In-depth | SAFETY
Martek targets fresh market for water ingress monitors
As rules making water ingress monitoring mandatory for all types of dry cargo tonnage approach entry into force, Martek Marine sets out the case afresh for Bulksafe, the water ingress detection system which has already proved itself as a means of enhancing ship and crew safety onboard bulk carriers.
Maritime Organization (IMO) to enhance the safety of bulk carriers in the wake of a spate of losses in the early 1990s. Such detection and alarm systems are designed to provide the maximum possible early warning of a cargo hold flooding condition that might seriously threaten a ship’s survival by giving a reliable indication of water reaching a pre-set level. Flooding can mark the beginning of
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sinking and should be the highest alert condition onboard, asserts BIMCO. Designed for stowing large volumes,
the cargo holds of bulk carriers represent the potential for a significant loss of hull buoyancy in the event of flooding. Additionally, there is the possibility that the cargo in the holds may be small in volume but of high density, thus allowing a larger volume of water to enter the hold than is the case with ships carrying lighter cargoes that occupy higher volumes of internal space. Serving a similar function to a fire
alarm, a water ingress monitor warns of a condition that requires immediate attention that could – if allowed to progress – eventually dictate evacuation of the ship. Monitors should make it possible from the bridge to know the condition in each hold without the need for local investigation. Systems not only monitor for the
presence of water in the cargo hold spaces but the speed of ingress as well via a two-stage alarm: one warning at a low level in the hold, the second at a higher level. Adopted in December 2002 by the
IMO’s Maritime Safety Committee, SOLAS XII Regulation 12 called for water ingress detection systems to be fitted on all bulk carriers, regardless of their date
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ater ingress monitoring was among a number or measures adopted by the Internatinal
Bulksafe enhances bulk carrier safety.
of construction, not later than the date of the first annual, intermediate or renewal survey carried out aſter 1 July 2004. A final standard defined a number of
key additional functional requirements for water ingress detection systems:
• A separate and distinguishable audible alarm to be provided at the control
• Equipment to be corrosion resistant for all intended cargoes
panel covering the 0.5m pre-alarm and 2m alarm levels in the cargo holds
• Time delays to be incorporated in the control and alarm system to prevent
spurious alarms due to sloshing effects
• Detectors to be capable of in-situ functional testing
before cargo loading. Water level detectors fitted in each
cargo hold are required to signal audible and visual alarms: one when the water level above the inner bottom in any hold reaches a height of 0.5m and another at a height not less than 15% of the depth of the hold but not more than 2m. (On bulk carriers to which Regulation 9.2 applies, only the latter alarm needs to be installed.)
The Naval Architect July/August 2010
• Filter elements fitted to the detectors should be capable of being cleaned
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