Bridge layout and design
Updated 11 Oct 2019
Most modern ships feature some form of integrated bridge system with multiple screens allowing navigators to swap between views from different navigation equipment. Older vessels will have equipment installed over time and sometimes fitted in less-than-optimal positions. Regardless of vessel age and the position of equipment on the bridge, being able to observe other ships and the immediate environment from the bridge is essential.
Today there are several regulations affecting bridge design and layout. First among these is SOLAS V Regulation 22 that governs navigation bridge visibility requirements, and which applies to all vessels over 55m in length built after 1 July 1998. The requirements are quite comprehensive and extend to the layout, material and angle of bridge windows.
They do not however cover the overall design of the bridge in relation to the ship as a whole, other than with regards to line-of-sight requirements. Most modern ship designs have the bridge placed aft with most of the cargo holds extending forward. On ships with deck cargoes, this means that the line of sight does not allow vision of the area immediately in front of the ship. It is for this reason that the bridge position in very large container ships has been shifted forward from its traditional position to a point somewhere amidships.
Some ships do have a design which places the bridge at the most forward part of the vessel. This is particularly true of offshore ships and car carriers as well as some smaller ship types. Placing the bridge and other superstructure forward does have a negative effect on the aerodynamic properties of the vessel and some designs have sought to overcome this by removing hard edges.
This has been taken to extremes on a small number of ships including the car carrier City of Rotterdam which has an almost spherical section of the forward part of the ship. Initially this was hailed as an innovation but it was also cited as the cause of a collision between the ship and another vessel in the river Humber in the UK in 2015.
An official investigation by the UK’s Marine Accident Investigation Branch (MAIB) identified that the unconventional design caused the pilot to become disorientated and put the vessel on a collision course with the other ship. Apparently, the pilot’s disorientation was due to ‘relative motion illusion’, which caused him to think that the vessel was travelling in the direction in which he was looking when in fact it was not.
The MAIB investigation identified that the City of Rotterdam had been set into the path of the other vessel, but this had not been corrected because the pilot on board had become disoriented after looking through an off-axis window on the semi-circular shaped bridge.
Following the accident and an early MAIB recommendation, action has been taken by the City of Rotterdam’s managers to reduce the likelihood of relative motion illusion and to improve the bridge resource management of its deck officers.