Page 35 - Australian Defence Magazine Aug 2019
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An additional 14 possible capsizes were averted pro-actively. Second, apparent op- erational restrictions put in place to lower the number of capsizing incidents call into question Navy’s ability to board large ves- sels in rough seas. Third, the weight of the RHIBs currently prevents the davits on board the Hobart-class destroyers from deploying a fast boat with more than three embarked crew. Finally, the severe shock forces and cold temperatures experienced by RHIB passengers is likely causing signif- icant performance degradation and medi- cal issues amongst RAN’s most experienced operators with no exposure management
system or health monitoring in place off-set the heightened risk of chronic injury.
Operational restrictions
Questions around the operational suit- ability of the RHIBs revolve around the boats’ ability to launch and recover from the mother vessel. The instability caused by the RHIBs’ jet propulsion and shallow keels in the wash of a much larger ship pre- disposes the inflatables to pitch and take in water. As then-Chief of Navy VADM Ray Griggs admitted following the incident in- volving HMAS Darwin; “There were too many people too far forward so, when the boat lost directional stability, it allowed the bow to go into the water and chip the water over the bow.”
RAN videos of recent small craft inter- ceptions made by HMA Ships Ballarat, Darwin, and Arunta suggest that operating procedures now allow only six or seven per- sonnel to board a RHIB in open ocean or rougher seas, presumably to mitigate against the capsize risk when the boat launches and recovers, or when it crosses the ship’s white- wash. This number includes four to five in the boarding party and two crew, who stay on the inflatable whilst boarding takes place.
Larger targets, however, require larger boarding parties – yet RAN warships only carry two RHIBs. If each is only capable of carrying four to five operators at an accept- able level of risk in rough seas, then Navy’s ability to board larger vessels, such as North Korean oil tankers, depends almost entirely on embarked MH-60R Romeo helicopters.
These cannot conduct boarding opera- tions when configured for ASW operations with a dipping sonar unit installed, which reportedly takes four hours to remove and another four to re-install, and may not be available in the sort of weather conditions that create rough seas.
The warship could, of course, come to a complete stop to safely deploy two RHIBs with the full complement of passengers, but that creates its own problems. First, com- mercial ships do not stop in the middle of the ocean. Any clued-in radar operator could therefore identify the RAN ship and anticipate the boarding party’s imminent approach. Second, bringing a warship to a standstill would dramatically increase the time needed to launch two RHIBs.
In addition, the boat davits currently used to deploy the RHIBs from the new Hobart-class destroyers are only rated to take three embarked crew. Navy is in the process of procuring new davits from Na-
vantia, but the weight of the RHIBs is an equal contributor to that particular prob- lem - causing a trade-off between embarked personnel, equipment and effective range that further erodes the destroyers’ ability to board larger target vessels.
“The davits are used for the launch and recovery of the ship’s RHIB, used to rescue personnel, with three embarked crew,” a Defence spokesperson confirmed to ADM. “The boat davits have been installed in accor- dance with the ship’s design and meet Safety of Life at Sea requirements. Navy has updat- ed its requirement to launch and recover the RHIB with up to eight personnel embarked.
“Navantia, the ship designer, has pro- duced a new davit design to accommodate these functional changes, which is being implemented on all three ships, including current installation on HMAS Hobart.”
ADM Managing Editor Katherine Ziesing confirmed with CASG’s Director General of Naval Construction branch Commodore Steve Tiffen on a recent visit to the AWD yard that the davits are being replaced with a new configuration that lifts five tonnes rath- er than 3.5 tonne as previously fitted.
In short, the instability of RHIBs dur- ing launch and recovery, possible resultant operational restrictions and the current car- rying capacity of davits on board the DDGs raises significant questions around RAN’s ability to board large ships on the open ocean. These questions are lent urgency by recent Navy deployments to enforce sanc- tions on North Korea.
Performance and health degradation
Evidence also shows that RHIBs expose pas- sengers to extreme levels of impact trauma with repercussions on their physical and men- tal abilities post-transit and long-term health outcomes. According to research sponsored by the UK Ministry of Defence, RHIB crew and passengers experience “one of the harsh- est operating environments of any mode of transport” with impact and vibration expo- sure “potentially being of a greater magnitude than the forces experienced by a fast-jet pilot ejecting from their stricken aircraft.”
In a statement, Defence told ADM that there are ‘multiple controls’ in place to man- age the risk of RHIB travel.
“These include the use of pneumatic seats in the new J3 Jet rigid hulled inflatable boat (RHIB) to reduce the up and down motion that occurs in high environmental condi- tions,” a Defence spokesperson said.
“As part of the boat coxswain, bowman
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