For The Trailer
Gross trailer weight (GTW) is the weight of the
trailer fully loaded in its actual towing condition.
GTW is measured by placing the fully loaded trailer on a vehicle scale. The
entire weight of the trailer should be supported on the scale as shown in
Figure 1.
Tongue weight (TW) is the downward force exerted on the hitch ball by the
trailer coupler. In most cases, it is about 10 to 15 percent of GTW. TW of
up to 300 lbs. can be measured on a household scale by resting the trailer
coupler on the scale and placing the scale on a box so that the coupler is
at its normal towing height. The trailer must be fully loaded and level.
For heavier tongue weights, place a household scale and a brick that's as
thick as the scale three feet apart as shown in Figure 2. Set a length of
pipe on each and rest a beam across the pipes. Re-zero the scale to correct
for the weight of the beam and pipe. Securely block the trailer wheels. Rest
the trailer jack on the beam as shown, one (1) foot from the brick and two
(2) feet from the scale.
To obtain the TW, multiply the scale reading by three (3). For greater
tongue weights, place the scale and brick four (4) feet apart, rest the jack
on the beam three (3) feet from the scale and multiply the scale reading by
four (4).
For The Tow Vehicle
Like the trailer, the tow vehicle has a
maximum weight capacity it was designed to tow. Its maximum towing capacity
can be found in the owner's manual.