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Simon Clarke on the
detective work needed before
________ _______
repairs could begin
_____
THE RESTORATION OF
EROS
In August 1990, vandals climbed onto the statue of Eros in Piccadilly Circus, swinging on the outstretched leg. The statue suffered cracking in the calf of the supporting leg.
Eros was commissioned in 1893 and has required repair at various times in the past, the most recent in 1986 when Henshaws carried out a welding repair.
An initial examination carried out on site revealed a large crack spanning over 50% of the circumference in the calf of the supporting leg. Associated with the crack were a large number of dowels and, at the rear of the leg, a large aluminium core plug, approximately 30 mm in diameter; these had been part of earlier repairs. A core plug was carefully removed and examined in the laboratory, which revealed that the statue consisted of an outer aluminium skin, approximately 10 mm thick, and an aluminium fill material that had been cast around the iron armature supporting the statue. A series of craze cracks was also spotted on the front of the thigh of the supporting leg. Liquid penetrant inspection revealed that this cracking was just above the Roman joint. From the nature of the cracking it appeared to be in the form of a burst, that is, pressure from behind rupturing the surface and forcing it outwards. The core hole was repaired temporarily using an
aluminium core plug.
The core plug sample revealed the outer wall to be an aluminium alloy with a low alloy content that had fractured through the complete wall thickness in a tensile mode with minimal elongation. The infill material was an aluminium silicon alloy, of around eutectic composition, ie approximately 12% silicon. This material was full of large laps and oxide films and there did not appear to be any bonding between the infill and the outer skin. Microscopic examination of the skin material showed it to be full of oxide films and inclusions and possibly some heat affected material, such as that at the edge of a weld repair. This may indicate that the failure had occurred adjacent to the Henshaw repair.
English Heritage reported that both the thigh and calf areas of the statue had suffered similar damage in the past which had been repaired by welding of the calf and welding a plate in the thigh. It was thought that although the main part of the statue was hollow the armature extended up to the shoulder to provide some support over its full length. Infill material in the supporting leg had been added in the early 1930s, following similar damage, in an attempt to strengthen it. The statue had been cast in the early 1890s, using a nominally pure
aluminium that was as pure as the aluminium could be refined at that time. The aluminium silicon infill material has a much lower melting point and hence would have less effect on the statue when being poured in. However, because of the contamination and debris in the statue from the original core material, the fill material did not fuse or bond to the skin and hence the extra support gained was only marginal.
It was recommended that the statue’s calf should be repaired by welding and the patch in the thigh replaced. Also suggested was the possibility of filling the statue so that stresses from the upper part of the statue could be directly transmitted to the armature, relieving the problem area in the calf.
English Heritage wished any repairs or modifications to the statue to be reversible and to involve as little disruption to the original work as possible. With these conditions in mind it was recommended that welding should be carried out using compatible consumables, ie pure aluminium, and that any infill of the statue would need to be easily removable for which fine grain sand, compacted by vibrating, would be appropriate.
Radiographic inspection revealed that the armature had been incorporated into the leg during casting but that it only extended as far as the top of the Roman joint in the thigh of the supporting leg. Trials indicated that although the armature was securely located at the top of the thigh, it would obviously be of little value for using as an infill material to provide further support. Radiography also showed that the crack appeared at the change in section from the solid casting in the foot and ankle area and the hollow part of the leg. There were many foreign particles present, including possibly remnants from the original core materials and large voids in the infill material.
Detailed ultrasonic examination


Penetrant testing of welded repair on supporting leg (horizontal).
CONTEXT 42
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