His injuries were so severe his leg required amputation above the knee. His pelvis was also fractured in the incident on 30 June 2005.
Main contractor Sir Robert McAlpine Limited and sub-contractors McNicholas (now Skanska Utilities) and Maylim were all prosecuted by the Health and Safety Executive (HSE) over the incident.
The City of London Magistrates’ Court heard the HSE investigation showed all three companies had failed to ensure vehicles and pedestrians were properly segregated on site.
It also found the cleaning of shuttering was neither properly planned nor carried out safely.
Following the hearing HSE inspector Loraine Charles said: "Traffic needs to be managed effectively on all construction sites. Had proper controls been in place, this appalling incident would never have happened. As it is, Michael O’Donovan has suffered a severe injury and his life has been changed for ever.
"At construction sites, workers and vehicles need to be separated wherever reasonably practicable. There was no demarcation between the route the dumper took and areas where people could work or were working on this site.
Sir Robert McAlpine admitted breaching Section 3(1) of the Health and Safety at Work etc. Act 1974 and was fined £19,000 and ordered to pay costs of £10,000.
Sub-contractor Skanska Utilities admitted breaching Section 3(1) of the Health and Safety at Work etc. Act 1974 and was fined £17,000 and ordered to pay costs of £10,000.
Maylim, sub-contracted by McNicholas Plc to undertake the work on the South Bridge area of the site, pleaded guilty to the same breach and was fined £18,000 and ordered to pay costs of £10,000.