Accession Number:

ADA537572

Title:

Operational Considerations for the Standby Diver in CUMA Dives

Descriptive Note:

Technical memorandum

Corporate Author:

DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)

Personal Author(s):

Report Date:

2010-11-01

Pagination or Media Count:

36.0

Abstract:

The Canadian Underwater Minecountermeasures MCM Apparatus CUMA is a self-contained, semi-closed circuit breathing apparatus in service with the Canadian Forces CF and other North Atlantic Treaty Organization NATO Navies for MCM diving to a depth of 81 metres of seawater msw using a mixture of helium and oxygen. Current CF rules state that a diver completing more than 30 minutes min of oxygen decompression has to be accompanied by a standby diver at the 9 metre decompression stop. As there are no specific repetitive diving rules governing such shallow dives on CUMA, the procedure of adding bottom times to determine the decompression requirements of a second dive must be used. As a result, the standby diver may become unavailable for a subsequent dive to deeper depths. This affects the operational ability of a small team to continue diving as the divers, including the standby become dived out too quickly. Experimental dives to 9 msw to simulate a standby diver accompanying a CUMA diver were conducted in the DRDC Toronto Dive Research Facility to measure the inspired partial pressure of oxygen PiO2. The results showed that the time-weighted average PiO2 after 30 min at 9 msw was greater than 1.3 atmospheres absolute ATA. As a result, the inert gas loading should be minimal and there should be little or no decompression penalty associated with the standby diver diving again as a working CUMA diver. This will increase the operational ability of a small dive team to continue diving operations.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Marine Engineering
  • Land Mine Warfare
  • Life Support Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE