US embraces Diesel power at last

19 Aug 2014
‘Ville de Bordeaux’ employed a high level of machinery automation and relied on automatic filters for main engine fuel purification rather than centrifugal separators, allowing a 25% cut in manpower

‘Ville de Bordeaux’ employed a high level of machinery automation and relied on automatic filters for main engine fuel purification rather than centrifugal separators, allowing a 25% cut in manpower

The September 1964 issue of The Motor Ship led with news that a US company was to build a European-designed large marine Diesel engine. This may not seem a particularly newsworthy story in a magazine devoted to large Diesel-powered ships, but as the US had resolutely stuck to steam turbines for ship propulsion, bucking the trend of the rest of the world towards Diesel power, it had a certain significance.

There was little in the way of hard facts, because negotiations were still to be finalised – as well as commercial considerations there were other tricky issues like government subsidies and import restrictions to be dealt with. But an article in the same issue went into considerable detail about a cost study carried out by US marine consultant JJ Henry of New York into a proposed Sulzer-engined cargo ship, of about 10,000dwt and powered by a 13,800bhp direct-coupled 6RD90 engine running on heavy oil. Just about every aspect of the ship was considered, including optimising the hull design for the different weight distribution and various vibrations associated with this type of machinery compared with steam power, auxiliary power systems, and inclusion of various degrees of automation to minimise manning levels. Although light ship weight was slightly more for Diesel, and cargo capacity slightly less, there was a useful increase in cargo deadweight capacity because of the Diesel’s better fuel consumption, while the lower light ship CG would help improve stability.

Costs of fuel and lube oil for the Diesel plant were calculated at US$869/day, while an equivalent steam plant would cost $1.180/day. These figures were based on running close to full power – at reduced speed the Diesel would show an even bigger advantage. The Diesel plant, however, was expected to incur a considerably higher maintenance cost over the ship’s projected 24-year lifespan, but this was more than offset by reduced manning levels.

Such is our familiarity with reefer container ships that it is easy to forget that these were virtually unheard of in the mid-1960s. The Motor Ship reported on a new 22-knot banana carrier, the 8,010dwt Geestbay, described as one of the largest and fastest of its type. The insulated hold of 334,000ft³ could carry some 40 million bananas, and could be refrigerated to -18°C. But as well as its normal fruit cargoes, with meat on the return voyages, Geestbay boasted high-standard accommodation for 12 passengers. Despite a move to gas turbine machinery for two earlier Geest ships, Geestbay and her sister employed a single two-stroke Diesel power plant, in the form of a Werkspoor-Sulzer 7RD76 turbocharged engine rated 10,500bhp at 119rpm. The ships featured a US-designed flume stabilisation system to limit cargo damage in heavy seas.

Automation was still a hot topic, with a new system designed by Lyngsø of Denmark to electronically control B&W engines. This featured up-to-the-minute technology such as transistorised signal amplifiers, for enhanced accuracy.

Meanwhile, a new French cargo liner, the Ville de Bordeaux, had recently been delivered, with what was described as a “new approach to machinery operation”. This ship’s B&W main engine as well as all essential auxiliary plant, could be fully controlled from the bridge as well as from a control chamber in the engine room. This allowed a reduction in manpower – previous ships in the same fleet had needed a complement of 40 men, but the Ville de Bordeaux operated with 30. Another innovation was that the HFO bunkers relied on filtration, dispensing with the need for centrigugal separators. The owners felt that centrifuges required constant attention, so the filters, supplied by Sofrance, contributed to the lower manning levels.