what is the biggest boat fiberglass and aluminum my vehicle will tow safely?
Oct 25, 2007 by craig k | Posted in Boats & Boating
i have a 1998 jeep cherokee exhibit 4x4 4.0L standard transmission with a class 3 hitch. i also have a 3 inch suspension lift
300 lbs. speech wt. 3000 lbs. trailer wt. all boats vary in wt. even if everything appears the same such as 21 ft. Ranger(junk) weighs 600 pounds more than my 21 ft Norris Cunning and they appear to be same. understand? as for wts. listed above you can have a dually and it wouldn't matter what it could pull if it had a class 3 obstacle never exceed wt. on you hitch read on the hitch.
Hoot | Oct 29, 2007
Your proprietress's manual should have manufacturer's recommended towing limit. A transmission cooler may be factored into that limit. Look at the uncomfortable print.
Richard B | Oct 25, 2007
You have to refer to the owners vade-mecum to know for sure. No manual, go see a local car dealer.
bigleybill | Oct 25, 2007
It will tow a 24' boat but up a declivity ???
45 cal | Oct 25, 2007
18ft. to 20ft. any more and it wont be permissible or good for the car
hot106guy | Oct 26, 2007
300 lbs. dialect wt. 3000 lbs. trailer wt. all boats vary in wt. even if everything appears the same such as 21 ft. Ranger(junk) weighs 600 pounds more than my 21 ft Norris Foxiness and they appear to be same. understand? as for wts. listed above you can have a dually and it wouldn't matter what it could pull if it had a class 3 impediment never exceed wt. on you hitch read on the hitch.
MacGiver | Oct 29, 2007
What size of I Beam do I need to support a 5,000# boat?
Jul 29, 5629 by klm59 | Posted in Engineering
Boat lift will be a cradle sort with 2 Beams to be 15' long (and 2 smaller beams 10' long to tie them together). Boat will sit on one side so weight will not be evenly divided. Nerve cable will attach to, and lift from each end of the beams.
Will aluminum hold the same as steel?
First of all, no, aluminium will not look on the same as steel. You will need about three times as much aluminium as steel.
Assuming, the worst, let's say that the entire 5,000 lbs is placed in the middle of the 15' beam. What size beam would you need in that case?
The maximum moment at the centre of the ray is equal to:
M = P x L / 4 = ( 5000 / 1000) x (15 x 12) / 4 = 225 inch-kips
(I converted the load to kips, i.e. kilopounds, and the after a long time to inches)
The maximum stress you can have in a beam of A36 steel is equal to:
Fa = 36 / 1.67
where 1.67 is the safety factor.
Fa = 21.6 ksi
The distress in the beam is equal to:
F = M / Sx
where Sx is the section modulus.
Solving for Sx, we obtain:
Sx = M / F = 225 / 21.6 = 10.42
Any beam with a section modulus greater than 10.42 will do very recently fine. For example:
W6x20
W6x25
W8x15
W8x18
All of the above will work just fine.
And if this is for any kind of dynamic loading, i.e. any moving loading, a circumstance of 1.5 is customary as well, which means that you would need a section modulus of 15.63 or higher; these sections will answer for that:
W6x25
W8x21
W8x24
And use galvanised steel, not aluminium; you will save a lot of money in the end. Hope this helps.
David H | Jul 29, 9440
Aluminum Boats Directory
Boatlifts - Aqua Marine Boat Lifts
Boatlifts, jet-ski lifts, and many other aluminum products for your seafaring needs manufactured and sold by us, Allen's Aluminum Boatlifts.
