Ship Draughtsman Continued

Tyne and Wear shipbuilding companies, like their national colleagues, had developed a reputation over the nineteenth and twentieth centuries of being able to build any type of vessel. This had been a necessary skill for a trading island at the head of a worldwide Commonwealth which dealt in dry and liquid cargoes, cargo in bulk, bag, or cask, and carried at ambient or refrigerated temperatures. An idea of the great range of cargoes can be gained from Captain R.E. Thomas’s Stowage - the Properties and Stowage of Cargoes’ which gives details of how to handle over 2,500 commodities carried by cargo vessels. Volumes like this were part of the technical library of any drawing office, where carrying capacity, safety requirements, and stability were determined.

Whereas the steelwork draughtsman would ensure the strength of the hull, the outfit draughtsman would determine the stowage arrangements, cargo handling requirements, crew or passenger accommodation, and the related pipe work systems. In the late 1940s and ‘SOs cargo ships still catered for this wide range of commodities where, for example, a ship going to the African continent would carry manufactured goods out, and return with baled goods, timber, palm oil, food products, and other raw materials. Walton notes ‘special types of vessel’²² as being barges, trawlers, passenger ships and ferries, refrigerated cargo ships, and timber carriers. There were also the cable ships which laid the undersea links between continents, and the light ships which ringed the British Isles.

This wide range of vessels was a testimony to the maritime expertise of a trading nation. They were also a demonstration of the expertise and experience of the ship draughtsmen who were able to meet the diverse requirements of shipowners.

An assessment of British shipbuilding by John Spence notes, under a chapter entitled ‘Signs of Decline’, that ‘in 1954 West Germany overtook the UK in building for foreign owners’, and that in 1956 ‘Japan became the world’s biggest supplier of ships, helped by the boom in tankers following the Suez invasion’.²³ While it is true, and confirmed by shipping journals, that the gross registered tonnage of Japan outstripped that of other nations, this does not reflect the technical content of the vessels themselves. The work carried out by the ship draughtsmen in producing the design and detail of, for example, a SOC-foot cross-channel vehicle and passenger ferry is considerably more than in producing the plans for a 1,200 foot oil tanker.

As tanker sizes began to increase above the 20,000 gross registered tons mark in the 1950s, the problem of physical building space arose. Many yards were faced with the problem of building vessels which were growing too big for the building berths. The solution found by John Crown & Sons on the Wear was to build ships in two separate halves.

The Rondefjell, of 22,400 tons deadweight, built for Olsen & Ugelstad, was the first oil tanker in the world to be built in two parts. The two halves were launched in April and October 1951 from Crown’s North Sands yard, towed to the River Tvne, and joined in the Middle Docks at South Shields.²⁴ A number of vessels, known locally as ‘the half-crown ships’, were built in this way. Austin & Pickersgill’s Southwick yard also built the 46,000-ton deadweight tanker Happy Dragon in October 1966 and February 1967, the two halves again being towed to the Tyne for joining together.²⁵ Although the technical problems were mainly those of stability and ballasting, it did reinforce the region’s reputation for building anything that floated.

By 1969 the increased demand for oil, and the continuing closure of the Suez Canal, resulted in the building of the Very Large Crude Carriers (VLCCs) on the Tyne. In this year Swan Hunter launched the Esso Northumbria with a deadweight of 253,000 tons, which was followed by her sister-ship the Esso Hibernia. These vessels received their final inspections in dry dock in Portugal before handing over to the owners, for they were, at 1,100 feet long, ‘too big ever to return’ to the Tyne.²⁶ A similar situation occurred on the Wear with the Nordic Chieftain, built in 1974 of 158,000 tons deadweight.²⁷

Problems of physical size were, however, more easily overcome than problems of design. When Swan Hunter embarked upon the VLCCs of the late 1960s they were designing above the limits originally envisaged by Lloyds Rules, so that a new technique had to be devised to establish the stresses on these ship structures, where a 250,000-ton vessel with a liquid cargo, and over 1,000 feet long, was operating in mid-ocean conditions.

The technique evolved was described as ‘finite element analysis’, and was the subject of a number of papers published by the Royal Institution of Naval Architects (RINA) and the NECIES. Ship structures do flex in response to sea conditions and loading, and the draughtsman had been able to allow for these, and have his designs approved by the classification societies. The design and detailing of large vessels was no longer a response to past experience of loading conditions, but an attempt to predict the overall capability of ship structures subjected to stresses not experienced in past decades.

The commercial and political factors which caused the virtual demise of the VLCC supertankers did not reduce the need for large ships. This was maintained by the demand for large bulk carriers which carried the ores, grains, and oil cargo's of the world. Developed from the Canadian Great Lakes carriers, the ocean-going bulk carrier consisted of a series of large holds at the centre, with ballast tanks at each side, which could also carry oil cargo. The experience gained by designers and draughtsmen on the structures and pipe systems of VLCCs was therefore transferable.

One of the few completely new types of vessel to emerge in the postwar years has been the container ship. Essentially a large cargo ship, it has holds designed to carry pre-packed boxes measuring 40 feet, or 20 feet, by 8 feet square, which meant that new methods of loading had to be devised. During the war the US Army had converted cargo ships to carry pre-packed equipment to and from specially built port facilities, but it was not until 1966 that the ‘revolution got under way’, and this would be considered as ‘The year of the container’.²⁸ When design work began in 1966 on the first large container ships for the UK to Australia trade, there was ‘not a great deal of precedent to work on’, and ‘for the first time the designers, accustomed to cargo liner work, found themselves without a basic ship’.²⁹

The ‘container revolution’ is deserving of that epithet as it had a profound effect on the organization of ports and manning, reducing the dependency upon stevedoring,

and moving the distribution centres of commodities away from the sea ports and into distant areas of manufacturing and consumption. It also had a profound effect upon the cargo handling arrangements of merchant shipping.

A major economic consideration of shipping is to reduce loading and unloading time to a minimum, so that more cargo's can be carried per year. Container ports developed a range of cranes to facilitate rapid cargo handling, and to compete with this the more conventional cargo vessel had to modernize its shipboard systems. Cargo handling equipment consisting of winches and derricks, and their essential masts and rigging, had ‘remained relatively static for a long period’.³⁰ In the 1970s and ‘80s considerable attention was paid to the use of shipboard cranes and hydraulic hatch covers which, while cutting down the number of crew, reduced the time in port.

The effect upon the work of the ship draughtsman was also significant. Shipbuilders now bought hydraulic cranes and hatch covers which were delivered to the yard and bolted, or welded, straight aboard ship. The old systems of winches, derricks, and rigging became largely redundant, and from the late 1970s few draughtsmen were called upon to calculate and detail old-style rigging arrangements of wires, blocks, shackles, and associated fittings. The reduction in crew numbers also meant smaller accommodation areas, and proportionately less drawing work.

Just as developments in worldwide industry led to increasing ship sizes and the emergence of the container ship, developments in the oil industry produced its own ship types.

Although oil rig construction was carried out on the Tyne at one initial specialist company, with the rig being designed by structural engineers rather than ship designers, the production drawings and those for platform and accommodation modules were executed by ship draughtsmen moving into this new field from the shipyards from the early I 970s. While the oil companies did not train their own draughtsmen, they were able to use the ship draughtsman’s skills to produce the structural, accommodation services, and piping system drawings common to the marine environment.

The major shipbuilding work was for the rig service vessels such as supply ships, and tugs, which usually had the additional functions of fire-fighting, anchor handling, or carrying aerated cement. Although these were comparatively small vessels mainly between 120 and 250 feet long, they had a high technical content and involved the builder with the characteristic problem of small ships — how to get a large amount of equipment into a small hull. Because of these difficulties the large shipbuilders found them uneconomical to build, and this type of vessel was built at Cleland's yard at Howden on the Tyne who, with Mitchison's yard at Gateshead, were the only Tyne or Wear yards to build small steel vessels such as supply ships, tugs, and fishing vessels. The only other yard, Ryton Marine, only remained in business for two years. These two specialist small yards, while training their own draughtsmen, also recruited from the larger yards. The essential difference in drawing office organization was that draughtsmen in the small yards were required to cover all aspects of the work, from basic hull design to detail production drawings, and not, as in the big yards, work in separate departments for steel, outfit, piping, and design.

Such was the demand for specialist oil related vessels that a great deal of work was carried out by the Tyne dry dock companies converting vessels, such as stern trawlers, into diving support vessels, and altering the role of existing supply ships to perform additional tasks. In what is essentially a rapid turn-round industry, dry docks did not train their own draughtsmen, thus the increase in oil exploration work, at a time when shipbuilding orders were decreasing, ensured that the ship draughtsman still had a range of employers where the traditional ‘build anything’ skills could be used to good effect.

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