I'm starting out with the First Class Smoking Room, there's 5 plates from this interior in the Swan Hunters collection and a few more perspectives available on-line so visually there's enough to work from.
The plans to the left (Wikipedia) illustrate the Smoking Room's location, behind the 4th funnel on the Boat or A Deck.
The Shipbuilder, a maritime publication which ran from 1906 to 1964, published a souvenir issue of the Mauretania, a copy of which is held in the searchroom Library at Tyne and Wear Archives. It describes many features of the ship and combined with the plates and the plans to the left I've got the following -
It was 52ft long and 50ft wide
It had windows to both sides with semi circular arches
It was partitioned by veneered panelling concealing ventilation shafts
It was topped with a wagon headed roof
It was accessed via the Music Room/Lounge and the promenade
The carved cornice held a painting at each end, one of 'Old New York' and the other 'Old Liverpool'
The Swan Hunters Mauretania plates
There's a lot of information to be gathered from the 1st Class Smoking Room plates such as - furnishings, patterns and reliefs, but for the moment I'm only interested in dimensions. First I need to work out where the photographer was standing when the images were taken, this will help me visualise the room.
The images to the left are from photographic copies of the plates, these are made available on-line at Tyne and Wear Archives, Mauretania website. I've worked with the images here to get a uniform colour in sepia tone.
The remaining two plates show a view from 3 looking towards 1 and from a vestibule entrance looking through the alcove seating.
Dimensions - first go
The images reveal the symmetry of the room, with the port and starboard side a mirror of each other. The main interior is divided into six alcoves with a central area beneath the dome, it has a double door exit facing the stern and a partitioned opening to the second interior facing the bow. The second interior has a fireplace and four alcoves with a vestibule exit on both the port and starboard sides.
Working by eye
Placing a grid on the images provides good information on the ratio of one part to another, this can be translated into the 3D model to provide a good enough estimate of the room dimensions. The photographer of these images has made this possible by framing the images both level and central to specific areas of the room. To the left we see one of the alcoves, using a grid defining the wall space we find the perspective point fits perfectly into the centre of the middle alcove. Using the grid we find the relationships of one dimension to another.
At this point I'm compelled to compliment the photographer on their skill at utilising perspective and the positioning of their camera (there's an entry in the Swan Hunters Collection which states their early photographs were commissioned to Frank & Sons, South Shields). Cameras of 1907 were not easy instruments and I do not doubt that the setting up of these images required measurement and the use of sight lines for level framing. The grids I've used reveal the cameras position which, on every occasion is central to a feature and level. This position didn't occur by chance and in the process of finding it I got the faintest sliver of the photographers thoughts at the time.
Dimensions - first go - wireframe
Left you can see the first wire frame rendering of the First Class Smoking Room with the alcove image boundaries shown in green.
Above are the boundaries of the remaining plate images revealing the field of view for each plate. The interiors are laid out with several repeating elements, this greatly supports their translation into 3D.