Jbd:
John’s Definitive Guide to Measuring Tongue Weight on Non-Dainty rigs:
Every major truck stop in Florida has a CAT scale.
https://catscale.com/cat-scale-locator/
They all have 3 platforms, for ‘steering axle’, ‘drive axle’ and ‘trailer axle’ (A, B, C).
Position the trailer axles as near the middle of platform C as you can while still having the rear truck wheels just barely on the B scale and so that the trailer jack stand can be (in step 2) lowered onto the C (not B) scale. Push the intercom button and tell them you want a weight. The certified weighmaster will reply something like “ Issha shackles frissioned physicans share sure jaunt shemzzzzzttt?’ CAT Scales, Inc uses the same intercom company as McDonalds. Just say, ‘John Highsmith told me to do it this way.”
On this ticket #1, C is the boat + trailer, minus tongue wgt, which is included in PART of the B scale ‘drive axle’ wgt, but we can’t know which part, because that would make it too easy and inexpensive.
Pay up.
Now drop the trailer tongue jack stand leg and crank the coupler up off the ball. You don’t even have to disconnect the EOH or safety chains or trailer lights (under 5-10lbs). Use the intercom to request another wgt. The weighmaster will think you’re crazy and say something about whether you are here for the keys to the shackled trout; just say ‘John Highsmith told me to do it this way. And the only good trout is a shackled trout.’
On this ticket #2, C is the boat + trailer + tongue wgt. Pay up again.
The difference between #1 and #2 C scale wgt is the tongue weight.
(jbd, aghast: “I was told there would NO math on this post!”)
Your boat transom must be fully supported on the trailer and not hanging off the end, so there are limits to moving the winch post trickery to adjust tongue wgt.
You can’t just drop the jack stand on the end of a CAT scale to get the tongue wgt because 1), it could damage the scale, and 2) that would just be too easy and inexpensive. Nothing about owning a TC255 is allowed to be easy or inexpensive. If you choose to try that while the weighmaster isn’t looking and damage their C scale, just say “Bob Austin told me to do it this way”.
Eileen has a very fancy glass electronic bath scale, and using Bob’s method with the “1 inch iron rod” and blocks and her fancy glass bath scale is a no-go around here. On the other hand, we’ve only been together 40+ years, so maybe she’ll get more mellow about this kind of thing in a couple more decades, Bob. I bet NOT. You know her.
You will pay $10.50 each for the 2 tickets, which is under half the cost of Eileens fancy glass bath scale and therefore an excellent deal.
In Light Cruise mode with 21g gas total confirmed by fuel computers (at 6 lbs per gal), no water in the 30g tank (at 8.3lbs per gal) or 9g holding tank the rig is 10,760lbs, +/- 400 lbs with tongue wgt of 1,160lbs +/- 40lbs and total gross wgt of 17,800 to 18,200lbs with a GMC HD2500 with 20K parking prawl, Allison commercial transmission, turbo diesel with rear LSD for slick ramps. Full water and fuel would add 332 + 870lbs to the towed weight.
I don’t know whether sewage weighs more or less than straight water, but we can debate this around a campfire someday as Eileen is unwilling to allow me to perform this research myself with even her least-favorite buckets.
Inquiring Minds Would Want to Know.
If someone has a better way of measuring tongue wgts over 1,000 lbs let’s hear it.
Cheers!
John