Canadian naval architect Robert Allan Ltd has designed two dive support vessels (DSVs) to be operated by Brazilian firm Belov Engenharia Ltda
Newbuilds Belov Amaralina and Belov Humaitá have completed class commissioning and are currently performing client acceptance testing for Petrobras.
The vessels were built at Belov’s fabrication facility in Salvador and both vessels are part of Robert Allan’s RAlly 4000 class design.
RAlly 4000 models are designed to be fitted with an ROV launch and recovery system (LARS), an aft-mounted A-frame to operate the diving bell, a decompression chamber to support the divers, and spacious crew quarters. All of this is incorporated within a gross tonnage under 500 gt.
The 40.5-m newbuilds are fitted with DP2, four diesel generators, three water jet propulsors and triple bow thrusters for redundancy. The propulsion system is diesel-electric to improve efficiency when operating in lower power DP modes.
Robert Allan said the vessels were certified by Italian class society RINA as special diving support vessels suitable for unrestricted navigation. Both vessels will have a service speed of over 12 knots and accommodate a crew of 38.
The vessel incorporates waterjets to ensure diver safety. Robert Allan said the choice was made because waterjets are typically used on higher speed vessels.
Extensive self-propelled computational fluid dynamics analysis including waterjet tunnel flow was performed inhouse by Robert Allan to verify resistance and thrust at the slower speeds the design will operate at when on station.