Kingpin To Rear Axle Length

Patrick asked:

G-Town, I heard a rumor while I was at a Walmart DC in PA last week that Walmart is basically scaling back it's own truck operations to do more contracting out. Have you heard any such stuff?

I have not heard that, at least in the Pottsville D.C. WMPF is actually hiring here, in Johnstown NY and in Smyrna DE. I'll ask around though.

One point of clarity I want to make, since this seems to sometimes confuse even seasoned veterans who've been driving since God was a baby.

Those bridge law measurements, i.e. 40', 41', do NOT mean your tandems have to be set at that length, only that that is the furthest back they can be set.

I had this discussion last summer at a drop yard in CA with another Interstate driver. We were playing musical trailers, and as he handed me the bills and his scale ticket, I noticed he had the tandems set at 40', but when I looked at the scale ticket, his drives were 33880, and the tandems were 29400. When I asked him why he didn't slide them up and get some of the weight redistributed, he tried telling me you HAVE to run at 40' in CA no matter what. Five full minutes he argued this, even after I pulled the law up on my phone and pointed out that nowhere in there does it say that 40' is the minimum setting, only the maximum. I finally gave up, slide the axles up, and left.

The point here is to remember that maximum length does not also mean minimum length, or mandatory length.

One point of clarity I want to make, since this seems to sometimes confuse even seasoned veterans who've been driving since God was a baby.

Those bridge law measurements, i.e. 40', 41', do NOT mean your tandems have to be set at that length, only that that is the furthest back they can be set.

I had this discussion last summer at a drop yard in CA with another Interstate driver. We were playing musical trailers, and as he handed me the bills and his scale ticket, I noticed he had the tandems set at 40', but when I looked at the scale ticket, his drives were 33880, and the tandems were 29400. When I asked him why he didn't slide them up and get some of the weight redistributed, he tried telling me you HAVE to run at 40' in CA no matter what. Five full minutes he argued this, even after I pulled the law up on my phone and pointed out that nowhere in there does it say that 40' is the minimum setting, only the maximum. I finally gave up, slide the axles up, and left.

The point here is to remember that maximum length does not also mean minimum length, or mandatory length.

Fatsquatch the reference to Bridge Law as it applies to the 40' and 41' marks is irrelevant.

You are referring to individual State Kingpin Law and not Federal Bridge Law. The two laws are not interchangeable.

This is my first time here and everyone has touched on the subject but I would appreciate if someone could tell me if in California, I needed to move my tandem back by one hole which means that I would be at 40 feet and 4 or 6 inches depending on the trailer, I would be legal? Thank you JP

I meant to reply to this a while ago, but basically forgot about it...

Chris M wrote:

My personal opinion is that counting holes is not the best practice, for exactly the reason you stated. I don't ever count holes. I set my tandems based on the placement of the load if I can look in the trailer, or based on the lifting point if it's pre-loaded, and then go to a scale.

I don't completely agree with the above approach. When working with pallets of wildly different weights the above process is not going to be accurate or effective.

When you scale, if weight needs to be moved fore or aft you must count holes to ensure accuracy and reduce trial and error "re-weighs" on the scale. There are two trailer slide-rail designs when it comes to hole spacing. Standard hole spacing is one every 6" on-center and represents about 400 pounds of weight, plus or minus for each hole moved. A "micro set" (found on newer trailers) rail has one hole every 4" on-center, representing about 260 pounds, plus or minus for each hole moved. That said without counting holes; how can you accurately and efficiently determine weight balance and/or getting legal? You basically count holes; if you need to get 1600 pounds off your drives to be legal you move your tandems forward 4 holes if the rail is of conventional spacing. If a micro-spaced rail is on the trailer, tandems are moved forward 6 holes. No ambiguity or confusion. It works. I use this technique each and every time I scale a load.

Chris went on to state this:

And I see that this is an old topic, but this sorta fits. I ran into another swift driver a few days ago who absolutely swore "the bridge law is only for California".

I agree the driver you spoke to is definitely wrong, however possibly not for the reason you might think. Technically for a 48' or 53' tandem-axle trailer, the bridge law really doesn't apply or "restrict" in any way due to the spacing minimums mandated by the Law. Based on the length and design of 48' and 53' tandem (twin) axle trailers; it's virtually impossible NOT to be in compliance with Federal Bridge Law because the minimum distance from rear tractor axle and front trailer axle will not fall below the minimum distance restriction. That said, Bridge Laws are not applicable for most of the equipment we use; 53' vans or reefers. For shorter trailers and container chassis less than 48' in length, Bridge Laws definitely govern on minimum axle spacing. Kingpin Law however is definitely applicable and in many eastern states aggressively enforced.

Bridge Laws are Federal; Kingpin to Axle Spacing Laws are State mandated, varied, and although both Laws address weight and axle spacing, they are NOT interchangeable. Don't confuse the two of them. Not every state has Kingpin guidance (refer to Chris' flip chart). The Swift flip chart applies to Kingpin Law and highly relevant for the type of longer dry vans and reefers most of us work with.

To the marking arrow, over center of rear axle.......... if none, measure 10 feet from back corner of doors..... to mark it, you're good (on a 53')

Hi,

Sorry but I read all that info but the question remains. Will 40 feet 6inches be accepted? The California department of transportation will not rule on this question. They told me that it was up to each individual weight stations. So, I am looking for experienced drivers which have had to deal with a similar situation and whether or not in their case, it was accepted. Thanks JP

To the marking arrow, over center of rear axle.......... if none, measure 10 feet from back corner of doors..... to mark it, you're good (on a 53')

Legally you will be in violation. Will you get a ticket for this? Probably not, but you could be cited. Driver beware.