The history of the manufacturing and shaping of iron and steel components

From 1870 steel production increased while iron production remained fairly static.

The trend from iron to steel can be summarised in a table showing the production figures for different countries worldwide.  This shows a steady increase in steel production whilst iron production remains fairly static.  However, even in the first decade of the 20^th century iron production in the  UK still surpassed that of steel.

Year	UK Pig Iron	UK Wrought Iron	Steel (five year averages)
			World	UK	France	Germany	USA
1870-74	6.38	2.60	0.98	0.43	0.13	0.21	0.11
1875-79	6.38	2.27	2.46	0.88	0.25	0.41	0.64
1880-84	8.16	2.01	5.48	1.79	0.45	0.97	1.56
1885-89	7.66	1.91	8.84	2.81	0.53	1.57	2.78
1890-94	7.29	1.93	12.78	3.14	0.76	2.74	4.31
1895-99	8.64	1.15	21.54	4.26	1.24	4.85	7.63
1900-04	8.68	1.16	32.72	4.95	1.67	7.28	13.40
1905-09	9.70	0.94	48.16	5.99	2.60	10.67	20.94

Production of Iron and steel 1865-1906 (millions of tons) (Source: Burnham and Hoskins (1943), Tables 2 &70)

Iron before industrialisation: By the time that iron arrived as a 'new' material in the late 1700s the building industry had mastered the art and technology associated with heavy materials with good compressive, but little tensile strength. Then, here was the challenge of a new material which invited the development of new forms that could give a new lightness and transparency to buildings.

A great range of variants of heavyweight forms such as the dome, the arch and the buttress had evolved. Alongside stone and brick, timber use in building structures was commonly in the form of large section beams, trusses and arches. But this new material invited the development of new forms that could give a new lightness and transparency to buildings. By the beginning of the nineteenth century iron and steel structures had become a comparatively advanced industry, with heavy fixed capital equipment in the form of furnaces and forges. This section charts the early days and the important landmarks in the progress towards the kinds of contemporary materials and forms that we see today.

In fact, the story of iron and steel is similar to that of concrete in that it is a rediscovered material.

In the same way that concrete was invented by the Romans, only to be lost and rediscovered hundreds of years later, significant iron structures did exist many years before the famous 'Ironbridge'.  There appear to have been many early examples in  China, for instance an iron suspension bridge across the Kin-Sha river in  China in the 8th century. Around the same time, or even earlier, bridges and pagodas were being constructed with iron as the major structural material.

Wrought iron had been produced in  Europe from the time of the Middle Ages, if not before, through the firing of iron ore and charcoal in equipment called a bloomery.

The bloomery method had been replaced by the blast furnace from the 1490s onwards. With the aid of water-powered bellows the blast furnace permitted both increased output and continuous production. The other end of the production process was improved a century later by the introduction of the plain rolling and the slitting mill; again water-powered.

The traditional use of wrought iron in architecture was principally as dowels, cramps or ties to strengthen masonry structures.

As early as the 6th century iron tie-bars had been incorporated in the main arcades of Haghia Sophia in Istanbul. Renaissance domes often relied on linked bars to reinforce their bases. Such customary uses reached a new degree of sophistication in Jacques Germain Soufflot's design for the portico of the Pantheon in  Paris, 1770-2.

But it is the decorative uses of wrought iron that have always attracted most attention.

The decorative uses include ornamental scroll and repousse work on hinges, screens, gates and balustrades. As iron production improved, smiths could depend on reliable supplies of iron in standard measurements, and so could devote their total energies to the forging of elaborate designs. The most famous smiths working in England at the turn of the 18th century were Jean Tijou and Robert Bakewell, but there were also smiths of considerable local repute such as William Edney in Bristol and the Davies Brothers in northeast Wales. The White Gates at Leeswood in Clwyd c.1726 have long been attributed to Robert Davies. Their open-work pediments, and even more their piers, have an outstanding three-dimensional quality.

The output of charcoal-fired blast furnaces was almost all converted to wrought iron. In the early 18th century probably not more than 5% was used for casting.

The most obvious cast items were cannons, of which the first British example was made in 1543, but soon after 1700 cast iron began to be given architectural uses. When Scottish members first sat in the House of Commons in 1706, the accommodation was expanded by the addition of galleries on slender cast iron columns, and four years later cast iron railings, fabricated in Sussex, were erected around St. Paul's Cathedral. By 1750, 20% of iron output was devoted to casting, and thereafter architects began to put their trust in iron more frequently, especially as a substitute for stone in conventionally designed column and window tracery.

The Gothicist Thomas Rickman went further than others in pushing cast iron to its limits in the two churches he designed in Liverpool: St. George's Everton 1812-14 being particularly notable.

Thomas Rickman designed two churches in Liverpool in cooperation with the iron founder John Cragg. St. George's Everton 1812-14, the better of the pair, has a delicate galleried interior where iron is given full play, from the columns and gallery fronts to the ribbed panelling of the nave and aisle ceilings. The exuberance with which Rickman employed iron was exceptional.The decorative uses include ornamental scroll and repousse work on hinges, screens, gates and balustrades. As iron production improved, smiths could depend on reliable supplies of iron in standard measurements, and so could devote their total energies to the forging of elaborate designs. The most famous smiths working in England at the turn of the 18th century were Jean Tijou and Robert Bakewell, but there were also smiths of considerable local repute such as William Edney in Bristol and the Davies Brothers in northeast Wales. The White Gates at Leeswood in Clwyd c.1726 have long been attributed to Robert Davies. Their open-work pediments, and even more their piers, have an outstanding three-dimensional quality.

The decorative uses include ornamental scroll and repousse work on hinges, screens, gates and balustrades. As iron production improved, smiths could depend on reliable supplies of iron in standard measurements, and so could devote their total energies to the forging of elaborate designs. The most famous smiths working in England at the turn of the 18th century were Jean Tijou and Robert Bakewell, but there were also smiths of considerable local repute such as William Edney in Bristol and the Davies Brothers in northeast Wales. The White Gates at Leeswood in Clwyd c.1726 have long been attributed to Robert Davies. Their open-work pediments, and even more their piers, have an outstanding three-dimensional quality.

The decorative uses include ornamental scroll and repousse work on hinges, screens, gates and balustrades. As iron production improved, smiths could depend on reliable supplies of iron in standard measurements, and so could devote their total energies to the forging of elaborate designs. The most famous smiths working in England at the turn of the 18th century were Jean Tijou and Robert Bakewell, but there were also smiths of considerable local repute such as William Edney in Bristol and the Davies Brothers in northeast Wales. The White Gates at Leeswood in Clwyd c.1726 have long been attributed to Robert Davies. Their open-work pediments, and even more their piers, have an outstanding three-dimensional quality.

Rickman's fellow architects who shared his confidence in iron's potential were more likely to use it as a less explicit accessory in their work; for instance Nash, in the Pavilions at Brighton.

As Rickman's churches were nearing completion John Nash was embarking on his transformation of the Royal Pavilion at Brighton. There the exotic skyline of domes and minarets is carried on a cast iron framework, but as seen from the street, there is nothing to betray that fact.