Never was good at Math! Tank capacity given dimentions?

[rothfm]

Hi all,

Just picked up a very good condition used NMMA Marine/Baffled Alum tank for my replacement. Its one of the few ive come accoss to fit my hatch width. Having a local welder modify the Inlet, and add a 2nd Pickup.

Has a tag by Welding Dynamics Jupeter Fla. While the tag is in perfect shape, the fields dont appear filled in.

Given its 56L x 19 high x 22 wide....Any thoughts on its capacity? Just based on other tanks ive seen. My guess is appx 90-100?

Thanks in advance

 

[Alumarine]

https://www.calculatorsoup.com/calculators/construction/tank.php

 

[racerone]

Fill it with water and see how much is one way.----Or 1 US gallon is 231 cubic inches

 

[GA_Boater]

Need to deduct the step to be accurate. 101 gallons without deducting the step volume. Guessing about 90 Gal.

 

[rothfm]

Thanks all. Thats a cool calculator. Ran it for that step portion, deducted from the overall. Appears to be appx 97-98 gallons.
Not a bad replacement for the original 155, considering I also have 2 24gal saddle tanks.

Thanks for the help

 

[GA_Boater]

What is the size of the step? Maybe the pic makes it look larger than it is.

 

[tpenfield]

Here is the math . . .

I'll assume the notch is 4x4x28"

Tank = 56 x 19 x 22 = 23,408 cubic inches
Notch = 4 x 4 x 28 = 448 cubic inches

Net of tank outer dimensions MINUS the notch = 23,408 - 448 = 22,960 cubic inches

I cubic foot = 12 x 12 x 12 = 1,728 cubic inches

one cubic foot contains 7.49 gallons

Net tank in gallons = 22,960 / 1,728 x 7.49 = 99.52 gallons

 

[harringtondav]

I'll go with tpenfield . I challenged his calcs on tongue weight a couple years ago.....still wiping the egg of my face.

 

[Scott Danforth]

what does the required USCG fuel tank tag state it is?

33 CFR 183.514 Gasoline fuel tanks for boats must have a label certifying that they have been subjected to a Static Pressure Test

It doesn't have to look exactly like this but must contain the information seen on this label. That required information is:

Manufacturers Name and address:

Month and Year of Manufacture

Capacity in US gallons

Material of Construction

 

[rothfm]

hey guys, couple more quests on this Tank I got.

Thanks Tpen for the calculations, that is what I came up with too given the Notch.

Yes, the tank has the builders tag on it with thickness, Pressure test PSI etc...The fields for capacity are not stamped, or I cant make it out.

Since I got to get a 2nd pickup installed, does anyone know what size that is? Are they standard...Its twin Johnson 150's if that helps. I'm thinking 5/8 on the barb, and maybe 1/2 thread. wondering about the fill port also.

Was hoping to know before yanking the old fully out, so I can get the needed ports and arranging the welding.