Weighing at Cat Scales

[dryfly]

After watching a couple of youTube videos, apparently the only way to determine the exact pin weight of a 5th wheel trailer is to weigh the truck/trailer and then disconnect the trailer and weigh the truck by itself. The unloaded rear axle weight of the truck compared to the loaded rear axle weight should provide the trailer actual pin weight.

Having never weighed at a Cat Scale, is the procedure to go inside and explain what is needed before driving on the scale platforms? I assume there will be two charges.

[valhalla360]

JRscooby wrote:

valhalla360 wrote:


Tells you what the weight distributing part of the hitch is doing.

Very useful if you are trying to dial in the correct tension on the bars. If the tension is too light, it may be distributing very little to the front axle and that would show up as a having almost the same front axle weight with and without the bars tensioned down.

The only numbers that making a pass with bars loose can let you calculate that you can't get from the other 2 passes is the TW when not hooked, and what percentages is transferred to steer and trailer. The only way to change the percentages steer/trailer is change wheelbase ratio. If you can't change it, do you need to know it?
Tongue weight needs to stay in the range when bars are in place. Add the weights marked as 'steer' and 'drive' when hooked up, compare to gross of TV alone, you have the weight of the trailer the TV is carrying, the definition of TW.
Old school thinking was when loading a truck you always wanted your steering to carry part of the load. Towing a TT behind a Vista Cruiser, always put enough tension on the bars to mash front down too. Sometime in the safety evolution of pickups that idea way lost. From what I read, nowadays they only want the spring bars to return the front back to what you have with MT truck.

Lots of folks tow without any idea of their weights. If that's the approach you want to follow and you are no where close to your ratings...go for it.

For an extra $2.50 if you are going thru the trouble, no reason not to get all the info in my opinion

[JRscooby]

valhalla360 wrote:


Substantially cheaper re-weighs is a function of why truckers use their scales. They may need to redistribute the load to get all the axle groups within the legal limits (overload tickets start in the 4 figure range). So if they miss on the first pass, they go adjust the load and then re-weigh until they get within limits. CAT has a guarantee that they will assist in the court case if you get a ticket after using their services.

I think you have the order wrong. (I know you are wrong on the price of overload fines. I have paid more than a few in the '4 figure range, but most where a few hundred) The cheap re-weigh is a plus, and I have often used it. (Company rig, 1 load took 12 re-weighs the first time we moved 1 load) With my tractor and trailer I could tell within a 100 lbs what was on each pair of axles by looking at the pressure gauges on suspension. But 1 fight because of state scales off convinced me go across the Cat, or go around the state, if close.

I suppose, if you drive a short wheel base SUV towing a 15ft travel trailer, you might run into spacing problems getting the load spread over 3 platforms laid out for commercial trucks but full size trucks towing 25ft+ trailers won't typically be an issue. Worst case pull over and look at the scale before using it if you aren't sure.

Short bed, reg cab pickup pulling a 12 ft pop-up, I had to stop as soon as steer was on front platform to keep trailer on the right one. One issue, if nobody uses the scale for a while it will shut off, and none of my axles where heavy enough to turn it on. Operator had me pull up so I had 2 on front, then back into position.
Most places that buy/sell bulk by truckload will have a scale. And most would be willing to "weigh" your RV. But if you watch them certified, there is a expectation the truck will be near center of scale when weighed. When you are checking axles, you are working at the end. I have pulled steer on, then tag, drives, trailer to get gross, then dropped axles off 1 at a time and the numbers always said different end to end. If stop with only front axle on, scale reads 19,500, pull whole rig on, get a gross of 130,000 then pull the front off scale reads 109,000 how much does the front axle weigh? Now a RV will never get into this kind of numbers, but if they don't match you can't know any more than just a guess.

[JRscooby]

1st pass WDH spring bars attached shows you how the weight is distributed between the trailer and the trucks 2 axles.

2nd pass no spring bars shows how the trailer loads the rear axle of the truck and lightens the front because of the tongue weight which you can find from the 3rd pass.

3rd pass truck only.

To find tongue weight subtract the 3rd pass from the trucks weight you found with the second pass. That difference is the tongue weight.
You can determine how much weight the WDH is distributing by looking at your front axle weight of just the truck alone and when you have the spring bars connected. I like no more than a 100lb difference between truck alone and truck with WDH spring bars connected for the front axle.

valhalla360 wrote:


Tells you what the weight distributing part of the hitch is doing.

Very useful if you are trying to dial in the correct tension on the bars. If the tension is too light, it may be distributing very little to the front axle and that would show up as a having almost the same front axle weight with and without the bars tensioned down.

The only numbers that making a pass with bars loose can let you calculate that you can't get from the other 2 passes is the TW when not hooked, and what percentages is transferred to steer and trailer. The only way to change the percentages steer/trailer is change wheelbase ratio. If you can't change it, do you need to know it?
Tongue weight needs to stay in the range when bars are in place. Add the weights marked as 'steer' and 'drive' when hooked up, compare to gross of TV alone, you have the weight of the trailer the TV is carrying, the definition of TW.
Old school thinking was when loading a truck you always wanted your steering to carry part of the load. Towing a TT behind a Vista Cruiser, always put enough tension on the bars to mash front down too. Sometime in the safety evolution of pickups that idea way lost. From what I read, nowadays they only want the spring bars to return the front back to what you have with MT truck.

[dryfly]

Old-Biscuit wrote:
Pull pm to scales with truck and trailer
Truck front axle on forward platform
Truck rear axle on middle platform
Trailer axles on rearward platform

Push call button....tell them 'Private' when they ask for ID number

Clerk will trip scales....
Then drive off scales and go park trailer in parking lot.

Drive truck onto the forward and middle platforms
Push button----'Private' Reweigh

Go park truck, go inside, pay and get your weigh tickets
1st ticket
truck steer, drive axle and trailer axles plus total
2nd ticket
truck steer, drive axle and total

Difference between truck Front and rear axles with trailer and without trailer is trailer pin weight
It's not just rear axle...check for any differences in front axle weights
Depending on hitch placement in truck bed front axle weight could be same, could be less, could be more

My hitch is set 2" forward of rear axle center line and this transfers 150# to front axle when 5vr is hitched plus the weight added to rear axle
So I add the 2 figures to get my pin weight -- 3080# = 22% pin weight on my 5vr

Thank you. Exactly the info I needed.

[valhalla360]

CarnationSailor wrote:

My mistake. I used a "Washington State Certified Scale" on the grounds of CADMAN, Inc. which is a private construction materials company. If you go to the WA state DOT's list of Certified Scales, you will see dozens that are not part of the CAT chain.

Again, my mistake, as I thought "CAT" was a generic term for any certified scale.

Yeah, if you go to a scrap yard or grain elevator, they are using the scales to determine how much stuff you off loaded, so they don't really care about per axle weights.

[CarnationSailor]

Mike134 wrote:

CarnationSailor wrote:
I get the impression that those posting specifics believe that all CAT scales have the same number of "platforms", communication options, and pricing structure. However, the CAT scales I use in the Seattle area are not at all like the ones described here so it seems the specific steps suggested might be useful somewhere else, they wouldn't apply to the CAT scales I use.

Any thoughts on this?

Going to a couple scales close to me they match what's on the web site. I would think a chain would be all the same. interesting.........

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

My mistake. I used a "Washington State Certified Scale" on the grounds of CADMAN, Inc. which is a private construction materials company. If you go to the WA state DOT's list of Certified Scales, you will see dozens that are not part of the CAT chain.

Again, my mistake, as I thought "CAT" was a generic term for any certified scale.

[valhalla360]

CarnationSailor wrote:
I get the impression that those posting specifics believe that all CAT scales have the same number of "platforms", communication options, and pricing structure. However, the CAT scales I use in the Seattle area are not at all like the ones described here so it seems the specific steps suggested might be useful somewhere else, they wouldn't apply to the CAT scales I use.

Any thoughts on this?

Pricing might vary a little but just like McDonalds, it's a franchise deal, so CAT discourages wildly different pricing schemes.

Substantially cheaper re-weighs is a function of why truckers use their scales. They may need to redistribute the load to get all the axle groups within the legal limits (overload tickets start in the 4 figure range). So if they miss on the first pass, they go adjust the load and then re-weigh until they get within limits. CAT has a guarantee that they will assist in the court case if you get a ticket after using their services.

Yes, it's possible the platforms may vary but generally there will always be at least 3 if they are dealing with interstate semis as truckers can get a ticket for an axle/axle group being over the limits...so they need the steering axle, the drive axle group and the trailer axle group at a minimum. They could have more. For most RVs that works out fine.

I suppose, if you drive a short wheel base SUV towing a 15ft travel trailer, you might run into spacing problems getting the load spread over 3 platforms laid out for commercial trucks but full size trucks towing 25ft+ trailers won't typically be an issue. Worst case pull over and look at the scale before using it if you aren't sure.

[Mike134]

CarnationSailor wrote:
I get the impression that those posting specifics believe that all CAT scales have the same number of "platforms", communication options, and pricing structure. However, the CAT scales I use in the Seattle area are not at all like the ones described here so it seems the specific steps suggested might be useful somewhere else, they wouldn't apply to the CAT scales I use.

Any thoughts on this?

Going to a couple scales close to me they match what's on the web site. I would think a chain would be all the same. interesting.........

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

[valhalla360]

JRscooby wrote:

valhalla360 wrote:


If you are doing a bumper pull with a WDH, it's a good idea to do a 3rd weigh (again $2.50) with the tension released from the bars.

I have seen this advice many times but have never understood what useful info is gained

Tells you what the weight distributing part of the hitch is doing.

Very useful if you are trying to dial in the correct tension on the bars. If the tension is too light, it may be distributing very little to the front axle and that would show up as a having almost the same front axle weight with and without the bars tensioned down.

[CarnationSailor]

I get the impression that those posting specifics believe that all CAT scales have the same number of "platforms", communication options, and pricing structure. However, the CAT scales I use in the Seattle area are not at all like the ones described here so it seems the specific steps suggested might be useful somewhere else, they wouldn't apply to the CAT scales I use.

Any thoughts on this?

[dapperdan]

Mike134 wrote:

Walaby wrote:
Download the app and you don't even have to go inside. App will properly charge the reduced cost for the re-weigh.

Mike

X2 I've gone inside and used the app. SOOOO much easier/faster with the app.

This sounds like a really smart and convenient way to get your weights! Beats having to go inside! :B

Dan

[Mike134]

JRscooby wrote:

valhalla360 wrote:


If you are doing a bumper pull with a WDH, it's a good idea to do a 3rd weigh (again $2.50) with the tension released from the bars.

I have seen this advice many times but have never understood what useful info is gained

1st pass WDH spring bars attached shows you how the weight is distributed between the trailer and the trucks 2 axles.

2nd pass no spring bars shows how the trailer loads the rear axle of the truck and lightens the front because of the tongue weight which you can find from the 3rd pass.

3rd pass truck only.

To find tongue weight subtract the 3rd pass from the trucks weight you found with the second pass. That difference is the tongue weight.
You can determine how much weight the WDH is distributing by looking at your front axle weight of just the truck alone and when you have the spring bars connected. I like no more than a 100lb difference between truck alone and truck with WDH spring bars connected for the front axle.

hope this helps

[Mike134]

Walaby wrote:
Download the app and you don't even have to go inside. App will properly charge the reduced cost for the re-weigh.

Mike

X2 I've gone inside and used the app. SOOOO much easier/faster with the app.

[JRscooby]

valhalla360 wrote:


If you are doing a bumper pull with a WDH, it's a good idea to do a 3rd weigh (again $2.50) with the tension released from the bars.

I have seen this advice many times but have never understood what useful info is gained