Recent content by ram68ocean

Hello all, Firstly, would you know the history of Nordforsk (1987) - Seakeeping criteria? I believe it is used only for large ships, would you know the smallest size of vessel that it is reasonable to apply it to? And second, is there a similar 'general operability limiting criteria' for...

Would anyone know more about the history and background of Nordforsk (1987) - Seakeeping Criteria? And its use nowadays and applicability to different size of vessels?

Hi. The maximum rated power output of this generator set is 99ekW (but the question is generic to any size) It's the client who's asked this question about placing it transversely (to save some boat length), I don't like the idea. And I am looking for reasons why is better not to do it. My...

It would be for a 15m workboat with electric twin thrusters (no propeller shaft arrangement). To me placing the generator transversely sounds counter-intuitive, non-standard, out of place somehow, but I would like to know why. I thought about the effect of angular momentum on the wrong direction...

Could you think of any negative points or cons of placing a 100ekW main generator set placed transversely instead of longitudinally?

To my surprise, I am learning that in medium and large ships Skegs and Rudders are typically flooded with seawater (or even freshwater) instead of being 'empty with air'. First, is that true in most cases? If so, what is the main reason for doing so? Is generally the structure watertight...

They give the same result for 8 knots (NPL Bailey and Holtrop)! I am really impressed with the outcome.

Here are some Resistance and Power curves for different methods I got using Maxsurf. Holtrop and Fung give similar results. I am planning to use these results as a starting point. Bare Hull Resistance in calm water at 8 knots = 3.1 kilo Newtons Power in calm water at 8 knots (50% efficiency) =...

Thank you both. I'll do some further work and calculations and post it here.

What is the process one should make at the preliminary design phase to estimate fuel consumption at service speed with the aim to determine fuel tanks size? Basically, so that max fuel capacity is enough but not excessively more than what is needed as per requirements.

Thanks for pointing this out. Still the beam could be wider and the length shorter to bring down the L/B ratio. The idea behind making it slender is to reduce fuel consumption. I know. I was having issues with the trim at both conditions. Perhaps a water ballast tank(s) is needed. Interesting...