The digital age appears on the horizon

01 Oct 2013
The Harima-Sulzer 10 RD 90 engine fitted to the ‘Hatsushima Maru’ tanker- the largest and most powerful Sulzer-powered ship

The Harima-Sulzer 10 RD 90 engine fitted to the ‘Hatsushima Maru’ tanker- the largest and most powerful Sulzer-powered ship

The Motor Ship for October 1963 began with reports that Shell Tankers was bucking the trend away from opposed-piston engines by chartering a newbuild tanker with the latest Doxford J-type engine.

This was seen as significant because not only was Shell a recent convert to Diesel power, but the order was seen as a salvation for the British marine engine industry. The second leader was a justification for the economics of CP propellers. Our predecessors pointed out that when reduced engine maintenance – a consequence of fewer stop-start operations – was factored in, the balance was shifted firmly in favour of the initially more costly CP solution.

Remote control and automation seemed to be the coming trend 50 years ago. Not only had Lloyd’s Register’s Rules been revised to include centralised machinery controls, the normally highly-conservative Motor Ship included, of all things, an article on the use of digital shipboard computers. This was quite an advance in thinking over even the existing analogue machines. As well as the obvious applications in engine monitoring and control, a central shipboard computer was seen as opening the way to collision avoidance displays on radar screens – ARPA has been with us so long that it’s easy to forget that it was really a dream in 1963 – weather routing, another area where computers are taken for granted today, and performing stability calculations when loading.

Further into the future, computers could be used for administration, such as stock control, crew wages – even storing copies of all the ship’s documentation. And even, horror of horrors, computer modelling could be employed in research into strengths of ships, which could lead to reductions in weight and cost by avoiding material thicknesses which could be shown to be too great, compared with the somewhat empirical methods used in determining the then-current rules.

However, the most significant benefit was that increased automation would lead to reduced manning levels onboard, with a 25 crew being able to keep a typical tanker running rather than the 45 of the pre-digital age. And all of this from a box 1.5m high, 500mm wide and 400mm deep, compact enough to make installation on a submarine possible.

The large-bore engine saga went on and on. News in October 1963 was that the first of several Sulzer 10 RD 90 engines that had been ordered had entered service, in the 72,000dwt Japanese tanker Hatsushima Maru, built at IHI. This was the largest, and highest-powered Sulzer-engined ship to be built, with main engine rated 22,000bhp at 119rpm, though in service it was being operated at 115rpm, developing 19,800bhp. That seemed to bear out another of the predictions in the computer article which suggested that computer design and operation of engines could lead to ratings far in excess of the somewhat conservative marine power outputs of the time. Sulzer, of course, eventually became Wärtsilä, and despite many developments the present RT family is recognisably a descendant of the RD. Today’s nearest electronically-controlled equivalent to the 10 RD 90, the 10RT-flex 96C, can produces over 75,000bhp at 127rpm. Computer technology has to have played a part in this dramatic increase.

The Hatsushima Maru engine was, naturally, controlled remotely from an air-conditioned control room. But electro-hydraulics, magnetic valves and motors were used to control, respectively, ahead/astern, starting, fuel regulation and speed rather than a full electronic system.