high centered double drop trailers & neck extension question

If the trailer does not have an override control valve to manually put more air into the airbags of the trailer to raise it...either have one installed or be prepared to disconnect the ride height lever from the valve and "lie to the air suspension" making the trailer rise.
Same thing for the tractor...if it is your truck, I'd have one installed. They're just handy to have, my last three trucks have all had them, no matter what I do, I won't have a truck without one again.

Depending on the length of the extension, it may allow you to;
-put a jeep under the front of the trailer, for more axles for heavier loads
-allow you to slide the 5th wheel into a more forward position for a Tri-drive or four axle tractor
-if you are too heavy on the front end...truck...and it is a non divisible load, flipping it essentially moves the load backwards on the trailer the length of the extension to adjust weight. Depends on the jurisdiction you're in if they allow this

 

Do you understand why flipping the neck down takes weight off the tractor?

some trailers may not have a flip, they will have a long neck, for like a 4 axle truck to have clearance, but different holes for the kingpin. Works on the same principle as the flip neck.

 

But what HH didn't say was you try to never get in that situation to begin with. Texas has a wide route in the panhandle where love to send trucks across an old RR crossing alongside I-40 east of Amarillo where you cannot go with a double drop. There's even a towing company with a truck they keep about a 1/4 mile away just for that crossing and once he drags you over it he follows you north a few miles to the second one you'll ground on. Just in the past few month's I've been routed that way twice and both times I've had to do a little free-styling (running out of route) to avoid them.

Just yesterday Missouri had me routed around a railroad overpass and had I followed their route I would have been stuck on top of the same tracks 2 miles down the road. If fact they had me trying to cross those same tracks twice 8 miles apart and both places would have grounded me. Instead I squatted the truck and trailer and was able squeeze under with an inch to spare and avoid the whole fiasco.

 

Of course you do your best to avoid these situations in the first place, but if you move heavy long enough you eventually will;
-forget to disconnect glad hands and light cord while detaching, ripping them off (carry spares)
-forget to remove your traveling blocks before loading a coffin type trailer
-get to a structure you will not fit under. \
-get to a structure you will have difficulty getting over. } all of these while being on your permit route
-get to a structure you can not get over. /
-miss a turn and end up off route
If you haven't done all of the above & more, you haven't been doing it long enough, or you are lying. Always be vigilant and prepared, in this part of the industry things go sideways often. For the record, the only one I haven't done, YET, is the traveling blocks...the rest I have encountered multiple times. I'm human too.

"Freestyling" is NOT an advisable practice!

What separates the men from the boys in this segment of our industry is how you handle the situation you will encounter. If I need help, or won't fit, I immediately stop and call for assistance. I have never had a state permit office not work with me if I'm on route and encounter a situation. I've also never had a problem with them helping me when I have explained that I missed a sign,or marker & having inadvertently ended up off route and require assistance getting back to my route. If the permit office is closed I call the authorities, starting with the locals and working up from there. They are always happy to help you correct a situation BEFORE it becomes a collision or worse issue.

 

When you miss a turn and need locals to help get back on route , will they ticket you for being off route? Reason I ask is I missed a turn with a small O/S and had to turn around , was going to call a local to help me back off a connecting road into traffic but I figured they would use the opportunity to pick my pocket, I was able to get another driver to help eventually.

 

I have not yet encountered that.
A couple of things;
-I am extremely self confident and they do not intimidate me.
-I tell them exactly what happened, show them my permit, and what I propose to do, followed with "does this sound appropriate to you?" This portrays professionalism along with respect for their authority.
-I make it clear that I have asked for, and am thankful for their assistance in helping to keep a situation from becoming much larger issue.

The above actions show that I respect the authority, and that I am aware the police are here for our protection and assistance as a priority to revenue generation. Remember, you asked for help they "did not catch you", therefore in my opinion there is no citeable offence. You are human, just as the officer is, he puts his pants on one leg at a time just like you do...that means he makes mistakes just like you do...being man enough to admit it and ask for help...that commands respect!
So far it has for me. If one day I get a ticket for it, believe me, I'm not intimidated by a judge either, I'll stand before the court and state the above. Judges have the leeway to allow for common sense if an officer doesn't use his. If that doesn't work, I'll hold my head high, pay the fine and chalk it up to the cost of the assistance I have received this far, and continue with my exact same practices...because they have served me well.