Up until the 1950' and 1960 the ships lines would be run out full size on the loft floor, then with the advent of 1/10th scale lofting this would be done on very long tables and was considered to be a bit more accurate than drawing out lines full size on the floor of the loft, even with the 1/10th scale lofting all the template making of the structural steelwork still had to be laid out full size on the floor and of course full size scrieve boards were still done to enable the ships frames to be formed to the required shape, the laying out and fairing along with the marking up of the scrieve board was an art in itself. The frame lines of the body plan would be laid down once the lofted and faired offsets had been lifted from the completed body plan, and written up in the finished offset book, this offset book would be sent over to the drawing office so they could start to produce working drawings. A half-block model would also be produced prior to this from the same scantling offsets that the loft would start there lines with, at this time from which a shell expansion drawing could be created.
Picture of a Scrieve knife which was used to mark the ships frame lines into the wooden boards of the body plan full size, (Note the scrieve knifes used in the loft at Henry Robb were slightly different than that shown, but the same results were achieved) The scrieve knife was run along the side of a pinned wooden batten that had been meticulously faired through as many offset points as possible.
The loft would work in different ways depending on which shipyard and there use of lofting, the Leith Shipyards of Henry Robb would take the scantling lines from the naval architect and they would then run and fair the lines through the three views used to reach a fair surface, using the stations provided by the naval architect usually about 12 stations were used, from each station the frames would be drawn out and faired, and using horizontals called "Waterlines" and verticals called "Buttocks" through each view until a perfectly fair ships form was reached, the three views used to achieve the fair form would be the Sheer (profile/ side) view and the half breadth view (plan) working between these two views would produce the beginnings of the body plan which was the view looking aft from the forward end back to the mid-ship section and on the other side and upside down would be the aft view looking forward to the mid-ship section. So in effect one view would be laid on top of the other view to cut down on the amount of space required.
A simplified lines plan with just the scantling sections (in French) shown is seen below, this would then have all the ships frame lines drawn in and faired between all three views.
Above is another old American Loft note the templates behind the Loftsman who looks like he is working on heavy template paper.
Above we see the Mould Loft from the Hawthorn Leslie Shipyard and the Loftsmen and helpers are out in force for this photograph, looks like even the foreman is out on the floor (with bowler hat)
Note - Lots of light and space with many templates on-top of the Loft Floor. (photo copyright unknown-for now)