Phoenix columns were a new
development, patented in 1862; they are made from sections of wrought iron that were riveted
together. This technique meant they were
very strong, fire resistant and could withstand vibration. This innovation emerged from the Phoenix
Iron Company, Pennsylvania, USA, thus the name.
Phoenix columns were crucial to the development of modern architecture. Compared with the loading capabilities of cast iron columns, Phoenix columns could take a far greater weight. Their strength and ability to withstand movement allowed the creation of more complex bridges, high railways and the development of sky scrapers.
The above qualities made the columns ideal for solving the
problems associated with the General Market site. Horace Jones used sixteen Phoenix columns
with connecting lattice girders to support the entire roof, creating the open
floor plan perfect for the safe movement of goods and people. Four of these columns span the distance from
the basement up to the roof. The columns
could flex and withstand movement, ideal for dealing with the vibration from
the railway. They were resistant to fire
and also corrosion as they could be painted and the interior of the columns
filled with concrete (this also helped to deaden sound).
Jones used 16 Phoenix columns with connecting lattice girders in the General Market to support the entire roof. 4 of these columns span the distance from the basement up to the roof. Phoenix strength meant that less columns were needed to support the roof, and created a very open internal plan. Although Phoenix-style columns were used world-wide, there seem to be only two known uses in this country, Smithfield and Redhill railway station. In fact, Jones didn’t even refer to them as Phoenix columns in his plans for the General Market. Perhaps he thought the City of London would reject this new-fangled American technology as untested, too dangerous to take a chance on.
You can learn much more about the curiosity of the Smithfield Phoenix columns in a report by Dr. Jenny Freeman, written for SAVE Britain's Heritage.