This pair of powerful, purposeful offshore service vessels have a characteristic Robert Allan “look” about them, but they are actually quite unusual.
First of all, they are very substantial, steel and aluminium, offshore-operating vessels that have waterjet propulsion even though they are only intended to operate at about 12 knots.
Rugged and seaworthy, they represent a series of licensing compromises and considerable thought and innovation as to tonnage, propulsion and crewing requirements.
They have sleeping quarters for a crew of 38 plus plenty of deck and hold space for a myriad of equipment including that required for deep-water ROV operations. The 41-metre ships are diesel electric-driven via triple waterjets, for a cruising speed of 12 knots.
“These shallow water dive support vessels have a significant number of technical features that set them apart,” Robert Allan Ltd (RAL) told Baird Maritime. “We used extensive CFD to evaluate water flow through the waterjets and discharge to an immersed outlet to verify the slow speed thrust values. The hullform is unique with a displacement hull, but with flat aft sections to suit the waterjet inlets.”
Further, because the vessels are expected to spend significant time in DP2 mode, redundancy is essential, so triple waterjets and triple bow thrusters were installed. This extra redundancy means the vessels can continue to operate with one of these units out of service. As well, diesel electric propulsion with four generators is used, allowing the operator to shut down multiple generators when in DP mode, or when on standby near an oil rig – a feature that Belov claims has resulted in “significant” fuel savings compared to other DSVs in the same market.
“The biggest challenge, though, was incorporating a host of onboard facilities such as berths, a gym, an ROV, and workshops in a vessel whose gross tonnage should not exceed 500.”
The two DSVs are indeed highly versatile and capable vessels that were developed at a time when RAL began introducing designs with the aim of keeping environmental impact as low as possible.
“As the technology continues to advance and owners become more willing to invest in carbon neutrality,” commented RAL, “items such as alternative fuels that once may not have been technically well proven or economically feasible are becoming more feasible in new designs.”
The year 2020 was memorable for RAL, not only for the fact that it celebrated 90 years in business, but also for its having successfully endured the negative effects of the Covid-19 pandemic.
“We were quite fortunate to start 2020 with the largest amount of work we have ever had on hand,” RAL told Baird Maritime, “which in hindsight served us well throughout the year as the pandemic pushed back the start date on some projects that had been scheduled to start in 2020. As some businesses experienced slowdowns we were very honoured that our strong group of clients continued forward with their current projects.
“Also, due to some disaster planning that we had performed in prior years, we were thankfully able to adapt quite quickly to remote working situations and increased video conferencing with clients. Approximately 70 new vessels of our various designs were successfully delivered to their owners in 2020. ”
Short-term objectives were also met, as the company claimed. R&D projects are progressing well while additional newbuildings are scheduled to begin taking shape in the very near future.
When asked about future prospects, RAL went back to the trend towards carbon neutrality that it started observing among operators in 2020.
“Our expectation is that in the coming years, owners will further embrace green technologies to reduce environmental effects both above and below the waterline. As more regions adopt exhaust emissions controls restrictions or as owners choose to implement emissions reductions themselves, we are fitting, or designing in for future use, an increasing number of on-engine and exhaust aftertreatment systems.”
RAL is also working to address these concerns by offering solutions that include hybrid propulsion systems and batteries with large storage capacities.
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