Peter James Quinn

Men of steel

At the foundry of A & G Price in Thames, molten metal has been cast into everything from locomotives to pickaxes for close to 130 years.

Written by       Photographed by Peter James Quinn

Inside Waihi Gold's SAG mill, gold-bearing quartz is crushed by forged steel balls against the curiously wrought linings of a rotating drum. Prices cast the bolt-on lining plates, which last little more than a month in the brutal interior of the tumbler. The opportunities created by the Coromandel goldrush drew Prices to Thames last century, and in the last two decades mining work has again become a significant part of their business.
Inside Waihi Gold’s SAG mill, gold-bearing quartz is crushed by forged steel balls against the curiously wrought linings of a rotating drum. Prices cast the bolt-on lining plates, which last little more than a month in the brutal interior of the tumbler. The opportunities created by the Coromandel goldrush drew Prices to Thames last century, and in the last two decades mining work has again become a significant part of their business.

“I don’t like this. Let’s get out of here.” It was my son’s voice, shouting at me above the noise of the foundry. Safety clothing offers little protection against fear, and the electric arc furnace ten metres in front of us was radiating raw menace. With each shovelful of whatever was being tossed into its glowing maw, a shower of fiery embers leaped out, some dart­ing like firecrackers towards us. Smoke, fumes and wicked-looking flame belched out around the equator of the furnace, and an eerie blue beam periodically pierced the gloom. On the wall behind, needles on three dials jumped and relaxed, and indicator lamps flickered nervously. Most intimidating of all was the wavering, rumbling roar of that cauldron of fire, punctuated with ominous crackles and hisses. It was a scene that called up thoughts of maelstrom, volcano, dragons and doom.

We retreated. Outside, it was the late 20th century, and not a bad day to boot. Inside, it seemed as if the Industrial Revolution was just getting started.

In a way it was. Not because we had travelled back in time, but because the process of casting molten metal has not fundamentally changed in centuries. The oldest casting in existence is a bronze frog produced in Mesopotamia in 3200 B.C. Cast iron was used by the Han dynasty in China a few hundred years B.C., and cast steel was produced in India 1500 years ago. Vannoccio Biringuccio, the first true foundryman (and founder of the Vatican) wrote De La Pirotechnia, the original manual on foundry practice, about 1520.

Foundries spearheaded humankind’s emergence from the Dark Ages and were the midwives of the Industrial Revolution. Nowadays, sheetmetal and plastic dominate the realm of consumer goods, but when something really solid is needed, it’s still back to the foundry. Although the glamour of silicon chips, fibre optics, mobile phones and the like has meant that basic industries like metal casting are almost forgotten, the myriad items produced by foundries still undergird much of modern life. Late twentieth century technology means that you can produce stronger, more complex castings from a much wider range of metals than was ever dreamed of 50 years ago, but, despite the improve­ments, foundry operations retain a raw and other-worldly character.

In New Zealand there are dozens of iron and non-ferrous metal foundries—mostly small operations—but only three or four plants are capable of regularly producing large steel castings. And none is bigger or been around longer than A & G Price’s foundry at Thames, a cornerstone of New Zealand’s heavy industry since 1871, when brothers Alfred and George Price shifted much of their three-year-old company from Auckland to what was then a burgeoning gold town.

In many New Zealand goldfields, the yellow metal was alluvial and could be won by the digger with his pan. But not at Thames, or elsewhere in the Coromandel Ranges. Here gold was deposited in flinty reefs of quartz, and the only way it could be extracted was by pulverising the rock using heavy machinery.

The brothers Price saw an opportunity and seized it. Until then, producing machines that extracted fibre from flax had been their stock-in-trade (flax being the country’s main export for much of the nineteenth century), but they also made the water wheels that powered the flax mills, together with just about any other castings or machines that a growing colony required.

Just before they moved south, the Caledonian mine recovered 7700 ounces of gold from 80 tons of crushed rock—the richest crusling ever, and worth close to $4 million at today’s prices. More typical recoveries ran at 2 ounces of gold per ton of rock. (Today, gold is mined commercially from deposits that may have only a tenth of an ounce of gold per ton.)

Many of the reefs with the best prospects were at the northern end of Thames in Grahamstown (the area in which Prices built), and extended well below sea level. Shafts sunk to reach the rock were quickly flooded, so several companies formed the United Pumping Association and installed huge pumps that could lift 10,000 litres per minute 100-200 metres to the surface. It is unclear whether Prices was involved in the initial pump installation in 1872, but they were certainly the manufacturers of an even heftier set of pumps a few years later.

Over the next few decades, Prices produced hundreds of stamper batteries for crush­ing rock, dozens of Pelton wheels (the company acquired New Zealand manufacturing rights to this invention) to power the stampers and later generate electricity, crushers, ore feeders, berdans (devices for separating gold dust from crushed rock), steam engines and boilers for the goldfields at Thames and later those at Te Aroha and Waihi.

As steel—superheated to 1640°C—hisses into a ladle from a small induction furnace, a splash sends a shower of sparks cascading on to the melt shop floor.
As steel—superheated to 1640°C—hisses into a ladle from a small induction furnace, a splash sends a shower of sparks cascading on to the melt shop floor.

For a while, in the late 1880s, the brothers even owned their own mine: the Prince Imperial. It was thought that the mine was worked out, and the Prices bought it for £250, simply to acquire its machinery. But once in possession, they were persuaded to work it—profitable advice, as it turned out. The mine yielded 43,000 ounces of gold, worth £120,000. (As a price comparison, locomotives imported by New Zealand Rail­ways from the US and UK cost £2500 apiece at the time.)

The Thames works were capable of producing much more than just goldmining equipment. For the booming timber industry in the kauri forests of the Coromandel and throughout the north, Prices built everything from steam engines to timber jacks. (These same jacks would later find service hoisting beams and girders in bomb-damaged buildings in London during the blitz of World War II.)

Before the advent of road and rail, steam-powered coasters were one of the main means of communication and travel. In 1881, Prices built the paddle steamer Patiki, and two years later the ironclad 20-metre Despatch, which for many of its 26 years plied the waters of the Kaipara Harbour. From a financial viewpoint, the Despatch venture was a miserable failure. Prices spent £2000 on the ship, but depressed conditions meant she fetched barely £500 when a buyer was eventually found. For the rest of the century, Prices stuck to putting their engines and boilers into other people’s boats.

Soon Prices machinery was popping up everywhere. A lift was made for the New Zealand Herald building in Auckland; a 100 hp engine and boiler for a paper mill at Riverhead; a huge water wheel for Bycrofts, the Onehunga flour millers; gear wheels for motor coaches; castings for the Colonial Sugar Company; pumps for the copper mines on Kawau Island.

July 1903 saw an important milestone for Prices: the signing of a contract with New Zealand Railways for the construction of ten 43.5-ton Wf class locomotives for a total price of £28,000. Other locomotive orders followed. Twenty of the larger Class A engines and tenders for use on the Main Trunk Line were delivered between 1907 and 1909—one hauled the first through train over the northern half of the line—and a further 10 were ordered. On November 20, 1924, the 100th locomotive to be built by Prices puffed out of Thames.

In all, the company made over 200 railway engines—steam initially, but later small diesels. After orders for new locos tapered off about the middle of this century, Prices secured repair work on both locomotives and rolling stock.

Alfred Price died in 1907, but George continued with the company until his retire­ment on August 31, 1916. On the same day, John Watson, who had met the Price brothers on the boat journey from England, joined the firm as an accountant in the Auckland days and risen to become a partner, also retired. In a quiet room beneath the present offices, many hefty volumes of tissue-thin numbered pages contain copies of John Watson’s tens of thousands of items of correspondence. Until the mid-1890s, letters were all done in longhand.

Plans—once hand-drawn, but now generated with the aid of computers—for most of the castings ever produced by Prices are still in the company's files. Some date back to the 1870s. Throughout much of the history of A. & G. Price, railways were the bread-and-butter business.
Plans—once hand-drawn, but now generated with the aid of computers—for most of the castings ever produced by Prices are still in the company’s files. Some date back to the 1870s. Throughout much of the history of A & G Price, railways were the bread-and-butter business.

Management of the company passed to the second generation: Will Price, George Price Jr and Peter Watson, all of whom had started as boys in the foundry. Until 1927, business prospered, but then began the nosedive into depression which blighted the country and the world until the mid-1930s. But by 1937 there was again as much work on hand as the company could handle. Business was brisk through the Second World War with the manufacture of military equipment, and the years that followed were just as hectic. There were several orders for large conveyor belt systems (the Westport Coal Company purchased one), and Prices fabricated the bridge girders for the Maraetai hydroelectric station in 1947.

Although locomotive overhauls and the building of rolling stock meant that Prices remained heavily involved with railway work over succeeding decades, there were always new and challenging jobs. One such was the construction in 1954 of a complete wood preparation plant for Tasman Pulp and Paper at Kawerau.

In 1949, Prices amalgamated with the Petone-based firm of William Cable and Co., like themselves a long-established engineering firm. Cable and Co. was keen to establish a presence in Auckland, and Prices had reopened a branch there in 1906 that had concentrated on marine work. Within a decade of the merger, the Auckland branch was building barges and steel trawlers, fork lifts, lighting towers for the Harbour Bridge approaches, and the huge motorised pontoon for Auckland Harbour Board’s new float­ing crane Hikinui.

Cable Price merged with civil engineering and construction firm Downer and Co. in 1954, and the group acquired a number of other small companies, diversifying its interests and operations considerably.

Back in Thames, Prices rumbled on with its repair and maintenance of rolling stock and locomotives, and by the mid-1980s railways work formed 80 per cent of its business. And it was good, consistent business. Then came the Labour Government, flush with privatising zeal, and suddenly railways were out of the cosiness of the public purse. struggling to make a profit against deregulated and predatory truckers.

Prices’ railway contracts disappeared overnight, plunging the company into a sink-or­-swim situation. Financial troubleshooters were brought in to examine the viability not just of the Thames operation but of the substantial Auckland branch and Cable’s Petone workshop. Rationalisation was inevitable, with the result that the group’s heavy engi­neering and foundry work was consolidated at Thames.

This bush locomotive, Cb No. 117, built in 1927 to haul construction materials from Auckland to the Huia dam site in the Waitakere Ranges, has now been restored and runs on the Pukemiro line, west of Huntly.
This bush locomotive, Cb No. 117, built in 1927 to haul construction materials from Auckland to the Huia dam site in the Waitakere Ranges, has now been restored and runs on the Pukemiro line, west of Huntly.

To be sure, railway lines still issue from a couple of the great corrugated iron sheds, but they don’t go far: the branch line to Thames has been torn up. A couple of tarnished carriages from the Silver Star express that once proudly shuttled along the Main Trunk Line lie neglected in a yard. (Most of the carriages were sold to Malaysia for an express train, and refurbished by Prices before departure). What the visitor sees today are meticulously finished shrink-wrapped winch assemblies for ANZAC frigates peacefully awaiting completion of their host craft before dispatch to Melbourne; massive hydro­electric turbines (damaged by abrasive ash from Ruapehu’s tantrums) being ministered to by torch and tool bit; freshly cast keels for Whitbread yachts being roasted to the perfect amalgam of hardness and temper.

Amongst these bigger jobs are myriad smaller, more routine items, including a lot of work for the resurgent goldmining in the area. At any giyen time, there are several thousand items winding their convoluted course through the sprawl of buildings that spills over the four-hectare site.

[Chapter Break]

The essence of a foundry is the casting of molten metal into a hollow mould of the requisite shape. Not all metal products, though, need to be cast. Complicated lightweight shapes (car bodies, for instance) can be made by bending and stretching thin sheets of metal, and simple heavy-duty shapes (such as bridge girders) can be made from thick steel plate. But if you need both strength and a complicated shape, a casting is the usual approach.

First base in the process is the pattern shop, staffed by several craftsman patternmakers whose job it is to make a full-sized perfect wooden replica of the finished product. Here I find John McCormack working on what looks like a huge wooden bath, but turns out to be a vanadium slag recovery ladle for New Zealand Steel. “It will require us to pour eight tonnes of molten metal, which is a big job,” he tells me as he works.

Making the wooden pattern is also a big job—an estimated 300 hours of work. All the inside curves have to be seamlessly smooth. “In the old days, layers of leather were used to fill up cracks and smooth corners, but now we can use wood fillers and ‘Bondy.'” Heart kauri was once the preferred timber for patterns, and now Fijian kauri is often used in its stead. So are other materials—ply, a balsa-like wood, even polystyrene—especially if the pattern is only going to be used once.

Disposability, one suspects, is not a concept that sits comfortably with Prices. Since the first days in Thames, each of the tens of thousands of patterns which have been produced over the last century and a quarter has been stored. Not only was every nook and cranny in Prices’ works filled with patterns, but several old buildings nearby, including a couple of hotels, were literally splitting at the seams with patterns until a year or two ago.

A 70-year-old pattern takes on a fresh form at the lathe of John McCormack. Now that heart kauri—the preferred wood for patterns—is no longer available, old patterns are sometimes reshaped. Despite a recent clean-out, Prices retains tens of thousands of old patterns.
A 70-year-old pattern takes on a fresh form at the lathe of John McCormack. Now that heart kauri—the preferred wood for patterns—is no longer available, old patterns are sometimes reshaped. Despite a recent clean-out, Prices retains tens of thousands of old patterns.

Freshly minted patterns, or those being dusted off for re-use, go to the moulding shop, inside the foundry proper. Supervisor Wayne Heagney shows me around. The air here has a disconcerting pungency. Imagine an acrid amalgam of hot rubber and ozone, paint and Araldite, and you’ll have some idea of the smell. Much of the aroma has to do with the resins that are mixed with sand to harden it in the moulding bay.

To make a casting, sand is rammed around the wooden pattern in a moulding box, the pattern is removed, and molten metal poured into the cavity that’s left.

High up in the roof are arrays of hoppers and pipes, some no longer in use. Heagney nods towards them: “We used to mix green sand, bentonite, molasses and water to make the moulding sand. Now we mix synthetic resins with the sand and get much more satisfactory results.” Several different sorts of sand are used, some of them imported and costing up to 30 cents per kilogram. The main types are a coarse, very dark grey, glittering chromite sand from South Africa and a white silica sand, sourced locally. More than 80 per cent of the sand used for moulds is recycled from previous moulds, but, even so, some 500 tonnes of new sand is purchased each year.

I cast a nervous eye at the silent overhead cranes, from which heavy steel moulding boxes dangle at head height. Perhaps it’s because I’m tall, but the prospect of being brained has always troubled me. The fact is, everything here is too heavy to manhandle. “To cast 10 tonnes of metal you need to move 100 tonnes of material,” admits Heagney.

The main difficulty in making a mould is in getting the pattern out again. More complex shapes may demand that the pattern be in several pieces, and the mould is then built up in sections also. But even the simplest moulds are made in two pieces. I watch as the mould for a three-metre ring is prepared. The pattern is placed on the concrete floor, and a collection of ceramic pipes (termed the plumbing) attached above it. A steel moulding box is then positioned around the pattern, and sand, mixed with resin and hardener, is rammed into the mould box.

Paint, used to smooth the surface of polymerised sand in the mould, is ignited to cause rapid and complete drying. Traces of moisture or solvent in the moulds result in unwanted bubbles in the castings.
Paint, used to smooth the surface of polymerised sand in the mould, is ignited to cause rapid and complete drying. Traces of moisture or solvent in the moulds result in unwanted bubbles in the castings.

After the resin has polymerised—producing rock-hard sand—the moulding box is flipped over, chalk is dusted over the sand surface, and another moulding box is swung into position above the first. A “lid” of sand is added, and once it, too, has hardened, the two halves of the mould can be separated along the chalk line and the pattern removed. The surface of the sand exposed by removal of the pattern is then painted to impart a smoother surface, and the moulding boxes reassembled to give an intact mould. Molten metal will be poured into a tube that connects to the plumbing, the idea being that the metal will flow gently into the mould from below.

Cranes lug the assembled moulds into the metal pouring area, the heart of the foundry. This hall feels decidedly medieval. It is gloomy, smelly, noisy—and old. The roof framing is made from massive wooden beams, perhaps 150 by 300 mm. Architec­ture is one of Prices’ problems. Many of their elderly premises are classified as historic buildings, and must be preserved—yet how can you meet the demands of modern industry within the strait-jacket of geriatric buildings?

Contracts manager Wayne Price says the company does its best to preserve the exteriors of the older buildings, while making interior alterations where necessary. Much remains unchanged. To touch or lean on any surface in the foundry is to be soiled by the grime of decades. But this is not a good place to touch anything. Almost any object resting on the congested floor is cooling down—varying from the frankly red hot to a merely simmering couple of hundred degrees. Underfoot, the surface is black sand; above, another gliding overhead crane threatens decapitation—with cauterisation as a possible extra.

[Chapter Break]

At the south end of the hall is an induction furnace into which a heavily dressed furnaceman is emptying drums of scrap metal. Showers of sparks fly out with each addition. Beyond a loading bay near the furnace are scores of drums of rusting scrap, much of it industrial offcuts, labelled according to the type of metal. Beyond wait piles of more miscellaneous furnace fodder—old engine blocks, pipes, decrepit machinery. The foun­dry—a pariah in some eyes—is a great recycler.

Past a second induction furnace lies the big electric arc furnace (the snarling indoor volcano I encountered at the start of the story). Chris Johnson, the melt shop supervisor, explains how it works. “It’s like a giant arc welder. Electric current gets fed into carbon rods at the top, they press down on the scrap inside, and the heat of the electric arc passing through the metal melts it into a growing pool inside the furnace.” The carbon rods he indicates are 150 mm in diameter and project above the lid of the furnace for more than a metre. They seem to move up and down as if seeking new metal targets, but are slowly consumed by the conflagration they preside over. “Before we had our own power feed to the foundry, lights all around Thames would dim when we turned the juice on,” Johnson confides.

Knowing that sparks the size of lightning bolts were sizzling about inside its abdomen explained a lot of the furnace’s animosity. Johnson tells me how the induction furnaces work—something about electricity and coils—but I’m not taking it in. The cantanker­ous arc furnace, grumbling through its meal of metal, exercises a magnetism that the less flamboyant induction furnaces lack.

Trevor Finan removes a freshly annealed steel ring from an oven. Depending on the heating rate, final temperature and speed of cooling, such treatment can either harden or soften steel.
Trevor Finan removes a freshly annealed steel ring from an oven. Depending on the heating rate, final temperature and speed of cooling, such treatment can either harden or soften steel.

I ask a shaggy furnaceman about the merits of the two types of furnace. “Induction furnaces are quick and clean, but they require high-class scrap,” he tells me. “Arc furnaces are a lot less fussy. Although this one takes at least three hours to melt a load, you can boil the hell out of a melt and get rid of stuff you don’t want, such as hydrogen, nitrogen and phosphorus. You can’t do that with an induction furnace.”

There were other types of furnaces before these electrical giants. Peter Grant, 41 years with Prices, describes the operation of a cupola furnace—a vertical tower in which you start a wood fire in the bottom, then add a layer of coke, then a layer of iron, then more coke, more iron, etc. Air is blown into it from the side, and melted iron trickles downward, to be collected near the base.

Impatience with this furnace once led to a major embarrassment, says Grant. “The BNZ had a huge accumulation of old cheques that they wished to dispose of, and asked us to burn them. The boys tossed the whole lot into this thing one afternoon, but a solid mass of paper doesn’t burn well. They were in a hurry to get to the pub before 6 o’clock closing, so they turned on the blower. The town was showered with hot cheques.”

During one of my visits, several tonnes of metal were being melted to cast the keel of a Whitbread yacht. The moulding box—perhaps 4 m x 2.5 m x 1.5 m—stood ready with its cargo of sand-encased space. Metal in the small induction furnace was molten and at the right temperature. But there seemed to be a problem with the arc furnace. Dressed in protective suede clothing, a furnaceman periodically opened the door to the inferno and thrust a lance-like probe inside—a disposable temperature gauge that provides a readout on the handle. Others in the motley retinue tossed in odd shovelfuls of I know not what, and another snared gobs of molten metal on a rod. These samples were knocked off and carried away for analysis. The ritual continued—to the accompaniment of the sparks, crackles, glare and roar of the furnace—for close to two hours before the brewers considered their concoction ready.

The denouement happens quickly. An overhead crane whisks a huge ladle—preheated by big diesel torches—into a pit beside the recalcitrant arc furnace. The whole furnace is hydraulically tilted like a teapot, and a stream of molten metal, brilliant as the sun, spills into the ladle. More metal from the induction furnace tops it off.

Chris Johnson helps position the ladle above the opening that gives access to the mould’s plumbing, then releases a spout of incandescent liquid. When a little molten steel spills on to the top of the mould, billows of sparks envelop him. Within two minutes of issuing from the furnace, all the metal is solidifying in its new-found keel form. On the floor around the edges of the moulding box and along joins in the box, tongues of orange and blue flame lazily lick at the air. Heat from metal in the mould has vaporised resin in the adjacent sand, and it is these gases that are now burning.

Freshly broken from its mould, a casting looks dull and scaly compared with a machined product. The metal stumps spaced around the crude casting are "risers"—reservoirs of metal drawn upon as the casting contracts on cooling. They will be torched off in the finishing process.
Freshly broken from its mould, a casting looks dull and scaly compared with a machined product. The metal stumps spaced around the crude casting are “risers”—reservoirs of metal drawn upon as the casting contracts on cooling. They will be torched off in the finishing process.

On a later visit, the arc furnace is quiet, its top off, apparently lifeless. Behind it, braided copper cables, each as thick as my wrist, run loosely from the wall to brackets high on the machine. An engineer working on the machine’s hydraulics tells me that these huge uninsulated tresses conduct power to the carbon electrodes—four to each of the three electrodes. Wooden doughnuts, 300 mm across, prevent each bundle from contacting its neighbour. I have never seen such wires.

“Each electrode can draw up to 2000 amps at 60 or 70 volts DC,” he informs me. I don’t feel inclined to touch them, even if the beast is switched off. Just as uncertainly, I peer into the maw of the furnace, as if placing my hand within the mouth of a freshly dead shark, wondering whether it might not be good for one last bite. Foolish fears. Within, it is just a cauldron of weather-beaten, pitted, rusty steel—little different from the scrap it consumes. Actually, a lining of firebricks protects the steel of the furnace from the conflagration it normally holds, and the furnace is out of action this day and for the next few to allow rebricking. “If we’re re­ally busy, we have to rebrick the fur­nace once a month,” I’m told. It’s an expensive business. Grout alone costs $4000, and the whole job some $30,000.

Not only furnaces need protec­tion. The ladles which convey mol­ten metal from the furnaces to the moulds are carefully lined with ei­ther bricks or “planks” of a protective material set in sand. When molten metal is poured into the ladle, these linings react in a way that releases yet more heat to the molten metal. This is a not insignificant benefit, because most castings are small, and metal from a single ladle may have to stay molten while moulds in 20 or more boxes are filled. The plank linings are easy to remove from the ladles, and are replaced after every pour of steel, but they cost $100-$200 each. Bricks last for months, but the lava-like clinker remaining in the ladle after each pour has to be chipped out, a task that falls mostly to Brian Jackson.

“Jacko” has been here for 25 years. From the interior of a ladle, he mutters darkly about government policies that force 70-year-olds to keep working at this kind of stuff—”pretty hard work,” he says. There is no denying it, and Jacko’s battered features look to have spent too long, too close to things that are too hot.

During a breather from his ladle work—up to six ladles a day may be used—he tells me that everything that can go wrong has gone wrong here at some time or other, the most common mishap being molten metal leaking out of ladles and moulds.

Trevor Finan, a blacksmith who has been with Prices since 1966, describes a recent incident in which a ladle full of metal became snagged as it was being raised, and emptied itself into a doorway. “Anyone nearby would have got hot feet, but it just singed a wall. There was a lot of smoke, and a neighbour summoned the fire brigade. They couldn’t find the fire for the smoke, and charged up on to the floor above and attacked the tearoom. It was actually very funny.”

[Chapter Break]

The company’s metallurgist, Tony Hollis, shares a small laboratory with a magical piece of equipment called an optical emission spectrometer. Poke a blob of metal into its chamber and within 30 seconds you get a printout of the percentage of every element it contains—done by analysis of the spectrum of light given off by a spark struck from the surface of the metal. Some elements (molybdenum and manganese, for instance) are in­Auded in a melt to impart properties such as hardness and corrosion resist­ance to the metal. Others (silicon, aluminium, calcium) act as antioxidants.

Hollis shows me lists of the metals they cast. We do a quick count. Fifty varieties of steel, not including the 31 stainless steels in the standard range. Twenty-five grey cast irons (in which the carbon is graphite), 10 SG irons (where the graphite is in spherical particles), 10 or 12 white irons (with the carbon present as carbide), four high-nickel non-magnetic irons, and about 25 non-ferrous metals (aluminium, brass, copper, etc).

I’m staggered. I had heard of two or three types of stainless, and wrenches at times bear words like “chrome steel” or “vanadium steel,” but here were more than 125 types of steel and iron!

A standard production item, the timber jack (of which Prices produced 25,000), was an indispensible forestry tool for many decades.
A standard production item, the timber jack (of which Prices produced 25,000), was an indispensible forestry tool for many decades.

As far as the foundry is con­cerned, iron is much better to cast than steel. “Steel contains a lot less carbon, and is horrible, glutinous stuff,” Trevor Finan tells me. “Iron melts at a lower temperature than steel (1400° compared with 1640°C) and pours like water. It’s much easier to cast.”

Two days after casting, the Whitbread keel is cracked out of its mould. The metal is still at 400°C, and looks like concrete in colour and texture, with odd fins and protuberances of metal sticking out where there had been joins in the mould. After the risers and other pipes leading into the mould—now represented by sturdy rods of steel—are torched off, the keel is reheated to 920°C in a “top hat” furnace (a huge bottomless box fitted with electric heating elements along its inside walls) then allowed to cool slowly to anneal the metal. Anneal­ing evens out and reduces stresses in metal, and is necessary every time a casting is worked with torches.

The keel is then shot blasted and fettled—processes designed to re­move unwanted metal from the cast­ing. Shot blasting involves bombard­ing the object with tiny steel balls, while during fettling grinders are used to remove heavier encrusta­tions that have survived the shot blasting. They send firestorms of sparks streaking out across the foun­dry floor.

Nearby, a shuddering roar that threatens to drown out even the scream of the grinders comes from the first stage of the sand recycling plant. Clods of fused sand from the moulds are crushed and shaken through a heavy mesh, the start of a rough passage that eventually spews out single grains of sand.

A recent project-conducted under tight security—was the casting of the secret keel on Peter Blake's America's Cup challenger Black Magic. Such is Prices' reputation for this sort of work that the company is now making keels for yachts all around the world.
A recent project-conducted under tight security—was the casting of the secret keel on Peter Blake’s America’s Cup challenger Black Magic. Such is Prices’ reputation for this sort of work that the company is now making keels for yachts all around the world.

Cleaned up castings are examined for cracks by having a solution con­taining iron particles sprayed on to their surfaces. When an electric current is applied, fine cracks are made visible by virtue of particles lining up along their edges. Welding repairs these blemishes.

Some days later a crane lifts off the top hat furnace and then plunges the red-hot keel into a huge bath of oil. Flames lick over the surface of the vat as the keel is lowered in, but disappear once it is submerged. An hour later, the now glistening black keel is hoisted out and tested for hardness by Trevor Finan. A small probe produces satisfactory readouts from each of three shiny spots that Finan has ground.

“You always take the metal up to maximum hardness and stress, then temper it back to what you want,” he explains. “Now she’ll go back in the furnace, but just to 580°C, and then we’ll air cool it to get the hardness we want.”

[Chapter Break]

Many castings require further modi­fication in the machine shop that Prices run. It is housed in a separate hall from the foundry, and has a much more modern feel to it. Gone is the sand underfoot, the smell, the din, that sense of appre­hension that was my companion in the foundry. There is still noise, to be sure, but it is now the muted purr of big motors and machine tools peeling off writhing spirals of swarf with robotic precision. Here the workers have fingertip control of well-ordered machines. Back in the foundry, the forces were more pri­mal, the rule of humans less sure. Nature might just snap its chain and run amok. But not in here.

I chat to Stephen Walmsley, ma­chining a two-metre-diameter steel ring that will be used as a mould for making the end connections of con­crete pipes. He uses a vertical borer, a name that suggests a bigger ver­sion of a Tool Time drill press. In fact, the cutting tool that does the actual work is a little ceramic diamond no larger than a fingernail, but the ma­chine it is attached to is the size of an up-ended bus. This monster can spin a disk up to six metres in diam­eter at whatever speed is appropri­ate. “The inside tolerances on this job are 0.029 mm, and the outside an even more generous 0.05 mm,” Walmsley tells me, as though such precision was the most trivial thing in the world. Perfecting this casting will take 20-30 hours of machine time and produce a few drums of bright blue steel swarf—which will find its way back into the furnace.

There are dozens of machines in here. Some are a mere two or three metres in length, but one lathe can handle 30 tonnes with a turning length of 12 metres. Some of the newer machines are computer controlled. The opera­tor punches in dimensions and coordinates, and the machine executes the required cuts.

What Dennis Bernasconi carts today is mere swarf and rusting scrap, but what will it became?
What Dennis Bernasconi carts today is mere swarf and rusting scrap, but what will it became?

Another of the big new machines even selects and changes its tool heads automati­cally from its own armoury, and the actual cutting is carried out within a sound-deadening glass cabinet. I watch mesmerised as it pares down the inside of a large cylindrical casting, giving constantly changing readouts of how much it is removing and how much remains to be done. This particular job—destined to be a mould in which Air New Zealand engineers will cast carbon fibre engine covers for their jets—will continue on autopilot for many hours. Much of the work of the machine shop involves repairs to industrial equipment, such as to the huge turbines from the Rangipo power station near Ruapehu, seriously eroded by water-borne ash from recent eruptions.

John Hillery, general manager of Prices, says that securing long-term contracts, particularly ANZAC frigate work, has been pivotal in the company’s renaissance.

“Back about 1990, staff were always looking back, lamenting the loss of railway business. It was jeopardising our future development. Then we secured the 10-year frigate contract—that was an anchor of new hope for us.”

To meet the exacting specifications of defence work, the company had to win ISO 9002 certification, which meant a tightening up of quality control procedures and an across-the-board improvement in skills. “The net effect has been to improve the quality of all the work we carry out,” says Hillery.

My last visit is to sales manager Peter Grant, another long-serving Prices employee with a wealth of rec­ollections. “In 1956, when I started here as an apprentice, there were three cars,” he recalls, “and two of those belonged to the company. Everyone came to work on push bikes, and we had huge racks of bikes outside.

Inside an electric arc furnace, the rubbish of yesteryear is transformed into the metal of tomorrow.
Inside an electric arc furnace, the rubbish of yesteryear is transformed into the metal of tomorrow.

Steam locomo­tives were con­stantly being re­paired, and they had to be fired up in the shed. We worked in constant smoke and grime, yet English fitters came to work on those filthy locos in white shirts and ties.

“If any of us ap­prentices stepped out of line—by be­ing too smart—we’d get a hefty belt from one of the older men. There were a lot of pretty tough depression types who were big and strong, heavy drinkers and smokers. Apprentices only got to use the oldest machines. Nowadays it is the older men who are apt to be stuck on the older machines, while the younger guys pick up on the new computer-controlled models.

“Back then, home jobs were strictly forbidden, but everybody did them. I put to­gether a big three-bladed mower for the hockey club. We had to smuggle out all the components and assemble it elsewhere. Later, when I became works manager, I allowed the men to use the plant in their own time for private projects.

“Our greatest strength here is our staff. In a smallish place like Thames, we all work and socialise together, and that builds up a strong spirit in the plant. Well, mostly it does. I remember as works manager having one guy on the mat for some misdemeanour. But he was the chairman of the kindergarten committee, and when I turned up for a working bee the following Saturday, he made sure I got the worst possible job—digging post holes in ground like concrete.”

Family squabbles notwithstanding, the esprit de corps within the elderly walls of the works seems healthy. Perhaps it is helped by the fact that, despite economic downturns and the closure of other foundries (including hometown rival of more than a century, Charles Judd Ltd), despite the rise of plastics and the demise of steam, A & G Price is still flourishing—a multimillion-dollar enterprise employing 140 people.

Alfred and George would be pleased.

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