Dive support vessel

I just opened my spreadsheet and did some rough calcs based on the specs of Harkland Atlantis. I find nothing wrong in the specs.

Designed Displacement is given as 12,565t, Deadweight at 5,662t. That means Lightship is 6,903.

To check the computed Displacement Lwl x B x T x Cb x 1.024, Cb of 0.4 gives 6,912t(lightship). A Cb of 0.4 to 0.53 is well within the range of MARIN. Cb is increased to find full load displacement.

The Lightship weight ratio against Displacement is 55%, which means it is a good design and scantlings balance. I usually use 60% max.

Now, looking at the capacity of tanks, F.W. and F.O. is 2,600 tons, leaving 3,062 for all "others" to have a total deadweight of 5,662t. "Others" of 3,062 tons is not much if you divide it for all other stores and consumables.

The specs does not say it carries other supply or cargo (as I have speculated). There is no need as the figures tallies.

 

Now I know what dwt is good for, not useless after all.

 

I witnessed the loading of a dive support vessel with 24 well built divers. They were using all cranes available as the ship is leaving that afternoon. The bosun said they just loaded 3 tons of stores for the crew. I see cases and cases of bottled water, soft drinks, snacks, frozen foods, ect. The crews are well fed or the divers eat a lot. I like to be in that ship.

 

They do eat well. Even for a tug crew of 6 to 8 including capt, we try and eat well. There isn't much to look forward to in the daily routine EXCEPT a good meal and a nap. Everything else is work.
For divers, lots of boredom. Decompressing or waiting their turn to jump.

 

Thank you Rx, I missed to check with specs given, going by that, the figures make sense. My main doubt came when I saw that the dwt of the DSV is near about same as that of a 100m oil tanker. I presumed, the dwt of a 110m DSV should be way less than that of a slightly smaller oil tanker.(name mentioned above)