Two companies deemed responsible for the incident were in the dock on Friday and received fines totalling £110,000 plus more than £30,000 costs.
Richard Chodkiewicz, 53, from the Lawrence Weston area of Bristol, was working for Hoistway Ltd installing a lift at the construction site for a new Radisson Blu hotel in Marsh Street, Bristol, when the incident happened on 22 July 2008.
The court heard that three men had been working on the lift installation, with Mr Chodkiewicz and a colleague at the bottom of the shaft. Another man was 18 stories up, at the top of the shaft, raising a seven pound scaffolding tube tied to a length of piano wire up the shaft.
Mr Chodkiewicz had come away from the lift shaft but had returned before the tube had been lifted clear from the shaft. The tube had reached the 15th floor, when the piano wire became untied and the tube fell onto his head. He survived, but has suffered permanent brain damage as a result of his injuries.
An HSE investigation following the incident found that both Hoistway Ltd and the main building contractor on site, Miller Construction (UK) Ltd, had failed to ensure that a safe system of working was in place for the installation of lifts on the site.
Hoistway, based in Martock, Somerset, pleaded guilty at Bristol crown court to breaching Section 2(1) of the Health and Safety at Work etc Act 1974 and was fined £70,000 with £14,616 costs.
Miller Construction (UK), based in Edinburgh, pleaded guilty to breaching Section 3(1) of the same Act and was fined £40,000 plus £17,232 costs.
After the hearing, HSE inspector Steve Frain said: "The contractors involved should have had effective arrangements in place to ensure that Mr Chodkiewicz was not in the bottom of the lift shaft while anything was being raised or lowered. Even a smaller object falling on him from that height could have killed him or his colleagues.
"As it was, he was struck with such force by the pole that he now has severe brain damage and requires 24-hour care."
The investigation also found that there had been inadequate site management and insufficient risk assessments carried out before the work was undertaken. Openings had been left unguarded and not enough had been done on the site to prevent the risk of falling objects.