Additional requirements

Own requirements to steering of podded and geared thrusters and steering of water jets are available on DNV-RU-SHIP Pt.4 Ch.5 Sec.3 and DNV-RU-SHIP Pt.4 Ch.5 Sec.2.
There are also additional class requirements for vessels subjects to “Dynamic positioning system” and “Redundant propulsion” class notations. Own additional requirements apply for vessels navigating in ice (Ice, PC, Icebreaker) and for naval and naval support vessels.

M/S MERSol have two rudders and is capable of operating with only one those. This waives the requirement for auxiliary steering gear. Both steering gears are anyhow equipped with emergency steering.
Each of the steering gears have two separate pumps, and the electro-motors for each of the pumps have independent power supply from the switchboards. Pumps 1 and 3 are connected to the main switchboard, while pumps 2 and 4 are fed from the emergency switchboard. This means that the two systems for each of the steering gears are both hydraulically and electrically independent. Each of the steering gears are also arranged with both main and emergency power supply. Therefore, those are in compliance with the class requirements.
Fishing vessels are generally not required to comply with SOLAS, and exemptions for requirements directly adopted from SOLAS (like the steering capacity) can be granted. M/S MERSol is anyhow built to fulfill these requirements and cannot be modified for lower capacity without class approval.

The steering gears are also built with maximum mechanical rudder angle of 47.5⁰, meaning that the steering gear capacity shall be enough to returning the rudder from this angle to neutral position.