Bottons Pleasure Beach in Skegness has been fined more than £16,000 following the partial collapse of a flat ride two years ago.
The Surf Rider attraction suffered a mechanical failure on 30 August 2011, injuring seven people.
Pleasure Beach Amusements Skegness Limited pleaded guilty to offences under the Health and Safety at Work Act.
A investigation by the Health and Safety Executive (HSE) revealed that the ride failed due to a lack of lubrication in its gearbox.
Their inspector David Kivlin today said: “This was a frightening incident for many people that day and it could have been easily prevented.
“There was just not enough oil in the gearboxes.
“The injuries suffered by those on the ride that day could have been much worse.
“It was a traumatic experience for everyone on board and some are now unwilling to go on fair rides or in lifts.
“As the ride’s owner and operator, Pleasure Beach Amusements (Skegness) Ltd had a duty to ensure the ride was maintained in good working order. The company significantly failed in that duty.”
A statement from the park said: “We would like to take this opportunity to apologise to those of our customers who were on the ride at the time of the incident and their families for what must have been a very frightening incident.
“We hope that they can now, however, put the incident behind them and continue to enjoy all of the facilities which our fairground has to offer.”
The hearing at Skegness Magistrates heard that Bottons Pleasure Beach was expecting a £90,000 loss in 2013.