Residents living near the construction site in Essex were evacuated when a 45m JOST crane jib collapsed and was left swing dangerous in high winds.
It was one of two incidents with the crane at the Sutton Road site in December 2011.
Chelmsford Crown Court heard that McCarthy & Stone Retirement Lifestyles employed its own team of crane erectors to erect the 24m tall tower crane, which had a 45m long jib.
The court heard that on 15 December crane erectors were carrying out a test lift when the lifting rope broke, causing a heavy block and seven tonne test load to fall onto a trailer.
No one was injured but witnesses described how the crane and jib recoiled violently, bucking back and forth.
A new lifting rope was installed, but the crane remained unused pending the delivery of a new “load indicator” rope.
But two days before Christmas, the crane’s jib collapsed, causing the 280kg hook block to swing and fall outside the boundary, partly demolishing a garage and fence belonging to a neighbouring developer.
The bent jib was left hanging vertically from the top of the tower crane.
Fortunately, both construction sites had closed for the Christmas break and no one was injured.
But emergency services evacuated 30-40 residents from nearby homes while the area was made safe before they were able to return home for Christmas Day.
HSE found that safety-critical high-tensile steel bolt connections had not been suitably installed and maintained in the crane jib.
Evidence indicated that the correct pre-tension torque was not applied to tighten these vital components and that no suitable lubrication regime was implemented.
The crane had been subjected to damage in the first incident, when the lifting rope failed.
Clearly, at this point, the company could have ensured that a thorough mechanical examination of the crane was carried out, but it failed to do so.
In fact, little more than a visual examination was carried out and the crane later collapsed after the connecting components in the lower jib failed in tension.
McCarthy & Stone Retirement Lifestyles was fined £50,000 including a victim surcharge and ordered to pay £47,681 in costs after pleading to safety breaches.
HSE Principal Inspector Norman Macritchie, said: “It is only by good fortune that no one was injured or killed in these incidents.
“The jib collapse may have been avoided had the company identified and repaired any damage caused by the earlier incident when the lifting rope broke.”
