over the aisle roof to a pier outside the wall?

A flying buttress props the wall from outside, so Gothic builders could thin the walls and open them up into huge windows of stained glass.

Foundations are generally classified into which two broad types?

Shallow and deep: a footing spreads the load near the surface, while piles reach down to firmer ground; Pisa's tower leans because its foundation sits in soft soil that gave way as it was built.

Under which emperor did construction of the Colosseum begin in AD 72?

Vespasian had the lake in the grounds of Nero's palace drained and began the arena on its bed around AD 72; his son Titus opened it in AD 80.

Which emperor, Titus's younger brother, is credited with adding the hypogeum beneath the Colosseum's arena floor?

Domitian is credited with the hypogeum: two levels of tunnels and cages where animals and fighters waited, with shafts and trapdoors to bring them up through the arena floor.

The Colosseum's brick-faced concrete is combined with travertine limestone and which volcanic rock?

Tuff is volcanic ash that has hardened into rock: soft and common in Italy, it was used with brick for the inner walls, while tougher travertine formed the outer ring.

The best-known sections of the Great Wall of China were built by which dynasty?

The Ming (1368-1644) built the stone-and-brick walls near Beijing, including Badaling; earlier walls date to the 7th century BC and were joined under the Qin.

Which Mughal emperor commissioned the Taj Mahal in 1631?

Shah Jahan commissioned it after Mumtaz Mahal died in childbirth in 1631; it houses her tomb and, from 1666, his own.

On the bank of which river does the Taj Mahal stand?

The Yamuna: the tomb stands on the river's south bank at Agra, and its four minarets were built leaning slightly outward so that, if they ever fell, they would topple away from the dome.

Which French cathedral was begun in 1163 under Bishop Maurice de Sully?

Notre-Dame de Paris: Sully wanted one much larger church in place of the older ones on the site, and Pope Alexander III is said to have laid the first stone; work went on for nearly two centuries.

Which French president set a five-year deadline to restore Notre-Dame de Paris after the 2019 fire?

Emmanuel Macron promised on the night of the fire that the cathedral would be rebuilt and set the five-year target two days later; it reopened in December 2024.

In which style did Francisco de Paula del Villar begin the Sagrada Família before Gaudí took over in 1883?

Neo-Gothic: Villar planned a conventional church with pointed windows and a pointed bell tower but left after a year; Gaudí then transformed the design, and under a quarter was built when he died in 1926.

Which pope consecrated the Sagrada Família and proclaimed it a basilica in 2010?

Benedict XVI consecrated the still-unfinished church for worship on 7 November 2010, 128 years after work began in 1882, and named it a minor basilica.

Which building surpassed the Petronas Towers as the world's tallest in 2004?

Taipei 101, at 508 metres, held the title until the Burj Khalifa; a 660-tonne steel sphere hung inside its upper floors sways against typhoon winds to steady the tower.

Which American firm designed the twisting Shanghai Tower?

Gensler wrapped the tower in a second skin of glass that works as insulation, cutting the energy it needs for air conditioning.

To what symbolic height in feet does One World Trade Center rise?

1,776 feet, for the year of the Declaration of Independence; the final spire section was installed on May 10, 2013 and the tower opened in November 2014.

By what name was One World Trade Center known until 2009?

Freedom Tower: the name came from a 2003 speech by New York's governor, but the Port Authority said One World Trade Center, the legal name, was the one easiest for people to identify with.

Which London bridge did City Architect Horace Jones design with a steel frame hidden behind stonework?

Tower Bridge: Jones died in 1887, soon after work began, and engineer John Wolfe Barry saw it through to its 1894 opening; the stone cladding was added so it would fit in beside the Tower of London.

What term describes the lifting central spans of Tower Bridge?

Bascules: each counterweighted leaf pivots upward, originally driven by steam-pumped hydraulic power, so that tall ships could still reach the Pool of London upstream.

Which Scottish rail crossing collapsed in an 1879 storm, ruining its designer Thomas Bouch?

The Tay Bridge: its high girders fell on 28 December 1879 as a train crossed, killing everyone aboard; Bouch's next great bridge commission was cancelled and he died within a year.

Which Canadian bridge, finished in 1917 after two deadly collapses, has the world's longest cantilever span?

The Quebec Bridge: its 549-metre span first fell in 1907 because the designer had badly miscalculated the loads, and a replacement centre section dropped into the St Lawrence in 1916.

Which Turkish bridge across the Dardanelles became the world's longest suspension span in 2022?

The 1915 Çanakkale Bridge is the strait's first fixed crossing; its 2,023-metre main span, a nod to the Turkish Republic's centenary in 2023, beat the 1,991 metres of Japan's Akashi Kaikyo Bridge.

What forced the Akashi Kaikyo Bridge's span to be lengthened by a metre during construction?

Earthquake: the 1995 Kobe quake struck while the two towers were going up and pushed them about a metre further apart, stretching the span to 1,991 metres; the bridge links Kobe with Awaji Island.

The Itaipu Dam straddles the river border between Brazil and which other country?

Paraguay: a 1973 treaty shares the dam's output equally, but Paraguay needs only a fraction of its half and sells the rest to Brazil.

The Gotthard Base Tunnel opened under the Alps in 2016 as the world's longest tunnel of which kind?

Railway: at 57 km it runs almost level beneath the Alps, so longer and heavier freight trains can use it, helping shift goods from trucks to rail.

The Gotthard Base Tunnel runs south from the canton of Uri to emerge in which Swiss canton?

Ticino: the tunnel runs from Erstfeld in Uri to Bodio in Ticino in about 20 minutes, giving the canton south of the Alps a much faster link to the rest of Switzerland.

Which parks replaced Boston's elevated Central Artery after the Big Dig buried it?

Rose Kennedy Greenway: the Big Dig moved Interstate 93 into a tunnel, and the 17-acre strip its elevated deck had overshadowed was turned into a chain of parks and gardens.

Which cable-stayed crossing of the Charles River was built as part of the Big Dig?

The Zakim Bunker Hill Bridge, completed in 2003, carries Interstate 93 over the Charles on ten lanes; its towers are capped with obelisks to echo the nearby Bunker Hill Monument.

Which company led the management joint venture for Boston's Big Dig?

Bechtel, in a joint venture with Parsons Brinckerhoff, managed the project, whose cost rose from under $3 billion to nearly $15 billion; a 2006 ceiling collapse and tunnel leaks dogged it.

Which act signed by Eisenhower launched the Interstate system?

The Federal Aid Highway Act of 1956 funded more than 40,000 miles of interstate; Eisenhower had been struck by how the German autobahns moved troops and supplies in World War II.

The canal completed across upstate New York in 1825 links the Hudson River with which of the Great Lakes?

Lake Erie: dug in eight years, the 363-mile canal ran from Albany on the Hudson to Buffalo, opening a direct water route from New York City to the Midwest that drew trade and settlers west.

Which New York governor pushed through the state's 1825 canal to the Great Lakes, mocked by opponents as his 'Ditch'?

DeWitt Clinton won $7 million from the legislature in 1817 for what opponents called 'Clinton's Folly'; when the canal opened in 1825 he led the first fleet of boats along it to New York City.

Where was the 'Golden Spike' driven to complete America's first transcontinental railroad in 1869?

Promontory Summit, Utah, north of the Great Salt Lake: Leland Stanford tapped the golden spike with a silver maul on May 10, 1869; the spike itself is kept at Stanford University.

Which railroad built the first transcontinental line westward from Omaha?

Union Pacific: its crews, largely Irish immigrants and Civil War veterans, laid track west across the plains, while the Central Pacific's Chinese labourers blasted east from Sacramento through the Sierra Nevada.

Holt tractors hauled Allied artillery in World War I and helped inspire which new weapon?

The tank: Holt's crawler tracks carried heavy loads over ground that stopped wheels, and France's first tanks, the Schneider and the Saint-Chamond, were based directly on the Holt tractor.

Benjamin Holt's 1904 tractor swapped wheels for tracks to stop it doing what on California's delta farmland?

Sinking: Holt's heavy steam tractors bogged down in the peat around Stockton, so he fitted tracks; a company photographer is said to have remarked that they crawled like a caterpillar, and the name stuck.

To which city did Caterpillar move its headquarters in 2022?

Irving, Texas: Caterpillar announced the move from Deerfield, Illinois in June 2022; it had left Peoria for Deerfield in 2017 after scrapping plans for a new Peoria headquarters.

How did Bechtel's founder begin building railroads in Oklahoma Territory in 1898?

With a team of mules: Warren Bechtel left his farm at Peabody in 1898 to build railroads in Oklahoma Territory with his own mule team; three decades later his firm helped build Hoover Dam.

Which consortium of western contractors pooled its resources to win the contract to build Hoover Dam?

Six Companies, Inc.: Utah Construction could not post the $5 million performance bond alone, so it joined Morrison-Knudsen, Kaiser, Bechtel and others to bid $48.9 million.

What was the first product JCB founder Joseph Cyril Bamford built, from wartime scrap, in 1945?

A tipping trailer: Bamford welded it together in a rented lock-up garage from scrap steel and war-surplus parts, then sold it at a local market for £45.

In which English county is JCB based?

Staffordshire: JCB is based at Rocester, near Uttoxeter, where Bamford started out in 1945; its initials have become a generic British word for a digger, listed in the Oxford English Dictionary.

What does the name of Japanese equipment maker Komatsu mean?

Small pine tree: Komatsu is the city in Ishikawa Prefecture where Meitaro Takeuchi founded the company in 1921, and its kanji, ko-matsu, mean 'small pine'.

Under Hammurabi's Code, what happened if a house collapsed and killed the owner?

The builder was put to death: law 229 of the code, from about 1750 BC, prescribes death for a builder whose house collapses and kills its owner; law 230 kills the builder's son if the owner's son dies.

Which 1666 disaster prompted an act of Parliament setting how London's new houses must be built?

The Great Fire of London destroyed about 13,000 houses; because it had raced through tightly packed timber buildings, the Rebuilding of London Act demanded brick or stone and wider streets.

Which non-profit developed the LEED certification program?

U.S. Green Building Council: it wrote LEED as a voluntary standard, yet many US federal agencies and state and local governments now require it or reward builders who meet it.

Levittown, New York was built between 1947 and 1951 for whom?

Returning World War II veterans: William Levitt saw that ex-servicemen needed cheap homes and mass-produced them on Long Island, though his sales contracts barred Black buyers.

What covered the Long Island land that Levitt & Sons bought up to build Levittown?

Potato fields: Levitt took options on Long Island onion and potato farms, then ran house-building like an assembly line, his crews finishing as many as 30 houses a day by July 1948.

What did Sears offer buyers of its mail-order kit houses that backfired in the Great Depression?

Mortgages: Sears lent buyers the money as well as selling them the kit, but when the Depression hit many defaulted, and in 1934 the company liquidated $11 million in home loans.

The topping-out ceremony is traditionally traced to which culture's rite of placing a tree atop a new building?

Ancient Scandinavian: the rite is said to have placed a tree on a new building to appease the tree spirits displaced by its timber; builders still hoist a tree or leafy branch, often with flags, onto the last beam.

What does a contractor's punch list record near the end of a project?

Unfinished work to fix: the punch list, also called a snag list, names items that fall short of the contract, and the owner can hold back the final payment until the contractor has cleared them.

George Washington consecrated the US Capitol's cornerstone in 1793 with corn, wine and which third offering?

Oil: in a Masonic ceremony, three worshipful masters carried corn, wine and oil to the stone, which Washington then struck three times with a gavel.

Germany's Deutsche Fachwerkstraße links towns famed for what?

Half-timbered houses: the German Timber-Frame Road, running from the Elbe to Lake Constance, was founded in 1990 by an association of timber-framed towns that works to preserve them.

In timber framing and wooden shipbuilding, what is the peg driven through a joint called?

A treenail, also spelled trunnel: cut from dry timber, it swells in its hole when it gets damp, so in a ship's hull the peg only grips tighter.

Which type of nail, made by machine from iron plate, dominated between the hand-wrought and wire eras?

The cut nail: each one was sheared from a flat strip of iron, which left it a square, tapered shank, and the machines turned nails out in such numbers that they ruled until cheaper wire nails took over about a century later.

What is the distance between each thread of a screw called?

The pitch: on an ordinary single-start screw one full turn advances it by exactly that distance, and fine-pitch threads are less likely to vibrate loose than coarse ones.

Which screw drive is the oldest type, used for centuries before any of its rivals appeared?

The slot: a single groove could simply be sawn or filed, so for centuries it was the cheapest drive to make; the self-centring Phillips cross-head was devised in the 1930s for powered assembly lines.

Why is the steel blade of a retractable tape measure curved across its width?

To stay rigid when extended: Hiram Farrand patented the cupped blade in 1922, giving a thin ribbon of steel enough stiffness to stand out straight without buckling, yet still roll up into its case.

Why does the hook on a tape measure slide slightly on its rivets?

To compensate for its own thickness: the hook slides on loose rivets by exactly that amount, so the tape reads true whether the hook is pushed against a wall or pulled over an edge.

What does a surveyor's theodolite measure?

Angles: its telescope is sighted on one point after another, and the horizontal and vertical readings let a surveyor draw up a plan; the instrument goes back to the 16th-century mathematician Leonard Digges.

What do surveyors call a fixed reference point of known height, once cut into stone walls?

A benchmark: surveyors chiselled a horizontal notch into which an angle iron could be set as a 'bench' for the levelling rod; the word now means any standard to measure against.

What is the handle of a hammer also known as?

A haft or helve: the shaft, traditionally hickory or ash for shock absorption, is wedged into the eye of the head; the claw on a claw hammer pulls nails.

Which British prime minister took up bricklaying as a hobby?

Winston Churchill built garden walls and outbuildings with his own hands at Chartwell, his Kent home, and even joined the Amalgamated Union of Building Trade Workers.

On a British or Australian building site, which tradesman is called a 'chippie'?

A carpenter, from the wood chips of the trade; an electrician is a sparkie, a bricklayer a brickie, and any tradesperson a tradie in Australia.

Steel-frame construction took over from which earlier way of carrying a tall building's loads?

The iron skeleton: cast- and wrought-iron frames had let early tall buildings shed their thick masonry walls, but steel, stronger and lighter, made truly tall towers possible.

What does the R-value of building insulation measure?

Resistance to heat flow: the higher the R-value, the better the insulation; layers add up, but squashing a fibreglass batt into too thin a space lowers its rating.

China's outdoor Bailong Elevator carries tourists 326 metres up what?

A cliff face: the glass-fronted lifts climb it in about a minute and a half, sparing visitors a two-hour hike among the sandstone pillars; Guinness recognised it in 2015 as the world's tallest outdoor elevator.

Which London venue's roof hangs from twelve yellow steel masts?

The Millennium Dome, now The O2: its twelve masts echo the hours and the months, because time was the theme of a building that stands beside the Greenwich meridian.

The Pont du Gard carried water to which Roman colony?

Nemausus (Nîmes): the aqueduct ran some 50 km to the city, crossing the Gardon valley on the bridge; after the empire fell it stayed largely intact, kept in use as a toll bridge.

What was ancient Rome's Cloaca Maxima, which began as an open channel through the Forum?

A sewer: it first carried storm water from the Forum district to the Tiber, was later roofed over with a stone vault, and in imperial times took the waste of Rome's public baths and latrines.

How did Roman aqueducts move water?

By gravity alone: conduits were laid on a gentle, continuous downhill gradient, mostly buried and following the terrain, with bridges across valleys and inverted siphons where needed.

Which road, begun in 312 BC, was the first great Roman highway?

Via Appia: the censor Appius Claudius Caecus began it as a road from Rome to Capua, it was later pushed on to Brindisi, and the poet Statius called it the queen of long-distance roads.

What formed a World War II Quonset hut's curved shell?

Corrugated steel: the US Navy wanted a building that could be shipped anywhere in pieces and put up by untrained men, and a team of ten could assemble one in a day.

The Quonset hut was based on which British World War I design?

The Nissen hut: Major Peter Nissen of the Royal Engineers tried out three prototypes in April 1916 and it was in production by August; the US Navy's 1941 version took its name from Quonset Point.

What is a tunnel boring machine nicknamed?

A mole: like its namesake it burrows forward underground, a rotating cutterhead at the front chewing through rock or soil while the tunnel lining is built up behind it.

Which attachment, mounted at the rear of a heavy earthmover, breaks up rock and hard ground with hooked steel shanks?

A ripper: its shanks, tipped with replaceable tungsten-alloy points, tear shale, hardpan or old pavement into rubble that is then easily pushed away.

What raises the front of a modern dump truck's bed so the load slides out?

Hydraulic rams lift the front of the bed, which is hinged at the rear; a raised bed makes the truck unstable, so drivers unload only on firm, level ground.

On a backhoe, what is the arm section that carries the bucket called?

The dipper, also called the stick: it hinges from the boom, and the backhoe is named for the way it digs, drawing its bucket back toward the machine, not for sitting at the back of a tractor.

How does a skid-steer loader turn?

By running each side's wheels at different speeds: with one side driven forward and the other in reverse, the loader can turn around within its own length, ideal for cramped sites.

Which loader brand grew from a three-wheeled machine the Keller brothers built in 1957 for a Minnesota turkey farmer?

Bobcat: the farmer wanted something nimble enough to clean out his two-storey pole barn; Melroe Manufacturing of North Dakota bought the rights in 1958 and adopted the Bobcat name in 1962.

What is the chemical reaction between cement and water called?

Hydration: the reaction gives off heat, so much of it that big dams are poured in separate blocks threaded with cooling pipes to keep the concrete from cracking as it cools.

What does 'curing' freshly placed concrete mean?

Keeping it moist while it gains strength: concrete hardens by reacting with water, not by drying out, so a slab that dries too soon ends up weaker.

In welding, what is the molten zone at the joint called?

The weld pool: it cools into a joint that can be stronger than the metal around it; brazing and soldering, by contrast, never melt the base metal at all.

Why does a rivet driven red-hot clamp its plates tighter afterwards?

Cooling shrinks it: the glowing tail is hammered into a second head, and as the rivet cools it contracts along its length, pulling the plates hard together.

Hans Liebherr founded his crane and equipment group in 1949 in which country?

West Germany: Hans Liebherr, a master builder, made his first mobile tower crane in 1949 at Kirchdorf an der Iller in southern Germany; the family-owned group's holding company later moved to Bulle, Switzerland.

Who received the 1839 patent for the steam shovel?

William Otis, a cousin of elevator pioneer Elisha, patented it in 1839 and his steam shovel dug US railroad cuttings, but he died of typhoid that November, aged 26.

In cross-laminated timber, how does each layer's grain run relative to its neighbours?

At right angles: crossing the grain gives the glued panel rigidity in both directions and keeps it dimensionally stable, so the panels can serve as whole floors and walls.

Nobel's 1867 dynamite made which unstable explosive safe to handle by absorbing it into kieselguhr?

Nitroglycerine: an 1864 blast at Nobel's own factory had killed his younger brother Emil and several others, and soaking the liquid into kieselguhr gave a far safer solid he patented in 1867.

Why do welders flood a fresh weld with inert gas or cover it with flux?

To keep the air off it: oxygen and nitrogen from the air would react with the molten metal and leave the joint porous and brittle.

The knobbly drum roller that compacts soil under a new road is named after which farm animal's foot?

Sheep's foot rollers pack soil more densely than a smooth drum because each pad bears down on a much smaller area.

Why can a heavy crawler bulldozer cross soft mud that would bog down a far lighter wheeled truck?

Tracks spread its weight over a far larger contact patch than tyres, so even a 70-ton M1 Abrams tank presses on the ground only about half as hard as a family car.

Which Swedish maker brought the articulated hauler, a bendy off-road dump truck, to market in 1966?

Volvo pioneered the machine through its Bolinder-Munktell arm; the truck steers by pivoting its front section against the back on powered rams.

Which site machine, also called a reach forklift, lifts pallets on an extending arm onto rooftops?

Telehandler is short for telescopic handler, a machine one British firm launched in 1971 under the fitting name Giraffe.

On a bulldozer or tractor, the cab frame labelled ROPS protects the operator in which kind of accident?

A rollover is what a ROPS, or rollover protection structure, guards against, and worn with a seat belt it is rated 99% effective at preventing the operator's death.

Bagger 293, a 96-metre-tall machine that strips brown coal near Hambach, is which type of mining giant?

Bucket-wheel excavator is the type, and this one's digging wheel is over 21 metres across, ringed by 18 buckets that each hold more than 15 cubic metres.

How did Big Muskie, a 13,500-ton dragline standing 22 storeys tall, move around its Ohio mine?

On hydraulic feet, Big Muskie shuffled along at under two inches a second, over a roadbed of heavy wooden beams laid so that it would not sink.

The BelAZ 75710, a mining truck claimed to carry a 450-tonne load, is made in which country?

Belarus builds it at the BelAZ works, and the truck weighs 360 tonnes before a single rock is loaded.

Which earthmover, made self-propelled by R. G. LeTourneau, shaves soil into a bowl and hauls it away?

Scraper bowls fill as a sharp front edge cuts the soil like a cheese slicer; LeTourneau thought up the self-propelled version while recovering from a near-fatal car crash.

Which building method finishes sections up to 90% complete in a factory, then trucks them to site for assembly?

Modular construction lets factory work run in parallel with site preparation, which is the main reason it can finish a project sooner.

Type I construction, the most fire-resistive class in US building codes, is typically used for which buildings?

High-rises are Type I because their structure is concrete, or steel given a fire-resistive covering, made to withstand long exposure to a blaze.

A wall's fire-resistance rating, a key figure in every building code, is expressed as which kind of measurement?

A length of time is the measure: the rating says how long an assembly withstands a laboratory fire test, so a vault can be sold as a two-hour or four-hour class.

In the US construction classes that firefighters learn, which one is the wood frame of most new homes?

Type V sits at the far end of the scale from fire-resistive Type I, and also covers townhouses and garden apartments of four floors or fewer.

Which construction method casts concrete wall panels flat on the ground, then raises them upright with a crane?

Tilt-up panels are usually cast on the building's own floor slab, sprayed first with a bond breaker so the fresh concrete does not stick to it.

Brick walls around wood-framed floors, as in old city rowhouses, mark a Type III building, known by which name?

Ordinary construction is the label for brick walls with wood floors, ranked a step more fire-prone than Type II buildings such as steel-raftered strip malls.

Which light wooden framing method, once nicknamed Chicago construction, runs each stud unbroken through two storeys?

Balloon frame building swapped a few heavy jointed posts for many light studs simply nailed together, and its first clear use was an 1832 Chicago warehouse.

A 2021 change to the International Building Code lets buildings framed in which material rise 18 storeys?

Mass timber won three new construction types, IV-A, IV-B and IV-C, after fire tests showed that a char layer forms and shields the wood within.

The 5-over-1 apartment block, wood-framed storeys on a concrete podium, began with architect Tim Smith in which city?

Los Angeles architect Tim Smith used a code change allowing fire-retardant treated wood to go five storeys high, and the style spread nationwide in the 2010s.

Which technique, long used for grain silos, places concrete in a form that climbs steadily to leave no seams?

Slip forming was raising silos and grain elevators by the early 20th century; the mould creeps upward while concrete is placed without a break, so no cold joints appear.

Chinese builders made the famously tough mortar of the Great Wall by mixing in a soup of which food?

Sticky rice soup made the mortar stronger and more water-resistant, and the same recipe bound tombs, pagodas and city ramparts.

Which pointed hand tool does a bricklayer use to spread mortar on bricks, a technique known as buttering?

Trowel blades for brickwork are point-nosed, and the same tool levels and shapes the mortar bed as well as spreading it.

In a masonry arch, which wedge-shaped stone at the apex must be placed before the arch can support itself?

Keystone placement completes the arch, yet that stone bears the least stress of any block in the ring.

The indentation pressed into one face of a brick, limited to a fifth of its volume, is named after which animal?

Frog is the bricklayer's word for the dent, and bricks that have one are known as frogged bricks.

Which fraternal order, whose emblem is the square and compasses, traces its origins to medieval guilds of stone workers?

Freemasons still name their three degrees after the grades of a medieval craft guild, from Entered Apprentice up to Master Mason.

Which American civilisation fitted cut stones so precisely that its finest walls stand without mortar?

Inca walls have been seen to 'dance' in strong earthquakes, the blocks jumping and then settling back into their original places.

An American cinder block is known in Britain as which kind of block, after an old word for coal cinders?

Breeze once meant the small cinders and dust left by partly burned coal, the filler that gave the blocks both of their names.

In bricklaying, a brick laid flat with its long narrow side showing on the wall face is known by which name?

Stretcher bricks run lengthwise along the wall; turned so that the short end faces out instead, the same brick is called a header.

Which brick bond alternates long sides and short ends in every course, each short end centred over a long side below?

Flemish bond is sometimes picked out in two colours, the long sides in one shade and the short ends in another, to make a chequered wall.

Which term describes the salt coating left on a brick wall when water inside it migrates to the surface and evaporates?

Efflorescence comes from the Latin for 'to flower', and the salts can do real harm when they clog a brick's pores and make its face break away.

Which kind of accident, the focus of a US awareness week each spring, kills the most construction workers?

Falls kill more construction workers than anything else, ahead of electrocutions, being struck by objects and being caught between them.

The 1932 photo of eleven ironworkers eating lunch on a steel beam 850 feet up was staged at which New York landmark?

Rockefeller Center's publicists arranged the shot on the 69th floor of the RCA Building as a stunt to promote the new skyscraper, though the men were real ironworkers.

Which three-digit number do Americans call before digging so that buried utility lines can be located and marked?

811 was made the single national number in 2005, a shortcut to 71 regional call-before-you-dig services that each had a separate 800 line.

OSHA, the agency with federal powers to inspect American workplaces, is part of which government department?

Labor Department officials had handled some work safety issues since 1934 through an earlier bureau, decades before OSHA existed.

Which fibrous mineral, once sprayed onto buildings as fireproofing, can cause the cancer mesothelioma when inhaled?

Asbestos was tied to mesothelioma in the 1940s, about a decade after the cancer was first named in medical literature.

Which shock-absorbing line connects a roofer's full-body harness to an anchor point so a tumble is stopped short?

Lanyard systems matter sooner than many expect: US rules require employers to protect a construction worker at just six feet above a lower level.

Britain's first high-visibility jackets, the orange 'fire-flies' of 1964, went to workers in which industry?

Railways came first: track workers on an electrified Glasgow line wore the orange jackets, which reached other British Railways staff the following year.

Which safety procedure secures a machine's power switch off, with a label naming the worker, until repairs are finished?

Lockout-tagout gives each worker a personal padlock and the only key to it, so the machine cannot restart until every lock has been removed.

Which steel or aluminium structure is lowered into a utility excavation to protect workers if its earth sides cave in?

Trench box walls carry a depth rating: how deep a trench they can stand in and withstand a collapse without buckling.

Many of the men who drilled West Virginia's Hawks Nest Tunnel in the early 1930s died of which lung disease?

Silicosis struck because the tunnel cut through almost pure silica and the crews breathed its dust unprotected, some dying within a year.

Once a newly built home has passed its inspections, which local-government document confirms that people may move in?

Certificate of occupancy paperwork is the legal proof that a building meets the codes and is fit to live in, and one is generally required for every new building.

Which continuous concrete strip, always wider than the wall it carries, sits beneath a house's foundation walls?

Footing strips are commonly two to three times wider than the wall above, spreading the load until the soil can bear it.

Which asphalt-soaked sheet is rolled over a roof deck as underlayment before the shingles are nailed on?

Tar paper works as a back-up waterproof layer beneath the shingles, and before plastic house wrap took over it was stapled to walls for the same job.

In platform framing, where are the wall sections of a house usually nailed together?

Flat on the subfloor is quicker and more accurate: studs are easier to position lying down, and fewer hands are needed.

Which chemical company developed Tyvek, the white house wrap fixed around a framed home before the siding goes on?

DuPont stumbled on it in 1955, when a researcher noticed white polyethylene fluff coming out of a pipe in an experimental lab.

Which layer of plywood or OSB panels is nailed over a house's wall studs to brace the frame before siding goes on?

Sheathing stiff enough to resist sideways loads keeps a wall square, which is why codes in storm-prone regions insist on it whatever the outer finish.

In a wood-framed house, which treated lumber is bolted to the top of the foundation wall with J-bolts?

Sill plate anchoring keeps a house from coming off its foundation in a severe storm or an earthquake.

Before a rural home gets a septic drain field, which test measures how quickly the soil soaks up liquid?

Percolation test results, from what builders call the perc test, decide how large the drain field must be for the home it serves.

In British house building, which phase follows plastering, when sinks, baths, light fittings and doors go in?

Second fix is the British name for what North American builders call finish work, as opposed to the roughing in done before the walls are closed.

Which temporary frames, set just beyond the corners of a planned foundation, hold the string lines that mark its edges?

Batter boards are fixed at precise elevations, and the twine strung between them shows builders exactly where each corner of the foundation sits.

Which floating attachment at the back of an asphalt paver spreads the hot mix and gives it a first compaction?

Screeds have floated free since 1933, an invention that, paired with a tamper bar, gave new roads an even thickness and density.