Ship Draughtsman Continued
DEVELOPMENT in The Twentieth Century
At the turn of the century the industry saw
the development of design teams which replaced the tradition of the single,
brilliant designer such as William Pile of Sunderland, and G.B. Hunter on the
Tyne. Whereas the designer and shipwright once made the decisions, there were
now specialists who oversaw different aspects of each vessel. Without these
teams of specialist draughts men the development of, for example, a new class of
large, fast passenger ship could not have progressed. The sheer volume of
necessary drawings were now beyond the old-style tradition of designer and
shipwright. Swan Hunter & Whigham Richardson Ltd. were only able to commence
design work on the .Mattretania because of teams of Draughtsmen producing
the hundreds of working drawings and calculations, culminating in the vessel
entering the Atlantic passenger service in 1907.
From this era, through the First World War,
the cyclical depressions of the 1923s and ‘30s, and the Second World War,
technical development continued with the introduction of turbine and diesel
propulsion. Petrol and oil tankers were developed, along with longitudinal
framing, which replaced the traditional transverse frames. Other advances were
the supercharging of engines, turbo-electric propulsion and much higher engine
speeds. Towards the beginning of the Second World War, electric arc welding
began to be introduced into the yards, albeit on a limited scale.
Despite these technical advances, up to the
late 1950s the tools used by the draughtsmen had changed little since the
mid-nineteenth century. They consisted of drawing instruments for pencil and ink
work, a range of scales from 1/16 inch to the foot, and up to one inch to the
foot, and a range of curves usually made from thin boxwood or maple. These
fitted the tight curves used for small detail work, and the much flatter curves
of the deck sheer. In between were the curves used in drawing the
cross-sectional curves of the ship’s hull - known by their shape as ‘ram’s
horn’ or ‘pear’ curves. These were often acquired from retiring
draughtsmen, or by making your own from thin wood or transparent plastic. A set
of the most used curves was a valuable addition to the draughtsman’s tool box.
In the late I 950s it became part of the apprentice draughtsman’s training to
make a set of curves, as part of an eve-training exercise for a draughtsman who
would spend his life dealing with the curved surfaces of ships.
Large curves such as waterlines or deck
outlines were drawn with the aid of wooden battens, held in place by lead
weights, and while some draughtsmen had small battens of their own, battens and
weights were part of the drawing office equipment.
As drawing offices were handling arrangement
plans of ships drawn usually at a scale of ¼ inch to the foot, it was not
unusual to have drawings 10 feet in length. Adjustable drawing boards as used in
engineering were therefore of little use in ship drawing offices, and they were
equipped with flat benches up to 42 inches wide, and between 10 and 20 feet
long. They were about 39 inches high and fitted with shallow plan drawers,
shelves, and deep drawers. Being solidly built there was no movement to distort
the accuracy of the drawings.
Plans had been drawn in ink on translucent
tracing paper, or linen backed paper, until the advent of sized linen in the
inter war years, and this medium continued to be used for detail or sketch work.
Sized linen was a more robust material and was prepared by stretching onto the
bench with drawing pins and applying a light coat of chalk, which was then
dusted off. Useful additions to the draughtsman’s equipment were a small brush
and dusters. Plans continued to be mapped out in pencil, and then inked-in with
black Indian ink when the final details were decided.
At some time during the apprenticeship the
draughtsman would have a special draughtsman’s tool box constructed in the
Joiners Shop. He could then fill it with instruments, set squares, curves,
scales, and all the paraphernalia of a ‘proper’ draughtsman.
Essential for calculation work was a set of
mathematical tables containing trigonometric functions, logarithms, square and
cube roots, in addition to a slide rule. In the mid-1950s the mechanical
calculating machine was replaced by the electric-powered version. The
calculation of areas and volumes, and inertia's, vital for the determination of
ship stability, continued to be done manually in the Design Office using the
planimeter and integrator. The technique for using these instruments in the
1950s remained the same as was set out in the well-known ‘Attwood’s’ book
on naval architecture, first published in 1899.’
Hull forms were, in the 1940s and 1950s, still
designed largely as they had been decades before, by reducing the required
displacement volume of the ship to a series of transverse sectional areas, and
drawing the derived waterlines on linen-backed paper to a scale of ¼ inch to
the foot. The offsets, or dimensions of the Lines Plan, the waterlines,
sections, buttocks, and diagonals were then compiled into a table, and redrawn
full size on the floor of the Mould Loft. Writing in 1948 on the history of the
shipwright’s trade in the seventeenth century, Sir Westcott Abel notes that it
was curious to remark that this procedure was ‘common practice, nearly 250
years later’.2
With a broad-based apprenticeship in design,
construction, and outfitting, draughtsmen were expected, as a normal part of
their duties, to liaise with foremen in
other trades in ironing out design faults and
production problems, and to go into the yard or aboard ship to assess problems.
As they were, at times, in a supervisory role their status and salary reflected
this, and most senior draughtsmen were paid more than the foremen.
Responsibility and decision-making were, therefore, a feature of the job and
did, as many believed, elevate them to a status recognised as being between
management and manual worker.
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