Much has been made of the money currently pouring into Australia’s fleet. The new and forthcoming warships and submarines will form the backbone of Navy’s ability to compete in the high-end fights of tomorrow.
Comparatively little attention, on the other hand, seems to be paid to the auxiliary boats that allow heavy warships to do today’s jobs - tracking and boarding suspect craft ranging from Somali dhows to North Korean oil tankers. The RAN’s jet-propelled Juliet 3 Rigid Hull Inflatable Boats (RHIBS) are critical to these missions, carrying boarding parties at speed across the last kilometres of open ocean. Yet Navy’s RHIBs may not be fit for purpose.
The first hints of a problem emerged in 2012, when a RHIB carrying members of a Defence tribunal onto HMAS Darwin capsized and caused a number of injuries. The subsequent investigation found that Navy had “inadequate hazard identification and risk assessment arrangements in place for boarding [and] transfer of personnel” as well as an absence of capsize training or experience with RHIBs amongst senior officers. This appears to be the only such incident on the public record.
The problem, however, runs much deeper. First, information obtained by ADM under the Freedom of Information Act reveals that there have been 13 capsizing incidents and 19 near-misses involving fast boats since 2003, potentially injuring dozens of personnel. An additional 14 possible capsizes were averted pro-actively.
Second, apparent operational restrictions put in place to lower the number of capsizing incidents call into question Navy’s ability to board large vessels 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 significant performance degradation and medical 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 suitability 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 predisposes the inflatables to pitch and take in water. As then-Chief of Navy VADM Ray Griggs admitted following the incident involving 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 interceptions made by HMA Ships Ballarat, Darwin, and Arunta suggest that operating procedures now allow only six or seven personnel 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 whitewash. 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 acceptable 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 operations 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 the helicopters may not be available in the sort of weather conditions that create rough seas.
The warship could come to a complete stop to safely deploy two RHIBs with the full complement of passengers, but that creates its own problems. First, commercial 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 personnel. Navy is in the process of procuring new davits from Navantia, but the weight of the RHIBs is an equal contributor to that particular problem - 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 accordance with the ship’s design and meet Safety of Life at Sea requirements. Navy has updated its requirement to launch and recover the RHIB with up to eight personnel embarked.
“Navantia, the ship designer, has produced a new davit design to accommodate these functional changes, which is being implemented on all three ships, including current installation on HMAS Hobart.”
ADM's 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 rather than 3.5 tonnes as previously fitted.
In short, the instability of RHIBs during launch and recovery, possible resultant operational restrictions and the current carrying 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 sanctions on North Korea.
Performance and health degradation
Evidence also shows that RHIBs expose passengers to extreme levels of impact trauma with repercussions on their physical and mental 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 harshest operating environments of any mode of transport” with impact and vibration exposure “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 manage 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 conditions,” a Defence spokesperson said.
“As part of the boat coxswain, bowman and boarding party course, RAN personnel are instructed on ergonomics and body mechanics, including brace positions for extreme manoeuvres, bending of the knees and proper seating positions,” the Defence spokesperson added. “This is aimed at reducing the likelihood of injury in both the short and long term.”
However, evidence suggests that these controls may not be enough. The videos of RHIB small craft interceptions mentioned above show personnel sitting on the inflatable sides of the boat with a twisted posture. This exposes their vertebrae to shearing forces that are greatly magnified by the significant weight of equipment they carry, which can be upwards of 20 kilograms – or 280 kilograms at 14G (roughly the force a fighter pilot will experience in an ejection). The practice may not be in accordance with RAN training, but its visibility in official media channels suggests proper posture on RHIBs is either difficult to achieve or poorly enforced.
This means passengers are still placed at increased risk of chronic musculoskeletal injury. A US study into self-reported injuries amongst 154 operators from three Special Boat squadrons with roughly five years average exposure to fast boats found that 94.8 per cent of all their injuries occurred on the job.
These injuries resulted in a total of 145 days of hospitalization, 929 days of sick leave, 4,223 days of limited duty, 4,218 days of limited performance and 2,294 days of lost training. One case study describes a patient with ten years of exposure to high speed watercraft who required six spinal operations, had three hernias, tinnitus, artery entrapment in the knee, hypothyroidism, hypogonadism and multiple incidences of acute compartment syndrome, which can cause tissue death. The patient was 34 years old.
Environmental factors
Exposure to cold is an additional factor degrading performance post-transit and possibly chronic health outcomes. A basic wind chill calculation shows that personnel in a RHIB travelling at 40 knots in five degrees ambient temperature will experience a wind chill of -3 degrees.
When the ambient temperature drops to -5 degrees – not uncommon in winter in the Sea of Japan – the wind chill drops to -17 degrees. This is a best case scenario in which the occupants are dry and there is no prevailing wind, conditions that are unlikely on a fast boat approaching a suspect North Korean tanker.
Despite the consequentially high risk of chronic injury, ADM understands that there is currently no system in place to monitor the hours Navy personnel spend in RHIBs.
“Navy does not track and record the hours that individual personnel spend in boats, however boat coxswains track their experience in a watercraft operators log,” a Defence spokesperson said.
Defence’s response also did not mention whether personnel are covered for chronic injuries specifically sustained through prolonged RHIB exposure.
“All Defence personnel are required to record any incident or potential incident that has, or could have caused injury. These reports form a database that is used for safety trend analysis," a Defence spokesperson said.
"If a Defence member does get injured through the conduct of their duty, whether in a boat or from any other Defence related tasking, they are covered in accordance with the Safety, Rehabilitation and Compensation (Defence-related Claims) Act 1988 or the Military Rehabilitation and Compensation Act 2004. The member will receive immediate medical and ongoing rehabilitation with potential compensation and other benefits.
“Rehabilitation programs attempt to return members to work, in some capacity, as soon as possible after injury, with the aim of an eventual full return to their deployed role and normal employment. Rehabilitation consultants work closely with the Defence member, commander, supervisor and health professional to deliver a structured and monitored rehabilitation program. This includes identifying alternate suitable duties for the member in the workplace in line with their restrictions if required.”
This lack of exposure management or awareness of the risks of prolonged RHIB use is a likely contributor to deteriorating health outcomes in the wider Navy.
Recent research has revealed that the percentage of Navy personnel with a medical restriction has quadrupled since the 1990s, the number deemed medically unfit to deploy at sea has tripled, and the compensation claim rate is five times that of the ‘worst’ civilian serious workers’ claim rate. These statistics are made all the more poignant given that the same research shows up to 90 per cent of work-related injuries in the ADF are not reported.
What is to be done?
RAN is certainly cognisant of these issues. In a response to questions, Defence told ADM that boat coxswains are taught to take into account environment conditions, passenger safety and comfort. Coxswain training has also been improved with two new RHIB simulators at HMAS Cerberus. If operational procedures are in place that restrict the number of embarked personnel in rough weather, they are evidently there for good reason given the number of capsizes that have occurred.
The davit issue on the Hobart-class, as mentioned, is being fixed. Yet there are evident shortcomings in the weight and stability of the J3 RHIBs that carry significant operational consequences, including the potential inability to board large surface vessels in rough seas.
Moreover, awareness of the chronic health effects of extended RHIB use is evidently low. No RHIB can fully mitigate against this risk, but if fighter pilots undergo a full medical evaluation post-ejection to determine their suitability to continue flying, it stands to reason that personnel regularly using RHIBs should undergo similar evaluations. At the very least, the time they spend in RHIBs should be tracked.
Solving all of these problems is a long and complex road, but that road starts with better awareness and optimum equipment. Hence the question: are Navy’s fast boats still fit for purpose?
This article first appeared in the August 2019 edition of ADM.