Diving bell clamp mating screws
A member has reported the following issue discovered during a ‘routine’ inspection prior to the commencement of saturation diving activities using a bottom-mating system.
The bell mating screws and clamp nuts were found to be badly worn – one set to such an extent that the nut could actually be slid along the screw without rotating the screw.
Both the screws and nuts were inspected and appeared, visually, to be in a reasonable condition, with both sets of threads looking acceptable.
With the weight of the clamp laying on the nuts and threads, the clamp appeared to operate as it should, giving a false sense of security.
The company involved has noted the need to strip down the clamping system, take the weight off the nuts and screws and undertake thorough checks of these components on a regular basis.
Safety Event
Published: 30 July 2005
Download: 
IMCA SF 08/05
IMCA Safety Flashes
Submit a Report
IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of all. The effectiveness of the IMCA Safety Flash system depends on Members sharing information and so avoiding repeat incidents. Please consider adding safetyreports@imca-int.com to your internal distribution list for safety alerts or manually submitting information on incidents you consider may be relevant. All information is anonymised or sanitised, as appropriate.
IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.
IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall not be liable for any guidance and/or recommendation and/or statement herein contained. The information contained in this document does not fulfil or replace any individual’s or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.