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Author Topic: Tugboat power  (Read 1449 times)


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Tugboat power
« on: January 31, 2016, 10:10:02 am »

I was on a meeting the other day, it's a society for deck officers that meet for dinner and a lecture. This time the lecture was held by a man who had worked for different tugboat companies, one of them called Neptun. Interesting enough how he got the job in the early seventies, he was an electrician but was hired as a hydraulic expert. His boss said that he just had to think of the valves as relays, otherwise it's the same principle!
Anyway, he told a interesting thing about power of tugboats. Neptun company ordered two big tugboats, Neptun Suecia and Neptun Gothia. They later became Abeille Flandre/Languedoq for the French coastguard. They were delivered a few years after Smits tugs Smit London/Rotterdam and off course they were compared. The Smit tugs were one size bigger. This led to some creativity from the technicians from Neptun. At this time there was no real standard regarding measuring of bollard pull and often the power of tugs was measured in horsepowers. The Swedish tugs had some 12000hp compared to the Smit tugs 22000hp, but they managed to create a bollard pull test of 180tons. This was a very good result so this was calculated using some formula and transferred into something they called "towing horsepower" resulting in the figure 23000hp!!
Apparently this is not accepted today and the measuring of bollard pull is strictly standardised.
All the best!



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Re: Tugboat power
« Reply #1 on: January 31, 2016, 12:06:39 pm »

I also recall it was not unknown for some Owners to use metric horsepower (which is less than 'Imperial HP') in their publicity material. It was not always evident that this was the case and they hoped to benefit as a result.
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