Added second axle what do you think?

[OverEasy]

Hi Sheppie62

How goes your trailer mod?

Have you had a chance to check balance and handling?

Best Regards,
Over Easy

[Sheppie62]

Very soon! What would be the preferred tongue weight? I just hooked up the lights. Putting boat in slip in Mission Bay San Diego next week

[OverEasy]

Hi Sheppie62!

Ok, I’m envious! Mission Bay!
I’d never get out of the water there!!
(We lived up in the San Francisco Bay Area for nearly 20 years before moving to New England nearly as many years ago. )
We loved visiting San Diego and the water front!
What a marvelous area!

We had a nice 30 ft land barge (travel trailer) back then which was great for that stage of life and young kids…but always were enamored with the bay!

Anyway, per all the information and experience of towing stuff for the past 50+ years your best to provide at least 10% of the towed load as tongue weight. So if your all up weight of trailer & boat is 3500 lbs the tongue weight should be about 350 lbs.

If you are less than that you are at risk of developing a self sustaining fish tailing issue.
Not a good (or fun thing ) to experience.

Here is a great YouTube link to a UHaul Video:


Let us know how it works out!
You’ve done a lot of good work getting to this point! Good Luck!

Best Regards,
Over Easy

[Be Free]

Very soon! What would be the preferred tongue weight? I just hooked up the lights. Putting boat in slip in Mission Bay San Diego next week

Around 10% of the towed weight should be pretty close. You'll know if it is light when you try to tow it.

[Sheppie62]

Weighing tongue, using a lever calculation, 1’ on boat side, 7’1” on weight side (to middle of block). Multiplying block weight 48.2lbs by 7.0833 about 350lbs which is 10% of guessed weight. Is this correct way to do that? No Gas in tanks.

[Tomfoolery]

Yes, though you didn't include the self-weight and CG location of the balance beam.

But yes, weight of block multiplied by distance from block CG to fulcrum, divided by distance from tongue to fulcrum.

If you want to get fancy, include the weight of the beam times the distance from its CG to the fulcrum, added to the moment from the block weight times distance, and divide that total moment in lb-ft by the short lever distance (in ft) for tongue weight (in pounds).

[OverEasy]

Hi Sheppie62!

I think, as does Tomfoolery, that you are on the right approach.
The 10% aspect should be a minimum tongue weight (as you saw in the video.)
Given you have a pretty good idea of the spec weight of the vessel and motor (and hopefully the other stuff inside ) you can make an honest estimate of your boat loaded trailer weight.

Unless you have a large battery bank, a water bed or a jacuzzi on board the 3500 lb load weight should be a reasonable estimate and hence the 350 lb tongue weight should be about right.

Yes, as Tomfoolery mentioned, be sensitive when towing to make sure you are stable before getting up to speed.
Personally I limit our travel speed to 55 mph to minimize strain on our tow vehicle and to help ensure highway stability.
Force is mass times velocity squared. ( The faster you go the more it’s gonna hurt if/when things go awry )

Note: If you can get to a private truck scale that can provide you with the real weighted trailer/boat/stuff load.
Some are free (as a public service) and some charge a nominal fee. The staff are generally helpful and informative.
Some are savvy enough to actually help you find you fwd/aft and port/starboard CG location.
A bit complicated to explain here but it can be done.

Best Regards,
Over Easy

[Jimmyt]

Force is mass times velocity squared. ( The faster you go the more it’s gonna hurt if/when things go awry )

Not exactly.

Force is mass x acceleration
Kinetic Energy is 1/2 x mass x velocity squared.

But the energy of an accident may be what you were referring to I assume... . And, it clearly increases with the square of the velocity. So, your point is a valid one.

[Sheppie62]

Thanks everyone for your help! So the square tubing 1.25”x 1.25” .065 thickness weighs about 7 lbs and the block weight is 48.2lbs. I slid the square tubing into a spare hitch and ball, put it in the trailer’s coupler. How does that effect the outcome?

[Jimmyt]

I get 341.4 lbs without using the beam weight; and 366.2 lbs when I include it.

But I'll let Tomfoolery give the definitive answer...

[Tomfoolery]

I get 341.4 lbs without using the beam weight; and 366.2 lbs when I include it.

But I'll let Tomfoolery give the definitive answer...

That sounds about right, though nobody can give a definitive answer without knowing the actual weight of the beam with ball mount and ball, and the location of the CG of that complete assembly referenced to the fulcrum.

The ball mount and ball are relatively heavy and will somewhere counterbalance that beam, so I suspect the beam assembly's contribution is probably closer to negligible.

But I applaud the OP for using that method. It's easier than using a bathroom scale and 2:1 or 3:1 beam to keep the scale within its usable range. Just keep the trailer level or the weight measurement will be a little low if the coupler is high (if equalized leaf springs, or single axle) or high if it has two torsion (independent) axles.

As to the weight of the boat on the trailer, they always seem to register higher than expected. My trailer is only 3500 lb rated, and I've never seen anyone with an X boat that weighs that little in full travel mode. Roger wasted no money on trailers.

Best advice I could give would be to take it to a local CAT scale and get it weighed with the tow vehicle front axle on the front platform, the rear axle on the middle platform, and the trailer on the last one. Then take it to the parking area (or home), cut the trailer loose, then weigh the tow vehicle again, splitting the two vehicle axles between the first two platforms ($4 for the second weigh within 24 hours - use the same 'tractor' number, which you make up, and tell the weighmaster over the PA that it's a reweigh to get the discount). Do this with the boat and trailer in full travel mode with all the stuff normally kept in the boat, in the locations where it's kept, including full fuel if that's how you travel. Then you'll know what it really weighs, and for that matter, you can verify what the tongue weight is, too since that info is easy to back out of the two weights.

https://catscale.com/cat-scale-locator/

https://catscale.com/how-to-weigh/

[Sheppie62]

Wow there’s a scale 5 miles away! Thanks, thought it would be further away. $12.50 for first weigh. I got the app. Weighs front, back, and trailer axles separately! Thanks! If I’d known it was this easy, I would have gone there first. Reason I really didn’t use the bathroom scale was wife said “No Way your using the glass bathroom scale”

[Tomfoolery]

Wow there’s a scale 5 miles away! Thanks, thought it would be further away. $12.50 for first weigh. I got the app. Weighs front, back, and trailer axles separately! Thanks! If I’d known it was this easy, I would have gone there first. Reason I really didn’t use the bathroom scale was wife said “No Way your using the glass bathroom scale”

Yeah, most truck scales are just one long platform, which doesn't help drivers who need to keep axle weights below state maximums. I used to haul two loads a night in large compactor trailers (garbage - yeah, not fun, but it was my first trailer driving job way back in the 70's) from a municipal transfer station, and the NJ state trooper truck squad would only weigh the rear tandem axles (portable scales), since that end was always heavy. We even knew them, and they us, by name as they'd stop us a couple of nights each week on I-80. But I digress.

Since the scale is so close, it would behoove you to do a second weigh without the trailer. Only a few bucks additional, but will tell you a lot, especially axle weights, and by subtraction, exactly what the whole boat and trailer combo weighs.

I weighed my Sprinter van on the way to TX this spring and was surprised to find we had added a thousand pounds of 'stuff' to it since I weighed it empty (but with water, fuel, and propane), including a large enclosed hitch carrier cargo box with even more 'stuff' in it. Important 'stuff' like tools, computers, food, bottled water, sleeping gear, propane fire pit, camp chairs and table, gifts for grandchildren, more gifts for grandchildren - you know, the really important 'stuff'.





My rig in front of the Greenwich CT transfer station, long since demolished and replaced, as I was headed out the gate after my last day. An R800 Mack with whopping 237 hp Maxidyne diesel and Maxitorque 5+2 transmission system. Yeah, that was probably me, or one of the other four guys driving the same route, holding up all that traffic on the Third Avenue Hill on the Cross Bronx Expressway (southbound I-95) headed for the GW Bridge ha ha.



Posted because I'm bored, sitting in a hotel room while the admiral attends a meeting for work.

[OverEasy]

Hi Tomfoolery,

“An R800 Mack with whopping 237 hp Maxidyne diesel and Maxitorque 5+2 transmission system. “

So you got to keep the truck to tow your Mac …. Right?

I can sometimes appreciate the “bored” part while the Admiral works “on-line” and I have to keep myself “quietly” occupied till she’s done

Hi Sheppie62!

Tomfoolery is good! Real good!

So with the independent leaf & right axle weights and the tongue weight you can plot out where your loaded boat/trailer center of gravity is…. This can come in handy with knowing on dry land how your boat will float(list) “before” you get out on the water.

[On our current trip where we added the A/C (back in August when it was still 95F with equal humidity %) I didn’t have time/ability to do a weight & balance which was readily apparent when we floated off the trailer at a 5 degree list to port… . Easily fixed by relocation of some of the internal stores, ropes, spare anchors but it sure looked funny at the launch ramp ]

My prior local scale was pretty barebones simple and required me to do a bunch of positioning and uncoupling to get the left/right/tongue weights and the front/rear tow vehicle axle weights.

Gotta find me to one of those fancy CAT Scales on Tomfoolery’s app!
Thanks !!!

Best Regards,
Over Easy

[ris]

Our Mac loaded for our last trip weighed 4,175 lbs. That includes 30 gal of water in a plastimo water tank which is located in the very front compartment under the v-berth. There are also 2 of the 4 Trojan 105 batteries under the V-berth. (the other 2 are in the small compartment aft of the galley. The boat is not loaded with food and clothes at this time but we keep the the plastimo tank/bag full. As I mentioned before we simply added a second axle behind the first and did not move the spring hangers. The tongue weight today is 480 lbs. If I was doing a road trip I would not keep more than 5 gallons of water in the plastimo bag. But to go the Gulf or Atlantic coast we fill the water bag. (90 minute drive to either coast)
Richard