Vessel Gross Tonnage

[TwinFin]

Hi Mac.

To your knowledge has an official "vessel gross tonnage" ever been calculated for the 28?

Thanks,

Steve Pentoney

[Mac]

If you are referring to the gross tonage requirement for documentation, I'm not sure if it has or not. There is a formula that is used that has nothing to do with what the boat weighs but instead calculates the displacement of the hull at a point when water would enter.

This is used by the Coast Guard to document and I'm not sure what it is other than we are more than the minimum 5 gross tons required to document the vessel.

If this doesn't answer your qestion, give me a call.

Mac

[backman]

in the dry weight of the boat, w/ tower, canvas & outriggers, no fuel.

I can then add people, ice, fuel weight etc. and have a blast with prop. calculators!

[TwinFin]

Hi Mac.

Yes, I'm looking for the gross tonnage number the Coast Guard requires on seatime forms, etc.. I have found various definitions, none of which are particularly easy to make use of. Here is one of the simplest I found.

"A Gross ton is not, as some would expect, a unit of weight. Rather it is a marine term equal to 100 cubic feet (approximately 10 cubic meters) used to describe the size of vessel. Gross tonnage indicates the internal volume of a vessel, including cargo holds and other areas, while net tonnage is the commercially useful internal capacity of the ship, that is, gross tonnage less the crew quarters, engine rooms, and so on.
Gross tonnage or size of your vessel will determine in part which regulation and standards apply to your vessel. Tonnage is calculated by a measurement and calculation process or may be determined via a table."

I can calculate reasonable estimates for the internal volume but I wondered if this might have already been done more formally for the 28.

Hi Larry. For the first time ever, I did not quite follow your post. :-)

Steve

[biteme]

TWINFIN...my 2001 28 was documented with these figures...gross tonnage 9......net tonnage 7.... i dont know what the #s mean but they are on my doc. citf. hope that helps...charlie.

[backman]

by the line eater.

In any event - what i was asking is -

what is the dry weight of thr 28 w/ tower and outrigger/no fuel.

Frommthere I can add my own estimates of fuel (210* 7.5) , people ( 3 * 200), ice ( 300), equipment (1000), etc. to come up with a total weight.

I can then go take that weight to prop calculators like the one on boatdiesel.com and waste my time pretending to analyze the performance I am getting vs. the theoretical expected performance.

[TwinFin]

Biteme: Thanks very much for the feedback. Do you have any idea who came up with the 9 tons or how? Did someone from the Coast Guard actually come down to your boat?

Backman: Ahhh, the line eater. I figured you had not really gone incoherent. :-) Are you gonna wind up with any in-process pics of your repower job?

Steve

[backman]

I'm going to give Carlton a call tomorrow and ask him to snap a couple.

[biteme]

twinfin....a service did the paperwork..i paid some money and recd.the finished paperwork in the mail..